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=ham 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 9A71BC2BA1A for ; Fri, 24 Apr 2020 06:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72EE720700 for ; Fri, 24 Apr 2020 06:14:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ChzEHTsG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726602AbgDXGOL (ORCPT ); Fri, 24 Apr 2020 02:14:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726565AbgDXGOI (ORCPT ); Fri, 24 Apr 2020 02:14:08 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7278C09B045 for ; Thu, 23 Apr 2020 23:14:07 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id a6so7879651pfg.18 for ; Thu, 23 Apr 2020 23:14:07 -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=Ktlf9QISDdPRX1uK01ka9sL/IDfKnusqL4DRjBWXu7E=; b=ChzEHTsGqPRuCDwBSqzePHzbU3gd0vJ/obMVlNCqmZP6Bx9+LTIISm27bGINFK3ST6 U6egrTXZiDrcvjehCTkYlvCU6d9nsry4pNfwODvaALAVcnhYTx5axmEwIuK/GPq9Cfz8 UGfCyjVxVimTBu17eikwQb58W7KS5lsJoXPexDu9e8s4Peg0P3t/ZQHkcwab7oi7yoTM GLC50li+VxxNldpiZ2gmUfvc0iPOMQFq5Mp4IFhOcF+8qx+5jUNTDO2ek2PqzLQnG6bg 7HreaMnVbHJmtsy4iqk8Nnut8zz6Smp6nnpdPPhjNz3hvUT561nE2fr4u5OMGoXJ/3kc XalA== 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=Ktlf9QISDdPRX1uK01ka9sL/IDfKnusqL4DRjBWXu7E=; b=rUsiLTT2iN0l+S4aYFB1Kn4XOjh4ty3ZyODR3mHrFDOtHIPb65nFec0+XNIRN0Xukf XzaGytBm2rtQJkngqKHSIPKvPouPJ+iujFv9QnCgtdn+vMowxtvaPTHWk6VAu9bhVIwH jU6B8cB6N8eCPbIlxXY4CXIMQBnIeZRpvFlZC12/1pezsVAoae5ZRbqqcDB6o8i+vntB F9Xc86PnP6ncHT/5nPCoyUPqmSpbZZo18xf0/Hya57BX3ERI5rbUvzKfeZPzs6VICngT 38hp22mLD+x9H0tW0MbgtZpJbtn+bMek7fD1TXA/igZnMxYdzvYQiynYylSNFC36u48e kHuQ== X-Gm-Message-State: AGi0PuYVoA/rzxRZaiN2ALrR6b1W810hFHxE39lbS98U17m3k6y1T1L+ Jr4SmXbsD7xxar8G8CjqvChV+tHEk/dz/Q== X-Google-Smtp-Source: APiQypKOtuNJXwpmMrdTnwPQuAL+4H1Nq1T3AV8w+3m+0jNCAItOLBXkSV8iB3V7g9qIPYAGCP41cMK+FN/X1w== X-Received: by 2002:a17:90a:ba88:: with SMTP id t8mr4757997pjr.182.1587708847422; Thu, 23 Apr 2020 23:14:07 -0700 (PDT) Date: Thu, 23 Apr 2020 23:13:42 -0700 In-Reply-To: <20200424061342.212535-1-davidgow@google.com> Message-Id: <20200424061342.212535-6-davidgow@google.com> Mime-Version: 1.0 References: <20200424061342.212535-1-davidgow@google.com> X-Mailer: git-send-email 2.26.2.303.gf8c07b1a785-goog Subject: [PATCH v7 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 Cc: David Gow , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org, Andrey Konovalov 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 -- 2.26.2.303.gf8c07b1a785-goog