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 A07F9C6FA82 for ; Fri, 2 Sep 2022 18:58:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 303A6800E2; Fri, 2 Sep 2022 14:58:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B356800DD; Fri, 2 Sep 2022 14:58:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 17B13800E2; Fri, 2 Sep 2022 14:58:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 07B74800DD for ; Fri, 2 Sep 2022 14:58:43 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id C9EE61407AD for ; Fri, 2 Sep 2022 18:58:42 +0000 (UTC) X-FDA: 79868056884.02.B2F6B3C Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf31.hostedemail.com (Postfix) with ESMTP id 3F74B20057 for ; Fri, 2 Sep 2022 18:58:42 +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 dfw.source.kernel.org (Postfix) with ESMTPS id 409EE62249; Fri, 2 Sep 2022 18:58:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61534C433D6; Fri, 2 Sep 2022 18:58:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662145120; bh=I7EvjmBEJ+PK5VGQFpQlLdq2iNrwiITdaZk9IZZnYao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OP/lQQRO8c9wuvCWYQaoubDsk/jEGHP0zZ229BSegYVU791zGFlwUiZy08YW30rvb W8UnxZmh8PWs/dR9SiPM46i7jDQTALOpnSQSFNcm1vaKPE667YbiWrr2jDPatZpMJV BGTKtC1fSdKotpwFSIPqt8DFxBEMKjKmTTHpO/yI= Date: Fri, 2 Sep 2022 11:58:39 -0700 From: Andrew Morton To: "zhaoyang.huang" Cc: Catalin Marinas , Zhaoyang Huang , , , , Matthew Wilcox Subject: Re: [Resend RFC PATCH] mm: introduce __GFP_TRACKLEAK to track in-kernel allocation Message-Id: <20220902115839.1e3fafd159e42d4e7dae90af@linux-foundation.org> In-Reply-To: <1662116347-17649-1-git-send-email-zhaoyang.huang@unisoc.com> References: <1662116347-17649-1-git-send-email-zhaoyang.huang@unisoc.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662145122; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ecl3pjPGoep6S4uyQRVbdDTY4/E3WsM70/Hv13y+IYQ=; b=pYdUzqaCuhcQhp3rejrIGjUbAEZ4fmgVReczBa37qKsczKkbZ62e+WBc7UTbaupXwRViQe E1Y/HEXuLnIQQzH9h84dr91Vcm9kw+pgPIKFzsZG1ehA3JY9zrwaOl15eu8FEN4HJdmsHF h4qT+8w4/n9r+xvAqS2zrupADOvxhDc= ARC-Authentication-Results: i=1; imf31.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="OP/lQQRO"; spf=pass (imf31.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662145122; a=rsa-sha256; cv=none; b=3i9DUmGIfOl84GRP/SSN31wKcwEug3vZQXG0Y1OCBTNjKQ6cF9m0F/6FdeYQWTvhp69LN3 uQmpthfCbfYnrUG9s1V7IQdmk33tvblP7j/GqcVZyq7deVbiVw0Z0ACJ3GBTy5K4Ehb5R9 DXFvaU0YDIEalOi+YbDwIkgNDkvavnc= X-Stat-Signature: h6c5taus489eznom453rnerfxwzhaiuo X-Rspamd-Queue-Id: 3F74B20057 X-Rspam-User: Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="OP/lQQRO"; spf=pass (imf31.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam01 X-HE-Tag: 1662145122-69386 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: Cc willy for page-flags changes. On Fri, 2 Sep 2022 18:59:07 +0800 "zhaoyang.huang" wrote: > From: Zhaoyang Huang > > Kthread and drivers could fetch memory via alloc_pages directly which make them > hard to debug when leaking. Solve this by introducing __GFP_TRACELEAK and reuse > kmemleak mechanism which unified most of kernel cosuming pages into kmemleak. > > ... > cc wi > index 2d2ccae..081ab54 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -68,6 +68,7 @@ > #else > #define ___GFP_NOLOCKDEP 0 > #endif > +#define ___GFP_TRACKLEAK 0x10000000u > /* If the above are modified, __GFP_BITS_SHIFT may need updating */ > > /* > @@ -259,12 +260,13 @@ > #define __GFP_SKIP_ZERO ((__force gfp_t)___GFP_SKIP_ZERO) > #define __GFP_SKIP_KASAN_UNPOISON ((__force gfp_t)___GFP_SKIP_KASAN_UNPOISON) > #define __GFP_SKIP_KASAN_POISON ((__force gfp_t)___GFP_SKIP_KASAN_POISON) > +#define __GFP_TRACKLEAK ((__force gfp_t)___GFP_TRACKLEAK) > > /* Disable lockdep for GFP context tracking */ > #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) > > /* Room for N __GFP_FOO bits */ > -#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) > +#define __GFP_BITS_SHIFT (28 + IS_ENABLED(CONFIG_LOCKDEP)) > #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) > > /** > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index e66f7aa..ef0f814 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -942,6 +942,7 @@ static inline bool is_page_hwpoison(struct page *page) > #define PG_offline 0x00000100 > #define PG_table 0x00000200 > #define PG_guard 0x00000400 > +#define PG_trackleak 0x00000800 > > #define PageType(page, flag) \ > ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) > @@ -1012,6 +1013,8 @@ static inline int page_has_type(struct page *page) > */ > PAGE_TYPE_OPS(Guard, guard) > > +PAGE_TYPE_OPS(Trackleak, trackleak) We'd want this to evaluate to zero at compile time if CONFIG_HAVE_DEBUG_KMEMLEAK=n > extern bool is_free_buddy_page(struct page *page); > > PAGEFLAG(Isolated, isolated, PF_ANY); > diff --git a/mm/kmemleak.c b/mm/kmemleak.c > index 422f28f..a182f5d 100644 > --- a/mm/kmemleak.c > +++ b/mm/kmemleak.c > @@ -1471,7 +1471,7 @@ static void kmemleak_scan(void) > if (page_zone(page) != zone) > continue; > /* only scan if page is in use */ > - if (page_count(page) == 0 || PageReserved(page)) > + if (page_count(page) == 0) Please changelog this alteration. > continue; > scan_block(page, page + 1, NULL); > if (!(pfn & 63)) > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e008a3d..d8995c6 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1361,6 +1361,8 @@ static __always_inline bool free_pages_prepare(struct page *page, > page->mapping = NULL; > if (memcg_kmem_enabled() && PageMemcgKmem(page)) > __memcg_kmem_uncharge_page(page, order); > + if (PageTrackleak(page)) > + kmemleak_free(page); > if (check_free) > bad += check_free_page(page); > if (bad) > @@ -5444,6 +5446,10 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, > __free_pages(page, order); > page = NULL; > } > + if (gfp & __GFP_TRACKLEAK) { And we'd want __GFP_TRACKLEAK to evaluate to zero at compile time if CONFIG_HAVE_DEBUG_KMEMLEAK=n. > + kmemleak_alloc(page_address(page), PAGE_SIZE << order, 1, gfp & ~__GFP_TRACKLEAK); > + __SetPageTrackleak(page); > + } > > trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype); > > -- > 1.9.1