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 6EDCDC433EF for ; Fri, 27 May 2022 10:20:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DB9178D0003; Fri, 27 May 2022 06:20:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D67308D0002; Fri, 27 May 2022 06:20:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C2C7D8D0003; Fri, 27 May 2022 06:20:27 -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 B01788D0002 for ; Fri, 27 May 2022 06:20:27 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 696F2359A6 for ; Fri, 27 May 2022 10:20:27 +0000 (UTC) X-FDA: 79511128494.12.A7DAFE3 Received: from mail-vk1-f172.google.com (mail-vk1-f172.google.com [209.85.221.172]) by imf21.hostedemail.com (Postfix) with ESMTP id 53C921C003D for ; Fri, 27 May 2022 10:20:14 +0000 (UTC) Received: by mail-vk1-f172.google.com with SMTP id bs5so1825870vkb.4 for ; Fri, 27 May 2022 03:20:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=TZKGv1sVPbn33wSFQC2Hq1TTGl51W+KoM8tu8whSa+8=; b=QPJBbxLga9z4bh76vDTCdWiIm0fFqSq0xsZaD4/EcFAsk7UUqTJMVgbymVey6Y8rhP PboTeGA3VQ2Xk04Jjgj56gdD/R76WekWIn10md8C9xSA6SyQDTYEZQRdiVkTg3+ashWs QDz+w0fzSf3U8uVQe8l2oRu9SZfmbHFuRzlVO3JF5DpkGNudYVwnhl0SQRvY9f7YvbI6 BriJ6JmHW3g8ekfRRYekCrPj7hByDo5qlteqj/chMuFuzMDADe5I+n20pP1VqzgE5IB6 Thr5+ZRpZYeFE68q86npCR6iptHjCk+ekb5DlLWvC2h5HeIwDjVgExL1HfAwqSK9e1f6 GoQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TZKGv1sVPbn33wSFQC2Hq1TTGl51W+KoM8tu8whSa+8=; b=guMaXjKVxuEf8V/MBK5em4l5yulBTRUTNtL1XBoBS53SXDEOgoZl7O1eO2EyzXN1Ej 0+N3LymPf3oOZ1OjJYDeGClEJw26WRTWZ+HuwZNhr1K4u+OUhHIOVcKGVZ3zfM8n68kw HzSRCIMPyBHxvTMepr+GARPlFJBjGHncT27kGEtCXOJnuMRwusabeBQsx1gDAphXBNte gT9G+f6iDls46hoj09g06gaKWK81JNbAFxCPfyQW8UM1UC3yc2JMViveo+dGZjl6nESQ RVBkpgFPNSVErAy4+I1sOh/f3nNxBGrjmzpMbuCXZPTZNb89+Sv1pYxpDTm8LwxH74Wc /kiA== X-Gm-Message-State: AOAM530t2H1SzBMo49f8uCf7stBaWUqqr5ZzTFUndI4Q4QeixeXO6wxj ZTxB6DUh5LLaGH/+3Nx9XQr0dWwn+T+19ncOXzw= X-Google-Smtp-Source: ABdhPJzCvvChTLL1Ij936+gWZfCHT1cI1LarPkF1I6RwV3Pk4C5uy4ku0CQpduox7gHOYLFdtC0zFPW6WdlyCuyLSic= X-Received: by 2002:a1f:a107:0:b0:357:a962:cef8 with SMTP id k7-20020a1fa107000000b00357a962cef8mr9396561vke.10.1653646826292; Fri, 27 May 2022 03:20:26 -0700 (PDT) MIME-Version: 1.0 References: <20220527032504.30341-1-yee.lee@mediatek.com> In-Reply-To: <20220527032504.30341-1-yee.lee@mediatek.com> From: patrick wang Date: Fri, 27 May 2022 18:20:14 +0800 Message-ID: Subject: Re: [PATCH] mm: kmemleak: Skip check in kmemleak_*_phys when pfn bound is not ready To: yee.lee@mediatek.com Cc: linux-kernel@vger.kernel.org, Kuan-Ying.lee@mediatek.com, Andrew.Yang@mediatek.com, Sunny.Kao@mediatek.com, chinwen.chang@mediatek.com, Catalin Marinas , Andrew Morton , Matthias Brugger , "open list:MEMORY MANAGEMENT" , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: f7j6hdmrfcaxgh7gin8djexzh7o6rw4a Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=QPJBbxLg; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf21.hostedemail.com: domain of patrick.wang.shcn@gmail.com designates 209.85.221.172 as permitted sender) smtp.mailfrom=patrick.wang.shcn@gmail.com X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 53C921C003D X-HE-Tag: 1653646814-174243 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: 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 > > 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 >