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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 DE34BC433DF for ; Tue, 13 Oct 2020 23:55:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6E16B206D5 for ; Tue, 13 Oct 2020 23:55:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="v1Urg4Fm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E16B206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 066206B011C; Tue, 13 Oct 2020 19:55:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00A6D6B011D; Tue, 13 Oct 2020 19:55:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E8AD06B011E; Tue, 13 Oct 2020 19:55:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0137.hostedemail.com [216.40.44.137]) by kanga.kvack.org (Postfix) with ESMTP id B9AFF6B011C for ; Tue, 13 Oct 2020 19:55:16 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 644203625 for ; Tue, 13 Oct 2020 23:55:16 +0000 (UTC) X-FDA: 77368561032.25.goose60_4d0195a27207 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 36C951804E3A1 for ; Tue, 13 Oct 2020 23:55:16 +0000 (UTC) X-HE-Tag: goose60_4d0195a27207 X-Filterd-Recvd-Size: 3789 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 23:55:15 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 62F3E22227; Tue, 13 Oct 2020 23:55:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633315; bh=Hxmhxt1/97UskelHGmuFxRg221/RYeRUneOk15xwgK4=; h=Date:From:To:Subject:In-Reply-To:From; b=v1Urg4Fm9RHekEk3DfHoBk1JHgNb3r9TkginRl3NRWmQjcjVIrJeZmhs0xHrvgl1u 4kVqIC3eQk1JYU8baI0s+qbKW6Y2zk8OUoQYBwQj0iInBffQCKhn53NdAiTVctVRVX wYy8y5Pc0nsML1c2kVJ5m/UYKH0ui0QEPXOUDaSk= Date: Tue, 13 Oct 2020 16:55:13 -0700 From: Andrew Morton To: a.p.zijlstra@chello.nl, akpm@linux-foundation.org, andreyknvl@google.com, aryabinin@virtuozzo.com, brendanhiggins@google.com, davidgow@google.com, dvyukov@google.com, juri.lelli@redhat.com, linux-mm@kvack.org, mingo@redhat.com, mm-commits@vger.kernel.org, shuah@kernel.org, torvalds@linux-foundation.org, trishalfonso@google.com, vincent.guittot@linaro.org Subject: [patch 124/181] mm: kasan: do not panic if both panic_on_warn and kasan_multishot set Message-ID: <20201013235513.LlOSLYl1P%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: David Gow Subject: mm: kasan: do not panic if both panic_on_warn and kasan_multishot set KASAN errors will currently trigger a panic when panic_on_warn is set. This renders kasan_multishot useless, as further KASAN errors won't be reported if the kernel has already paniced. By making kasan_multishot disable this behaviour for KASAN errors, we can still have the benefits of panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot. This is particularly important when running KASAN tests, which need to trigger multiple KASAN errors: previously these would panic the system if panic_on_warn was set, now they can run (and will panic the system should non-KASAN warnings show up). Link: https://lkml.kernel.org/r/20200915035828.570483-6-davidgow@google.com Link: https://lkml.kernel.org/r/20200910070331.3358048-6-davidgow@google.com Signed-off-by: David Gow Reviewed-by: Andrey Konovalov Reviewed-by: Brendan Higgins Tested-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Juri Lelli Cc: Patricia Alfonso Cc: Peter Zijlstra Cc: Shuah Khan Cc: Vincent Guittot Signed-off-by: Andrew Morton --- mm/kasan/report.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/kasan/report.c~mm-kasan-do-not-panic-if-both-panic_on_warn-and-kasan_multishot-set +++ a/mm/kasan/report.c @@ -95,7 +95,7 @@ static void end_report(unsigned long *fl pr_err("==================================================================\n"); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irqrestore(&report_lock, *flags); - if (panic_on_warn) { + if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) { /* * This thread may hit another WARN() in the panic path. * Resetting this prevents additional WARN() from panicking the _