From patchwork Thu May 28 05:20:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11574671 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 46739913 for ; Thu, 28 May 2020 05:20:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1358621475 for ; Thu, 28 May 2020 05:20:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="bzvub9Au" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1358621475 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 533C7800B6; Thu, 28 May 2020 01:20:43 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 4BE3A80010; Thu, 28 May 2020 01:20:43 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 38643800B6; Thu, 28 May 2020 01:20:43 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0128.hostedemail.com [216.40.44.128]) by kanga.kvack.org (Postfix) with ESMTP id 2172B80010 for ; Thu, 28 May 2020 01:20:43 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D311F824556B for ; Thu, 28 May 2020 05:20:42 +0000 (UTC) X-FDA: 76864977924.26.cave95_23450d155570a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id B150C1804B647 for ; Thu, 28 May 2020 05:20:42 +0000 (UTC) X-Spam-Summary: 2,0,0,b4e726d535490438,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:966:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1542:1711:1730:1747:1777:1792:2196:2198:2199:2200:2393:2525:2559:2563:2682:2685:2693:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3866:3870:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:4385:5007:6119:6261:6653:7208:7558:7576:7903:8540:8599:8603:9025:9113:9545:10004:10913:11026:11658:11914:12043:12048:12297:12438:12517:12519:12555:12679:12740:12783:12895:12986:13846:14093:14181:14721:14849:21080:21451:21627:21939:30004:30054:30056,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none X-HE-Tag: cave95_23450d155570a X-Filterd-Recvd-Size: 4273 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Thu, 28 May 2020 05:20:42 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 49D4B206F1; Thu, 28 May 2020 05:20:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590643241; bh=2UAjUUYLxMivA2Au93dCVE1CTPvV3a5kfwE193chDr8=; h=Date:From:To:Subject:In-Reply-To:From; b=bzvub9AuPEG+cxNDfK9Eqg3yW9QlXx209kyROmfiNZwmLqJgxxvdhAfkMaJzaxr5g g0zhGlwjx9uhwJk9I9vnIlFzlewI+5NnAQgVKnamlm9ezCrK6KS9nlZLjzUspwuG5Y x2kmEDWO+csR22ZA+YhA19vkDZEJjo82QLyl1t1Y= Date: Wed, 27 May 2020 22:20:40 -0700 From: Andrew Morton To: akpm@linux-foundation.org, cai@lca.pw, catalin.marinas@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vitaly.wool@konsulko.com Subject: [patch 1/5] mm/z3fold: silence kmemleak false positives of slots Message-ID: <20200528052040.tET7TeyHc%akpm@linux-foundation.org> In-Reply-To: <20200527222015.62ba8592af63dae12ab58ffe@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: B150C1804B647 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Qian Cai Subject: mm/z3fold: silence kmemleak false positives of slots Kmemleak reported many leaks while under memory pressue in, slots = alloc_slots(pool, gfp); which is referenced by "zhdr" in init_z3fold_page(), zhdr->slots = slots; However, "zhdr" could be gone without freeing slots as the later will be freed separately when the last "handle" off of "handles" array is freed. It will be within "slots" which is always aligned. unreferenced object 0xc000000fdadc1040 (size 104): comm "oom04", pid 140476, jiffies 4295359280 (age 3454.970s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d1f0f5eb>] z3fold_zpool_malloc+0x7b0/0xe10 alloc_slots at mm/z3fold.c:214 (inlined by) init_z3fold_page at mm/z3fold.c:412 (inlined by) z3fold_alloc at mm/z3fold.c:1161 (inlined by) z3fold_zpool_malloc at mm/z3fold.c:1735 [<0000000064a2e969>] zpool_malloc+0x34/0x50 [<00000000af63e491>] zswap_frontswap_store+0x60c/0xda0 zswap_frontswap_store at mm/zswap.c:1093 [<00000000af5e07e0>] __frontswap_store+0x128/0x330 [<00000000de2f582b>] swap_writepage+0x58/0x110 [<000000000120885f>] pageout+0x16c/0xa40 [<00000000444c1f68>] shrink_page_list+0x1ac8/0x25c0 [<00000000d19e8610>] shrink_inactive_list+0x270/0x730 [<00000000e17df726>] shrink_lruvec+0x444/0xf30 [<000000005f02ab35>] shrink_node+0x2a4/0x9c0 [<00000000014cabbd>] do_try_to_free_pages+0x158/0x640 [<00000000dcfaba07>] try_to_free_pages+0x1bc/0x5f0 [<00000000fa207ab8>] __alloc_pages_slowpath.constprop.60+0x4dc/0x15a0 [<000000003669f1d2>] __alloc_pages_nodemask+0x520/0x650 [<0000000011fa4168>] alloc_pages_vma+0xc0/0x420 [<0000000098b376f2>] handle_mm_fault+0x1174/0x1bf0 Link: http://lkml.kernel.org/r/20200522220052.2225-1-cai@lca.pw Signed-off-by: Qian Cai Acked-by: Vitaly Wool Acked-by: Catalin Marinas Signed-off-by: Andrew Morton --- mm/z3fold.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/z3fold.c~mm-z3fold-silence-kmemleak-false-positives-of-slots +++ a/mm/z3fold.c @@ -43,6 +43,7 @@ #include #include #include +#include /* * NCHUNKS_ORDER determines the internal allocation granularity, effectively @@ -215,6 +216,8 @@ static inline struct z3fold_buddy_slots (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE))); if (slots) { + /* It will be freed separately in free_handle(). */ + kmemleak_not_leak(slots); memset(slots->slot, 0, sizeof(slots->slot)); slots->pool = (unsigned long)pool; rwlock_init(&slots->lock);