From patchwork Fri Apr 26 23:22:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10920089 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F15C912 for ; Sat, 27 Apr 2019 06:46:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D84728BC3 for ; Sat, 27 Apr 2019 06:46:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7EC6A28E78; Sat, 27 Apr 2019 06:46:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=2.0 tests=BAYES_00,DATE_IN_PAST_06_12, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 8DCE128BC3 for ; Sat, 27 Apr 2019 06:46:16 +0000 (UTC) Received: (qmail 5289 invoked by uid 550); 27 Apr 2019 06:43:37 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 5166 invoked from network); 27 Apr 2019 06:43:35 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=g3nO4xFM3yb0X+OIqTEtEp6LbffMj61RqStKCNeSSiM=; b=IhMsROzOX/uvsuQybijdR85Kqaxq4yWzjUoagIOqk1LVY6OLTEXQbjBmXHD5WxbAzP cmCoo1zMlycyEW/HfwZCgn/X+0dMFPFHyqqtEUKq6AZF6jWZrRVIUAiE8jxYjY0M9MT3 Ik7ZKhQeM7kg+3gB06XcTjx2xBZpPGhS55GH7o8s674YL85Zg5fEINa05kjxM9iG+Kfo SEIwp8JxZ7vs+rhoqI+mg8MouUQf2Zul6cu4rspQPkk8FxQa/9RXPXX4OwkD3jy0+Z/+ SBrns4/qvGYQvjrl9OPoH7DBVBfA0arFpsKvUBwFWEn4L2+Z7qiKOGh0M4x1w7s8Fe9M Y7uQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=g3nO4xFM3yb0X+OIqTEtEp6LbffMj61RqStKCNeSSiM=; b=Z2ggl54odupGVs6OKbzLS8jN6yoOTIOcRE/GJnrZzA/rIN9pYwEI4JBrgqQhiyPVme oazVWWAwvupNkyWZOJwgVhWL6RKBSV9BPBqkXyA9W/dvqJnLdhtt5WX62/wL+OzXh5n3 aEo8ciZwNlp4SblP5qVwU4TS5Uwg15aCit43EKFM26XGxvA1lGz6Cg0MThCugT6ePxyX TX7mF0jy4yEQWuS5gnCn7NnGAiJnYYPh9SqVq3NW25/L+iBOTXO0mV+yQErpMwTz8k6z 7nbon/uMBxPrpSzQGjuQ11ulKmBoQTs4RvlmLqwgSjzdoG7HHXY4MWgWCpzOg1clhZtc f1UA== X-Gm-Message-State: APjAAAX4m03PXb9y//wMeNuStX5qgowUsJUw0lCyzNfW20Jakv6sHn5O 23BXGMoM6DNC+uQeR4izWyo= X-Google-Smtp-Source: APXvYqyXozv8RJ3un5KRfku6J9oOZngaXmf1Y0t3bUJMwzL1TSTEhjmbFCgyEeDgaxJqumt2ZQ+7aA== X-Received: by 2002:a62:5fc7:: with SMTP id t190mr50793424pfb.191.1556347403359; Fri, 26 Apr 2019 23:43:23 -0700 (PDT) From: nadav.amit@gmail.com To: Peter Zijlstra , Borislav Petkov , Andy Lutomirski , Ingo Molnar Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, Thomas Gleixner , Nadav Amit , Dave Hansen , linux_dti@icloud.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, akpm@linux-foundation.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, will.deacon@arm.com, ard.biesheuvel@linaro.org, kristen@linux.intel.com, deneen.t.dock@intel.com, Rick Edgecombe , Nadav Amit , Kees Cook , Dave Hansen , Masami Hiramatsu Subject: [PATCH v6 13/24] x86/jump-label: Remove support for custom poker Date: Fri, 26 Apr 2019 16:22:52 -0700 Message-Id: <20190426232303.28381-14-nadav.amit@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190426232303.28381-1-nadav.amit@gmail.com> References: <20190426232303.28381-1-nadav.amit@gmail.com> X-Virus-Scanned: ClamAV using ClamSMTP From: Nadav Amit There are only two types of poking: early and breakpoint based. The use of a function pointer to perform poking complicates the code and is probably inefficient due to the use of indirect branches. Cc: Andy Lutomirski Cc: Kees Cook Cc: Dave Hansen Cc: Masami Hiramatsu Acked-by: Peter Zijlstra (Intel) Signed-off-by: Nadav Amit Signed-off-by: Rick Edgecombe --- arch/x86/kernel/jump_label.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index e7d8c636b228..e631c358f7f4 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -37,7 +37,6 @@ static void bug_at(unsigned char *ip, int line) static void __ref __jump_label_transform(struct jump_entry *entry, enum jump_label_type type, - void *(*poker)(void *, const void *, size_t), int init) { union jump_code_union jmp; @@ -50,14 +49,6 @@ static void __ref __jump_label_transform(struct jump_entry *entry, jmp.offset = jump_entry_target(entry) - (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); - /* - * As long as only a single processor is running and the code is still - * not marked as RO, text_poke_early() can be used; Checking that - * system_state is SYSTEM_BOOTING guarantees it. - */ - if (system_state == SYSTEM_BOOTING) - poker = text_poke_early; - if (type == JUMP_LABEL_JMP) { if (init) { expect = default_nop; line = __LINE__; @@ -80,16 +71,19 @@ static void __ref __jump_label_transform(struct jump_entry *entry, bug_at((void *)jump_entry_code(entry), line); /* - * Make text_poke_bp() a default fallback poker. + * As long as only a single processor is running and the code is still + * not marked as RO, text_poke_early() can be used; Checking that + * system_state is SYSTEM_BOOTING guarantees it. It will be set to + * SYSTEM_SCHEDULING before other cores are awaken and before the + * code is write-protected. * * At the time the change is being done, just ignore whether we * are doing nop -> jump or jump -> nop transition, and assume * always nop being the 'currently valid' instruction - * */ - if (poker) { - (*poker)((void *)jump_entry_code(entry), code, - JUMP_LABEL_NOP_SIZE); + if (init || system_state == SYSTEM_BOOTING) { + text_poke_early((void *)jump_entry_code(entry), code, + JUMP_LABEL_NOP_SIZE); return; } @@ -101,7 +95,7 @@ void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { mutex_lock(&text_mutex); - __jump_label_transform(entry, type, NULL, 0); + __jump_label_transform(entry, type, 0); mutex_unlock(&text_mutex); } @@ -131,5 +125,5 @@ __init_or_module void arch_jump_label_transform_static(struct jump_entry *entry, jlstate = JL_STATE_NO_UPDATE; } if (jlstate == JL_STATE_UPDATE) - __jump_label_transform(entry, type, text_poke_early, 1); + __jump_label_transform(entry, type, 1); }