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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 B975EC48BE5 for ; Wed, 16 Jun 2021 16:25:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9DCAF61351 for ; Wed, 16 Jun 2021 16:25:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235317AbhFPQ2B (ORCPT ); Wed, 16 Jun 2021 12:28:01 -0400 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]:17894 "EHLO alexa-out-sd-02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231511AbhFPQ2A (ORCPT ); Wed, 16 Jun 2021 12:28:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1623860754; x=1655396754; h=from:to:cc:subject:date:message-id:mime-version; bh=3+Q6ffjeuIyWeUXeB/hUGVYYFCK/LW+an/k3cvbcW7E=; b=QL/gleAjgIxEdlX1FMqHlL6PmsHGkAF/i6+vZABShDEXDOhh/ymi3fw8 7ELpsM2GJ/BhEhzSpzAb97EifRzRqu5ZgPa4FuoFcxvlpKHH47SGSGEWx uGJooBOLv/kIV2ZsLZNF50awDm/1fZlhfoAgC04mVgH+EaCHg/btXvtB5 M=; Received: from unknown (HELO ironmsg01-sd.qualcomm.com) ([10.53.140.141]) by alexa-out-sd-02.qualcomm.com with ESMTP; 16 Jun 2021 09:25:54 -0700 X-QCInternal: smtphost Received: from nasanexm03e.na.qualcomm.com ([10.85.0.48]) by ironmsg01-sd.qualcomm.com with ESMTP/TLS/AES256-SHA; 16 Jun 2021 09:25:53 -0700 Received: from th-lint-040.qualcomm.com (10.80.80.8) by nasanexm03e.na.qualcomm.com (10.85.0.48) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Wed, 16 Jun 2021 09:25:51 -0700 From: Georgi Djakov To: , , , , , CC: , , Subject: [PATCH] mm/slub: Add taint after the errors are printed Date: Wed, 16 Jun 2021 09:25:38 -0700 Message-ID: <1623860738-146761-1-git-send-email-quic_c_gdjako@quicinc.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanexm03e.na.qualcomm.com (10.85.0.48) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When running the kernel with panic_on_taint, the usual slub debug error messages are not being printed when object corruption happens. That's because we panic in add_taint(), which is called before printing the additional information. This is a bit unfortunate as the error messages are actually very useful, especially before a panic. Let's fix this by moving add_taint() after the errors are printed on the console. Signed-off-by: Georgi Djakov --- mm/slub.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index a8b0daa1a307..ce7b8e4551b5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -719,8 +719,6 @@ static void slab_bug(struct kmem_cache *s, char *fmt, ...) pr_err("=============================================================================\n"); pr_err("BUG %s (%s): %pV\n", s->name, print_tainted(), &vaf); pr_err("-----------------------------------------------------------------------------\n\n"); - - add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); va_end(args); } @@ -801,6 +799,7 @@ void object_err(struct kmem_cache *s, struct page *page, slab_bug(s, "%s", reason); print_trailer(s, page, object); + add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); } static __printf(3, 4) void slab_err(struct kmem_cache *s, struct page *page, @@ -818,6 +817,7 @@ static __printf(3, 4) void slab_err(struct kmem_cache *s, struct page *page, slab_bug(s, "%s", buf); print_page_info(page); dump_stack(); + add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); } static void init_object(struct kmem_cache *s, void *object, u8 val) @@ -869,6 +869,7 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page, fault, end - 1, fault - addr, fault[0], value); print_trailer(s, page, object); + add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); skip_bug_print: restore_bytes(s, what, value, fault, end);