From patchwork Wed Sep 25 14:08:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miles Chen X-Patchwork-Id: 11160765 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 B6ABF14E5 for ; Wed, 25 Sep 2019 14:08:25 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9355521D80 for ; Wed, 25 Sep 2019 14:08:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="cKx/xD6j" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9355521D80 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Hkw1HXqvMDLkn+7q69Y8GUmhHnuJy65G7o/ZWBeRtOQ=; b=cKx/xD6jQ3wxxn S6hHMfltt16UbzrWTft1vTdzCQCPuPm+l9qCUWzXj7uGbTjYNm1eTc7IgWJvQOa7xaARWwY79fEKR ifD1TXLWNcqTqh+VUTb8orMqpwlx6GfEWaz/k7k3Mtt5K2Ux1cBcOGYdI9sC2YAgtCLunIYkH4Uza xYOrY/wwZgFIuab6ry2qvp314oKPlxqdpUcecAH+aQoyw0Kunpt7svd8HO0BlttXdxatTkLMX3PCm OzhgEs1lbQgRzCZLhR7ZddKpC1ferYiCBMkTncLhyEhlS9KI85ZCglEuAsxbQHORjO4lZscxr9U+m lxj7drljEOZ5L6nyUbcg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iD7xt-0006Rq-CM; Wed, 25 Sep 2019 14:08:21 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iD7xp-0006N6-GG for linux-mediatek@lists.infradead.org; Wed, 25 Sep 2019 14:08:19 +0000 X-UUID: 02ff240604e24be0b8ff84492d2f2845-20190925 X-UUID: 02ff240604e24be0b8ff84492d2f2845-20190925 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 864056621; Wed, 25 Sep 2019 06:08:10 -0800 Received: from mtkmbs07n1.mediatek.inc (172.21.101.16) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 25 Sep 2019 07:08:09 -0700 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 25 Sep 2019 22:08:08 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 25 Sep 2019 22:08:08 +0800 From: Miles Chen To: Christoph Lameter , Pekka Enberg , "David Rientjes" , Joonsoo Kim , "Andrew Morton" Subject: [PATCH v2] mm: slub: print the offset of fault addresses Date: Wed, 25 Sep 2019 22:08:07 +0800 Message-ID: <20190925140807.20490-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190925_070817_549743_01C04132 X-CRM114-Status: GOOD ( 10.47 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-mm@kvack.org, Miles Chen , linux-mediatek@lists.infradead.org Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org With the commit ad67b74d2469d9b8 ("printk: hash addresses printed with %p"), it is a little bit harder to match the fault addresses printed by check_bytes_and_report() or slab_pad_check() in the dump because the fault addresses may not show up in the dump. Print the offset of the fault addresses to make it easier to match the incorrect poison or padding values in the dump. Before: We have to search the "63" in the dump. If we want to get the offset of 63, we have to count it from the start of Object dump. ============================================================= BUG kmalloc-128 (Not tainted): Poison overwritten ------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: 0x00000000570da294-0x00000000570da294. First byte 0x63 instead of 0x6b ... INFO: Object 0x000000006ebb3b9e @offset=14208 fp=0x0000000065862488 Redzone 00000000a6abccff: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 00000000741c16f0: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 0000000061ad278f: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 000000000467c1bd: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 000000008812766b: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 000000003d9b8f25: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 0000000000d80c33: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 00000000867b0d90: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Object 000000006ebb3b9e: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000005ea59a9f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000003ef8bddc: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000008190375d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000006df7fb32: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 0000000069474eae: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 0000000008073b7d: 6b 6b 6b 6b 63 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 00000000b45ae74d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 After: We know the fault address is at @offset=1508, and the Object is at @offset=1408, so we know the fault address is at offset=100 within the object. ========================================================= BUG kmalloc-128 (Not tainted): Poison overwritten --------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: 0x00000000638ec1d1-0x00000000638ec1d1 @offset=1508. First byte 0x63 instead of 0x6b ... INFO: Object 0x000000008171818d @offset=1408 fp=0x0000000066dae230 Redzone 00000000e2697ab6: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 0000000064b6a381: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 00000000e413a234: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 0000000004c1dfeb: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 000000009ad24d42: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 000000002a196a23: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 00000000a7b8468a: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Redzone 0000000088db6da3: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb Object 000000008171818d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000007c4035d4: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000004dd281a4: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 0000000079121dff: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 00000000756682a9: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 0000000053b7e541: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 0000000091f8d530: 6b 6b 6b 6b 63 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Object 000000009c76035c: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 Change since v1: 1. do not replace DUMP_PREFIX_ADDRESS with DUMP_PREFIX_OFFSET because the hash addresses are useful 2. print the offset of the fault address Cc: Christoph Lameter Cc: Matthew Wilcox Cc: David Rientjes Signed-off-by: Miles Chen --- mm/slub.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 42c1b3af3c98..21d26cd3e3bc 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -736,6 +736,7 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page, { u8 *fault; u8 *end; + u8 *addr = page_address(page); metadata_access_enable(); fault = memchr_inv(start, value, bytes); @@ -748,8 +749,9 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page, end--; slab_bug(s, "%s overwritten", what); - pr_err("INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", - fault, end - 1, fault[0], value); + pr_err("INFO: 0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n", + fault, end - 1, fault - addr, + fault[0], value); print_trailer(s, page, object); restore_bytes(s, what, value, fault, end); @@ -844,7 +846,8 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page) while (end > fault && end[-1] == POISON_INUSE) end--; - slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); + slab_err(s, page, "Padding overwritten. 0x%p-0x%p @offset=%tu", + fault, end - 1, fault - start); print_section(KERN_ERR, "Padding ", pad, remainder); restore_bytes(s, "slab padding", POISON_INUSE, fault, end);