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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 2B34EC433DF for ; Sat, 6 Jun 2020 04:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 042FC20723 for ; Sat, 6 Jun 2020 04:04:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="YHJ+OxXk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728527AbgFFEEQ (ORCPT ); Sat, 6 Jun 2020 00:04:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726976AbgFFEEG (ORCPT ); Sat, 6 Jun 2020 00:04:06 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D58B8C08C5C3 for ; Fri, 5 Jun 2020 21:04:04 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id s90so14280134ybi.6 for ; Fri, 05 Jun 2020 21:04:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Bno6lpmXJK51n5a5Nx8tNY64fz3MIJ1lkOtErirSr6A=; b=YHJ+OxXkKPDeM+7ELMewnwd+Ffd3T7tSXxbbkvE9Wj7weFnG3Q8LKA8LUT6tXC6f/p sIbOnONsYBskP1Y3SPq2vQzpvPJEUP7+B1ZmGjvQSssiGqqjj5HDdRcFvZ2ybIK9yWf/ j6j+GMKsYKIw3LH4dk2PCMfZxUdt8GXgai1P/MTj0v2UoF/gav8ycpZBleH2wMzxIfyc Y0V54/Ag7MMP61uxDwq4z3o6dkh9u5457FPbAcgHRve6KHb0x3bDwJjxvxYNIyQxV+wK fCUxURx9kmWQWcwPOAjcLTShq1EL1uQoIYCXlGem4xyMNw85p0u6XL/OzfNBBbBQsg0c I2dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Bno6lpmXJK51n5a5Nx8tNY64fz3MIJ1lkOtErirSr6A=; b=fXDTsxcDlV+gcw2QDszbzEaqQviMuRYwOj2UEFRrmRdfbD89N0cUPkE4og2V9PWAZu UbQEizMExv/DTEjK9u+S0gAYGUj4mGnZ6QwwVsUweSFHQ8/wEjCLfMuLfPXwB3Bjc/jO IqTkvtbF2BN/oWqPSWL2WceQiqA5+52UBz34wVn9A8X50sr4twqOSheeobGVRbMfjATA o0yIMVunjtQIQO4+Rcb06aklZCziaZ31+O7lhfLKgOrZLQcE+Uxn0cXe2rUDyjZiJtym M5xo8UneoTSYLCOJgzBMbabiBDRA1JyLng2nD93U5FDz2cZilkXtM7UGhpENgMnmscOw gWGg== X-Gm-Message-State: AOAM531nB29EHYcWiIsDkGjHVVUA6Yyzt/03BR/iSCV/cPiS9Wxi2pdA VQN4oCHntQYCFBTrXL4wbYF2La4bgZMwAg== X-Google-Smtp-Source: ABdhPJxlU491uKsxwRao6XvYxlOdKzykd3Y4Y+nbo1iQnitptU5xhr1Ml21x6KURK0uGhshDvIETBl7GDDZr/A== X-Received: by 2002:a5b:785:: with SMTP id b5mr20722587ybq.96.1591416244078; Fri, 05 Jun 2020 21:04:04 -0700 (PDT) Date: Fri, 5 Jun 2020 21:03:49 -0700 In-Reply-To: <20200606040349.246780-1-davidgow@google.com> Message-Id: <20200606040349.246780-6-davidgow@google.com> Mime-Version: 1.0 References: <20200606040349.246780-1-davidgow@google.com> X-Mailer: git-send-email 2.27.0.278.ge193c7cf3a9-goog Subject: [PATCH v8 5/5] mm: kasan: Do not panic if both panic_on_warn and kasan_multishot set From: David Gow To: trishalfonso@google.com, brendanhiggins@google.com, aryabinin@virtuozzo.com, dvyukov@google.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, andreyknvl@google.com, shuah@kernel.org Cc: David Gow , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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). Signed-off-by: David Gow Reviewed-by: Andrey Konovalov --- mm/kasan/report.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 45f3c23f54cb..dc9fc5c09ea3 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -94,7 +94,7 @@ static void end_report(unsigned long *flags) 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 -- 2.27.0.278.ge193c7cf3a9-goog