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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6794DC433EF for ; Fri, 27 May 2022 11:28:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CD69B8D0003; Fri, 27 May 2022 07:28:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C898C8D0002; Fri, 27 May 2022 07:28:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B76578D0003; Fri, 27 May 2022 07:28:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id A6E9D8D0002 for ; Fri, 27 May 2022 07:28:00 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6611A143D for ; Fri, 27 May 2022 11:28:00 +0000 (UTC) X-FDA: 79511298720.19.E43B360 Received: from mailgw02.mediatek.com (mailgw02.mediatek.com [216.200.240.185]) by imf11.hostedemail.com (Postfix) with ESMTP id 0C0EE40047 for ; Fri, 27 May 2022 11:27:51 +0000 (UTC) X-UUID: 5449f12bf3e843ffaae095bc24d6b8d6-20220527 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:d4f725f5-52a0-42d0-ae9b-71b94f82c945,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-META: VersionHash:2a19b09,CLOUDID:c851bc47-4fb1-496b-8f1d-39e733fed1ea,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil ,QS:0,BEC:nil X-UUID: 5449f12bf3e843ffaae095bc24d6b8d6-20220527 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1544856304; Fri, 27 May 2022 04:27:45 -0700 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 27 May 2022 04:17:43 -0700 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by mtkmbs11n2.mediatek.inc (172.21.101.187) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Fri, 27 May 2022 19:17:42 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Fri, 27 May 2022 19:17:42 +0800 Message-ID: <3b1542b95a3d322b798bf212b22c6c3567a76c13.camel@mediatek.com> Subject: Re: [PATCH] mm: kmemleak: Skip check in kmemleak_*_phys when pfn bound is not ready From: Yee Lee To: patrick wang CC: , , , , , Catalin Marinas , Andrew Morton , Matthias Brugger , "open list:MEMORY MANAGEMENT" , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" Date: Fri, 27 May 2022 19:17:42 +0800 In-Reply-To: References: <20220527032504.30341-1-yee.lee@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N X-Rspamd-Queue-Id: 0C0EE40047 X-Stat-Signature: mxkpbobjehqzh5e63jm7ho3fstrjhfye Authentication-Results: imf11.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=mediatek.com; spf=pass (imf11.hostedemail.com: domain of yee.lee@mediatek.com designates 216.200.240.185 as permitted sender) smtp.mailfrom=yee.lee@mediatek.com X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1653650871-162657 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000168, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 2022-05-27 at 18:20 +0800, patrick wang wrote: > On Fri, May 27, 2022 at 11:25 AM wrote: > > > > From: Yee Lee > > > > In some archs (arm64), memblock allocates memory in boot time when > > the pfn boundary (max_pfn/min_pfn) is not ready. The lowmen checks > > in > > kmemleak_*_phys() drop those blocks and cause some false leak > > alarms > > on common kernel objects. > > If I understand correctly, if those blocks are dropped, they will > not be added as kmemleak objects. So how could this affect > other objects? > > Thanks, > Patrick Yes, in fact, memblock needs those areas never reported as leaks and add them as grey blocks. More detailed comments can be found inside memblock_alloc_range_nid. > > > > > Kmemleak output: (Qemu/arm64) > > unreferenced object 0xffff0000c0170a00 (size 128): > > comm "swapper/0", pid 1, jiffies 4294892404 (age 126.208s) > > hex dump (first 32 bytes): > > 62 61 73 65 00 00 00 00 00 00 00 00 00 00 00 > > 00 base............ > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > 00 ................ > > backtrace: > > [<(____ptrval____)>] __kmalloc_track_caller+0x1b0/0x2e4 > > [<(____ptrval____)>] kstrdup_const+0x8c/0xc4 > > [<(____ptrval____)>] kvasprintf_const+0xbc/0xec > > [<(____ptrval____)>] kobject_set_name_vargs+0x58/0xe4 > > [<(____ptrval____)>] kobject_add+0x84/0x100 > > [<(____ptrval____)>] __of_attach_node_sysfs+0x78/0xec > > [<(____ptrval____)>] of_core_init+0x68/0x104 > > [<(____ptrval____)>] driver_init+0x28/0x48 > > [<(____ptrval____)>] do_basic_setup+0x14/0x28 > > [<(____ptrval____)>] kernel_init_freeable+0x110/0x178 > > [<(____ptrval____)>] kernel_init+0x20/0x1a0 > > [<(____ptrval____)>] ret_from_fork+0x10/0x20 > > > > This patch relaxs the boundary checking in kmemleak_*_phys api > > if max_low_pfn is uninitialzed. > > > > Fixes: 23c2d4 (mm: kmemleak: take a full lowmem check in > > kmemleak_*_phy) > > Signed-off-by: Yee Lee > > --- > > mm/kmemleak.c | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/mm/kmemleak.c b/mm/kmemleak.c > > index a182f5ddaf68..6b2af544aa0f 100644 > > --- a/mm/kmemleak.c > > +++ b/mm/kmemleak.c > > @@ -1132,7 +1132,7 @@ EXPORT_SYMBOL(kmemleak_no_scan); > > void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int > > min_count, > > gfp_t gfp) > > { > > - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < > > max_low_pfn) > > + if (!max_low_pfn || (PHYS_PFN(phys) >= min_low_pfn && > > PHYS_PFN(phys) < max_low_pfn)) > > kmemleak_alloc(__va(phys), size, min_count, gfp); > > } > > EXPORT_SYMBOL(kmemleak_alloc_phys); > > @@ -1146,7 +1146,7 @@ EXPORT_SYMBOL(kmemleak_alloc_phys); > > */ > > void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size) > > { > > - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < > > max_low_pfn) > > + if (!max_low_pfn || (PHYS_PFN(phys) >= min_low_pfn && > > PHYS_PFN(phys) < max_low_pfn)) > > kmemleak_free_part(__va(phys), size); > > } > > EXPORT_SYMBOL(kmemleak_free_part_phys); > > @@ -1158,7 +1158,7 @@ EXPORT_SYMBOL(kmemleak_free_part_phys); > > */ > > void __ref kmemleak_not_leak_phys(phys_addr_t phys) > > { > > - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < > > max_low_pfn) > > + if (!max_low_pfn || (PHYS_PFN(phys) >= min_low_pfn && > > PHYS_PFN(phys) < max_low_pfn)) > > kmemleak_not_leak(__va(phys)); > > } > > EXPORT_SYMBOL(kmemleak_not_leak_phys); > > @@ -1170,7 +1170,7 @@ EXPORT_SYMBOL(kmemleak_not_leak_phys); > > */ > > void __ref kmemleak_ignore_phys(phys_addr_t phys) > > { > > - if (PHYS_PFN(phys) >= min_low_pfn && PHYS_PFN(phys) < > > max_low_pfn) > > + if (!max_low_pfn || (PHYS_PFN(phys) >= min_low_pfn && > > PHYS_PFN(phys) < max_low_pfn)) > > kmemleak_ignore(__va(phys)); > > } > > EXPORT_SYMBOL(kmemleak_ignore_phys); > > -- > > 2.18.0 > >