From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 6EE7DC282C8 for ; Mon, 28 Jan 2019 16:12:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38B192177E for ; Mon, 28 Jan 2019 16:12:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691924; bh=KZ51WbxuHMBDzOgtr0oM85ZM/uLWiX2hpYMI96fMqh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jaQcj1rg7Rd0GnZ/9rnLiuqytPBPzr8zPI/FPsq5S8s15Eo28O6QzV4TSexTNq2FD XIBanEDhwKoLDZdoVjW653MEAwooLV4xsn8sOAlBjgRT3AJiBLvfSr/bywoLUI0+4N d93uG692usmn7eZcnmwtSiwcK4Cc8C6S9TyLjgUs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733068AbfA1QMC (ORCPT ); Mon, 28 Jan 2019 11:12:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:39460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733054AbfA1QL4 (ORCPT ); Mon, 28 Jan 2019 11:11:56 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 959272147A; Mon, 28 Jan 2019 16:11:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691915; bh=KZ51WbxuHMBDzOgtr0oM85ZM/uLWiX2hpYMI96fMqh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bK4TvwSJXm9XA2vfv7vMatb5SIjipCoqhMca+w+uaKL5GjV8SLXdCn05y9CDSe/UR 3eM+Uh9uPBe3zuoKUBUjzlgrutd/eyMxbXX/MO1NGHBeTyhnC0Fsh2BJh3luvAl3ar R1F/silbCS+V0Eh9+lPwirkNmVYb4BCkAaDrMpnc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anders Roxell , Arnd Bergmann , Will Deacon , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.19 257/258] kernel/kcov.c: mark write_comp_data() as notrace Date: Mon, 28 Jan 2019 10:59:23 -0500 Message-Id: <20190128155924.51521-257-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128155924.51521-1-sashal@kernel.org> References: <20190128155924.51521-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anders Roxell [ Upstream commit 634724431607f6f46c495dfef801a1c8b44a96d9 ] Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the function called from __sanitizer_cov_trace_const_cmp4 shouldn't be traceable either. ftrace_graph_caller() gets called every time func write_comp_data() gets called if it isn't marked 'notrace'. This is the backtrace from gdb: #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116 #3 0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=, arg2=) at ../kernel/kcov.c:188 #4 0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27 #5 0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Rework so that write_comp_data() that are called from __sanitizer_cov_trace_*_cmp*() are marked as 'notrace'. Commit 903e8ff86753 ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace") missed to mark write_comp_data() as 'notrace'. When that patch was created gcc-7 was used. In lib/Kconfig.debug config KCOV_ENABLE_COMPARISONS depends on $(cc-option,-fsanitize-coverage=trace-cmp) That code path isn't hit with gcc-7. However, it were that with gcc-8. Link: http://lkml.kernel.org/r/20181206143011.23719-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell Signed-off-by: Arnd Bergmann Co-developed-by: Arnd Bergmann Acked-by: Steven Rostedt (VMware) Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- kernel/kcov.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kcov.c b/kernel/kcov.c index 97959d7b77e2..c2277dbdbfb1 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -112,7 +112,7 @@ void notrace __sanitizer_cov_trace_pc(void) EXPORT_SYMBOL(__sanitizer_cov_trace_pc); #ifdef CONFIG_KCOV_ENABLE_COMPARISONS -static void write_comp_data(u64 type, u64 arg1, u64 arg2, u64 ip) +static void notrace write_comp_data(u64 type, u64 arg1, u64 arg2, u64 ip) { struct task_struct *t; u64 *area; -- 2.19.1