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 45A02ECAAA1 for ; Fri, 28 Oct 2022 11:57:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 912CA6B0072; Fri, 28 Oct 2022 07:57:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C2796B0073; Fri, 28 Oct 2022 07:57:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B1476B0074; Fri, 28 Oct 2022 07:57:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 69AAA6B0072 for ; Fri, 28 Oct 2022 07:57:34 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 31BA21211D3 for ; Fri, 28 Oct 2022 11:57:34 +0000 (UTC) X-FDA: 80070208428.01.C357B33 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf05.hostedemail.com (Postfix) with ESMTP id 9A1E110003F for ; Fri, 28 Oct 2022 11:57:33 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2AE4CB829B6; Fri, 28 Oct 2022 11:57:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A713C433C1; Fri, 28 Oct 2022 11:57:29 +0000 (UTC) Date: Fri, 28 Oct 2022 12:57:25 +0100 From: Catalin Marinas To: "zhaoyang.huang" Cc: Andrew Morton , Matthew Wilcox , Zhaoyang Huang , linux-mm@kvack.org, linux-kernel@vger.kernel.org, ke.wang@unisoc.com, steve.kang@unisoc.com Subject: Re: [RFC PATCH] mm: track bad page via kmemleak Message-ID: References: <1663679468-16757-1-git-send-email-zhaoyang.huang@unisoc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1663679468-16757-1-git-send-email-zhaoyang.huang@unisoc.com> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666958253; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FeECF3UoaaYUKfSQQXGSMIB/4V+R3eUMEcJhQlWIfuY=; b=hWJJqHKkLM/nzJfeLtA6qjg9JqE7gqly0G76zqIsqkCoJ0s+aHvlIk9MduTfZ4curkW0UR RqjRORUoxiyS+7G3jFNNU+CL+dEdLKaG1voTui0cDoNP93mW0AA5gMxFeZrYQx3zzAjFeZ RCXjKQRcFSGcVJZSOmlo44NA4vXztyE= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none); spf=pass (imf05.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666958253; a=rsa-sha256; cv=none; b=HPCxDhV14IRBwnY6VrvbB9UAQB04qP4MqFrR6TrAqjnNBJk4Z40P+Dl2l92ILcqmpqaxxC anxDIXio7Onu7z1qk/dwn96X5LuZD+lMjGdSpqN0+Y5v2KdyFMPfOGj/luozmY6wKATusJ xdUnYR8KL5KnKXuXcQeWAvzw4nSmAeg= X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9A1E110003F Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none); spf=pass (imf05.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org X-Stat-Signature: 89e6u5mg3wxw6k1zbogixykahuko3fkf X-Rspam-User: X-HE-Tag: 1666958253-173197 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: (sorry, I missed this last month when it was posted) On Tue, Sep 20, 2022 at 09:11:08PM +0800, zhaoyang.huang wrote: > From: Zhaoyang Huang > > Bad pages will failed go back to allocator and leaved as orphan pages, track > them down via kmemleak. > > Signed-off-by: Zhaoyang Huang > --- > mm/page_alloc.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e5486d4..24f682e 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1408,7 +1408,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > __memcg_kmem_uncharge_page(page, order); > reset_page_owner(page, order); > page_table_check_free(page, order); > - return false; > + goto err; > } > > /* > @@ -1442,7 +1442,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > if (check_free) > bad += check_free_page(page); > if (bad) > - return false; > + goto err; > > page_cpupid_reset_last(page); > page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; > @@ -1486,6 +1486,10 @@ static __always_inline bool free_pages_prepare(struct page *page, > debug_pagealloc_unmap_pages(page, 1 << order); > > return true; > +err: > + kmemleak_alloc(page_address(page), PAGE_SIZE << order, 1, GFP_KERNEL); > + return false; > + > } What's the aim of this tracking? First of all, that's a HWPoison page and it should note be touched, so the min_count should be -1 otherwise kmemleak will try to read it for references to other objects. Now, if all you need is a list of the bad pages, I don't think that's kmemleak's job. Maybe add them to a list and expose it somewhere else via debugfs. -- Catalin