From patchwork Sat Apr 18 03:18:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 11496267 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2AE701871 for ; Sat, 18 Apr 2020 03:19:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1364A21D94 for ; Sat, 18 Apr 2020 03:19:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tsvxfJmT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726105AbgDRDTA (ORCPT ); Fri, 17 Apr 2020 23:19:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726099AbgDRDS7 (ORCPT ); Fri, 17 Apr 2020 23:18:59 -0400 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38C00C061A0F for ; Fri, 17 Apr 2020 20:18:59 -0700 (PDT) Received: by mail-pl1-x64a.google.com with SMTP id w16so3514924plq.1 for ; Fri, 17 Apr 2020 20:18:59 -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=3docRvuzttJC+Wkb9Bk065FrkPZtq4zMQ8pW4rPpfW0=; b=tsvxfJmTMqQagdYMcGxWaiaBVUv/Xj9MJWLW8Dkj2Rh+QyEZNG2meafwJo1YjCR9XR 5kx/fQJl2afogVcJn5Fxz2Yyqo1pSLded1b4yj6BSbRR1X95xnMUj3NqcfpA+oTcmuck tSepuqs2CyUuCHzyjGJkqpQsPa9q+FIQrEEcEiqjfrxZw0D2zASxS1frtHURyy5tmApZ jhOTxK+GmZ1vc4ixnC/CjwFtdbHrQZQu2edc8kcXC+9dYUYgxU7QpnWG5zWylmT1HWaz I43ZoSfAC+4PqweU7MfKrkmONOwe8xum+hRW/iXwKhmNMNScqfk044TyaoabJvSyyda5 Qf7Q== 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=3docRvuzttJC+Wkb9Bk065FrkPZtq4zMQ8pW4rPpfW0=; b=Z+j1hJ304JHQyXnteWBHYLMbqgRMXU7nPtC3E2u1nSsoAQEA0uivbvykJI+PJ/Am+m 2tljQ8FyngS5+AzfZnpgE3MpQvYUregePuDhXTu2TpDPb0o6Jx2yN+WuBLq/xA6tYDub xppKA+LnWrNYVyEkY+cShpTEQhZieO661NCoOWgaLAqRmGZ/9CwRmofN7bgZ4WMrzcf5 onfZKcAMjNA1xstEqKmYZ6pVcwX4Z3LYSjWAGy2G4ZkouO13KVEcHQYTanOLY4e6TxRa 1Z8NWNxrUNFA4xpdg/XZasPaSp1hWM6MH5NA3avt5jL4DDTCvPjlrO8Y4HzVbuZLiJrL +64w== X-Gm-Message-State: AGi0PuZCPQGLwmY038CFZ29IAHuekYPB4lpF7N1wxNmg7JeoEOIUN5m0 MShw4cNvqYYAUjn/LQv/zfMcNe4ZrvKGqA== X-Google-Smtp-Source: APiQypJ0AKcRxyISi/BREL+Gq9cGtfXhBaacb3y/m8Wu+YUwFvaWrTgT/CZZ/6bzqf8Z0LckGONfr57QZCTIUw== X-Received: by 2002:a63:f64d:: with SMTP id u13mr6075605pgj.151.1587179938644; Fri, 17 Apr 2020 20:18:58 -0700 (PDT) Date: Fri, 17 Apr 2020 20:18:33 -0700 In-Reply-To: <20200418031833.234942-1-davidgow@google.com> Message-Id: <20200418031833.234942-6-davidgow@google.com> Mime-Version: 1.0 References: <20200418031833.234942-1-davidgow@google.com> X-Mailer: git-send-email 2.26.1.301.g55bc3eb7cb9-goog Subject: [PATCH v6 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 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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 0c206bbf9cb3..79fe23bd4f60 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