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=-20.6 required=3.0 tests=BAYES_00,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 BFD81C433DF for ; Tue, 11 Aug 2020 05:39:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C70220678 for ; Tue, 11 Aug 2020 05:39:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tHAO4iJN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728336AbgHKFju (ORCPT ); Tue, 11 Aug 2020 01:39:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728293AbgHKFjr (ORCPT ); Tue, 11 Aug 2020 01:39:47 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09354C061756 for ; Mon, 10 Aug 2020 22:39:47 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id o8so15433183ybg.16 for ; Mon, 10 Aug 2020 22:39:47 -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=z+/W2Lb1k0h/CCYiwDe5JijUnwa2JcEcWzU8gpWcUfw=; b=tHAO4iJNAEzJVYvZQdBfl/Z0HJY38AuKODLE4Ch1wZBc8FPg/7KBHMPJyf8/uTGa2e E6klPsx4jU07UlBRuauki8fP8QiBAPYycbCl1RDqcjzChLjeDP4E2k1e1NnpULdZnzv1 Pl8iQesn3UiLyjEZOnShWyZkTZA+n4xtyP8tzlxbdeudDI8XTUsWsGqywXNK1eIeCWBz 3qjrz1HaOS6k9W/9yXae8zdCnwm1yQpe5q7lFbbL0i94z9RVr+3vhvKoInjL+Nblfb0t cJpkzK5h/Tri0RocDIDd2pIR/eUsEGMktj67qOjOYUxaBd3zxwrutEWKbzr0abxxWFdS +mbQ== 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=z+/W2Lb1k0h/CCYiwDe5JijUnwa2JcEcWzU8gpWcUfw=; b=rJA7hcAZFEMcSIX9nxD0Rc+jx1cFTG8rK2UFTrpV28XIR4dD114Coqz07BD9SrA3bw B24YZ0aSvEV3fcR2xW448gX520ldzvT7oaTp3tpQBnI0ynhsNwZYBwBZ9fQgXNqX4Ra/ xaFfRjSYfAYZfXmlY361r6ID0XgGgfuIKLVvSOg7r/7AN0DoBNOc7r3LdvEJkUvZX8L7 pOI7oPpuHZwu/FSzE9iHFFTkoEHwwow8wM2eLo80E7/ADmSfBe1m302DfOBXJWHM32X5 4yQY9ZmXP6y5HBILfCEDThHXy1eN7H+GD+mVEQaevjbX6jTh11klV+ITUb/GhUik6Q/n bwYQ== X-Gm-Message-State: AOAM530IsD2WDnbDiIStDfvcqgPPJQfgoS+UVK0bRKEn57vtSjmQkcdt quz+sVmWQIle4JjdY1fVmxFkoFQMoUqOgQ== X-Google-Smtp-Source: ABdhPJx02k8uMoR6T3Ar7ZJVf6WCI2ZKosVhH/to+X0ddTMzwXgqLTS/eGRWzl6vu4PuJiIyGRtJ9xX8Em6y5A== X-Received: by 2002:a5b:308:: with SMTP id j8mr41696962ybp.185.1597124386219; Mon, 10 Aug 2020 22:39:46 -0700 (PDT) Date: Mon, 10 Aug 2020 22:39:15 -0700 In-Reply-To: <20200811053914.652710-1-davidgow@google.com> Message-Id: <20200811053914.652710-7-davidgow@google.com> Mime-Version: 1.0 References: <20200811053914.652710-1-davidgow@google.com> X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog Subject: [PATCH v12 6/6] 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, akpm@linux-foundation.org Cc: David Gow , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, linux-mm@kvack.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 Reviewed-by: Brendan Higgins Tested-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 e2c14b10bc81..00a53f1355ae 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -95,7 +95,7 @@ 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 -- 2.28.0.236.gb10cc79966-goog