From patchwork Sun Jul 11 13:36:14 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: 12369143 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=-19.7 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 778C6C07E96 for ; Sun, 11 Jul 2021 13:36:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62C5C613BE for ; Sun, 11 Jul 2021 13:36:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233090AbhGKNjG (ORCPT ); Sun, 11 Jul 2021 09:39:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:49206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232907AbhGKNjG (ORCPT ); Sun, 11 Jul 2021 09:39:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 60DCC61279; Sun, 11 Jul 2021 13:36:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626010579; bh=jM/E5qbkTRhtXvBgC/DCoql0xzq9kLErr23TZymhaCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oldi7o/2eNUWkWMMoMQHDyx6VfpPXQJpEfoX6r6uI486G8olewdnejDkXsa0ZHX5y oezcFHsx3ACsUqMJ8950H0fPSYC3gWfuAUctzCOyojttTcTgmad7ZAbDcO2igqOpJi PgOdY/JqG+ePIwBeDmF9zD25Y5rh5eVGyLPDBCDRGXQxdvxP5rO0zYj/Rs4yawy0zB RtMVEXuYEWTwHSXzu2uL9guipfBzxSuZfCP907TqbUcTEZyTOrpbvzdwHSwuw22vLB 2O/Ng4zUB5r5Y2u0TEA2mAcrZV3jH9pCVQe7AnivrhnsUT9BHI6NYMcFOWzPFpPo4n kzEHIaEEvPhLw== 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 Subject: [PATCH -tip v9 09/14] arm: kprobes: Make space for instruction pointer on stack Date: Sun, 11 Jul 2021 22:36:14 +0900 Message-Id: <162601057463.1318837.12052634205343013760.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162601048053.1318837.1550594515476777588.stgit@devnote2> References: <162601048053.1318837.1550594515476777588.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