From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E01501A071F for ; Thu, 11 Jul 2024 22:24:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720736652; cv=none; b=VopT9SDqhCpkGDxl/6w0/FTJhfRnylKKqapPMPPh6kmV3i5ISX2/323VY2ldrMdxd2IQ0zwihhBAvw0atrWNjgVvbTVhm/2wHW/Onk1q/ClCLpAYH5YiSXFPb2evS/wgMJst2BQQbBBvQW5O6EG9ZwO1+kL9usDPJLQIej1pSg8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720736652; c=relaxed/simple; bh=7ty2N876q9ilsz9sxq8Xx9N0w3MqxUTNCMTVgBeN3DU=; h=Date:To:From:Subject:Message-Id; b=FEcI0ZraACes0H/4agp3TB/Qvm6PWXMiDYtvT4ZNVfkna015+TzWx19rvYxyT/0DruqF50vkCqrz4ZChWEETosDMs0UCqhrfwtBSDTpgkZCC6pA2Y1QezDRNXJ3k9ALrp429qyXoljcjtJUcdhXo2IQdq9PXpTBJmp548Sow69c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=kU2yqxkE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="kU2yqxkE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA8ABC32782; Thu, 11 Jul 2024 22:24:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1720736651; bh=7ty2N876q9ilsz9sxq8Xx9N0w3MqxUTNCMTVgBeN3DU=; h=Date:To:From:Subject:From; b=kU2yqxkEVwkBz+KQ5xrYgct5n7sTsjDk/tcgQLCEWjZdnTXsYd9/vbXuXxxK7qX5P 40vi2/AjtsqhmUd/yXQyHDzxRhEB6++ws6ne3nsoP711TgzUhrqhs7taM3vOghafJb Y7HB0MUHPgdj/HV1ixm5PjppS9VqQaDX/oyM2A5M= Date: Thu, 11 Jul 2024 15:24:11 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,souravpanda@google.com,pasha.tatashin@soleen.com,kent.overstreet@linux.dev,keescook@chromium.org,surenb@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + alloc_tag-fix-page_ext_get-page_ext_put-sequence-during-page-splitting.patch added to mm-unstable branch Message-Id: <20240711222411.AA8ABC32782@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting has been added to the -mm mm-unstable branch. Its filename is alloc_tag-fix-page_ext_get-page_ext_put-sequence-during-page-splitting.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alloc_tag-fix-page_ext_get-page_ext_put-sequence-during-page-splitting.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Suren Baghdasaryan Subject: alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting Date: Thu, 11 Jul 2024 15:04:57 -0700 pgalloc_tag_sub() might call page_ext_put() using a page different from the one used in page_ext_get() call. This does not pose an issue since page_ext_put() ignores this parameter as long as it's non-NULL but technically this is wrong. Fix it by storing the original page used in page_ext_get() and passing it to page_ext_put(). Link: https://lkml.kernel.org/r/20240711220457.1751071-3-surenb@google.com Fixes: be25d1d4e822 ("mm: create new codetag references during page splitting") Signed-off-by: Suren Baghdasaryan Cc: Kees Cook Cc: Kent Overstreet Cc: Pasha Tatashin Cc: Sourav Panda Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/pgalloc_tag.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/include/linux/pgalloc_tag.h~alloc_tag-fix-page_ext_get-page_ext_put-sequence-during-page-splitting +++ a/include/linux/pgalloc_tag.h @@ -71,6 +71,7 @@ static inline void pgalloc_tag_sub(struc static inline void pgalloc_tag_split(struct page *page, unsigned int nr) { int i; + struct page_ext *first_page_ext; struct page_ext *page_ext; union codetag_ref *ref; struct alloc_tag *tag; @@ -78,7 +79,7 @@ static inline void pgalloc_tag_split(str if (!mem_alloc_profiling_enabled()) return; - page_ext = page_ext_get(page); + first_page_ext = page_ext = page_ext_get(page); if (unlikely(!page_ext)) return; @@ -94,7 +95,7 @@ static inline void pgalloc_tag_split(str page_ext = page_ext_next(page_ext); } out: - page_ext_put(page_ext); + page_ext_put(first_page_ext); } static inline struct alloc_tag *pgalloc_tag_get(struct page *page) _ Patches currently in -mm which might be from surenb@google.com are alloc_tag-export-memory-allocation-profiling-symbols-used-by-modules.patch mm-add-comments-for-allocation-helpers-explaining-why-they-are-macros.patch lib-add-missing-newline-character-in-the-warning-message.patch lib-reuse-page_ext_data-to-obtain-codetag_ref.patch alloc_tag-fix-page_ext_get-page_ext_put-sequence-during-page-splitting.patch