From patchwork Tue Sep 14 14:38:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493671 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F415C433EF for ; Tue, 14 Sep 2021 14:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46F73610D1 for ; Tue, 14 Sep 2021 14:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233687AbhINOj7 (ORCPT ); Tue, 14 Sep 2021 10:39:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:60920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233614AbhINOj6 (ORCPT ); Tue, 14 Sep 2021 10:39:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6CAC1610CE; Tue, 14 Sep 2021 14:38:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630321; bh=4xQiQDDV7nXJL8Xan+15i4FwcNOTqTiYzYCdCLjItZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N5F7dsm3oC3uWyspwozTKIHTqoDUSpeWzd2cFIzjDhYfwuHRmblgxYcBS5r4Q0hms fV6v7crr6GMxQwrgBCCrY8zspDHYWnYlynmfEFDiFfSdHSuYNpSfYCIPmyUL6uVj6C v6g9TBqpQQk24LXe4gWje5oEYx9+og5T5QUDYso7jq/CcYRb1pWEWy6YMhY1nlj83x pbsBqG8FU5CXWkJjtxzRvRL5FT2Eem287aIg7Tz9NYhMLpoWEd8NjMBExtzw0PW4tf 9jbYizbkmoOzNSXoB+A1KHa+ItddVhB5fNLXLaNScI8Vjydfb90NMdcNPaLrRPNzxF O6FpkVf8diEJQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 01/27] kprobes: Do not use local variable when creating debugfs file Date: Tue, 14 Sep 2021 23:38:37 +0900 Message-Id: <163163031686.489837.4476867635937014973.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Punit Agrawal debugfs_create_file() takes a pointer argument that can be used during file operation callbacks (accessible via i_private in the inode structure). An obvious requirement is for the pointer to refer to valid memory when used. When creating the debugfs file to dynamically enable / disable kprobes, a pointer to local variable is passed to debugfs_create_file(); which will go out of scope when the init function returns. The reason this hasn't triggered random memory corruption is because the pointer is not accessed during the debugfs file callbacks. Since the enabled state is managed by the kprobes_all_disabled global variable, the local variable is not needed. Fix the incorrect (and unnecessary) usage of local variable during debugfs_file_create() by passing NULL instead. Fixes: bf8f6e5b3e51 ("Kprobes: The ON/OFF knob thru debugfs") Signed-off-by: Punit Agrawal Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- kernel/kprobes.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 790a573bbe00..1cf8bca1ea86 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2809,13 +2809,12 @@ static const struct file_operations fops_kp = { static int __init debugfs_kprobe_init(void) { struct dentry *dir; - unsigned int value = 1; dir = debugfs_create_dir("kprobes", NULL); debugfs_create_file("list", 0400, dir, NULL, &kprobes_fops); - debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); + debugfs_create_file("enabled", 0600, dir, NULL, &fops_kp); debugfs_create_file("blacklist", 0400, dir, NULL, &kprobe_blacklist_fops); From patchwork Tue Sep 14 14:38:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493673 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5528CC4332F for ; Tue, 14 Sep 2021 14:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C9F4610D1 for ; Tue, 14 Sep 2021 14:39:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234404AbhINOkP (ORCPT ); Tue, 14 Sep 2021 10:40:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:33466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234250AbhINOkJ (ORCPT ); Tue, 14 Sep 2021 10:40:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6D6C761166; Tue, 14 Sep 2021 14:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630331; bh=oAqCBuqVjpZ5iefHB0MM8nDjvpho+9id+MYRlbmVcnY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hHn3yMB4HYLvj7zjWfQkipry55hbyowo9RJUYfSIz4zippAHUdb61Fpy7jnzD4Ihq dm258oIxRRCqnYfFca+eKNf/V/BRWBz+OobD6wXIkVZQjVseAjW+XXJlME0bYdiN57 TD+dC9mwGjISd0lu9g0jwTQogY6KCB0eoJU1cBWjRhCep4pNpboT0TSnM4fiqvajUL GTfnl9iiEph+UTbDIuB/2Ymd+apDYJgJvPbU+h19l5SwsGtogDA2Lw4RMYKnOxNh4T 4aYjCFKODEZKmdmwWM7oggvlRSc8mqv0gfxNYW1yAHjXbhcnWUl3uw3A0Y6tmmXLsg 1ddKk2JVi5FwQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 02/27] kprobes: Use helper to parse boolean input from userspace Date: Tue, 14 Sep 2021 23:38:46 +0900 Message-Id: <163163032637.489837.10678039554832855327.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Punit Agrawal The "enabled" file provides a debugfs interface to arm / disarm kprobes in the kernel. In order to parse the buffer containing the values written from userspace, the callback manually parses the user input to convert it to a boolean value. As taking a string value from userspace and converting it to boolean is a common operation, a helper kstrtobool_from_user() is already available in the kernel. Update the callback to use the common helper to parse the write buffer from userspace. Signed-off-by: Punit Agrawal Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- kernel/kprobes.c | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1cf8bca1ea86..26fc9904c3b1 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2770,30 +2770,14 @@ static ssize_t read_enabled_file_bool(struct file *file, static ssize_t write_enabled_file_bool(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { - char buf[32]; - size_t buf_size; - int ret = 0; - - buf_size = min(count, (sizeof(buf)-1)); - if (copy_from_user(buf, user_buf, buf_size)) - return -EFAULT; + bool enable; + int ret; - buf[buf_size] = '\0'; - switch (buf[0]) { - case 'y': - case 'Y': - case '1': - ret = arm_all_kprobes(); - break; - case 'n': - case 'N': - case '0': - ret = disarm_all_kprobes(); - break; - default: - return -EINVAL; - } + ret = kstrtobool_from_user(user_buf, count, &enable); + if (ret) + return ret; + ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); if (ret) return ret; From patchwork Tue Sep 14 14:38:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493675 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 667EFC433EF for ; Tue, 14 Sep 2021 14:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5692F610E6 for ; Tue, 14 Sep 2021 14:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234434AbhINOkk (ORCPT ); Tue, 14 Sep 2021 10:40:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:33814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234058AbhINOkS (ORCPT ); Tue, 14 Sep 2021 10:40:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 75010610E6; Tue, 14 Sep 2021 14:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630340; bh=gXV9kTWCvJThDIWiGCWSE/MEIc6zem6E9osIJWS2Eho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lVrSKpN4YZJJHWg6zx7tVFrHSa/lAl/kNqxWn85sDWav9HiFDdlHDKyASrgUyf+WD zTebMqfU7AB9sApCzmNJGdVj6/HpuCC2gJVnQBiYVuCM9PFPlpQ6yTRi1cmwXlCWQg vApcqXjPYJSKVuXCt9kSL0ZMlUVR3miyABuOewWKXEQPA5Lcwqcn4gUtwc/6se1yBh xokO1gtaNRXJwWMQx+01QenGd1YMiQKkLBK40ZJgyemPLhKt17gm2HoTWLn/OV+CsF T67emIn9173wP1GUrVUicC1XbkcXTF7X/OORlmdZZLv/2p+RiweRLA6txmPpwk1WHA oQxHXgn5JL5Rg== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 03/27] kprobe: Simplify prepare_kprobe() by dropping redundant version Date: Tue, 14 Sep 2021 23:38:57 +0900 Message-Id: <163163033696.489837.9264661820279300788.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Punit Agrawal The function prepare_kprobe() is called during kprobe registration and is responsible for ensuring any architecture related preparation for the kprobe is done before returning. One of two versions of prepare_kprobe() is chosen depending on the availability of KPROBE_ON_FTRACE in the kernel configuration. Simplify the code by dropping the version when KPROBE_ON_FTRACE is not selected - instead relying on kprobe_ftrace() to return false when KPROBE_ON_FTRACE is not set. No functional change. Signed-off-by: Punit Agrawal Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- include/linux/kprobes.h | 5 +++++ kernel/kprobes.c | 23 +++++++++-------------- 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index e4f3bfe08757..0b75549b2815 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -354,6 +354,11 @@ static inline void wait_for_kprobe_optimizer(void) { } extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct ftrace_regs *fregs); extern int arch_prepare_kprobe_ftrace(struct kprobe *p); +#else +static inline int arch_prepare_kprobe_ftrace(struct kprobe *p) +{ + return -EINVAL; +} #endif int arch_check_ftrace_location(struct kprobe *p); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 26fc9904c3b1..cfa9d3c263eb 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1033,15 +1033,6 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { static int kprobe_ipmodify_enabled; static int kprobe_ftrace_enabled; -/* Must ensure p->addr is really on ftrace */ -static int prepare_kprobe(struct kprobe *p) -{ - if (!kprobe_ftrace(p)) - return arch_prepare_kprobe(p); - - return arch_prepare_kprobe_ftrace(p); -} - /* Caller must lock kprobe_mutex */ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) @@ -1113,11 +1104,6 @@ static int disarm_kprobe_ftrace(struct kprobe *p) ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); } #else /* !CONFIG_KPROBES_ON_FTRACE */ -static inline int prepare_kprobe(struct kprobe *p) -{ - return arch_prepare_kprobe(p); -} - static inline int arm_kprobe_ftrace(struct kprobe *p) { return -ENODEV; @@ -1129,6 +1115,15 @@ static inline int disarm_kprobe_ftrace(struct kprobe *p) } #endif +static int prepare_kprobe(struct kprobe *p) +{ + /* Must ensure p->addr is really on ftrace */ + if (kprobe_ftrace(p)) + return arch_prepare_kprobe_ftrace(p); + + return arch_prepare_kprobe(p); +} + /* Arm a kprobe with text_mutex */ static int arm_kprobe(struct kprobe *kp) { From patchwork Tue Sep 14 14:39:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493677 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8454CC433EF for ; Tue, 14 Sep 2021 14:39:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68B0B61165 for ; Tue, 14 Sep 2021 14:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234606AbhINOk5 (ORCPT ); Tue, 14 Sep 2021 10:40:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:34168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234634AbhINOk2 (ORCPT ); Tue, 14 Sep 2021 10:40:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C888E60698; Tue, 14 Sep 2021 14:39:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630351; bh=Ts/h7mGNCMrQe1saq26gi6wFqSuBUa6bKhvGbOtlAa0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DpnQYub5dNKDYUSyo6O3HaHYuLKiLqspd0eSbO1C3vrjn8ox9Lz1q988hNxNy2w9H 72ZmFw1Kqc1ccBkBW01idQLUEQ+XEx2z7AjBE4WKEyGIbk6RGz3CSWXlTTFURdiNGF lBoAKgvom6iP6iuIdPQwezqPcbgJLDbdHI+b8QHI6/RiwDfaaSKBnXnTU/IpoFYDxS tvBwvESfvuFP6sn1JJ4vxEF3l3Exyv8QXfC7g9tYldtGbuYKgi6+knlgMdzckd69tP qNlJW9ceBxSuNnGO0ZTj3y25rENNy8pBwjl0joQ22oAZWFaZRcC7HFAwACViuGWLMO 3JWIm/3eVprjw== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 04/27] csky: ftrace: Drop duplicate implementation of arch_check_ftrace_location() Date: Tue, 14 Sep 2021 23:39:06 +0900 Message-Id: <163163034617.489837.7789033031868135258.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Punit Agrawal The csky specific arch_check_ftrace_location() shadows a weak implementation of the function in core code that offers the same functionality but with additional error checking. Drop the architecture specific function as a step towards further cleanup in core code. Signed-off-by: Punit Agrawal Acked-by: Guo Ren Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- arch/csky/kernel/probes/ftrace.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c index ef2bb9bd9605..b388228abbf2 100644 --- a/arch/csky/kernel/probes/ftrace.c +++ b/arch/csky/kernel/probes/ftrace.c @@ -2,13 +2,6 @@ #include -int arch_check_ftrace_location(struct kprobe *p) -{ - if (ftrace_location((unsigned long)p->addr)) - p->flags |= KPROBE_FLAG_FTRACE; - return 0; -} - /* Ftrace callback handler for kprobes -- called under preepmt disabled */ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct ftrace_regs *fregs) From patchwork Tue Sep 14 14:39:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493679 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BDBDC433EF for ; Tue, 14 Sep 2021 14:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 357F4610E6 for ; Tue, 14 Sep 2021 14:39:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234673AbhINOlG (ORCPT ); Tue, 14 Sep 2021 10:41:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234270AbhINOkh (ORCPT ); Tue, 14 Sep 2021 10:40:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C509610F9; Tue, 14 Sep 2021 14:39:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630360; bh=dLEXA0c32zAO/OxwC4RSb6MzIoMznRgqiTxAuTIvdtQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gfkbkcMR3qNFA4rPdoe/b8gxTIGdhxqSVs7mSOQoJzgRUOmrQZEE5Jr/eni3Fls4x Vv0yR7HubTr2XXVEJg99txCC+YcVsXh/ZoeHN3XkdGusyGi1ImCffbeM3DIMX2bPiq PN6LWj7MYUdvNpi0Ykv0dYAt3Bsk7VUlTgXQlIn0IYfqp1dX+1O9ykIdG64jUhRgEc EUdraEGUBQOfy5/vqPPROQWcNLaH4RxFwLlmHp+ggRdPLtMjuUiapP4TbNs+hJm87S r2Umb6AIlnynwwWy8O3qVjtmvtBKuD8piZYfT1xLX/hvow3RNz+bAuvJC7Rc+zd8MC S69Mw5g1mluSA== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 05/27] kprobes: Make arch_check_ftrace_location static Date: Tue, 14 Sep 2021 23:39:16 +0900 Message-Id: <163163035673.489837.2367816318195254104.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Punit Agrawal arch_check_ftrace_location() was introduced as a weak function in commit f7f242ff004499 ("kprobes: introduce weak arch_check_ftrace_location() helper function") to allow architectures to handle kprobes call site on their own. Recently, the only architecture (csky) to implement arch_check_ftrace_location() was migrated to using the common version. As a result, further cleanup the code to drop the weak attribute and rename the function to remove the architecture specific implementation. Signed-off-by: Punit Agrawal Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- include/linux/kprobes.h | 2 -- kernel/kprobes.c | 4 ++-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 0b75549b2815..8a9412bb0d5e 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -361,8 +361,6 @@ static inline int arch_prepare_kprobe_ftrace(struct kprobe *p) } #endif -int arch_check_ftrace_location(struct kprobe *p); - /* Get the kprobe at this addr (if any) - called with preemption disabled */ struct kprobe *get_kprobe(void *addr); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index cfa9d3c263eb..30199bfcc74a 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1524,7 +1524,7 @@ static inline int warn_kprobe_rereg(struct kprobe *p) return ret; } -int __weak arch_check_ftrace_location(struct kprobe *p) +static int check_ftrace_location(struct kprobe *p) { unsigned long ftrace_addr; @@ -1547,7 +1547,7 @@ static int check_kprobe_address_safe(struct kprobe *p, { int ret; - ret = arch_check_ftrace_location(p); + ret = check_ftrace_location(p); if (ret) return ret; jump_label_lock(); From patchwork Tue Sep 14 14:39:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493681 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63836C433F5 for ; Tue, 14 Sep 2021 14:40:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 499C96113E for ; Tue, 14 Sep 2021 14:40:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235029AbhINOlT (ORCPT ); Tue, 14 Sep 2021 10:41:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:34620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234776AbhINOkq (ORCPT ); Tue, 14 Sep 2021 10:40:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2BEBC610CE; Tue, 14 Sep 2021 14:39:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630369; bh=KU2JYPK+cMCaLmePVFC3LxfPd7UfHdLIC2wSTH94K2s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WL+GJmeNuknhbjQYKUboc103WqrwBQCtlBUIU9faYeyGYo6bVz7U/8ltPnhorwJ2D 6SuMhix51aUXrmU139H4v+P48XSTJu/3m34+GQbhbtQsHpDF8n51eVRIty51RbX7+q momoaC9+xfmgbc2KT8F/xZkqvHnBMZFTCK3vDJhWMlRQUnImya8zU+868ELVIM0v8u 12Xd7BbApJ/7CZjY7He551rcmPseik1aw+cFrQQ/iYBOYDVJ1p2/HF8ILYN3U7uzf0 bWyCquOYRa3VcnS/64ON6ONw2ql2EOTD3JEqRiGN8RVujpp0mPK8BlAuhXJZ0MzsJF Z2F7WnBcp90Ew== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 06/27] kprobes: treewide: Cleanup the error messages for kprobes Date: Tue, 14 Sep 2021 23:39:25 +0900 Message-Id: <163163036568.489837.14085396178727185469.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This clean up the error/notification messages in kprobes related code. Basically this defines 'pr_fmt()' macros for each files and update the messages which describes - what happened, - what is the kernel going to do or not do, - is the kernel fine, - what can the user do about it. Also, if the message is not needed (e.g. the function returns unique error code, or other error message is already shown.) remove it, and replace the message with WARN_*() macros if suitable. Signed-off-by: Masami Hiramatsu --- arch/arm/probes/kprobes/core.c | 4 +++- arch/arm64/kernel/probes/kprobes.c | 5 ++++- arch/csky/kernel/probes/kprobes.c | 10 +++++----- arch/mips/kernel/kprobes.c | 11 +++++------ arch/riscv/kernel/probes/kprobes.c | 11 +++++------ arch/s390/kernel/kprobes.c | 4 +++- kernel/kprobes.c | 36 ++++++++++++++++-------------------- 7 files changed, 41 insertions(+), 40 deletions(-) diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 27e0af78e88b..a59e38de4a03 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -11,6 +11,8 @@ * Copyright (C) 2007 Marvell Ltd. */ +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -278,7 +280,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs) break; case KPROBE_REENTER: /* A nested probe was hit in FIQ, it is a BUG */ - pr_warn("Unrecoverable kprobe detected.\n"); + pr_warn("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); fallthrough; default: diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 6dbcc89f6662..ce429cbacd35 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -7,6 +7,9 @@ * Copyright (C) 2013 Linaro Limited. * Author: Sandeepa Prabhu */ + +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -218,7 +221,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p, break; case KPROBE_HIT_SS: case KPROBE_REENTER: - pr_warn("Unrecoverable kprobe detected.\n"); + pr_warn("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); BUG(); break; diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c index 8fffa34d4e1c..632407bf45d5 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -77,10 +79,8 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) { unsigned long probe_addr = (unsigned long)p->addr; - if (probe_addr & 0x1) { - pr_warn("Address not aligned.\n"); - return -EINVAL; - } + if (probe_addr & 0x1) + return -EILSEQ; /* copy instruction */ p->opcode = le32_to_cpu(*p->addr); @@ -225,7 +225,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p, break; case KPROBE_HIT_SS: case KPROBE_REENTER: - pr_warn("Unrecoverable kprobe detected.\n"); + pr_warn("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); BUG(); break; diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index 75bff0f77319..b0934a0d7aed 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -11,6 +11,8 @@ * Copyright (C) IBM Corporation, 2002, 2004 */ +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -80,8 +82,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) insn = p->addr[0]; if (insn_has_ll_or_sc(insn)) { - pr_notice("Kprobes for ll and sc instructions are not" - "supported\n"); + pr_notice("Kprobes for ll and sc instructions are not supported\n"); ret = -EINVAL; goto out; } @@ -219,7 +220,7 @@ static int evaluate_branch_instruction(struct kprobe *p, struct pt_regs *regs, return 0; unaligned: - pr_notice("%s: unaligned epc - sending SIGBUS.\n", current->comm); + pr_notice("Failed to emulate branch instruction because of unaligned epc - sending SIGBUS to %s.\n", current->comm); force_sig(SIGBUS); return -EFAULT; @@ -238,10 +239,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, regs->cp0_epc = (unsigned long)p->addr; else if (insn_has_delayslot(p->opcode)) { ret = evaluate_branch_instruction(p, regs, kcb); - if (ret < 0) { - pr_notice("Kprobes: Error in evaluating branch\n"); + if (ret < 0) return; - } } regs->cp0_epc = (unsigned long)&p->ainsn.insn[0]; } diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 00088dc6da4b..cab6f874358e 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -50,11 +52,8 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) { unsigned long probe_addr = (unsigned long)p->addr; - if (probe_addr & 0x1) { - pr_warn("Address not aligned.\n"); - - return -EINVAL; - } + if (probe_addr & 0x1) + return -EILSEQ; /* copy instruction */ p->opcode = *p->addr; @@ -191,7 +190,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p, break; case KPROBE_HIT_SS: case KPROBE_REENTER: - pr_warn("Unrecoverable kprobe detected.\n"); + pr_warn("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); BUG(); break; diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 52d056a5f89f..952d44b0610b 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -7,6 +7,8 @@ * s390 port, used ppc64 as template. Mike Grundy */ +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -259,7 +261,7 @@ static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p) * is a BUG. The code path resides in the .kprobes.text * section and is executed with interrupts disabled. */ - pr_err("Invalid kprobe detected.\n"); + pr_err("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); BUG(); } diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 30199bfcc74a..7663c8a51889 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -18,6 +18,9 @@ * and Prasanna S Panchamukhi * added function-return probes. */ + +#define pr_fmt(fmt) "kprobes: " fmt + #include #include #include @@ -892,7 +895,7 @@ static void optimize_all_kprobes(void) optimize_kprobe(p); } cpus_read_unlock(); - printk(KERN_INFO "Kprobes globally optimized\n"); + pr_info("kprobe jump-optimization is enabled. All kprobes are optimized if possible.\n"); out: mutex_unlock(&kprobe_mutex); } @@ -925,7 +928,7 @@ static void unoptimize_all_kprobes(void) /* Wait for unoptimizing completion */ wait_for_kprobe_optimizer(); - printk(KERN_INFO "Kprobes globally unoptimized\n"); + pr_info("kprobe jump-optimization is disabled. All kprobes are based on software breakpoint.\n"); } static DEFINE_MUTEX(kprobe_sysctl_mutex); @@ -1003,7 +1006,7 @@ static int reuse_unused_kprobe(struct kprobe *ap) * unregistered. * Thus there should be no chance to reuse unused kprobe. */ - printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); + WARN_ON_ONCE(1); return -EINVAL; } @@ -1040,18 +1043,13 @@ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int ret = 0; ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); - if (ret) { - pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n", - p->addr, ret); + if (WARN_ONCE(ret < 0, "Failed to arm kprobe-ftrace at %pS (error %d)\n", p->addr, ret)) return ret; - } if (*cnt == 0) { ret = register_ftrace_function(ops); - if (ret) { - pr_debug("Failed to init kprobe-ftrace (%d)\n", ret); + if (WARN(ret < 0, "Failed to register kprobe-ftrace (error %d)\n", ret)) goto err_ftrace; - } } (*cnt)++; @@ -1083,14 +1081,14 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, if (*cnt == 1) { ret = unregister_ftrace_function(ops); - if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret)) + if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (error %d)\n", ret)) return ret; } (*cnt)--; ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); - WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n", + WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (error %d)\n", p->addr, ret); return ret; } @@ -1880,7 +1878,7 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, node = node->next; } - pr_err("Oops! Kretprobe fails to find correct return address.\n"); + pr_err("kretprobe: Return address not found, not execute handler. Maybe there is a bug in the kernel.\n"); BUG_ON(1); found: @@ -2209,8 +2207,7 @@ EXPORT_SYMBOL_GPL(enable_kprobe); /* Caller must NOT call this in usual path. This is only for critical case */ void dump_kprobe(struct kprobe *kp) { - pr_err("Dumping kprobe:\n"); - pr_err("Name: %s\nOffset: %x\nAddress: %pS\n", + pr_err("Dump kprobe:\n.symbol_name = %s, .offset = %x, .addr = %pS\n", kp->symbol_name, kp->offset, kp->addr); } NOKPROBE_SYMBOL(dump_kprobe); @@ -2473,8 +2470,7 @@ static int __init init_kprobes(void) err = populate_kprobe_blacklist(__start_kprobe_blacklist, __stop_kprobe_blacklist); if (err) { - pr_err("kprobes: failed to populate blacklist: %d\n", err); - pr_err("Please take care of using kprobes.\n"); + pr_err("Failed to populate blacklist (error %d), kprobes not restricted, be careful using them!\n", err); } if (kretprobe_blacklist_size) { @@ -2483,7 +2479,7 @@ static int __init init_kprobes(void) kretprobe_blacklist[i].addr = kprobe_lookup_name(kretprobe_blacklist[i].name, 0); if (!kretprobe_blacklist[i].addr) - printk("kretprobe: lookup failed: %s\n", + pr_err("Failed to lookup symbol '%s' for kretprobe blacklist. Maybe the target function is removed or renamed.\n", kretprobe_blacklist[i].name); } } @@ -2687,7 +2683,7 @@ static int arm_all_kprobes(void) } if (errors) - pr_warn("Kprobes globally enabled, but failed to arm %d out of %d probes\n", + pr_warn("Kprobes globally enabled, but failed to enable %d out of %d probes. Please check which kprobes are kept disabled via debugfs.\n", errors, total); else pr_info("Kprobes globally enabled\n"); @@ -2730,7 +2726,7 @@ static int disarm_all_kprobes(void) } if (errors) - pr_warn("Kprobes globally disabled, but failed to disarm %d out of %d probes\n", + pr_warn("Kprobes globally disabled, but failed to disable %d out of %d probes. Please check which kprobes are kept enabled via debugfs.\n", errors, total); else pr_info("Kprobes globally disabled\n"); From patchwork Tue Sep 14 14:39:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493685 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44917C433FE for ; Tue, 14 Sep 2021 14:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23376610CE for ; Tue, 14 Sep 2021 14:40:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234321AbhINOl5 (ORCPT ); Tue, 14 Sep 2021 10:41:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:34902 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234376AbhINOk5 (ORCPT ); Tue, 14 Sep 2021 10:40:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7F8D8610A2; Tue, 14 Sep 2021 14:39:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630380; bh=tsxQfM/LKrO1aD4HJEXtW/RfIYBJH2jMBYS/QbFeAdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y/WN9lHig791S8YeRnuVqflDpiZvyMvwnjicOVJTCNKU3j5byUsBD4lTvsX4I2gJv hA2Y2M1CHexmJv3x9FPmtK3hOfxP/8gzg3/dOGKcKHUMnQmQpic7qibj6AU9kPLbUH zT+AbHlEO3+tokgq7jvz4c9x4wGIajpDP8EBQsDLCS3UtKD+uUkxe+irjMJN4zsWoV vBkKlu0MTrUolbFCeL1zh8ZPziNk+OQBJ+w/sdXegBkH4a7u5G9X2lRSjZ/KaDxGkL cOW1zeBsUUEWbZtydmhMRz3yWgWIdyMQQl/FNNWTXpJrgQlYZQZxw57lw/xoQE4LgH D6UJ8tZbRndkQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 07/27] kprobes: Fix coding style issues Date: Tue, 14 Sep 2021 23:39:34 +0900 Message-Id: <163163037468.489837.4282347782492003960.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Fix coding style issues reported by checkpatch.pl and update comments to quote variable names and add "()" to function name. One TODO comment in __disarm_kprobe() is removed because it has been done by following commit. Signed-off-by: Masami Hiramatsu --- include/linux/kprobes.h | 40 +++++--- kernel/kprobes.c | 236 ++++++++++++++++++++++++----------------------- 2 files changed, 145 insertions(+), 131 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 8a9412bb0d5e..756d3d23ce37 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -3,7 +3,6 @@ #define _LINUX_KPROBES_H /* * Kernel Probes (KProbes) - * include/linux/kprobes.h * * Copyright (C) IBM Corporation, 2002, 2004 * @@ -39,7 +38,7 @@ #define KPROBE_REENTER 0x00000004 #define KPROBE_HIT_SSDONE 0x00000008 -#else /* CONFIG_KPROBES */ +#else /* !CONFIG_KPROBES */ #include typedef int kprobe_opcode_t; struct arch_specific_insn { @@ -228,7 +227,7 @@ static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance return READ_ONCE(ri->rph->rp); } -#else /* CONFIG_KRETPROBES */ +#else /* !CONFIG_KRETPROBES */ static inline void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) { @@ -239,11 +238,15 @@ static inline int arch_trampoline_kprobe(struct kprobe *p) } #endif /* CONFIG_KRETPROBES */ +/* Markers of '_kprobe_blacklist' section */ +extern unsigned long __start_kprobe_blacklist[]; +extern unsigned long __stop_kprobe_blacklist[]; + extern struct kretprobe_blackpoint kretprobe_blacklist[]; #ifdef CONFIG_KPROBES_SANITY_TEST extern int init_test_probes(void); -#else +#else /* !CONFIG_KPROBES_SANITY_TEST */ static inline int init_test_probes(void) { return 0; @@ -303,7 +306,7 @@ static inline bool is_kprobe_##__name##_slot(unsigned long addr) \ #define KPROBE_OPTINSN_PAGE_SYM "kprobe_optinsn_page" int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum, unsigned long *value, char *type, char *sym); -#else /* __ARCH_WANT_KPROBES_INSN_SLOT */ +#else /* !__ARCH_WANT_KPROBES_INSN_SLOT */ #define DEFINE_INSN_CACHE_OPS(__name) \ static inline bool is_kprobe_##__name##_slot(unsigned long addr) \ { \ @@ -345,11 +348,12 @@ extern int sysctl_kprobes_optimization; extern int proc_kprobes_optimization_handler(struct ctl_table *table, int write, void *buffer, size_t *length, loff_t *ppos); -#endif +#endif /* CONFIG_SYSCTL */ extern void wait_for_kprobe_optimizer(void); -#else +#else /* !CONFIG_OPTPROBES */ static inline void wait_for_kprobe_optimizer(void) { } #endif /* CONFIG_OPTPROBES */ + #ifdef CONFIG_KPROBES_ON_FTRACE extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct ftrace_regs *fregs); @@ -359,7 +363,7 @@ static inline int arch_prepare_kprobe_ftrace(struct kprobe *p) { return -EINVAL; } -#endif +#endif /* CONFIG_KPROBES_ON_FTRACE */ /* Get the kprobe at this addr (if any) - called with preemption disabled */ struct kprobe *get_kprobe(void *addr); @@ -367,7 +371,7 @@ struct kprobe *get_kprobe(void *addr); /* kprobe_running() will just return the current_kprobe on this CPU */ static inline struct kprobe *kprobe_running(void) { - return (__this_cpu_read(current_kprobe)); + return __this_cpu_read(current_kprobe); } static inline void reset_current_kprobe(void) @@ -431,11 +435,11 @@ static inline struct kprobe *kprobe_running(void) } static inline int register_kprobe(struct kprobe *p) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline int register_kprobes(struct kprobe **kps, int num) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline void unregister_kprobe(struct kprobe *p) { @@ -445,11 +449,11 @@ static inline void unregister_kprobes(struct kprobe **kps, int num) } static inline int register_kretprobe(struct kretprobe *rp) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline int register_kretprobes(struct kretprobe **rps, int num) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline void unregister_kretprobe(struct kretprobe *rp) { @@ -465,11 +469,11 @@ static inline void kprobe_free_init_mem(void) } static inline int disable_kprobe(struct kprobe *kp) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline int enable_kprobe(struct kprobe *kp) { - return -ENOSYS; + return -EOPNOTSUPP; } static inline bool within_kprobe_blacklist(unsigned long addr) @@ -482,6 +486,7 @@ static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, return -ERANGE; } #endif /* CONFIG_KPROBES */ + static inline int disable_kretprobe(struct kretprobe *rp) { return disable_kprobe(&rp->kp); @@ -496,13 +501,14 @@ static inline bool is_kprobe_insn_slot(unsigned long addr) { return false; } -#endif +#endif /* !CONFIG_KPROBES */ + #ifndef CONFIG_OPTPROBES static inline bool is_kprobe_optinsn_slot(unsigned long addr) { return false; } -#endif +#endif /* !CONFIG_OPTPROBES */ /* Returns true if kprobes handled the fault */ static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs, diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 7663c8a51889..ad39eeaa4371 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* * Kernel Probes (KProbes) - * kernel/kprobes.c * * Copyright (C) IBM Corporation, 2002, 2004 * @@ -52,18 +51,18 @@ static int kprobes_initialized; /* kprobe_table can be accessed by - * - Normal hlist traversal and RCU add/del under kprobe_mutex is held. + * - Normal hlist traversal and RCU add/del under 'kprobe_mutex' is held. * Or * - RCU hlist traversal under disabling preempt (breakpoint handlers) */ static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; -/* NOTE: change this value only with kprobe_mutex held */ +/* NOTE: change this value only with 'kprobe_mutex' held */ static bool kprobes_all_disarmed; -/* This protects kprobe_table and optimizing_list */ +/* This protects 'kprobe_table' and 'optimizing_list' */ static DEFINE_MUTEX(kprobe_mutex); -static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; +static DEFINE_PER_CPU(struct kprobe *, kprobe_instance); kprobe_opcode_t * __weak kprobe_lookup_name(const char *name, unsigned int __unused) @@ -71,12 +70,15 @@ kprobe_opcode_t * __weak kprobe_lookup_name(const char *name, return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); } -/* Blacklist -- list of struct kprobe_blacklist_entry */ +/* + * Blacklist -- list of 'struct kprobe_blacklist_entry' to store info where + * kprobes can not probe. + */ static LIST_HEAD(kprobe_blacklist); #ifdef __ARCH_WANT_KPROBES_INSN_SLOT /* - * kprobe->ainsn.insn points to the copy of the instruction to be + * 'kprobe::ainsn.insn' points to the copy of the instruction to be * single-stepped. x86_64, POWER4 and above have no-exec support and * stepping on the instruction on a vmalloced/kmalloced/data page * is a recipe for disaster @@ -107,6 +109,12 @@ enum kprobe_slot_state { void __weak *alloc_insn_page(void) { + /* + * Use module_alloc() so this page is within +/- 2GB of where the + * kernel image and loaded module images reside. This is required + * for most of the architectures. + * (e.g. x86-64 needs this to handle the %rip-relative fixups.) + */ return module_alloc(PAGE_SIZE); } @@ -142,6 +150,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) list_for_each_entry_rcu(kip, &c->pages, list) { if (kip->nused < slots_per_page(c)) { int i; + for (i = 0; i < slots_per_page(c); i++) { if (kip->slot_used[i] == SLOT_CLEAN) { kip->slot_used[i] = SLOT_USED; @@ -167,11 +176,6 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) if (!kip) goto out; - /* - * Use module_alloc so this page is within +/- 2GB of where the - * kernel image and loaded module images reside. This is required - * so x86_64 can correctly handle the %rip-relative fixups. - */ kip->insns = c->alloc(); if (!kip->insns) { kfree(kip); @@ -233,6 +237,7 @@ static int collect_garbage_slots(struct kprobe_insn_cache *c) list_for_each_entry_safe(kip, next, &c->pages, list) { int i; + if (kip->ngarbage == 0) continue; kip->ngarbage = 0; /* we will collect all garbages */ @@ -313,7 +318,7 @@ int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum, list_for_each_entry_rcu(kip, &c->pages, list) { if ((*symnum)--) continue; - strlcpy(sym, c->sym, KSYM_NAME_LEN); + strscpy(sym, c->sym, KSYM_NAME_LEN); *type = 't'; *value = (unsigned long)kip->insns; ret = 0; @@ -361,9 +366,9 @@ static inline void reset_kprobe_instance(void) /* * This routine is called either: - * - under the kprobe_mutex - during kprobe_[un]register() - * OR - * - with preemption disabled - from arch/xxx/kernel/kprobes.c + * - under the 'kprobe_mutex' - during kprobe_[un]register(). + * OR + * - with preemption disabled - from architecture specific code. */ struct kprobe *get_kprobe(void *addr) { @@ -383,22 +388,20 @@ NOKPROBE_SYMBOL(get_kprobe); static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); -/* Return true if the kprobe is an aggregator */ +/* Return true if 'p' is an aggregator */ static inline int kprobe_aggrprobe(struct kprobe *p) { return p->pre_handler == aggr_pre_handler; } -/* Return true(!0) if the kprobe is unused */ +/* Return true if 'p' is unused */ static inline int kprobe_unused(struct kprobe *p) { return kprobe_aggrprobe(p) && kprobe_disabled(p) && list_empty(&p->list); } -/* - * Keep all fields in the kprobe consistent - */ +/* Keep all fields in the kprobe consistent. */ static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) { memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); @@ -406,11 +409,11 @@ static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) } #ifdef CONFIG_OPTPROBES -/* NOTE: change this value only with kprobe_mutex held */ +/* NOTE: This is protected by 'kprobe_mutex'. */ static bool kprobes_allow_optimization; /* - * Call all pre_handler on the list, but ignores its return value. + * Call all 'kprobe::pre_handler' on the list, but ignores its return value. * This must be called from arch-dep optimized caller. */ void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) @@ -438,7 +441,7 @@ static void free_aggr_kprobe(struct kprobe *p) kfree(op); } -/* Return true(!0) if the kprobe is ready for optimization. */ +/* Return true if the kprobe is ready for optimization. */ static inline int kprobe_optready(struct kprobe *p) { struct optimized_kprobe *op; @@ -451,7 +454,7 @@ static inline int kprobe_optready(struct kprobe *p) return 0; } -/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ +/* Return true if the kprobe is disarmed. Note: p must be on hash list */ static inline int kprobe_disarmed(struct kprobe *p) { struct optimized_kprobe *op; @@ -465,7 +468,7 @@ static inline int kprobe_disarmed(struct kprobe *p) return kprobe_disabled(p) && list_empty(&op->list); } -/* Return true(!0) if the probe is queued on (un)optimizing lists */ +/* Return true if the probe is queued on (un)optimizing lists */ static int kprobe_queued(struct kprobe *p) { struct optimized_kprobe *op; @@ -480,7 +483,7 @@ static int kprobe_queued(struct kprobe *p) /* * Return an optimized kprobe whose optimizing code replaces - * instructions including addr (exclude breakpoint). + * instructions including 'addr' (exclude breakpoint). */ static struct kprobe *get_optimized_kprobe(unsigned long addr) { @@ -501,7 +504,7 @@ static struct kprobe *get_optimized_kprobe(unsigned long addr) return NULL; } -/* Optimization staging list, protected by kprobe_mutex */ +/* Optimization staging list, protected by 'kprobe_mutex' */ static LIST_HEAD(optimizing_list); static LIST_HEAD(unoptimizing_list); static LIST_HEAD(freeing_list); @@ -512,20 +515,20 @@ static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); /* * Optimize (replace a breakpoint with a jump) kprobes listed on - * optimizing_list. + * 'optimizing_list'. */ static void do_optimize_kprobes(void) { lockdep_assert_held(&text_mutex); /* - * The optimization/unoptimization refers online_cpus via - * stop_machine() and cpu-hotplug modifies online_cpus. - * And same time, text_mutex will be held in cpu-hotplug and here. - * This combination can cause a deadlock (cpu-hotplug try to lock - * text_mutex but stop_machine can not be done because online_cpus - * has been changed) - * To avoid this deadlock, caller must have locked cpu hotplug - * for preventing cpu-hotplug outside of text_mutex locking. + * The optimization/unoptimization refers 'online_cpus' via + * stop_machine() and cpu-hotplug modifies the 'online_cpus'. + * And same time, 'text_mutex' will be held in cpu-hotplug and here. + * This combination can cause a deadlock (cpu-hotplug tries to lock + * 'text_mutex' but stop_machine() can not be done because + * the 'online_cpus' has been changed) + * To avoid this deadlock, caller must have locked cpu-hotplug + * for preventing cpu-hotplug outside of 'text_mutex' locking. */ lockdep_assert_cpus_held(); @@ -539,7 +542,7 @@ static void do_optimize_kprobes(void) /* * Unoptimize (replace a jump with a breakpoint and remove the breakpoint - * if need) kprobes listed on unoptimizing_list. + * if need) kprobes listed on 'unoptimizing_list'. */ static void do_unoptimize_kprobes(void) { @@ -554,7 +557,7 @@ static void do_unoptimize_kprobes(void) return; arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); - /* Loop free_list for disarming */ + /* Loop on 'freeing_list' for disarming */ list_for_each_entry_safe(op, tmp, &freeing_list, list) { /* Switching from detour code to origin */ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; @@ -565,7 +568,7 @@ static void do_unoptimize_kprobes(void) /* * Remove unused probes from hash list. After waiting * for synchronization, these probes are reclaimed. - * (reclaiming is done by do_free_cleaned_kprobes.) + * (reclaiming is done by do_free_cleaned_kprobes().) */ hlist_del_rcu(&op->kp.hlist); } else @@ -573,7 +576,7 @@ static void do_unoptimize_kprobes(void) } } -/* Reclaim all kprobes on the free_list */ +/* Reclaim all kprobes on the 'freeing_list' */ static void do_free_cleaned_kprobes(void) { struct optimized_kprobe *op, *tmp; @@ -645,9 +648,9 @@ void wait_for_kprobe_optimizer(void) while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { mutex_unlock(&kprobe_mutex); - /* this will also make optimizing_work execute immmediately */ + /* This will also make 'optimizing_work' execute immmediately */ flush_delayed_work(&optimizing_work); - /* @optimizing_work might not have been queued yet, relax */ + /* 'optimizing_work' might not have been queued yet, relax */ cpu_relax(); mutex_lock(&kprobe_mutex); @@ -678,7 +681,7 @@ static void optimize_kprobe(struct kprobe *p) (kprobe_disabled(p) || kprobes_all_disarmed)) return; - /* kprobes with post_handler can not be optimized */ + /* kprobes with 'post_handler' can not be optimized */ if (p->post_handler) return; @@ -698,7 +701,10 @@ static void optimize_kprobe(struct kprobe *p) } op->kp.flags |= KPROBE_FLAG_OPTIMIZED; - /* On unoptimizing/optimizing_list, op must have OPTIMIZED flag */ + /* + * On the 'unoptimizing_list' and 'optimizing_list', + * 'op' must have OPTIMIZED flag + */ if (WARN_ON_ONCE(!list_empty(&op->list))) return; @@ -768,7 +774,7 @@ static int reuse_unused_kprobe(struct kprobe *ap) WARN_ON_ONCE(list_empty(&op->list)); /* Enable the probe again */ ap->flags &= ~KPROBE_FLAG_DISABLED; - /* Optimize it again (remove from op->list) */ + /* Optimize it again. (remove from 'op->list') */ if (!kprobe_optready(ap)) return -EINVAL; @@ -818,7 +824,7 @@ static void prepare_optimized_kprobe(struct kprobe *p) __prepare_optimized_kprobe(op, p); } -/* Allocate new optimized_kprobe and try to prepare optimized instructions */ +/* Allocate new optimized_kprobe and try to prepare optimized instructions. */ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -837,19 +843,19 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); /* - * Prepare an optimized_kprobe and optimize it - * NOTE: p must be a normal registered kprobe + * Prepare an optimized_kprobe and optimize it. + * NOTE: 'p' must be a normal registered kprobe. */ static void try_to_optimize_kprobe(struct kprobe *p) { struct kprobe *ap; struct optimized_kprobe *op; - /* Impossible to optimize ftrace-based kprobe */ + /* Impossible to optimize ftrace-based kprobe. */ if (kprobe_ftrace(p)) return; - /* For preparing optimization, jump_label_text_reserved() is called */ + /* For preparing optimization, jump_label_text_reserved() is called. */ cpus_read_lock(); jump_label_lock(); mutex_lock(&text_mutex); @@ -860,14 +866,14 @@ static void try_to_optimize_kprobe(struct kprobe *p) op = container_of(ap, struct optimized_kprobe, kp); if (!arch_prepared_optinsn(&op->optinsn)) { - /* If failed to setup optimizing, fallback to kprobe */ + /* If failed to setup optimizing, fallback to kprobe. */ arch_remove_optimized_kprobe(op); kfree(op); goto out; } init_aggr_kprobe(ap, p); - optimize_kprobe(ap); /* This just kicks optimizer thread */ + optimize_kprobe(ap); /* This just kicks optimizer thread. */ out: mutex_unlock(&text_mutex); @@ -882,7 +888,7 @@ static void optimize_all_kprobes(void) unsigned int i; mutex_lock(&kprobe_mutex); - /* If optimization is already allowed, just return */ + /* If optimization is already allowed, just return. */ if (kprobes_allow_optimization) goto out; @@ -908,7 +914,7 @@ static void unoptimize_all_kprobes(void) unsigned int i; mutex_lock(&kprobe_mutex); - /* If optimization is already prohibited, just return */ + /* If optimization is already prohibited, just return. */ if (!kprobes_allow_optimization) { mutex_unlock(&kprobe_mutex); return; @@ -926,7 +932,7 @@ static void unoptimize_all_kprobes(void) cpus_read_unlock(); mutex_unlock(&kprobe_mutex); - /* Wait for unoptimizing completion */ + /* Wait for unoptimizing completion. */ wait_for_kprobe_optimizer(); pr_info("kprobe jump-optimization is disabled. All kprobes are based on software breakpoint.\n"); } @@ -953,12 +959,12 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write, } #endif /* CONFIG_SYSCTL */ -/* Put a breakpoint for a probe. Must be called with text_mutex locked */ +/* Put a breakpoint for a probe. Must be called with 'text_mutex' locked. */ static void __arm_kprobe(struct kprobe *p) { struct kprobe *_p; - /* Check collision with other optimized kprobes */ + /* Find the overlapping optimized kprobes. */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p)) /* Fallback to unoptimized kprobe */ @@ -968,7 +974,7 @@ static void __arm_kprobe(struct kprobe *p) optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ } -/* Remove the breakpoint of a probe. Must be called with text_mutex locked */ +/* Remove the breakpoint of a probe. Must be called with 'text_mutex' locked. */ static void __disarm_kprobe(struct kprobe *p, bool reopt) { struct kprobe *_p; @@ -978,12 +984,17 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) if (!kprobe_queued(p)) { arch_disarm_kprobe(p); - /* If another kprobe was blocked, optimize it. */ + /* If another kprobe was blocked, re-optimize it. */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p) && reopt) optimize_kprobe(_p); } - /* TODO: reoptimize others after unoptimized this probe */ + /* + * TODO: Since unoptimization and real disarming will be done by + * the worker thread, we can not check whether another probe are + * unoptimized because of this probe here. It should be re-optimized + * by the worker thread. + */ } #else /* !CONFIG_OPTPROBES */ @@ -1036,7 +1047,7 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { static int kprobe_ipmodify_enabled; static int kprobe_ftrace_enabled; -/* Caller must lock kprobe_mutex */ +/* Caller must lock 'kprobe_mutex' */ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { @@ -1073,7 +1084,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); } -/* Caller must lock kprobe_mutex */ +/* Caller must lock 'kprobe_mutex'. */ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { @@ -1122,7 +1133,7 @@ static int prepare_kprobe(struct kprobe *p) return arch_prepare_kprobe(p); } -/* Arm a kprobe with text_mutex */ +/* Arm a kprobe with 'text_mutex'. */ static int arm_kprobe(struct kprobe *kp) { if (unlikely(kprobe_ftrace(kp))) @@ -1137,7 +1148,7 @@ static int arm_kprobe(struct kprobe *kp) return 0; } -/* Disarm a kprobe with text_mutex */ +/* Disarm a kprobe with 'text_mutex'. */ static int disarm_kprobe(struct kprobe *kp, bool reopt) { if (unlikely(kprobe_ftrace(kp))) @@ -1187,17 +1198,17 @@ static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, } NOKPROBE_SYMBOL(aggr_post_handler); -/* Walks the list and increments nmissed count for multiprobe case */ +/* Walks the list and increments 'nmissed' if 'p' has child probes. */ void kprobes_inc_nmissed_count(struct kprobe *p) { struct kprobe *kp; + if (!kprobe_aggrprobe(p)) { p->nmissed++; } else { list_for_each_entry_rcu(kp, &p->list, list) kp->nmissed++; } - return; } NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); @@ -1215,9 +1226,9 @@ static void recycle_rp_inst(struct kretprobe_instance *ri) { struct kretprobe *rp = get_kretprobe(ri); - if (likely(rp)) { + if (likely(rp)) freelist_add(&ri->freelist, &rp->freelist); - } else + else call_rcu(&ri->rcu, free_rp_inst_rcu); } NOKPROBE_SYMBOL(recycle_rp_inst); @@ -1243,8 +1254,8 @@ void kprobe_busy_end(void) } /* - * This function is called from finish_task_switch when task tk becomes dead, - * so that we can recycle any function-return probe instances associated + * This function is called from finish_task_switch() when task 'tk' becomes + * dead, so that we can recycle any kretprobe instances associated * with this task. These left over instances represent probed functions * that have been called but will never return. */ @@ -1292,7 +1303,7 @@ static inline void free_rp_inst(struct kretprobe *rp) } } -/* Add the new probe to ap->list */ +/* Add the new probe to 'ap->list'. */ static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) { if (p->post_handler) @@ -1306,12 +1317,12 @@ static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) } /* - * Fill in the required fields of the "manager kprobe". Replace the - * earlier kprobe in the hlist with the manager kprobe + * Fill in the required fields of the aggregator kprobe. Replace the + * earlier kprobe in the hlist with the aggregator kprobe. */ static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) { - /* Copy p's insn slot to ap */ + /* Copy the insn slot of 'p' to 'ap'. */ copy_kprobe(p, ap); flush_insn_slot(ap); ap->addr = p->addr; @@ -1329,8 +1340,7 @@ static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) } /* - * This is the second or subsequent kprobe at the address - handle - * the intricacies + * This registers the second or subsequent kprobe at the same address. */ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) { @@ -1344,7 +1354,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) mutex_lock(&text_mutex); if (!kprobe_aggrprobe(orig_p)) { - /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ + /* If 'orig_p' is not an 'aggr_kprobe', create new one. */ ap = alloc_aggr_kprobe(orig_p); if (!ap) { ret = -ENOMEM; @@ -1369,8 +1379,8 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) if (ret) /* * Even if fail to allocate new slot, don't need to - * free aggr_probe. It will be used next time, or - * freed by unregister_kprobe. + * free the 'ap'. It will be used next time, or + * freed by unregister_kprobe(). */ goto out; @@ -1385,7 +1395,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) | KPROBE_FLAG_DISABLED; } - /* Copy ap's insn slot to p */ + /* Copy the insn slot of 'p' to 'ap'. */ copy_kprobe(ap, p); ret = add_new_kprobe(ap, p); @@ -1411,7 +1421,7 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) bool __weak arch_within_kprobe_blacklist(unsigned long addr) { - /* The __kprobes marked functions and entry code must not be probed */ + /* The '__kprobes' functions and entry code must not be probed. */ return addr >= (unsigned long)__kprobes_text_start && addr < (unsigned long)__kprobes_text_end; } @@ -1423,8 +1433,8 @@ static bool __within_kprobe_blacklist(unsigned long addr) if (arch_within_kprobe_blacklist(addr)) return true; /* - * If there exists a kprobe_blacklist, verify and - * fail any probe registration in the prohibited area + * If 'kprobe_blacklist' is defined, check the address and + * reject any probe registration in the prohibited area. */ list_for_each_entry(ent, &kprobe_blacklist, list) { if (addr >= ent->start_addr && addr < ent->end_addr) @@ -1454,7 +1464,7 @@ bool within_kprobe_blacklist(unsigned long addr) } /* - * If we have a symbol_name argument, look it up and add the offset field + * If 'symbol_name' is specified, look it up and add the 'offset' * to it. This way, we can specify a relative address to a symbol. * This returns encoded errors if it fails to look up symbol or invalid * combination of parameters. @@ -1484,7 +1494,10 @@ static kprobe_opcode_t *kprobe_addr(struct kprobe *p) return _kprobe_addr(p->addr, p->symbol_name, p->offset); } -/* Check passed kprobe is valid and return kprobe in kprobe_table. */ +/* + * Check the 'p' is valid and return the aggregator kprobe + * at the same address. + */ static struct kprobe *__get_valid_kprobe(struct kprobe *p) { struct kprobe *ap, *list_p; @@ -1561,7 +1574,7 @@ static int check_kprobe_address_safe(struct kprobe *p, goto out; } - /* Check if are we probing a module */ + /* Check if 'p' is probing a module. */ *probed_mod = __module_text_address((unsigned long) p->addr); if (*probed_mod) { /* @@ -1574,7 +1587,7 @@ static int check_kprobe_address_safe(struct kprobe *p, } /* - * If the module freed .init.text, we couldn't insert + * If the module freed '.init.text', we couldn't insert * kprobes in there. */ if (within_module_init((unsigned long)p->addr, *probed_mod) && @@ -1621,7 +1634,7 @@ int register_kprobe(struct kprobe *p) old_p = get_kprobe(p->addr); if (old_p) { - /* Since this may unoptimize old_p, locking text_mutex. */ + /* Since this may unoptimize 'old_p', locking 'text_mutex'. */ ret = register_aggr_kprobe(old_p, p); goto out; } @@ -1660,7 +1673,7 @@ int register_kprobe(struct kprobe *p) } EXPORT_SYMBOL_GPL(register_kprobe); -/* Check if all probes on the aggrprobe are disabled */ +/* Check if all probes on the 'ap' are disabled. */ static int aggr_kprobe_disabled(struct kprobe *ap) { struct kprobe *kp; @@ -1670,15 +1683,15 @@ static int aggr_kprobe_disabled(struct kprobe *ap) list_for_each_entry(kp, &ap->list, list) if (!kprobe_disabled(kp)) /* - * There is an active probe on the list. - * We can't disable this ap. + * Since there is an active probe on the list, + * we can't disable this 'ap'. */ return 0; return 1; } -/* Disable one kprobe: Make sure called under kprobe_mutex is locked */ +/* Disable one kprobe: Make sure called under 'kprobe_mutex' is locked. */ static struct kprobe *__disable_kprobe(struct kprobe *p) { struct kprobe *orig_p; @@ -1697,7 +1710,7 @@ static struct kprobe *__disable_kprobe(struct kprobe *p) /* Try to disarm and disable this/parent probe */ if (p == orig_p || aggr_kprobe_disabled(orig_p)) { /* - * If kprobes_all_disarmed is set, orig_p + * If 'kprobes_all_disarmed' is set, 'orig_p' * should have already been disarmed, so * skip unneed disarming process. */ @@ -1984,7 +1997,7 @@ int register_kretprobe(struct kretprobe *rp) if (ret) return ret; - /* If only rp->kp.addr is specified, check reregistering kprobes */ + /* If only 'rp->kp.addr' is specified, check reregistering kprobes */ if (rp->kp.addr && warn_kprobe_rereg(&rp->kp)) return -EINVAL; @@ -2089,13 +2102,13 @@ EXPORT_SYMBOL_GPL(unregister_kretprobes); #else /* CONFIG_KRETPROBES */ int register_kretprobe(struct kretprobe *rp) { - return -ENOSYS; + return -EOPNOTSUPP; } EXPORT_SYMBOL_GPL(register_kretprobe); int register_kretprobes(struct kretprobe **rps, int num) { - return -ENOSYS; + return -EOPNOTSUPP; } EXPORT_SYMBOL_GPL(register_kretprobes); @@ -2144,7 +2157,7 @@ static void kill_kprobe(struct kprobe *p) /* * The module is going away. We should disarm the kprobe which * is using ftrace, because ftrace framework is still available at - * MODULE_STATE_GOING notification. + * 'MODULE_STATE_GOING' notification. */ if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed) disarm_kprobe_ftrace(p); @@ -2317,13 +2330,13 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret; } - /* Symbols in __kprobes_text are blacklisted */ + /* Symbols in '__kprobes_text' are blacklisted */ ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start, (unsigned long)__kprobes_text_end); if (ret) return ret; - /* Symbols in noinstr section are blacklisted */ + /* Symbols in 'noinstr' section are blacklisted */ ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start, (unsigned long)__noinstr_text_end); @@ -2395,9 +2408,9 @@ static int kprobes_module_callback(struct notifier_block *nb, return NOTIFY_DONE; /* - * When MODULE_STATE_GOING was notified, both of module .text and - * .init.text sections would be freed. When MODULE_STATE_LIVE was - * notified, only .init.text section would be freed. We need to + * When 'MODULE_STATE_GOING' was notified, both of module '.text' and + * '.init.text' sections would be freed. When 'MODULE_STATE_LIVE' was + * notified, only '.init.text' section would be freed. We need to * disable kprobes which have been inserted in the sections. */ mutex_lock(&kprobe_mutex); @@ -2414,9 +2427,9 @@ static int kprobes_module_callback(struct notifier_block *nb, * * Note, this will also move any optimized probes * that are pending to be removed from their - * corresponding lists to the freeing_list and + * corresponding lists to the 'freeing_list' and * will not be touched by the delayed - * kprobe_optimizer work handler. + * kprobe_optimizer() work handler. */ kill_kprobe(p); } @@ -2432,10 +2445,6 @@ static struct notifier_block kprobe_module_nb = { .priority = 0 }; -/* Markers of _kprobe_blacklist section */ -extern unsigned long __start_kprobe_blacklist[]; -extern unsigned long __stop_kprobe_blacklist[]; - void kprobe_free_init_mem(void) { void *start = (void *)(&__init_begin); @@ -2446,7 +2455,7 @@ void kprobe_free_init_mem(void) mutex_lock(&kprobe_mutex); - /* Kill all kprobes on initmem */ + /* Kill all kprobes on initmem because the target code has been freed. */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry(p, head, hlist) { @@ -2469,9 +2478,8 @@ static int __init init_kprobes(void) err = populate_kprobe_blacklist(__start_kprobe_blacklist, __stop_kprobe_blacklist); - if (err) { + if (err) pr_err("Failed to populate blacklist (error %d), kprobes not restricted, be careful using them!\n", err); - } if (kretprobe_blacklist_size) { /* lookup the function address from its name */ @@ -2488,7 +2496,7 @@ static int __init init_kprobes(void) kprobes_all_disarmed = false; #if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT) - /* Init kprobe_optinsn_slots for allocation */ + /* Init 'kprobe_optinsn_slots' for allocation */ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; #endif @@ -2622,7 +2630,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) list_entry(v, struct kprobe_blacklist_entry, list); /* - * If /proc/kallsyms is not showing kernel address, we won't + * If '/proc/kallsyms' is not showing kernel address, we won't * show them here either. */ if (!kallsyms_show_value(m->file->f_cred)) From patchwork Tue Sep 14 14:39:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493683 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5C8DC433EF for ; Tue, 14 Sep 2021 14:40:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EE02610A2 for ; Tue, 14 Sep 2021 14:40:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234036AbhINOlx (ORCPT ); Tue, 14 Sep 2021 10:41:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:35176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234927AbhINOlH (ORCPT ); Tue, 14 Sep 2021 10:41:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B98760698; Tue, 14 Sep 2021 14:39:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630390; bh=pS3y9et2p/dkxzeM2EJ7grzyp84IGtDqnN8Te94o73g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QYrtxnC20Z1mfmqeKqSo1Mn0bb8n+QNBwUs3gIwa8zE3TZa0pSNBxYKbQXw8p6jDQ T5bRhqdqXlkRUg8of6b7T1mFrNPLs8FK8Wlo/B3nU0Jno1WDwfdW3WO+PBuvNAomis vIqdaysjdhSIWzLjE9VMfQz9ILxg/WzjPIdgEKprOBlg3D//Lsos9kOAj6/Lp/NyqL KtukThkqtrVDKb2QcOIokQO5SR8h6nTyx0ZhNdSJYjkdGTYfay7xbbia0ej1mXynwE bC8xuTPBu7LUr9FcRMeNwWrBa77EllwvvW1ObaXvkTITv9oYGvpy7i7tHL8CmMdCjW jO5A4mEoGsGBw== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 08/27] kprobes: Use IS_ENABLED() instead of kprobes_built_in() Date: Tue, 14 Sep 2021 23:39:46 +0900 Message-Id: <163163038581.489837.2805250706507372658.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Use IS_ENABLED(CONFIG_KPROBES) instead of kprobes_built_in(). This inline function is introduced only for avoiding #ifdef. But since now we have IS_ENABLED(), it is no longer needed. Signed-off-by: Masami Hiramatsu --- include/linux/kprobes.h | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 756d3d23ce37..9c28fbb18e74 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -180,14 +180,6 @@ struct kprobe_blacklist_entry { DECLARE_PER_CPU(struct kprobe *, current_kprobe); DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); -/* - * For #ifdef avoidance: - */ -static inline int kprobes_built_in(void) -{ - return 1; -} - extern void kprobe_busy_begin(void); extern void kprobe_busy_end(void); @@ -417,10 +409,6 @@ int arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, char *type, char *sym); #else /* !CONFIG_KPROBES: */ -static inline int kprobes_built_in(void) -{ - return 0; -} static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { return 0; @@ -514,7 +502,7 @@ static inline bool is_kprobe_optinsn_slot(unsigned long addr) static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs, unsigned int trap) { - if (!kprobes_built_in()) + if (!IS_ENABLED(CONFIG_KPROBES)) return false; if (user_mode(regs)) return false; From patchwork Tue Sep 14 14:39:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493687 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42507C433EF for ; Tue, 14 Sep 2021 14:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D39B61107 for ; Tue, 14 Sep 2021 14:40:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234944AbhINOmM (ORCPT ); Tue, 14 Sep 2021 10:42:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:35414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234270AbhINOlS (ORCPT ); Tue, 14 Sep 2021 10:41:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C605C610E6; Tue, 14 Sep 2021 14:39:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630401; bh=LeW+FpjWCoF8S7HB9VLImulpdbgkWfK0a1HfGP8n+lc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XOz28LWDlX0b6eeoTS5bcIurHSaAI5lRXlb1YVvTI4XGwGA+TaTM2xMCc5arQPcZO +cQ7vwmJhaZbqhfU3/OfpNFV1pzPn+IHYAVWWP0RTyz9u974wVdhbgoCq2bCRD+e// SB+1psdR3aWpMMgbAPLyRO0mWLezNk0BXfh70QqZH1LHNMyelueWLlpJ+6aDIRFJGX V21/bLg2E0Um6hZswymx9yckupKxqqGDlkLzfk8GNHSBuWWpFY/lzkrTe2YKOk6eAc aaeJeolLatp1XAMeszcb03Veri4O2C/CabKAQXjd8cP/ukR34zggtsIacDNoKyB0jm HHCz52DnvKNZw== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 09/27] kprobes: Add assertions for required lock Date: Tue, 14 Sep 2021 23:39:55 +0900 Message-Id: <163163039572.489837.18011973177537476885.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add assertions for required locks instead of comment it so that the lockdep can inspect locks automatically. Signed-off-by: Masami Hiramatsu --- kernel/kprobes.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ad39eeaa4371..ec3d97fd8c6b 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -959,11 +959,13 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write, } #endif /* CONFIG_SYSCTL */ -/* Put a breakpoint for a probe. Must be called with 'text_mutex' locked. */ +/* Put a breakpoint for a probe. */ static void __arm_kprobe(struct kprobe *p) { struct kprobe *_p; + lockdep_assert_held(&text_mutex); + /* Find the overlapping optimized kprobes. */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p)) @@ -974,11 +976,13 @@ static void __arm_kprobe(struct kprobe *p) optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ } -/* Remove the breakpoint of a probe. Must be called with 'text_mutex' locked. */ +/* Remove the breakpoint of a probe. */ static void __disarm_kprobe(struct kprobe *p, bool reopt) { struct kprobe *_p; + lockdep_assert_held(&text_mutex); + /* Try to unoptimize */ unoptimize_kprobe(p, kprobes_all_disarmed); @@ -1047,12 +1051,13 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { static int kprobe_ipmodify_enabled; static int kprobe_ftrace_enabled; -/* Caller must lock 'kprobe_mutex' */ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { int ret = 0; + lockdep_assert_held(&kprobe_mutex); + ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); if (WARN_ONCE(ret < 0, "Failed to arm kprobe-ftrace at %pS (error %d)\n", p->addr, ret)) return ret; @@ -1084,12 +1089,13 @@ static int arm_kprobe_ftrace(struct kprobe *p) ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); } -/* Caller must lock 'kprobe_mutex'. */ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { int ret = 0; + lockdep_assert_held(&kprobe_mutex); + if (*cnt == 1) { ret = unregister_ftrace_function(ops); if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (error %d)\n", ret)) @@ -1133,7 +1139,6 @@ static int prepare_kprobe(struct kprobe *p) return arch_prepare_kprobe(p); } -/* Arm a kprobe with 'text_mutex'. */ static int arm_kprobe(struct kprobe *kp) { if (unlikely(kprobe_ftrace(kp))) @@ -1148,7 +1153,6 @@ static int arm_kprobe(struct kprobe *kp) return 0; } -/* Disarm a kprobe with 'text_mutex'. */ static int disarm_kprobe(struct kprobe *kp, bool reopt) { if (unlikely(kprobe_ftrace(kp))) @@ -1691,12 +1695,13 @@ static int aggr_kprobe_disabled(struct kprobe *ap) return 1; } -/* Disable one kprobe: Make sure called under 'kprobe_mutex' is locked. */ static struct kprobe *__disable_kprobe(struct kprobe *p) { struct kprobe *orig_p; int ret; + lockdep_assert_held(&kprobe_mutex); + /* Get an original kprobe for return */ orig_p = __get_valid_kprobe(p); if (unlikely(orig_p == NULL)) From patchwork Tue Sep 14 14:40:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493689 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C3F1C433EF for ; Tue, 14 Sep 2021 14:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DBD9610A2 for ; Tue, 14 Sep 2021 14:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234318AbhINOmT (ORCPT ); Tue, 14 Sep 2021 10:42:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:35758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233803AbhINOl2 (ORCPT ); Tue, 14 Sep 2021 10:41:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A56AF610F9; Tue, 14 Sep 2021 14:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630411; bh=iJwpXsKZ09Nzj3SzlL+t4RJ/RQtXzdCPhjS/z0l95zs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KrB2AsBHTvJOhfHdljoO1bYRxMGREntmgEuJTbjXtWLKeQOrtDUjOfSqkh0yrte1G PSpfeNA+LJ8kK/eXvjOKLgQvCj6EK+1+DcuBv3lbaCjTGHYbsND7B6Mmc9mWM6amkl IekH8Bs40GG+x/So3hK3/3eYMOowsrJJndM2iWWNv/MQhOnr03LHGOHgvc1kOR7UIB KKGEiFSR9yEwnNXzLfCVgcCuuCIH7EaiAFaJhb4NREr49F0CDHrK7kjiIefk/XsoFP tPAXpDgPFlauqN5hIfcuHOqhX41P/llRuH/CrdASxTsp6OKECgGUSBpJb8ofgxxuhS bTGn7hKw1bEGQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 10/27] kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in get_optimized_kprobe() Date: Tue, 14 Sep 2021 23:40:07 +0900 Message-Id: <163163040680.489837.12133032364499833736.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since get_optimized_kprobe() is only used inside kprobes, it doesn't need to use 'unsigned long' type for 'addr' parameter. Make it use 'kprobe_opcode_t *' for the 'addr' parameter and subsequent call of arch_within_optimized_kprobe() also should use 'kprobe_opcode_t *'. Note that MAX_OPTIMIZED_LENGTH and RELATIVEJUMP_SIZE are defined by byte-size, but the size of 'kprobe_opcode_t' depends on the architecture. Therefore, we must be careful when calculating addresses using those macros. Signed-off-by: Masami Hiramatsu --- arch/arm/probes/kprobes/opt-arm.c | 7 ++++--- arch/powerpc/kernel/optprobes.c | 6 +++--- arch/x86/kernel/kprobes/opt.c | 6 +++--- include/linux/kprobes.h | 2 +- kernel/kprobes.c | 10 +++++----- 5 files changed, 16 insertions(+), 15 deletions(-) diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c index c78180172120..dbef34ed933f 100644 --- a/arch/arm/probes/kprobes/opt-arm.c +++ b/arch/arm/probes/kprobes/opt-arm.c @@ -347,10 +347,11 @@ void arch_unoptimize_kprobes(struct list_head *oplist, } int arch_within_optimized_kprobe(struct optimized_kprobe *op, - unsigned long addr) + kprobe_opcode_t *addr) { - return ((unsigned long)op->kp.addr <= addr && - (unsigned long)op->kp.addr + RELATIVEJUMP_SIZE > addr); + return (op->kp.addr <= addr && + op->kp.addr + (RELATIVEJUMP_SIZE / sizeof(kprobe_opcode_t)) > addr); + } void arch_remove_optimized_kprobe(struct optimized_kprobe *op) diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index c79899abcec8..325ba544883c 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -301,8 +301,8 @@ void arch_unoptimize_kprobes(struct list_head *oplist, struct list_head *done_li } } -int arch_within_optimized_kprobe(struct optimized_kprobe *op, unsigned long addr) +int arch_within_optimized_kprobe(struct optimized_kprobe *op, kprobe_opcode_t *addr) { - return ((unsigned long)op->kp.addr <= addr && - (unsigned long)op->kp.addr + RELATIVEJUMP_SIZE > addr); + return (op->kp.addr <= addr && + op->kp.addr + (RELATIVEJUMP_SIZE / sizeof(kprobe_opcode_t)) > addr); } diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 71425ebba98a..b4a54a52aa59 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -367,10 +367,10 @@ int arch_check_optimized_kprobe(struct optimized_kprobe *op) /* Check the addr is within the optimized instructions. */ int arch_within_optimized_kprobe(struct optimized_kprobe *op, - unsigned long addr) + kprobe_opcode_t *addr) { - return ((unsigned long)op->kp.addr <= addr && - (unsigned long)op->kp.addr + op->optinsn.size > addr); + return (op->kp.addr <= addr && + op->kp.addr + op->optinsn.size > addr); } /* Free optimized instruction slot */ diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 9c28fbb18e74..6a5995f334a0 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -329,7 +329,7 @@ extern void arch_unoptimize_kprobes(struct list_head *oplist, struct list_head *done_list); extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, - unsigned long addr); + kprobe_opcode_t *addr); extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ec3d97fd8c6b..b6f1dcf4bff3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -485,15 +485,15 @@ static int kprobe_queued(struct kprobe *p) * Return an optimized kprobe whose optimizing code replaces * instructions including 'addr' (exclude breakpoint). */ -static struct kprobe *get_optimized_kprobe(unsigned long addr) +static struct kprobe *get_optimized_kprobe(kprobe_opcode_t *addr) { int i; struct kprobe *p = NULL; struct optimized_kprobe *op; /* Don't check i == 0, since that is a breakpoint case. */ - for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) - p = get_kprobe((void *)(addr - i)); + for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH / sizeof(kprobe_opcode_t); i++) + p = get_kprobe(addr - i); if (p && kprobe_optready(p)) { op = container_of(p, struct optimized_kprobe, kp); @@ -967,7 +967,7 @@ static void __arm_kprobe(struct kprobe *p) lockdep_assert_held(&text_mutex); /* Find the overlapping optimized kprobes. */ - _p = get_optimized_kprobe((unsigned long)p->addr); + _p = get_optimized_kprobe(p->addr); if (unlikely(_p)) /* Fallback to unoptimized kprobe */ unoptimize_kprobe(_p, true); @@ -989,7 +989,7 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) if (!kprobe_queued(p)) { arch_disarm_kprobe(p); /* If another kprobe was blocked, re-optimize it. */ - _p = get_optimized_kprobe((unsigned long)p->addr); + _p = get_optimized_kprobe(p->addr); if (unlikely(_p) && reopt) optimize_kprobe(_p); } From patchwork Tue Sep 14 14:40:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493691 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A276C433EF for ; Tue, 14 Sep 2021 14:41:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F6EB610D1 for ; Tue, 14 Sep 2021 14:41:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233550AbhINOm6 (ORCPT ); Tue, 14 Sep 2021 10:42:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:35842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233968AbhINOlj (ORCPT ); Tue, 14 Sep 2021 10:41:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 14D4B610D1; Tue, 14 Sep 2021 14:40:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630421; bh=PMfLP00PTvIAVFwzl7khtgbFp1PkY8LekgAvH6msKko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KtaI3UOGXWgILa66TCUiSY3P/yZBY8yKkrhys9UWvGIIqVAgiTlbWa2sVhGn2Cq4k quUvWaE32N1/lL/4CssQRPTyev988dwIwRsRt0akP3gKu0UQfGmrrEOByA1OkAAzOo whEAQEhSPldoHtC5kHXHxY1ehAplGDGt0cBUsl7BSTSHPBtJttz5Z8eA1EX1oLlylY gO+EXlh7e8F908g0P8kuH4wIFHOcKvZPvZ6X071M8qaGNH8bHAyQqiCn7JCiKY1JZB 9fjtHB/Dks5HNVG9Xdo/joHqwCrdd143LBrQikaaBkakcLkROtnxWJo4VaQ+U8fss1 Lx9sJ4z0Rc/XQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 11/27] kprobes: Use bool type for functions which returns boolean value Date: Tue, 14 Sep 2021 23:40:16 +0900 Message-Id: <163163041649.489837.17311187321419747536.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Use the 'bool' type instead of 'int' for the functions which returns a boolean value, because this makes clear that those functions don't return any error code. Signed-off-by: Masami Hiramatsu --- Changes in v2: - Fix trace_kprobe's kprobe_gone() too. --- include/linux/kprobes.h | 8 ++++---- kernel/kprobes.c | 26 +++++++++++++------------- kernel/trace/trace_kprobe.c | 2 +- 3 files changed, 18 insertions(+), 18 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 6a5995f334a0..0ba3f9e316d4 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -104,25 +104,25 @@ struct kprobe { #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */ /* Has this kprobe gone ? */ -static inline int kprobe_gone(struct kprobe *p) +static inline bool kprobe_gone(struct kprobe *p) { return p->flags & KPROBE_FLAG_GONE; } /* Is this kprobe disabled ? */ -static inline int kprobe_disabled(struct kprobe *p) +static inline bool kprobe_disabled(struct kprobe *p) { return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); } /* Is this kprobe really running optimized path ? */ -static inline int kprobe_optimized(struct kprobe *p) +static inline bool kprobe_optimized(struct kprobe *p) { return p->flags & KPROBE_FLAG_OPTIMIZED; } /* Is this kprobe uses ftrace ? */ -static inline int kprobe_ftrace(struct kprobe *p) +static inline bool kprobe_ftrace(struct kprobe *p) { return p->flags & KPROBE_FLAG_FTRACE; } diff --git a/kernel/kprobes.c b/kernel/kprobes.c index b6f1dcf4bff3..8021bccb7770 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -198,8 +198,8 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) return slot; } -/* Return 1 if all garbages are collected, otherwise 0. */ -static int collect_one_slot(struct kprobe_insn_page *kip, int idx) +/* Return true if all garbages are collected, otherwise false. */ +static bool collect_one_slot(struct kprobe_insn_page *kip, int idx) { kip->slot_used[idx] = SLOT_CLEAN; kip->nused--; @@ -223,9 +223,9 @@ static int collect_one_slot(struct kprobe_insn_page *kip, int idx) kip->cache->free(kip->insns); kfree(kip); } - return 1; + return true; } - return 0; + return false; } static int collect_garbage_slots(struct kprobe_insn_cache *c) @@ -389,13 +389,13 @@ NOKPROBE_SYMBOL(get_kprobe); static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); /* Return true if 'p' is an aggregator */ -static inline int kprobe_aggrprobe(struct kprobe *p) +static inline bool kprobe_aggrprobe(struct kprobe *p) { return p->pre_handler == aggr_pre_handler; } /* Return true if 'p' is unused */ -static inline int kprobe_unused(struct kprobe *p) +static inline bool kprobe_unused(struct kprobe *p) { return kprobe_aggrprobe(p) && kprobe_disabled(p) && list_empty(&p->list); @@ -455,7 +455,7 @@ static inline int kprobe_optready(struct kprobe *p) } /* Return true if the kprobe is disarmed. Note: p must be on hash list */ -static inline int kprobe_disarmed(struct kprobe *p) +static inline bool kprobe_disarmed(struct kprobe *p) { struct optimized_kprobe *op; @@ -469,16 +469,16 @@ static inline int kprobe_disarmed(struct kprobe *p) } /* Return true if the probe is queued on (un)optimizing lists */ -static int kprobe_queued(struct kprobe *p) +static bool kprobe_queued(struct kprobe *p) { struct optimized_kprobe *op; if (kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) - return 1; + return true; } - return 0; + return false; } /* @@ -1678,7 +1678,7 @@ int register_kprobe(struct kprobe *p) EXPORT_SYMBOL_GPL(register_kprobe); /* Check if all probes on the 'ap' are disabled. */ -static int aggr_kprobe_disabled(struct kprobe *ap) +static bool aggr_kprobe_disabled(struct kprobe *ap) { struct kprobe *kp; @@ -1690,9 +1690,9 @@ static int aggr_kprobe_disabled(struct kprobe *ap) * Since there is an active probe on the list, * we can't disable this 'ap'. */ - return 0; + return false; - return 1; + return true; } static struct kprobe *__disable_kprobe(struct kprobe *p) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3a64ba4bbad6..0e1e7ce5f7ed 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -97,7 +97,7 @@ static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) { - return !!(kprobe_gone(&tk->rp.kp)); + return kprobe_gone(&tk->rp.kp); } static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, From patchwork Tue Sep 14 14:40:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493693 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF0C6C433F5 for ; Tue, 14 Sep 2021 14:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FA7F60698 for ; Tue, 14 Sep 2021 14:41:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234237AbhINOnA (ORCPT ); Tue, 14 Sep 2021 10:43:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:35924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234540AbhINOls (ORCPT ); Tue, 14 Sep 2021 10:41:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 77E98610FB; Tue, 14 Sep 2021 14:40:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630431; bh=ZNH37xRqRkeLbZ1aRCFRgCl0otMIRMYADO1YOQyAq1c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N6V/Bs+fEbkae985bgY/OhAZW/evyfTR4skoNAMGYZDV545jQf4VT0ptoU3E5whXr 1R+CX0KAIIlBytMj0y7E7W2mXtkCxvWi5DIwx5VHwPLCMkSWXKrTIcnQ31yREII46m +zAs56qTJxJRoGS1nakj/nxC7R23mR5c+Hzvu3D+V87KYxaYJJe8ySTTjoEdbD94LR YazKaalCB3PYS4aMj6NtuiTUzwIdF/AggbExYcLlma62CHB58LXJ1dTIV4Ny0wyw/F rGSLu8NNH0jtMwhEnFAyCbPz712OBQWJrpdEtiu+o1TChaaCv8dIZg8Qkvc5NHjvV6 Ks42dZzKZOBqQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 12/27] ia64: kprobes: Fix to pass correct trampoline address to the handler Date: Tue, 14 Sep 2021 23:40:27 +0900 Message-Id: <163163042696.489837.12551102356265354730.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The following commit: Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Passed the wrong trampoline address to __kretprobe_trampoline_handler(): it passes the descriptor address instead of function entry address. Pass the right parameter. Also use correct symbol dereference function to get the function address from 'kretprobe_trampoline' - an IA64 special. Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu --- Changes in v9: - Update changelog according to Ingo's suggestion. - Add Cc: stable tag. Changes in v5: - Fix a compile error typo. --- arch/ia64/kernel/kprobes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 441ed04b1037..d4048518a1d7 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -398,7 +398,8 @@ static void kretprobe_trampoline(void) int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL); + regs->cr_iip = __kretprobe_trampoline_handler(regs, + dereference_function_descriptor(kretprobe_trampoline), NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler @@ -414,7 +415,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip; + regs->b0 = (unsigned long)dereference_function_descriptor(kretprobe_trampoline); } /* Check the instruction in the slot is break */ @@ -902,14 +903,14 @@ static struct kprobe trampoline_p = { int __init arch_init_kprobes(void) { trampoline_p.addr = - (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; + dereference_function_descriptor(kretprobe_trampoline); return register_kprobe(&trampoline_p); } int __kprobes arch_trampoline_kprobe(struct kprobe *p) { if (p->addr == - (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip) + dereference_function_descriptor(kretprobe_trampoline)) return 1; return 0; From patchwork Tue Sep 14 14:40:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493695 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FF98C4332F for ; Tue, 14 Sep 2021 14:41:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28BDE60F26 for ; Tue, 14 Sep 2021 14:41:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233968AbhINOnG (ORCPT ); Tue, 14 Sep 2021 10:43:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:36030 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233905AbhINOl5 (ORCPT ); Tue, 14 Sep 2021 10:41:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E319260698; Tue, 14 Sep 2021 14:40:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630440; bh=wna5SXIMl7v8yyj1i0j59bQ9E+u/wHsbcUVgie//ts0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VvzgWxdYiodK7xnHWa3jJbkXfxtnrWSF2v5716mYY/v0B1eju2Up4Me7s/q3Y8EtM ghDBenNpOJaDaYZjkBPOF1rcUqPgtw2SeB0cONgji0fepxOPYDfodLNyh6pzMyuzXH oqFTAhFjq6FO9L7sI4zQvNs+3wi95gYdcdLXiDj3Z5jvQ6xXl15/YCO0p6nsJw4YFf mS7z2wbOjqzXAA5JpVHC86kI/YsO9fT+BV5x0tDDIO4P9laBYwcor1f8Z5ePgroM1T cgcdrIUYHZLYXs3QrsqiUfyWu5dJC0vsf53AS4++sXZPISVfP3MbP79MOTanRZC1zP Z+PNWV/Au+67A== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 13/27] kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor() Date: Tue, 14 Sep 2021 23:40:36 +0900 Message-Id: <163163043630.489837.7924988885652708696.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ~15 years ago kprobes grew the 'arch_deref_entry_point()' __weak function: 3d7e33825d87: ("jprobes: make jprobes a little safer for users") But this is just open-coded dereference_symbol_descriptor() in essence, and its obscure nature was causing bugs. Just use the real thing and remove arch_deref_entry_point(). Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v9: - Update changelog according to Ingo's suggestion. Changes in v6: - Use dereference_symbol_descriptor() so that it can handle address in modules correctly. --- arch/ia64/kernel/kprobes.c | 5 ----- arch/powerpc/kernel/kprobes.c | 11 ----------- include/linux/kprobes.h | 1 - kernel/kprobes.c | 7 +------ lib/error-inject.c | 3 ++- 5 files changed, 3 insertions(+), 24 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index d4048518a1d7..0f8573bbf520 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -891,11 +891,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, return ret; } -unsigned long arch_deref_entry_point(void *entry) -{ - return ((struct fnptr *)entry)->ip; -} - static struct kprobe trampoline_p = { .pre_handler = trampoline_probe_handler }; diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 7a7cd6bda53e..d422e297978b 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -542,17 +542,6 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) } NOKPROBE_SYMBOL(kprobe_fault_handler); -unsigned long arch_deref_entry_point(void *entry) -{ -#ifdef PPC64_ELF_ABI_v1 - if (!kernel_text_address((unsigned long)entry)) - return ppc_global_function_entry(entry); - else -#endif - return (unsigned long)entry; -} -NOKPROBE_SYMBOL(arch_deref_entry_point); - static struct kprobe trampoline_p = { .addr = (kprobe_opcode_t *) &kretprobe_trampoline, .pre_handler = trampoline_probe_handler diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 0ba3f9e316d4..2ed61fcbc89c 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -381,7 +381,6 @@ int register_kprobe(struct kprobe *p); void unregister_kprobe(struct kprobe *p); int register_kprobes(struct kprobe **kps, int num); void unregister_kprobes(struct kprobe **kps, int num); -unsigned long arch_deref_entry_point(void *); int register_kretprobe(struct kretprobe *rp); void unregister_kretprobe(struct kretprobe *rp); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 8021bccb7770..550042d9a6ef 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1861,11 +1861,6 @@ static struct notifier_block kprobe_exceptions_nb = { .priority = 0x7fffffff /* we need to be notified first */ }; -unsigned long __weak arch_deref_entry_point(void *entry) -{ - return (unsigned long)entry; -} - #ifdef CONFIG_KRETPROBES unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, @@ -2327,7 +2322,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, int ret; for (iter = start; iter < end; iter++) { - entry = arch_deref_entry_point((void *)*iter); + entry = (unsigned long)dereference_symbol_descriptor((void *)*iter); ret = kprobe_add_ksym_blacklist(entry); if (ret == -EINVAL) continue; diff --git a/lib/error-inject.c b/lib/error-inject.c index c73651b15b76..2ff5ef689d72 100644 --- a/lib/error-inject.c +++ b/lib/error-inject.c @@ -8,6 +8,7 @@ #include #include #include +#include /* Whitelist of symbols that can be overridden for error injection. */ static LIST_HEAD(error_injection_list); @@ -64,7 +65,7 @@ static void populate_error_injection_list(struct error_injection_entry *start, mutex_lock(&ei_mutex); for (iter = start; iter < end; iter++) { - entry = arch_deref_entry_point((void *)iter->addr); + entry = (unsigned long)dereference_symbol_descriptor((void *)iter->addr); if (!kernel_text_address(entry) || !kallsyms_lookup_size_offset(entry, &size, &offset)) { From patchwork Tue Sep 14 14:40:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493697 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 449DFC433FE for ; Tue, 14 Sep 2021 14:41:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34D6B60F26 for ; Tue, 14 Sep 2021 14:41:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234710AbhINOnJ (ORCPT ); Tue, 14 Sep 2021 10:43:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:36204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234905AbhINOmG (ORCPT ); Tue, 14 Sep 2021 10:42:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 06DFD6113B; Tue, 14 Sep 2021 14:40:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630449; bh=8nv+wepyZ4/qM1+cCtHbUR0gu8ZFpjVBicqnOCWhUUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H3aS5ty0tf1hfb4ropxsnFFhE480tsKrrDdsAsf5F0UMZJukzVcgMBCChqwZQ3raF y4b/UgdVEvQWYMOyP8+4kTFkdIzJjt0kGF8+Yqw1NphaPT1WxM3VzHk7csXKpl767s UOMthoqnt7+60URRIFLBSFwUsrfa+DpaQyKc24umPhhfD5uxwjbI7FtqPb+OQq7JcH /bCXi4lvgtezXdF8kX2XK5KtBWwKWCedB3gn0vTODnDsvJ/+PoxOHDZwGazxstjjGn zk1TjfklncsJlzbGVwbeMlY5LGWRFQlhn4aIpQCZiky/iiwZA2w1LxKrvio3n6Y+l6 4umcsSmstVT3Q== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 14/27] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Date: Tue, 14 Sep 2021 23:40:45 +0900 Message-Id: <163163044546.489837.13505751885476015002.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The __kretprobe_trampoline_handler() callback, called from low level arch kprobes methods, has the 'trampoline_address' parameter, which is entirely superfluous as it basically just replicates: dereference_kernel_function_descriptor(kretprobe_trampoline) In fact we had bugs in arch code where it wasn't replicated correctly. So remove this superfluous parameter and use kretprobe_trampoline_addr() instead. Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v9: - Update changelog according to Ingo's suggestion. Changes in v8: - Use dereference_kernel_function_descriptor() to get the kretprobe_trampoline address. Changes in v3: - Remove wrong kretprobe_trampoline declaration from arch/x86/include/asm/kprobes.h. Changes in v2: - Remove arch_deref_entry_point() from comment. --- arch/arc/kernel/kprobes.c | 2 +- arch/arm/probes/kprobes/core.c | 3 +-- arch/arm64/kernel/probes/kprobes.c | 3 +-- arch/csky/kernel/probes/kprobes.c | 2 +- arch/ia64/kernel/kprobes.c | 5 ++--- arch/mips/kernel/kprobes.c | 3 +-- arch/parisc/kernel/kprobes.c | 4 ++-- arch/powerpc/kernel/kprobes.c | 2 +- arch/riscv/kernel/probes/kprobes.c | 2 +- arch/s390/kernel/kprobes.c | 2 +- arch/sh/kernel/kprobes.c | 2 +- arch/sparc/kernel/kprobes.c | 2 +- arch/x86/include/asm/kprobes.h | 1 - arch/x86/kernel/kprobes/core.c | 2 +- include/linux/kprobes.h | 18 +++++++++++++----- kernel/kprobes.c | 3 +-- 16 files changed, 29 insertions(+), 27 deletions(-) diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c index 5f0415fc7328..3cee75c87f97 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -381,7 +381,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->ret = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->ret = __kretprobe_trampoline_handler(regs, NULL); /* By returning a non zero value, we are telling the kprobe handler * that we don't want the post_handler to run diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index a59e38de4a03..08098ed6f035 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -392,8 +392,7 @@ void __naked __kprobes kretprobe_trampoline(void) /* Called from kretprobe_trampoline */ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, - (void *)regs->ARM_fp); + return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index ce429cbacd35..f627a12984a8 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -401,8 +401,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, - (void *)kernel_stack_pointer(regs)); + return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(regs)); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c index 632407bf45d5..784c5aba7f66 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -386,7 +386,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + return (void *)kretprobe_trampoline_handler(regs, NULL); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 0f8573bbf520..44c84c20b626 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -392,14 +392,13 @@ static void __kprobes set_current_kprobe(struct kprobe *p, __this_cpu_write(current_kprobe, p); } -static void kretprobe_trampoline(void) +void kretprobe_trampoline(void) { } int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->cr_iip = __kretprobe_trampoline_handler(regs, - dereference_function_descriptor(kretprobe_trampoline), NULL); + regs->cr_iip = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index b0934a0d7aed..b33bd2498651 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -485,8 +485,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, - kretprobe_trampoline, NULL); + instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c index 6d21a515eea5..4a35ac6e2ca2 100644 --- a/arch/parisc/kernel/kprobes.c +++ b/arch/parisc/kernel/kprobes.c @@ -175,7 +175,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) return 1; } -static inline void kretprobe_trampoline(void) +void kretprobe_trampoline(void) { asm volatile("nop"); asm volatile("nop"); @@ -193,7 +193,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, { unsigned long orig_ret_address; - orig_ret_address = __kretprobe_trampoline_handler(regs, trampoline_p.addr, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); instruction_pointer_set(regs, orig_ret_address); return 1; diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index d422e297978b..43c77142a262 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -417,7 +417,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { unsigned long orig_ret_address; - orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); /* * We get here through one of two paths: * 1. by taking a trap -> kprobe_handler() -> here diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index cab6f874358e..62d477cf11da 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -347,7 +347,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + return (void *)kretprobe_trampoline_handler(regs, NULL); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 952d44b0610b..5fa86e54f129 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -343,7 +343,7 @@ static void __used kretprobe_trampoline_holder(void) */ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->psw.addr = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->psw.addr = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index 1c7f358ef0be..8e76a35e6e33 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -303,7 +303,7 @@ static void __used kretprobe_trampoline_holder(void) */ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->pc = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->pc = __kretprobe_trampoline_handler(regs, NULL); return 1; } diff --git a/arch/sparc/kernel/kprobes.c b/arch/sparc/kernel/kprobes.c index 4c05a4ee6a0e..401534236c2e 100644 --- a/arch/sparc/kernel/kprobes.c +++ b/arch/sparc/kernel/kprobes.c @@ -451,7 +451,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, { unsigned long orig_ret_address = 0; - orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); regs->tpc = orig_ret_address; regs->tnpc = orig_ret_address + 4; diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index bd7f5886a789..71ea2eab43d5 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -49,7 +49,6 @@ extern __visible kprobe_opcode_t optprobe_template_end[]; extern const int kretprobe_blacklist_size; void arch_remove_kprobe(struct kprobe *p); -asmlinkage void kretprobe_trampoline(void); extern void arch_kprobe_override_function(struct pt_regs *regs); diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index b6e046e4b289..0c59ef5971de 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1064,7 +1064,7 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) regs->ip = (unsigned long)&kretprobe_trampoline; regs->orig_ax = ~0UL; - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, ®s->sp); + return (void *)kretprobe_trampoline_handler(regs, ®s->sp); } NOKPROBE_SYMBOL(trampoline_handler); diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 2ed61fcbc89c..96f5df93e36e 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -188,15 +188,23 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); +void kretprobe_trampoline(void); +/* + * Since some architecture uses structured function pointer, + * use dereference_function_descriptor() to get real function address. + */ +static nokprobe_inline void *kretprobe_trampoline_addr(void) +{ + return dereference_kernel_function_descriptor(kretprobe_trampoline); +} + /* If the trampoline handler called from a kprobe, use this version */ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, - void *frame_pointer); + void *frame_pointer); static nokprobe_inline unsigned long kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, - void *frame_pointer) + void *frame_pointer) { unsigned long ret; /* @@ -205,7 +213,7 @@ unsigned long kretprobe_trampoline_handler(struct pt_regs *regs, * be running at this point. */ kprobe_busy_begin(); - ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer); + ret = __kretprobe_trampoline_handler(regs, frame_pointer); kprobe_busy_end(); return ret; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 550042d9a6ef..6ed755111eea 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1864,7 +1864,6 @@ static struct notifier_block kprobe_exceptions_nb = { #ifdef CONFIG_KRETPROBES unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, void *frame_pointer) { kprobe_opcode_t *correct_ret_addr = NULL; @@ -1879,7 +1878,7 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, BUG_ON(ri->fp != frame_pointer); - if (ri->ret_addr != trampoline_address) { + if (ri->ret_addr != kretprobe_trampoline_addr()) { correct_ret_addr = ri->ret_addr; /* * This is the real return address. Any other From patchwork Tue Sep 14 14:40:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493699 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49E85C433EF for ; Tue, 14 Sep 2021 14:42:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EEA6610E6 for ; Tue, 14 Sep 2021 14:42:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234768AbhINOnS (ORCPT ); Tue, 14 Sep 2021 10:43:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:36356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233800AbhINOmQ (ORCPT ); Tue, 14 Sep 2021 10:42:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 261CE610E6; Tue, 14 Sep 2021 14:40:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630459; bh=yeRFeUd/KgyJTDNVp6FsHy8WEdLmP7WisOVoh49povE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qK/36IdUOUBStuyacLxhjlBQAP9Kz8x1/gYmQFxDS+obRsQDSKiBU2Zmyuy/t5W8b 01pMxs3+RhVcmlnqTq8Rkx+5Q2x+ZRWM+rW/TBd7v9lkX9kGyiwDllAC4UV22CLPED aBI1N/GM8a0igfuG2utiMcmQsO+2UiGCB6TLu3W0dSuqLemPtGJP0ryGdnonVTVX32 HqirJXjUWDvdP8SU+sOL8bcqjh5Vrk1HjtGCL1NAXx/U2oeYrY29RaGEvgMJiCwQtj X+HXhEVFv5kWEaRUNE3RvUjEUY46k4aBNwKsgUlw0a2JimrY466L0EBXeWvAfkYoKB m3lg/7rVxzs2Q== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 15/27] kprobes: treewide: Make it harder to refer kretprobe_trampoline directly Date: Tue, 14 Sep 2021 23:40:54 +0900 Message-Id: <163163045446.489837.14510577516938803097.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since now there is kretprobe_trampoline_addr() for referring the address of kretprobe trampoline code, we don't need to access kretprobe_trampoline directly. Make it harder to refer by renaming it to __kretprobe_trampoline(). Suggested-by: Ingo Molnar Signed-off-by: Masami Hiramatsu --- arch/arc/include/asm/kprobes.h | 2 +- arch/arc/kernel/kprobes.c | 11 ++++++----- arch/arm/probes/kprobes/core.c | 6 +++--- arch/arm64/include/asm/kprobes.h | 2 +- arch/arm64/kernel/probes/kprobes.c | 2 +- arch/arm64/kernel/probes/kprobes_trampoline.S | 4 ++-- arch/csky/include/asm/kprobes.h | 2 +- arch/csky/kernel/probes/kprobes.c | 2 +- arch/csky/kernel/probes/kprobes_trampoline.S | 4 ++-- arch/ia64/kernel/kprobes.c | 8 ++++---- arch/mips/kernel/kprobes.c | 12 ++++++------ arch/parisc/kernel/kprobes.c | 4 ++-- arch/powerpc/include/asm/kprobes.h | 2 +- arch/powerpc/kernel/kprobes.c | 16 ++++++++-------- arch/powerpc/kernel/optprobes.c | 2 +- arch/powerpc/kernel/stacktrace.c | 2 +- arch/riscv/include/asm/kprobes.h | 2 +- arch/riscv/kernel/probes/kprobes.c | 2 +- arch/riscv/kernel/probes/kprobes_trampoline.S | 4 ++-- arch/s390/include/asm/kprobes.h | 2 +- arch/s390/kernel/kprobes.c | 10 +++++----- arch/s390/kernel/stacktrace.c | 2 +- arch/sh/include/asm/kprobes.h | 2 +- arch/sh/kernel/kprobes.c | 10 +++++----- arch/sparc/include/asm/kprobes.h | 2 +- arch/sparc/kernel/kprobes.c | 10 +++++----- arch/x86/kernel/kprobes/core.c | 18 +++++++++--------- include/linux/kprobes.h | 4 ++-- kernel/trace/trace_output.c | 2 +- 29 files changed, 76 insertions(+), 75 deletions(-) diff --git a/arch/arc/include/asm/kprobes.h b/arch/arc/include/asm/kprobes.h index 2134721dce44..de1566e32cb8 100644 --- a/arch/arc/include/asm/kprobes.h +++ b/arch/arc/include/asm/kprobes.h @@ -46,7 +46,7 @@ struct kprobe_ctlblk { }; int kprobe_fault_handler(struct pt_regs *regs, unsigned long cause); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); void trap_is_kprobe(unsigned long address, struct pt_regs *regs); #else #define trap_is_kprobe(address, regs) diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c index 3cee75c87f97..e71d64119d71 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -363,8 +363,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, static void __used kretprobe_trampoline_holder(void) { - __asm__ __volatile__(".global kretprobe_trampoline\n" - "kretprobe_trampoline:\n" "nop\n"); + __asm__ __volatile__(".global __kretprobe_trampoline\n" + "__kretprobe_trampoline:\n" + "nop\n"); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, @@ -375,7 +376,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->blink = (unsigned long)&kretprobe_trampoline; + regs->blink = (unsigned long)&__kretprobe_trampoline; } static int __kprobes trampoline_probe_handler(struct kprobe *p, @@ -390,7 +391,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, } static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &kretprobe_trampoline, + .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; @@ -402,7 +403,7 @@ int __init arch_init_kprobes(void) int __kprobes arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *) &kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *) &__kretprobe_trampoline) return 1; return 0; diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 08098ed6f035..67ce7eb8f285 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -373,7 +373,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, * for kretprobe handlers which should normally be interested in r0 only * anyway. */ -void __naked __kprobes kretprobe_trampoline(void) +void __naked __kprobes __kretprobe_trampoline(void) { __asm__ __volatile__ ( "stmdb sp!, {r0 - r11} \n\t" @@ -389,7 +389,7 @@ void __naked __kprobes kretprobe_trampoline(void) : : : "memory"); } -/* Called from kretprobe_trampoline */ +/* Called from __kretprobe_trampoline */ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) { return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp); @@ -402,7 +402,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = (void *)regs->ARM_fp; /* Replace the return addr with trampoline addr. */ - regs->ARM_lr = (unsigned long)&kretprobe_trampoline; + regs->ARM_lr = (unsigned long)&__kretprobe_trampoline; } int __kprobes arch_trampoline_kprobe(struct kprobe *p) diff --git a/arch/arm64/include/asm/kprobes.h b/arch/arm64/include/asm/kprobes.h index 5d38ff4a4806..05cd82eeca13 100644 --- a/arch/arm64/include/asm/kprobes.h +++ b/arch/arm64/include/asm/kprobes.h @@ -39,7 +39,7 @@ void arch_remove_kprobe(struct kprobe *); int kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr); int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); void __kprobes *trampoline_probe_handler(struct pt_regs *regs); #endif /* CONFIG_KPROBES */ diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index f627a12984a8..e7ad6da980e8 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -411,7 +411,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = (void *)kernel_stack_pointer(regs); /* replace return addr (x30) with trampoline */ - regs->regs[30] = (long)&kretprobe_trampoline; + regs->regs[30] = (long)&__kretprobe_trampoline; } int __kprobes arch_trampoline_kprobe(struct kprobe *p) diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/kernel/probes/kprobes_trampoline.S index 288a84e253cc..520ee8711db1 100644 --- a/arch/arm64/kernel/probes/kprobes_trampoline.S +++ b/arch/arm64/kernel/probes/kprobes_trampoline.S @@ -61,7 +61,7 @@ ldp x28, x29, [sp, #S_X28] .endm -SYM_CODE_START(kretprobe_trampoline) +SYM_CODE_START(__kretprobe_trampoline) sub sp, sp, #PT_REGS_SIZE save_all_base_regs @@ -79,4 +79,4 @@ SYM_CODE_START(kretprobe_trampoline) add sp, sp, #PT_REGS_SIZE ret -SYM_CODE_END(kretprobe_trampoline) +SYM_CODE_END(__kretprobe_trampoline) diff --git a/arch/csky/include/asm/kprobes.h b/arch/csky/include/asm/kprobes.h index b647bbde4d6d..55267cbf5204 100644 --- a/arch/csky/include/asm/kprobes.h +++ b/arch/csky/include/asm/kprobes.h @@ -41,7 +41,7 @@ void arch_remove_kprobe(struct kprobe *p); int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr); int kprobe_breakpoint_handler(struct pt_regs *regs); int kprobe_single_step_handler(struct pt_regs *regs); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); void __kprobes *trampoline_probe_handler(struct pt_regs *regs); #endif /* CONFIG_KPROBES */ diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c index 784c5aba7f66..42920f25e73c 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -394,7 +394,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, { ri->ret_addr = (kprobe_opcode_t *)regs->lr; ri->fp = NULL; - regs->lr = (unsigned long) &kretprobe_trampoline; + regs->lr = (unsigned long) &__kretprobe_trampoline; } int __kprobes arch_trampoline_kprobe(struct kprobe *p) diff --git a/arch/csky/kernel/probes/kprobes_trampoline.S b/arch/csky/kernel/probes/kprobes_trampoline.S index b1fe3af24f03..ba48ad04a847 100644 --- a/arch/csky/kernel/probes/kprobes_trampoline.S +++ b/arch/csky/kernel/probes/kprobes_trampoline.S @@ -4,7 +4,7 @@ #include -ENTRY(kretprobe_trampoline) +ENTRY(__kretprobe_trampoline) SAVE_REGS_FTRACE mov a0, sp /* pt_regs */ @@ -16,4 +16,4 @@ ENTRY(kretprobe_trampoline) RESTORE_REGS_FTRACE rts -ENDPROC(kretprobe_trampoline) +ENDPROC(__kretprobe_trampoline) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 44c84c20b626..1a7bab1c5d7c 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -392,7 +392,7 @@ static void __kprobes set_current_kprobe(struct kprobe *p, __this_cpu_write(current_kprobe, p); } -void kretprobe_trampoline(void) +void __kretprobe_trampoline(void) { } @@ -414,7 +414,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->b0 = (unsigned long)dereference_function_descriptor(kretprobe_trampoline); + regs->b0 = (unsigned long)dereference_function_descriptor(__kretprobe_trampoline); } /* Check the instruction in the slot is break */ @@ -897,14 +897,14 @@ static struct kprobe trampoline_p = { int __init arch_init_kprobes(void) { trampoline_p.addr = - dereference_function_descriptor(kretprobe_trampoline); + dereference_function_descriptor(__kretprobe_trampoline); return register_kprobe(&trampoline_p); } int __kprobes arch_trampoline_kprobe(struct kprobe *p) { if (p->addr == - dereference_function_descriptor(kretprobe_trampoline)) + dereference_function_descriptor(__kretprobe_trampoline)) return 1; return 0; diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index b33bd2498651..6c7f3b143fdc 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -460,14 +460,14 @@ static void __used kretprobe_trampoline_holder(void) /* Keep the assembler from reordering and placing JR here. */ ".set noreorder\n\t" "nop\n\t" - ".global kretprobe_trampoline\n" - "kretprobe_trampoline:\n\t" + ".global __kretprobe_trampoline\n" + "__kretprobe_trampoline:\n\t" "nop\n\t" ".set pop" : : : "memory"); } -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) @@ -476,7 +476,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->regs[31] = (unsigned long)kretprobe_trampoline; + regs->regs[31] = (unsigned long)__kretprobe_trampoline; } /* @@ -496,14 +496,14 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, int __kprobes arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)__kretprobe_trampoline) return 1; return 0; } static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *)kretprobe_trampoline, + .addr = (kprobe_opcode_t *)__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c index 4a35ac6e2ca2..e2bdb5a5f93e 100644 --- a/arch/parisc/kernel/kprobes.c +++ b/arch/parisc/kernel/kprobes.c @@ -175,7 +175,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) return 1; } -void kretprobe_trampoline(void) +void __kretprobe_trampoline(void) { asm volatile("nop"); asm volatile("nop"); @@ -217,6 +217,6 @@ int __kprobes arch_trampoline_kprobe(struct kprobe *p) int __init arch_init_kprobes(void) { trampoline_p.addr = (kprobe_opcode_t *) - dereference_function_descriptor(kretprobe_trampoline); + dereference_function_descriptor(__kretprobe_trampoline); return register_kprobe(&trampoline_p); } diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h index 4fc0e15e23a5..bab364152b29 100644 --- a/arch/powerpc/include/asm/kprobes.h +++ b/arch/powerpc/include/asm/kprobes.h @@ -51,7 +51,7 @@ extern kprobe_opcode_t optprobe_template_end[]; #define flush_insn_slot(p) do { } while (0) #define kretprobe_blacklist_size 0 -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); extern void arch_remove_kprobe(struct kprobe *p); /* Architecture specific copy of original instruction */ diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 43c77142a262..86d77ff056a6 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -237,7 +237,7 @@ void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->link = (unsigned long)kretprobe_trampoline; + regs->link = (unsigned long)__kretprobe_trampoline; } NOKPROBE_SYMBOL(arch_prepare_kretprobe); @@ -403,12 +403,12 @@ NOKPROBE_SYMBOL(kprobe_handler); * - When the probed function returns, this probe * causes the handlers to fire */ -asm(".global kretprobe_trampoline\n" - ".type kretprobe_trampoline, @function\n" - "kretprobe_trampoline:\n" +asm(".global __kretprobe_trampoline\n" + ".type __kretprobe_trampoline, @function\n" + "__kretprobe_trampoline:\n" "nop\n" "blr\n" - ".size kretprobe_trampoline, .-kretprobe_trampoline\n"); + ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n"); /* * Called when the probe at kretprobe trampoline is hit @@ -427,7 +427,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) * as it is used to determine the return address from the trap. * For (2), since nip is not honoured with optprobes, we instead setup * the link register properly so that the subsequent 'blr' in - * kretprobe_trampoline jumps back to the right instruction. + * __kretprobe_trampoline jumps back to the right instruction. * * For nip, we should set the address to the previous instruction since * we end up emulating it in kprobe_handler(), which increments the nip @@ -543,7 +543,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) NOKPROBE_SYMBOL(kprobe_fault_handler); static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &kretprobe_trampoline, + .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; @@ -554,7 +554,7 @@ int __init arch_init_kprobes(void) int arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) return 1; return 0; diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index 325ba544883c..ce1903064031 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -56,7 +56,7 @@ static unsigned long can_optimize(struct kprobe *p) * has a 'nop' instruction, which can be emulated. * So further checks can be skipped. */ - if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) return addr + sizeof(kprobe_opcode_t); /* diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index 9e4a4a7af380..a2443d61728e 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -155,7 +155,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum * Mark stacktraces with kretprobed functions on them * as unreliable. */ - if (ip == (unsigned long)kretprobe_trampoline) + if (ip == (unsigned long)__kretprobe_trampoline) return -EINVAL; #endif diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h index 9ea9b5ec3113..217ef89f22b9 100644 --- a/arch/riscv/include/asm/kprobes.h +++ b/arch/riscv/include/asm/kprobes.h @@ -40,7 +40,7 @@ void arch_remove_kprobe(struct kprobe *p); int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr); bool kprobe_breakpoint_handler(struct pt_regs *regs); bool kprobe_single_step_handler(struct pt_regs *regs); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); void __kprobes *trampoline_probe_handler(struct pt_regs *regs); #endif /* CONFIG_KPROBES */ diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 62d477cf11da..e6e950b7cf32 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -355,7 +355,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, { ri->ret_addr = (kprobe_opcode_t *)regs->ra; ri->fp = NULL; - regs->ra = (unsigned long) &kretprobe_trampoline; + regs->ra = (unsigned long) &__kretprobe_trampoline; } int __kprobes arch_trampoline_kprobe(struct kprobe *p) diff --git a/arch/riscv/kernel/probes/kprobes_trampoline.S b/arch/riscv/kernel/probes/kprobes_trampoline.S index 6e85d021e2a2..7bdb09ded39b 100644 --- a/arch/riscv/kernel/probes/kprobes_trampoline.S +++ b/arch/riscv/kernel/probes/kprobes_trampoline.S @@ -75,7 +75,7 @@ REG_L x31, PT_T6(sp) .endm -ENTRY(kretprobe_trampoline) +ENTRY(__kretprobe_trampoline) addi sp, sp, -(PT_SIZE_ON_STACK) save_all_base_regs @@ -90,4 +90,4 @@ ENTRY(kretprobe_trampoline) addi sp, sp, PT_SIZE_ON_STACK ret -ENDPROC(kretprobe_trampoline) +ENDPROC(__kretprobe_trampoline) diff --git a/arch/s390/include/asm/kprobes.h b/arch/s390/include/asm/kprobes.h index 09cdb632a490..5eb722c984e4 100644 --- a/arch/s390/include/asm/kprobes.h +++ b/arch/s390/include/asm/kprobes.h @@ -70,7 +70,7 @@ struct kprobe_ctlblk { }; void arch_remove_kprobe(struct kprobe *p); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); int kprobe_fault_handler(struct pt_regs *regs, int trapnr); int kprobe_exceptions_notify(struct notifier_block *self, diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 5fa86e54f129..c505c0ee5f47 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -242,7 +242,7 @@ void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->gprs[14] = (unsigned long) &kretprobe_trampoline; + regs->gprs[14] = (unsigned long) &__kretprobe_trampoline; } NOKPROBE_SYMBOL(arch_prepare_kretprobe); @@ -334,8 +334,8 @@ NOKPROBE_SYMBOL(kprobe_handler); */ static void __used kretprobe_trampoline_holder(void) { - asm volatile(".global kretprobe_trampoline\n" - "kretprobe_trampoline: bcr 0,0\n"); + asm volatile(".global __kretprobe_trampoline\n" + "__kretprobe_trampoline: bcr 0,0\n"); } /* @@ -509,7 +509,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, NOKPROBE_SYMBOL(kprobe_exceptions_notify); static struct kprobe trampoline = { - .addr = (kprobe_opcode_t *) &kretprobe_trampoline, + .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; @@ -520,6 +520,6 @@ int __init arch_init_kprobes(void) int arch_trampoline_kprobe(struct kprobe *p) { - return p->addr == (kprobe_opcode_t *) &kretprobe_trampoline; + return p->addr == (kprobe_opcode_t *) &__kretprobe_trampoline; } NOKPROBE_SYMBOL(arch_trampoline_kprobe); diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 101477b3e263..b7bb1981e9ee 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -46,7 +46,7 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, * Mark stacktraces with kretprobed functions on them * as unreliable. */ - if (state.ip == (unsigned long)kretprobe_trampoline) + if (state.ip == (unsigned long)__kretprobe_trampoline) return -EINVAL; #endif diff --git a/arch/sh/include/asm/kprobes.h b/arch/sh/include/asm/kprobes.h index 6171682f7798..eeba83e0a7d2 100644 --- a/arch/sh/include/asm/kprobes.h +++ b/arch/sh/include/asm/kprobes.h @@ -26,7 +26,7 @@ typedef insn_size_t kprobe_opcode_t; struct kprobe; void arch_remove_kprobe(struct kprobe *); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); /* Architecture specific copy of original instruction*/ struct arch_specific_insn { diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index 8e76a35e6e33..aed1ea8e2c2f 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -207,7 +207,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->pr = (unsigned long)kretprobe_trampoline; + regs->pr = (unsigned long)__kretprobe_trampoline; } static int __kprobes kprobe_handler(struct pt_regs *regs) @@ -293,13 +293,13 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) */ static void __used kretprobe_trampoline_holder(void) { - asm volatile (".globl kretprobe_trampoline\n" - "kretprobe_trampoline:\n\t" + asm volatile (".globl __kretprobe_trampoline\n" + "__kretprobe_trampoline:\n\t" "nop\n"); } /* - * Called when we hit the probe point at kretprobe_trampoline + * Called when we hit the probe point at __kretprobe_trampoline */ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { @@ -442,7 +442,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, } static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *)&kretprobe_trampoline, + .addr = (kprobe_opcode_t *)&__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; diff --git a/arch/sparc/include/asm/kprobes.h b/arch/sparc/include/asm/kprobes.h index bfcaa6326c20..06c2bc767ef7 100644 --- a/arch/sparc/include/asm/kprobes.h +++ b/arch/sparc/include/asm/kprobes.h @@ -24,7 +24,7 @@ do { flushi(&(p)->ainsn.insn[0]); \ flushi(&(p)->ainsn.insn[1]); \ } while (0) -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); /* Architecture specific copy of original instruction*/ struct arch_specific_insn { diff --git a/arch/sparc/kernel/kprobes.c b/arch/sparc/kernel/kprobes.c index 401534236c2e..535c7b35cb59 100644 --- a/arch/sparc/kernel/kprobes.c +++ b/arch/sparc/kernel/kprobes.c @@ -440,7 +440,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, /* Replace the return addr with trampoline addr */ regs->u_regs[UREG_RETPC] = - ((unsigned long)kretprobe_trampoline) - 8; + ((unsigned long)__kretprobe_trampoline) - 8; } /* @@ -465,13 +465,13 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, static void __used kretprobe_trampoline_holder(void) { - asm volatile(".global kretprobe_trampoline\n" - "kretprobe_trampoline:\n" + asm volatile(".global __kretprobe_trampoline\n" + "__kretprobe_trampoline:\n" "\tnop\n" "\tnop\n"); } static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &kretprobe_trampoline, + .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; @@ -482,7 +482,7 @@ int __init arch_init_kprobes(void) int __kprobes arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) return 1; return 0; diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 0c59ef5971de..79cd23dba5b5 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -809,7 +809,7 @@ void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) ri->fp = sara; /* Replace the return addr with trampoline addr */ - *sara = (unsigned long) &kretprobe_trampoline; + *sara = (unsigned long) &__kretprobe_trampoline; } NOKPROBE_SYMBOL(arch_prepare_kretprobe); @@ -1019,9 +1019,9 @@ NOKPROBE_SYMBOL(kprobe_int3_handler); */ asm( ".text\n" - ".global kretprobe_trampoline\n" - ".type kretprobe_trampoline, @function\n" - "kretprobe_trampoline:\n" + ".global __kretprobe_trampoline\n" + ".type __kretprobe_trampoline, @function\n" + "__kretprobe_trampoline:\n" /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 " pushq %rsp\n" @@ -1045,14 +1045,14 @@ asm( " popfl\n" #endif " ret\n" - ".size kretprobe_trampoline, .-kretprobe_trampoline\n" + ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" ); -NOKPROBE_SYMBOL(kretprobe_trampoline); -STACK_FRAME_NON_STANDARD(kretprobe_trampoline); +NOKPROBE_SYMBOL(__kretprobe_trampoline); +STACK_FRAME_NON_STANDARD(__kretprobe_trampoline); /* - * Called from kretprobe_trampoline + * Called from __kretprobe_trampoline */ __used __visible void *trampoline_handler(struct pt_regs *regs) { @@ -1061,7 +1061,7 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) #ifdef CONFIG_X86_32 regs->gs = 0; #endif - regs->ip = (unsigned long)&kretprobe_trampoline; + regs->ip = (unsigned long)&__kretprobe_trampoline; regs->orig_ax = ~0UL; return (void *)kretprobe_trampoline_handler(regs, ®s->sp); diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 96f5df93e36e..b6b2370f4a4c 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -188,14 +188,14 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); /* * Since some architecture uses structured function pointer, * use dereference_function_descriptor() to get real function address. */ static nokprobe_inline void *kretprobe_trampoline_addr(void) { - return dereference_kernel_function_descriptor(kretprobe_trampoline); + return dereference_kernel_function_descriptor(__kretprobe_trampoline); } /* If the trampoline handler called from a kprobe, use this version */ diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index c2ca40e8595b..5a5949c659d0 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -349,7 +349,7 @@ EXPORT_SYMBOL_GPL(trace_output_call); #ifdef CONFIG_KRETPROBES static inline const char *kretprobed(const char *name) { - static const char tramp_name[] = "kretprobe_trampoline"; + static const char tramp_name[] = "__kretprobe_trampoline"; int size = sizeof(tramp_name); if (strncmp(tramp_name, name, size) == 0) From patchwork Tue Sep 14 14:41:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493701 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E28FC433EF for ; Tue, 14 Sep 2021 14:42:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35603610FB for ; Tue, 14 Sep 2021 14:42:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233688AbhINOna (ORCPT ); Tue, 14 Sep 2021 10:43:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:36492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234802AbhINOmZ (ORCPT ); Tue, 14 Sep 2021 10:42:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 44317610A2; Tue, 14 Sep 2021 14:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630468; bh=m0w+6fZCQCy0gdqhL8LsWosP3J2P38jldAkchB4zGxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z8GUc9DbBXmu3rz+XaPACjxWQOYx8iGI1XzJ5Rx/rQR/h04j5+mN8gPAp7M34RRQN WAHUXEe0L7tMKnyjlvzbb8kn9DUQ1Mcq+6GK061+8sBoVkJ3ypY1bUcCQkp7COy3XU w7stJaCeVipdaucHrz+5GTzKmZBoEdGx0g0UbS0xYaXsSCe3btbR1akLgmm8UDqkrp Sca36kUV9uqgVwQA5KoEIHFPZS/w0/tOCNX18qB0/90kF+oY5/8NhoZe9gDZ5FRupM LH4lTKxU1ruYb66CIFfm4VNdX4jiGeQTX+KtSkRBpyTLKrUceqZfjUekSQCBcoCptp qsB87gR6Khw0Q== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 16/27] kprobes: Add kretprobe_find_ret_addr() for searching return address Date: Tue, 14 Sep 2021 23:41:04 +0900 Message-Id: <163163046461.489837.1044778356430293962.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Introduce kretprobe_find_ret_addr() and is_kretprobe_trampoline(). These APIs will be used by the ORC stack unwinder and ftrace, so that they can check whether the given address points kretprobe trampoline code and query the correct return address in that case. Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v10: - Add a document about kretprobe_find_ret_addr() and check cur == NULL. Changes in v9: - Update changelog to explain why this is introduced. - Move the prototype of kretprobe_find_ret_addr() and is_kretprobe_trampoline() in the same place. - Make __kretprobe_find_ret_addr() return 'kprobe_opcode_t *'. - Update comments in the __kretprobe_trampoline_handler(). Changes in v6: - Replace BUG_ON() with WARN_ON_ONCE() in __kretprobe_trampoline_handler(). Changes in v3: - Remove generic stacktrace fixup. Instead, it should be solved in each unwinder. This just provide the generic interface. Changes in v2: - Add is_kretprobe_trampoline() for checking address outside of kretprobe_find_ret_addr() - Remove unneeded addr from kretprobe_find_ret_addr() - Rename fixup_kretprobe_tramp_addr() to fixup_kretprobe_trampoline() --- include/linux/kprobes.h | 22 +++++++++ kernel/kprobes.c | 109 ++++++++++++++++++++++++++++++++++++----------- 2 files changed, 105 insertions(+), 26 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index b6b2370f4a4c..6d47a9da1e0a 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -505,6 +505,28 @@ static inline bool is_kprobe_optinsn_slot(unsigned long addr) } #endif /* !CONFIG_OPTPROBES */ +#ifdef CONFIG_KRETPROBES +static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr) +{ + return (void *)addr == kretprobe_trampoline_addr(); +} + +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur); +#else +static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr) +{ + return false; +} + +static nokprobe_inline +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur) +{ + return 0; +} +#endif + /* Returns true if kprobes handled the fault */ static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs, unsigned int trap) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 6ed755111eea..833f07f33115 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1863,45 +1863,87 @@ static struct notifier_block kprobe_exceptions_nb = { #ifdef CONFIG_KRETPROBES -unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *frame_pointer) +/* This assumes the 'tsk' is the current task or the is not running. */ +static kprobe_opcode_t *__kretprobe_find_ret_addr(struct task_struct *tsk, + struct llist_node **cur) { - kprobe_opcode_t *correct_ret_addr = NULL; struct kretprobe_instance *ri = NULL; - struct llist_node *first, *node; - struct kretprobe *rp; + struct llist_node *node = *cur; + + if (!node) + node = tsk->kretprobe_instances.first; + else + node = node->next; - /* Find all nodes for this frame. */ - first = node = current->kretprobe_instances.first; while (node) { ri = container_of(node, struct kretprobe_instance, llist); - - BUG_ON(ri->fp != frame_pointer); - if (ri->ret_addr != kretprobe_trampoline_addr()) { - correct_ret_addr = ri->ret_addr; - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - goto found; + *cur = node; + return ri->ret_addr; } - node = node->next; } - pr_err("kretprobe: Return address not found, not execute handler. Maybe there is a bug in the kernel.\n"); - BUG_ON(1); + return NULL; +} +NOKPROBE_SYMBOL(__kretprobe_find_ret_addr); -found: - /* Unlink all nodes for this frame. */ - current->kretprobe_instances.first = node->next; - node->next = NULL; +/** + * kretprobe_find_ret_addr -- Find correct return address modified by kretprobe + * @tsk: Target task + * @fp: A frame pointer + * @cur: a storage of the loop cursor llist_node pointer for next call + * + * Find the correct return address modified by a kretprobe on @tsk in unsigned + * long type. If it finds the return address, this returns that address value, + * or this returns 0. + * The @tsk must be 'current' or a task which is not running. @fp is a hint + * to get the currect return address - which is compared with the + * kretprobe_instance::fp field. The @cur is a loop cursor for searching the + * kretprobe return addresses on the @tsk. The '*@cur' should be NULL at the + * first call, but '@cur' itself must NOT NULL. + */ +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur) +{ + struct kretprobe_instance *ri = NULL; + kprobe_opcode_t *ret; + + if (WARN_ON_ONCE(!cur)) + return 0; + + do { + ret = __kretprobe_find_ret_addr(tsk, cur); + if (!ret) + break; + ri = container_of(*cur, struct kretprobe_instance, llist); + } while (ri->fp != fp); - /* Run them.. */ + return (unsigned long)ret; +} +NOKPROBE_SYMBOL(kretprobe_find_ret_addr); + +unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, + void *frame_pointer) +{ + kprobe_opcode_t *correct_ret_addr = NULL; + struct kretprobe_instance *ri = NULL; + struct llist_node *first, *node = NULL; + struct kretprobe *rp; + + /* Find correct address and all nodes for this frame. */ + correct_ret_addr = __kretprobe_find_ret_addr(current, &node); + if (!correct_ret_addr) { + pr_err("kretprobe: Return address not found, not execute handler. Maybe there is a bug in the kernel.\n"); + BUG_ON(1); + } + + /* Run the user handler of the nodes. */ + first = current->kretprobe_instances.first; while (first) { ri = container_of(first, struct kretprobe_instance, llist); - first = first->next; + + if (WARN_ON_ONCE(ri->fp != frame_pointer)) + break; rp = get_kretprobe(ri); if (rp && rp->handler) { @@ -1912,6 +1954,21 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, rp->handler(ri, regs); __this_cpu_write(current_kprobe, prev); } + if (first == node) + break; + + first = first->next; + } + + /* Unlink all nodes for this frame. */ + first = current->kretprobe_instances.first; + current->kretprobe_instances.first = node->next; + node->next = NULL; + + /* Recycle free instances. */ + while (first) { + ri = container_of(first, struct kretprobe_instance, llist); + first = first->next; recycle_rp_inst(ri); } From patchwork Tue Sep 14 14:41:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493703 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D9B6C433EF for ; Tue, 14 Sep 2021 14:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9CBF610CE for ; Tue, 14 Sep 2021 14:42:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234264AbhINOng (ORCPT ); Tue, 14 Sep 2021 10:43:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:36622 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234299AbhINOmg (ORCPT ); Tue, 14 Sep 2021 10:42:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 315A761107; Tue, 14 Sep 2021 14:41:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630477; bh=ycaasLRNKeb4PrJCUm1tk0Rz6wHrs2EJsJbv1cIxaz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R2/jYfcXXtOvHiN1w9cVkLFItB/sxD4wBMXcJ3Rx449BhYcrkBxsEbBJQv++3CwOY Esxv6m0IZ+Zf8lJfPQq16gGK0pLFqu6HtugCvYAH075CR/RqZQh+XJxqc7dllTGtSY /Y14sUOuNP1PN0a5mqqC+0NjXmi9Sobq7ie/UW04qJJn6vhWGD+Plo9NtHGsWzTw5a K5hP5AktYpW9ecur7hNP0jX2AxXyrPm9nM+bBI6yKBZj3mhhAHZ6bet6os+q8xlXJW xgpMfOUGmi6oBoPeHmpuevZjsJC0YRi6a6hYZEIR236nFKvCP1yAG9mi3fs6kxcYaT NGV4csZTMRykQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 17/27] objtool: Add frame-pointer-specific function ignore Date: Tue, 14 Sep 2021 23:41:13 +0900 Message-Id: <163163047364.489837.17377799909553689661.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Josh Poimboeuf Add a CONFIG_FRAME_POINTER-specific version of STACK_FRAME_NON_STANDARD() for the case where a function is intentionally missing frame pointer setup, but otherwise needs objtool/ORC coverage when frame pointers are disabled. Signed-off-by: Josh Poimboeuf Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- Changes in v10: - Fixes error in CONFIG_STACK_VALIDATION=n case. --- include/linux/objtool.h | 12 ++++++++++++ tools/include/linux/objtool.h | 12 ++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/objtool.h b/include/linux/objtool.h index 7e72d975cb76..aca52db2f3f3 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -66,6 +66,17 @@ struct unwind_hint { static void __used __section(".discard.func_stack_frame_non_standard") \ *__func_stack_frame_non_standard_##func = func +/* + * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore + * for the case where a function is intentionally missing frame pointer setup, + * but otherwise needs objtool/ORC coverage when frame pointers are disabled. + */ +#ifdef CONFIG_FRAME_POINTER +#define STACK_FRAME_NON_STANDARD_FP(func) STACK_FRAME_NON_STANDARD(func) +#else +#define STACK_FRAME_NON_STANDARD_FP(func) +#endif + #else /* __ASSEMBLY__ */ /* @@ -127,6 +138,7 @@ struct unwind_hint { #define UNWIND_HINT(sp_reg, sp_offset, type, end) \ "\n\t" #define STACK_FRAME_NON_STANDARD(func) +#define STACK_FRAME_NON_STANDARD_FP(func) #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index 7e72d975cb76..aca52db2f3f3 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -66,6 +66,17 @@ struct unwind_hint { static void __used __section(".discard.func_stack_frame_non_standard") \ *__func_stack_frame_non_standard_##func = func +/* + * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore + * for the case where a function is intentionally missing frame pointer setup, + * but otherwise needs objtool/ORC coverage when frame pointers are disabled. + */ +#ifdef CONFIG_FRAME_POINTER +#define STACK_FRAME_NON_STANDARD_FP(func) STACK_FRAME_NON_STANDARD(func) +#else +#define STACK_FRAME_NON_STANDARD_FP(func) +#endif + #else /* __ASSEMBLY__ */ /* @@ -127,6 +138,7 @@ struct unwind_hint { #define UNWIND_HINT(sp_reg, sp_offset, type, end) \ "\n\t" #define STACK_FRAME_NON_STANDARD(func) +#define STACK_FRAME_NON_STANDARD_FP(func) #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 From patchwork Tue Sep 14 14:41:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493705 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 317C0C433FE for ; Tue, 14 Sep 2021 14:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1530E60F26 for ; Tue, 14 Sep 2021 14:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234997AbhINOng (ORCPT ); Tue, 14 Sep 2021 10:43:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:36700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233874AbhINOmo (ORCPT ); Tue, 14 Sep 2021 10:42:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ABA73610CE; Tue, 14 Sep 2021 14:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630487; bh=PKI/11VUgofsqKtIxhbATROKObOP+Kwnqz32HDODdGE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HGB87MJ7+KwchYoMM7AajMZQOrGm+n2sGKRCRgQaV0TA71beLJbLmYmhmukbaRzWu dYizsIBQaaqf9Bvhf4hFGnG/FGyS8yEAR/0q1dwxO4JtyyYpO3OWtjpl7Od+XH7acW i4rtdvKrKpnuKwCXcss6R/XeWIgxGCjrlEZCzzR1lBg4xTwa3Y2ERU9thHexdZMtb9 g9ISYfQtB5U2FtkmHlDutf3f3gehA+1RWccApUbfQ+5b/+mqOT71fmcahDU/AacFB0 TyIoKyl5QBOHWl29SnfUpjOI9uPtvOgiFUwlGYKjcQt6uw1VhCWQWDaO/dmvwon7HD AxnmZS4mHkm3g== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 18/27] objtool: Ignore unwind hints for ignored functions Date: Tue, 14 Sep 2021 23:41:23 +0900 Message-Id: <163163048317.489837.10988954983369863209.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Josh Poimboeuf If a function is ignored, also ignore its hints. This is useful for the case where the function ignore is conditional on frame pointers, e.g. STACK_FRAME_NON_STANDARD_FP(). Signed-off-by: Josh Poimboeuf Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu --- tools/objtool/check.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e5947fbb9e7a..67cbdcfcabae 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2909,7 +2909,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) } while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) { - if (insn->hint && !insn->visited) { + if (insn->hint && !insn->visited && !insn->ignore) { ret = validate_branch(file, insn->func, insn, state); if (ret && backtrace) BT_FUNC("<=== (hint)", insn); From patchwork Tue Sep 14 14:41:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493707 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3881EC433F5 for ; Tue, 14 Sep 2021 14:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25946610FB for ; Tue, 14 Sep 2021 14:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235044AbhINOnh (ORCPT ); Tue, 14 Sep 2021 10:43:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:36810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234420AbhINOmx (ORCPT ); Tue, 14 Sep 2021 10:42:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E254F603E8; Tue, 14 Sep 2021 14:41:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630496; bh=Rdr5qCe1gNFYBhdSCbvzhAs4VdI1+Mgp+bv4Bzlp+MA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vHG+giDP/dbUyac5wxc/wk2mx/ILtd1Htz1XmZB6NiW73iFZjLUoWsEP0hiJl2iPk eggeks+/ndGy5u9EglW237kI/e2TRDxpzjOdYUqTLNC93CzVJs0hLtXAaee9ScMcIE 59ijkYdFS9xo3/79kCaR4DVycu9TDbFFpOp5IjK5YN/HysIXj5j2kGEIaQyKujTJaS 43Xz2KVo0m5PuNJJuhOLV6fqvXtnE/JgDniwFkHEq/30j5a6xzJnn/IOgrJP+VlBD1 4rP5LlmjMQSIztoUY3aw+Zf5wMCs8BmM2/lz6tTsef5c8O70nBjerXB31dQJp9ESrN 4Bw+j8nEj0FPg== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 19/27] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline() Date: Tue, 14 Sep 2021 23:41:32 +0900 Message-Id: <163163049242.489837.11970969750993364293.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Josh Poimboeuf Add UNWIND_HINT_FUNC on __kretprobe_trampoline() code so that ORC information is generated on the __kretprobe_trampoline() correctly. Also, this uses STACK_FRAME_NON_STANDARD_FP(), CONFIG_FRAME_POINTER- -specific version of STACK_FRAME_NON_STANDARD(). Signed-off-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v9: - Update changelog and fix comment. - Use STACK_FRAME_NON_STANDARD_FP(). Changes in v4: - Apply UNWIND_HINT_FUNC only if CONFIG_FRAME_POINTER=n. --- arch/x86/include/asm/unwind_hints.h | 5 +++++ arch/x86/kernel/kprobes/core.c | 13 +++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 8e574c0afef8..8b33674288ea 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -52,6 +52,11 @@ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC .endm +#else + +#define UNWIND_HINT_FUNC \ + UNWIND_HINT(ORC_REG_SP, 8, UNWIND_HINT_TYPE_FUNC, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 79cd23dba5b5..d1436d7463fd 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1025,6 +1025,7 @@ asm( /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 " pushq %rsp\n" + UNWIND_HINT_FUNC " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" @@ -1035,6 +1036,7 @@ asm( " popfq\n" #else " pushl %esp\n" + UNWIND_HINT_FUNC " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" @@ -1048,8 +1050,15 @@ asm( ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(__kretprobe_trampoline); -STACK_FRAME_NON_STANDARD(__kretprobe_trampoline); - +/* + * __kretprobe_trampoline() skips updating frame pointer. The frame pointer + * saved in trampoline_handler() points to the real caller function's + * frame pointer. Thus the __kretprobe_trampoline() doesn't have a + * standard stack frame with CONFIG_FRAME_POINTER=y. + * Let's mark it non-standard function. Anyway, FP unwinder can correctly + * unwind without the hint. + */ +STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline); /* * Called from __kretprobe_trampoline From patchwork Tue Sep 14 14:41:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493709 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8340C433EF for ; Tue, 14 Sep 2021 14:42:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9045E60F11 for ; Tue, 14 Sep 2021 14:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234832AbhINOnu (ORCPT ); Tue, 14 Sep 2021 10:43:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:36030 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233765AbhINOnD (ORCPT ); Tue, 14 Sep 2021 10:43:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5730560F11; Tue, 14 Sep 2021 14:41:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630506; bh=KEe5WdEyJHtzuPMGzpiocUmfrX3xOnunn5dZvpKwBh8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H0O7KnjhENSKmymiA5AxlQMCLHYg2ceHsvASG+IFQBPitXqJgEtKcmTy+nr49fhnL g0s7MfkeO3HE80yGuVRkDI+kGC14tnhxbdCtYGY1O8bB+i50VEjZhyNX6H7bTFHA3S NpqCCWHm6vPzLRiCAUjJMS1ni9RPTH7Cbgk0/FbXrOi4nsdZJgrst5f1lKNe5+kZeG MQns1JpgsOL9GS2uWv+7CL93cE9g0RoXWQea906+LQNpn1PyXs82dfxB0mWJqcA0zw WDDlXpN44zB5wg19AUokdc3xyqoZVlhiJUYbMkBpRolTbOkCeDB0XSFsBUAPSxLU3Y /ht2po03iTdCQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 20/27] ARC: Add instruction_pointer_set() API Date: Tue, 14 Sep 2021 23:41:41 +0900 Message-Id: <163163050148.489837.15187799269793560256.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add instruction_pointer_set() API for arc. Signed-off-by: Masami Hiramatsu --- arch/arc/include/asm/ptrace.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 4c3c9be5bd16..cca8d6583e31 100644 --- a/arch/arc/include/asm/ptrace.h +++ b/arch/arc/include/asm/ptrace.h @@ -149,6 +149,11 @@ static inline long regs_return_value(struct pt_regs *regs) return (long)regs->r0; } +static inline void instruction_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + instruction_pointer(regs) = val; +} #endif /* !__ASSEMBLY__ */ #endif /* __ASM_PTRACE_H */ From patchwork Tue Sep 14 14:41:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493711 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E766C433F5 for ; Tue, 14 Sep 2021 14:42:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28E30603E8 for ; Tue, 14 Sep 2021 14:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234025AbhINOnz (ORCPT ); Tue, 14 Sep 2021 10:43:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:37234 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234870AbhINOnO (ORCPT ); Tue, 14 Sep 2021 10:43:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 330C06112E; Tue, 14 Sep 2021 14:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630517; bh=Z7dFFREwwQHrQdB1bENhzb91hET8Wq84SoeFv9Bi8NM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r7zbmDdkUismlNm077fkPECw78l5ZmSmD+iOdcmVuM2vQlFZhow7qxuMqW76c5FvR rvH/u8DjDfsPgcufFcXZR0uoFlZNzKkfJSDFQAC6r8qrEboaw4UuUTPqD4eJfr8DTI 3Z45C4ug7V/bUHTvhxEYb2nyNQnvTAarMpSTAJt8ZDjs13/yzBHAw5im2VYEYRon2a I2pSBwWG0SOAXa/a/DmCkYlpB0RTf6/z6o4qpDATPF81eOf2Rpv2uzgwniYx9xhKtu QRlf0bFeKdd+7PG84I/1PynK6KNhg+g+692Z8sPfkQ46HKme+G0+kmxzeujWDqLX3t tCfmGfR8K7I8w== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 21/27] ia64: Add instruction_pointer_set() API Date: Tue, 14 Sep 2021 23:41:52 +0900 Message-Id: <163163051195.489837.1039597819838213481.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add instruction_pointer_set() API for ia64. Signed-off-by: Masami Hiramatsu --- Changes in v9: - Fix "space at the start of a line" checkpatch warnings. Changes in v4: - Make the API macro for avoiding a build error. --- arch/ia64/include/asm/ptrace.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h index 08179135905c..8a2d0f72b324 100644 --- a/arch/ia64/include/asm/ptrace.h +++ b/arch/ia64/include/asm/ptrace.h @@ -51,6 +51,11 @@ * the canonical representation by adding to instruction pointer. */ # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri) +# define instruction_pointer_set(regs, val) \ +({ \ + ia64_psr(regs)->ri = (val & 0xf); \ + regs->cr_iip = (val & ~0xfULL); \ +}) static inline unsigned long user_stack_pointer(struct pt_regs *regs) { From patchwork Tue Sep 14 14:42:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493713 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E1E1C433F5 for ; Tue, 14 Sep 2021 14:43:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F506610A2 for ; Tue, 14 Sep 2021 14:43:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234769AbhINOoF (ORCPT ); Tue, 14 Sep 2021 10:44:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:37424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234353AbhINOnY (ORCPT ); Tue, 14 Sep 2021 10:43:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6C74D610E6; Tue, 14 Sep 2021 14:42:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630527; bh=jM/E5qbkTRhtXvBgC/DCoql0xzq9kLErr23TZymhaCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jlCaPgcJhWUO+i9/EysWC59P/e3Mf+EtfSanbyZejo32D+FMKaBZnJSHVZ6hKfABp WEgh66BhjEFoshS/x9skRs8MxeczHQ9dTxInEG1kbVEIMr+QCUb6XcvTEIYNW6dIGC qmbRAo7UKGEAQQbmdREJQjcykU0qVe8s+/cjJ9zcpsaY5lViLl+E6+JJAsWuTl8l8l GW8J53lrRtxgpoKVQZCYRd7DbOYLfmVap7kfXSZVXNvq+qouDHc7CgkFvmIvIO8TAI eLKG80VAOUyugEdxYtbQCn8kzgFXVrBzFVgMNIqHJIT0hqiqJvY+UCedT2HcifvWJV KKdOjXNl29AvA== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 22/27] arm: kprobes: Make space for instruction pointer on stack Date: Tue, 14 Sep 2021 23:42:02 +0900 Message-Id: <163163052262.489837.10327621053231461255.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the stack, 'regs->ARM_pc' (instruction pointer) is not accessible from the kretprobe handler. This means if instruction_pointer_set() is used from kretprobe handler, it will break the data on the stack. Make space for instruction pointer (ARM_pc) on the stack in the __kretprobe_trampoline() for fixing this problem. Signed-off-by: Masami Hiramatsu --- Changes in v9: - Update changelog. --- arch/arm/probes/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 67ce7eb8f285..95f23b47ba27 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -376,11 +376,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, void __naked __kprobes __kretprobe_trampoline(void) { __asm__ __volatile__ ( + "sub sp, sp, #16 \n\t" "stmdb sp!, {r0 - r11} \n\t" "mov r0, sp \n\t" "bl trampoline_handler \n\t" "mov lr, r0 \n\t" "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" #ifdef CONFIG_THUMB2_KERNEL "bx lr \n\t" #else From patchwork Tue Sep 14 14:42:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493715 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CDACC433EF for ; Tue, 14 Sep 2021 14:43:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7465A60698 for ; Tue, 14 Sep 2021 14:43:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233713AbhINOom (ORCPT ); Tue, 14 Sep 2021 10:44:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:37564 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234718AbhINOne (ORCPT ); Tue, 14 Sep 2021 10:43:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2CC9260698; Tue, 14 Sep 2021 14:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630536; bh=3BqLLykrOHv7GrNy26CHO6BhcUQk9jcyV1ViRuIHq5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gqIHQ0Gt2EqUIueVcGydp3rBk92Jdp1Pe3e5fWRbDSm2kyzTdJvKEpyqGHpEIrANP OyawhObNC4MAXVJhvwuAF+DA53+bAXuF5x4eUnyIttUXMkEmc3W9oKJ7G9NPmZeOIk SYOInDQ1VAHSxPOQQyxHI+TxrtRP6ALShyNQVLXPdNN9Zr45COpRSFOICRPbJmo/V1 /qziE1BEjbDAmjCEyhJ8K676C0F5hhuh4GPDTb1g011ivk3HBXIKfmvmpX5Q5NUuVc q9SC5o476A9aVXCVHz9jLnq6x78vlj/l9NTSH130E4IcmqIVUCj+RpVhv6W7TDA55m V2DzkOor2RwIQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 23/27] kprobes: Enable stacktrace from pt_regs in kretprobe handler Date: Tue, 14 Sep 2021 23:42:12 +0900 Message-Id: <163163053237.489837.4272653874525136832.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since the ORC unwinder from pt_regs requires setting up regs->ip correctly, set the correct return address to the regs->ip before calling user kretprobe handler. This allows the kretrprobe handler to trace stack from the kretprobe's pt_regs by stack_trace_save_regs() (eBPF will do this), instead of stack tracing from the handler context by stack_trace_save() (ftrace will do this). Suggested-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko Acked-by: Josh Poimboeuf --- Changes in v9: - Update comment to explain specifically why this is necessary. Changes in v8: - Update comment to clarify why this is needed. Changes in v3: - Cast the correct_ret_addr to unsigned long. --- kernel/kprobes.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 833f07f33115..ebc587b9a346 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1937,6 +1937,13 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, BUG_ON(1); } + /* + * Set the return address as the instruction pointer, because if the + * user handler calls stack_trace_save_regs() with this 'regs', + * the stack trace will start from the instruction pointer. + */ + instruction_pointer_set(regs, (unsigned long)correct_ret_addr); + /* Run the user handler of the nodes. */ first = current->kretprobe_instances.first; while (first) { From patchwork Tue Sep 14 14:42:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493717 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EB13C433F5 for ; Tue, 14 Sep 2021 14:43:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6375260F26 for ; Tue, 14 Sep 2021 14:43:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234484AbhINOom (ORCPT ); Tue, 14 Sep 2021 10:44:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:37716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235070AbhINOnn (ORCPT ); Tue, 14 Sep 2021 10:43:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8B2E760F26; Tue, 14 Sep 2021 14:42:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630546; bh=b5f2P/y2shO+S47LUkQKIDybO3DPdanNyRLlemEbyJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q+pX6J70edoXPy6i7djpdQXB3gUchZaaMjGFwEXO6ywbOJmdi47/79QQYqzL8pK2W ynR3Zcm43f0o0bGtT95wf6aPTp/GJqigvpSBpbIghagjJRTPmR9Aom6XgH1XjFXz2C 7zs7KjwOhl6Znz7sKCZuNwEkr7u06btW4jGyfJujg6jI36wnp+PWFO+aY/jf64qVN9 TYfZR3pQCjcqm+im9GP0FO+ZedQomr20/yTGFQiGtWioESzmQWl5RA1pLYz1Ys2r3v b1HLubozk8ay/sxYoFQk+1Abc/uZD70d9sG8XBut5eUOBGUDWWSkKrVtE8ZujAfcpv Hw/BHOLLuqjDQ== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 24/27] x86/kprobes: Push a fake return address at kretprobe_trampoline Date: Tue, 14 Sep 2021 23:42:22 +0900 Message-Id: <163163054185.489837.14338744048957727386.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Change __kretprobe_trampoline() to push the address of the __kretprobe_trampoline() as a fake return address at the bottom of the stack frame. This fake return address will be replaced with the correct return address in the trampoline_handler(). With this change, the ORC unwinder can check whether the return address is modified by kretprobes or not. Signed-off-by: Masami Hiramatsu Suggested-by: Josh Poimboeuf Tested-by: Andrii Nakryiko Acked-by: Josh Poimboeuf --- Changes in v9: - Update changelog and comment. - Remove unneeded type casting. --- arch/x86/kernel/kprobes/core.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index d1436d7463fd..7e1111c19605 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1022,28 +1022,33 @@ asm( ".global __kretprobe_trampoline\n" ".type __kretprobe_trampoline, @function\n" "__kretprobe_trampoline:\n" - /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 - " pushq %rsp\n" + /* Push a fake return address to tell the unwinder it's a kretprobe. */ + " pushq $__kretprobe_trampoline\n" UNWIND_HINT_FUNC + /* Save the 'sp - 8', this will be fixed later. */ + " pushq %rsp\n" " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" " call trampoline_handler\n" - /* Replace saved sp with true return address. */ - " movq %rax, 19*8(%rsp)\n" RESTORE_REGS_STRING + /* In trampoline_handler(), 'regs->flags' is copied to 'regs->sp'. */ + " addq $8, %rsp\n" " popfq\n" #else - " pushl %esp\n" + /* Push a fake return address to tell the unwinder it's a kretprobe. */ + " pushl $__kretprobe_trampoline\n" UNWIND_HINT_FUNC + /* Save the 'sp - 4', this will be fixed later. */ + " pushl %esp\n" " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" " call trampoline_handler\n" - /* Replace saved sp with true return address. */ - " movl %eax, 15*4(%esp)\n" RESTORE_REGS_STRING + /* In trampoline_handler(), 'regs->flags' is copied to 'regs->sp'. */ + " addl $4, %esp\n" " popfl\n" #endif " ret\n" @@ -1063,8 +1068,10 @@ STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline); /* * Called from __kretprobe_trampoline */ -__used __visible void *trampoline_handler(struct pt_regs *regs) +__used __visible void trampoline_handler(struct pt_regs *regs) { + unsigned long *frame_pointer; + /* fixup registers */ regs->cs = __KERNEL_CS; #ifdef CONFIG_X86_32 @@ -1072,8 +1079,17 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) #endif regs->ip = (unsigned long)&__kretprobe_trampoline; regs->orig_ax = ~0UL; + regs->sp += sizeof(long); + frame_pointer = ®s->sp + 1; + + /* Replace fake return address with real one. */ + *frame_pointer = kretprobe_trampoline_handler(regs, frame_pointer); - return (void *)kretprobe_trampoline_handler(regs, ®s->sp); + /* + * Copy FLAGS to 'pt_regs::sp' so that __kretprobe_trapmoline() + * can do RET right after POPF. + */ + regs->sp = regs->flags; } NOKPROBE_SYMBOL(trampoline_handler); From patchwork Tue Sep 14 14:42:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493719 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F488C4332F for ; Tue, 14 Sep 2021 14:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FE0E603E8 for ; Tue, 14 Sep 2021 14:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234781AbhINOon (ORCPT ); Tue, 14 Sep 2021 10:44:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:37916 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234359AbhINOnw (ORCPT ); Tue, 14 Sep 2021 10:43:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E4C53610CE; Tue, 14 Sep 2021 14:42:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630555; bh=juSmhxL2xpDmE4nzcIHTKDR3pzJZ+yWbGObEWpwCpho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PZ/qNmAZcrQwVPCzPPCGH9wQ6R45z0vu/AUPStlFjpz9ePnkbLSL8Q+xNXd+FW5wB fi+glgnyZc6ft830YvM6QTjNDiPrtdKXIULLrO8vJZudR1IvHe4ZbMTG8Dg7QuqzZk VXNJ4/TVQd/V2qwfmmrnWpymFeKfTrKo8vFDV++Il25NqRRmgkNxj11ixNE0wIgdbh NBFFogEoyjZ6uix7qvRp4fyk3eK/BYJB7vqgUnZle7mHks0NckGaPewStHldHnY+Cs QSfuZi/+ZVaK26zCdzrRuPQLQasxMIjweiAiNQ6VV/1q5jy0PTBlUvcR469UNrP8ep FBcXyzXwQ4wbA== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 25/27] x86/unwind: Recover kretprobe trampoline entry Date: Tue, 14 Sep 2021 23:42:31 +0900 Message-Id: <163163055130.489837.5161749078833497255.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, x86 unwinders can not continue the stack unwinding at that point, or record kretprobe_trampoline instead of correct return address. To fix this issue, find the correct return address from task's kretprobe_instances as like as function-graph tracer does. With this fix, the unwinder can correctly unwind the stack from kretprobe event on x86, as below. <...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read) <...>-135 [003] ...1 6.722377: => kretprobe_trace_func+0x209/0x2f0 => kretprobe_dispatcher+0x4a/0x70 => __kretprobe_trampoline_handler+0xca/0x150 => trampoline_handler+0x44/0x70 => kretprobe_trampoline+0x2a/0x50 => vfs_read+0xab/0x1a0 => ksys_read+0x5f/0xe0 => do_syscall_64+0x33/0x40 => entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: Daniel Xu Signed-off-by: Masami Hiramatsu Suggested-by: Josh Poimboeuf Tested-by: Andrii Nakryiko Acked-by: Josh Poimboeuf --- Changes in v9: - Update comment so that it explains why the strange address passed to unwind_recover_kretprobe(). Changes in v7: - Remove superfluous #include . Changes in v5: - Fix the case of interrupt happens on kretprobe_trampoline+0. Changes in v3: - Split out the kretprobe side patch - Fix build error when CONFIG_KRETPROBES=n. Changes in v2: - Remove kretprobe wrapper functions from unwind_orc.c - Do not fixup state->ip when unwinding with regs because kretprobe fixup instruction pointer before calling handler. --- arch/x86/include/asm/unwind.h | 23 +++++++++++++++++++++++ arch/x86/kernel/unwind_frame.c | 3 +-- arch/x86/kernel/unwind_guess.c | 3 +-- arch/x86/kernel/unwind_orc.c | 21 +++++++++++++++++---- 4 files changed, 42 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h index 70fc159ebe69..fca2e783e3ce 100644 --- a/arch/x86/include/asm/unwind.h +++ b/arch/x86/include/asm/unwind.h @@ -4,6 +4,7 @@ #include #include +#include #include #include @@ -15,6 +16,7 @@ struct unwind_state { unsigned long stack_mask; struct task_struct *task; int graph_idx; + struct llist_node *kr_cur; bool error; #if defined(CONFIG_UNWINDER_ORC) bool signal, full_regs; @@ -99,6 +101,27 @@ void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, void *orc, size_t orc_size) {} #endif +static inline +unsigned long unwind_recover_kretprobe(struct unwind_state *state, + unsigned long addr, unsigned long *addr_p) +{ + return is_kretprobe_trampoline(addr) ? + kretprobe_find_ret_addr(state->task, addr_p, &state->kr_cur) : + addr; +} + +/* Recover the return address modified by kretprobe and ftrace_graph. */ +static inline +unsigned long unwind_recover_ret_addr(struct unwind_state *state, + unsigned long addr, unsigned long *addr_p) +{ + unsigned long ret; + + ret = ftrace_graph_ret_addr(state->task, &state->graph_idx, + addr, addr_p); + return unwind_recover_kretprobe(state, ret, addr_p); +} + /* * This disables KASAN checking when reading a value from another task's stack, * since the other task could be running on another CPU and could have poisoned diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index d7c44b257f7f..8e1c50c86e5d 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -240,8 +240,7 @@ static bool update_stack_state(struct unwind_state *state, else { addr_p = unwind_get_return_address_ptr(state); addr = READ_ONCE_TASK_STACK(state->task, *addr_p); - state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, addr_p); + state->ip = unwind_recover_ret_addr(state, addr, addr_p); } /* Save the original stack pointer for unwind_dump(): */ diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index c49f10ffd8cd..884d68a6e714 100644 --- a/arch/x86/kernel/unwind_guess.c +++ b/arch/x86/kernel/unwind_guess.c @@ -15,8 +15,7 @@ unsigned long unwind_get_return_address(struct unwind_state *state) addr = READ_ONCE_NOCHECK(*state->sp); - return ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, state->sp); + return unwind_recover_ret_addr(state, addr, state->sp); } EXPORT_SYMBOL_GPL(unwind_get_return_address); diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index a1202536fc57..e6f7592790af 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -534,9 +534,8 @@ bool unwind_next_frame(struct unwind_state *state) if (!deref_stack_reg(state, ip_p, &state->ip)) goto err; - state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - state->ip, (void *)ip_p); - + state->ip = unwind_recover_ret_addr(state, state->ip, + (unsigned long *)ip_p); state->sp = sp; state->regs = NULL; state->prev_regs = NULL; @@ -549,7 +548,18 @@ bool unwind_next_frame(struct unwind_state *state) (void *)orig_ip); goto err; } - + /* + * There is a small chance to interrupt at the entry of + * __kretprobe_trampoline() where the ORC info doesn't exist. + * That point is right after the RET to __kretprobe_trampoline() + * which was modified return address. + * At that point, the @addr_p of the unwind_recover_kretprobe() + * (this has to point the address of the stack entry storing + * the modified return address) must be "SP - (a stack entry)" + * because SP is incremented by the RET. + */ + state->ip = unwind_recover_kretprobe(state, state->ip, + (unsigned long *)(state->sp - sizeof(long))); state->regs = (struct pt_regs *)sp; state->prev_regs = NULL; state->full_regs = true; @@ -562,6 +572,9 @@ bool unwind_next_frame(struct unwind_state *state) (void *)orig_ip); goto err; } + /* See UNWIND_HINT_TYPE_REGS case comment. */ + state->ip = unwind_recover_kretprobe(state, state->ip, + (unsigned long *)(state->sp - sizeof(long))); if (state->full_regs) state->prev_regs = state->regs; From patchwork Tue Sep 14 14:42:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493803 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58945C433FE for ; Tue, 14 Sep 2021 14:44:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41A3A610CE for ; Tue, 14 Sep 2021 14:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234020AbhINOqM (ORCPT ); Tue, 14 Sep 2021 10:46:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:38100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234454AbhINOoD (ORCPT ); Tue, 14 Sep 2021 10:44:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 394EF603E8; Tue, 14 Sep 2021 14:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630565; bh=TUCsxly137sqYFrcw/nhrPHVZpvyjgU/5fxaIE/rkoA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SfdvhyAXdrfDz/ean1GBuf2G+Sb0a8z85QZ6YotOejjwe827lMbyt8diZxcwnboEG /xWmp9KavjsczacvC4LdcMp1VlYDEhdz7+Irr0r98gg2mYf6tpt28EExDgJrnNLzA0 THaL1yAkSuswO30oKwqi3PuNuGOJyYD1U1z68QfctN9fKSAGsS52GFJ3VKvcto7fma Ho3X71JVagSyEokQ/5tt4kGogpj9qB2bIYorOPtU4VCfZKPGesGCxOxWyBjWvnEQ86 ce6u1DBFLpQvdSJ4CQEcZG18BomkuhJnQIyAOSWeZE3gJ9lOb9OnsvlMog0swjbij3 0XEdZZ/nHVh1Q== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 26/27] tracing: Show kretprobe unknown indicator only for kretprobe_trampoline Date: Tue, 14 Sep 2021 23:42:40 +0900 Message-Id: <163163056044.489837.794883849706638013.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the kretprobe_trampoline, but the modified address by kretprobe should be only kretprobe_trampoline+0. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt (VMware) Tested-by: Andrii Nakryiko --- kernel/trace/trace_output.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 5a5949c659d0..3547e7176ff7 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -346,22 +347,12 @@ int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...) } EXPORT_SYMBOL_GPL(trace_output_call); -#ifdef CONFIG_KRETPROBES -static inline const char *kretprobed(const char *name) +static inline const char *kretprobed(const char *name, unsigned long addr) { - static const char tramp_name[] = "__kretprobe_trampoline"; - int size = sizeof(tramp_name); - - if (strncmp(tramp_name, name, size) == 0) + if (is_kretprobe_trampoline(addr)) return "[unknown/kretprobe'd]"; return name; } -#else -static inline const char *kretprobed(const char *name) -{ - return name; -} -#endif /* CONFIG_KRETPROBES */ void trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) @@ -374,7 +365,7 @@ trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) sprint_symbol(str, address); else kallsyms_lookup(address, NULL, NULL, NULL, str); - name = kretprobed(str); + name = kretprobed(str, address); if (name && strlen(name)) { trace_seq_puts(s, name); From patchwork Tue Sep 14 14:42:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12493721 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B577C433EF for ; Tue, 14 Sep 2021 14:43:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 645A26113B for ; Tue, 14 Sep 2021 14:43:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234933AbhINOow (ORCPT ); Tue, 14 Sep 2021 10:44:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:37716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235303AbhINOoM (ORCPT ); Tue, 14 Sep 2021 10:44:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 746F460698; Tue, 14 Sep 2021 14:42:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631630574; bh=vq57kfNtne2ZkfDVHujGhteCErzVm2gfEbZS/xIziG0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mCpDHh5Lm+mE8XL6aKyUPTMVSL/FmzJvwE6mT8TZHhAJpdtudU+Fmdf1NYwCF5Wg/ yMtm1hNCW/FWvD3vxVtP3fhXfKuZYG5Xi5TKvvr7zQRH0QbMLxtsuHXJS40XbMg8sM Mef5EapdnXdCXxXMUbRjWrszEqbEe3a7Db7qc0qlvjFzLvaMpmyaKHEeWEzfupp21Z oC2ilE47cptRJ9JGw4vAc8qJkwTN2Evp7p7vvW3W9xBCNuyidi127/0gBlqFK0qC90 zg7nUjLhD7E+kmGoE9Auwsj36Gg35ieD7zmxDCdlwbQofBQ7TZP1fDI4/0DjH2Kco2 qi9yyeM8YK9Iw== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko , Paul McKenney Subject: [PATCH -tip v11 27/27] x86/kprobes: Fixup return address in generic trampoline handler Date: Tue, 14 Sep 2021 23:42:51 +0900 Message-Id: <163163057094.489837.9044470370440745866.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163163030719.489837.2236069935502195491.stgit@devnote2> References: <163163030719.489837.2236069935502195491.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org In x86, the fake return address on the stack saved by __kretprobe_trampoline() will be replaced with the real return address after returning from trampoline_handler(). Before fixing the return address, the real return address can be found in the 'current->kretprobe_instances'. However, since there is a window between updating the 'current->kretprobe_instances' and fixing the address on the stack, if an interrupt happens at that timing and the interrupt handler does stacktrace, it may fail to unwind because it can not get the correct return address from 'current->kretprobe_instances'. This will eliminate that window by fixing the return address right before updating 'current->kretprobe_instances'. Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v9: - Fixes the changelog. This can eliminate the window. - Add more comment how it works. Changes in v7: - Add a prototype for arch_kretprobe_fixup_return() --- arch/x86/kernel/kprobes/core.c | 18 ++++++++++++++++-- include/linux/kprobes.h | 3 +++ kernel/kprobes.c | 11 +++++++++++ 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7e1111c19605..fce99e249d61 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1065,6 +1065,16 @@ NOKPROBE_SYMBOL(__kretprobe_trampoline); */ STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline); +/* This is called from kretprobe_trampoline_handler(). */ +void arch_kretprobe_fixup_return(struct pt_regs *regs, + kprobe_opcode_t *correct_ret_addr) +{ + unsigned long *frame_pointer = ®s->sp + 1; + + /* Replace fake return address with real one. */ + *frame_pointer = (unsigned long)correct_ret_addr; +} + /* * Called from __kretprobe_trampoline */ @@ -1082,8 +1092,12 @@ __used __visible void trampoline_handler(struct pt_regs *regs) regs->sp += sizeof(long); frame_pointer = ®s->sp + 1; - /* Replace fake return address with real one. */ - *frame_pointer = kretprobe_trampoline_handler(regs, frame_pointer); + /* + * The return address at 'frame_pointer' is recovered by the + * arch_kretprobe_fixup_return() which called from the + * kretprobe_trampoline_handler(). + */ + kretprobe_trampoline_handler(regs, frame_pointer); /* * Copy FLAGS to 'pt_regs::sp' so that __kretprobe_trapmoline() diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 6d47a9da1e0a..e974caf39d3e 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -188,6 +188,9 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); +void arch_kretprobe_fixup_return(struct pt_regs *regs, + kprobe_opcode_t *correct_ret_addr); + void __kretprobe_trampoline(void); /* * Since some architecture uses structured function pointer, diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ebc587b9a346..b62af9fc3607 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1922,6 +1922,15 @@ unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, } NOKPROBE_SYMBOL(kretprobe_find_ret_addr); +void __weak arch_kretprobe_fixup_return(struct pt_regs *regs, + kprobe_opcode_t *correct_ret_addr) +{ + /* + * Do nothing by default. Please fill this to update the fake return + * address on the stack with the correct one on each arch if possible. + */ +} + unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, void *frame_pointer) { @@ -1967,6 +1976,8 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, first = first->next; } + arch_kretprobe_fixup_return(regs, correct_ret_addr); + /* Unlink all nodes for this frame. */ first = current->kretprobe_instances.first; current->kretprobe_instances.first = node->next;