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 4C85444CF37; Tue, 20 Jan 2026 15:24:09 +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=1768922649; cv=none; b=oeEzh14nTVH2RNtCM0/Nr0E06N7PIieCZXzoUIRipboZ1zQiTdcsIerrmFY4LUC6CyYyb3xKZI/0tBv0iVQm/9d6lSQqCVVkPFcEd8nwczFbvXOhs23Y69hlWd1eB2W27lI+iP9YDTXeKIhPYhnsoOFA5kXHF31yE5JULYxZJ9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768922649; c=relaxed/simple; bh=9jRhlOcB/BCAcsGAE6E2GxTLrKYlRd8V5vOhZYZPVfA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=uOu0Ivw2O3Rh2Ad29rc4fDDA69Rs/7TQRf0uxCDzm/07OKUagaunEUlByBvbysNv1VAvGYbOWllIli2YjATtxkaNqmdr1DsvTTRjOir88DK7DqEVPBWi5ReMOi21QTYppCOZ5TLn/lKNOv2qGat2DQlbRy4TCZRD9rR+nWcxOgY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ew1eoVWJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ew1eoVWJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94F36C16AAE; Tue, 20 Jan 2026 15:24:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768922649; bh=9jRhlOcB/BCAcsGAE6E2GxTLrKYlRd8V5vOhZYZPVfA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=ew1eoVWJ54oFj/fHJHf3R4ddG73yX/O+h1arlczZW/Y0qoDGHJK4xUDuDseOZn96J O5PSCx0qh6qm9XCIobNNDkFAlJc/IuZTCWhqVaZRjdtaId2V13S6DyE1EXJAnRbegv WSUCtHwY44USLA63eUbZcWN9+LHTjl+RVrtukk9y22GwIzUfR4J/ajXbDBIBq+JdbI mMHTgSg8nxbG0i7ru/nn/6qRH3QtOiSsUKHvu5PPQJXtC0jXMtz89tvdqxFpKhxadT lJhpskuWvRXZ1+jYaBe6qVVAGb8B6rGWrRhLtTdxic8wTFK3/nNUJ03J2fJTOcdbaI YoD49CQ1I1Q4A== From: Pratyush Yadav To: Andrew Morton Cc: mm-commits@vger.kernel.org, surenb@google.com, stable@vger.kernel.org, rppt@kernel.org, pratyush@kernel.org, pasha.tatashin@soleen.com, graf@amazon.com, ran.xiaokai@zte.com.cn Subject: Re: [merged mm-hotfixes-stable] kho-init-alloc-tags-when-restoring-pages-from-reserved-memory.patch removed from -mm tree In-Reply-To: <20260119203054.70AE8C116C6@smtp.kernel.org> (Andrew Morton's message of "Mon, 19 Jan 2026 12:30:53 -0800") References: <20260119203054.70AE8C116C6@smtp.kernel.org> Date: Tue, 20 Jan 2026 15:24:06 +0000 Message-ID: <2vxzqzrke295.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Hi Andrew, On Mon, Jan 19 2026, Andrew Morton wrote: > The quilt patch titled > Subject: kho: init alloc tags when restoring pages from reserved memory > has been removed from the -mm tree. Its filename was > kho-init-alloc-tags-when-restoring-pages-from-reserved-memory.patch > > This patch was dropped because it was merged into the mm-hotfixes-stable branch > of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm This patch isn't quite complete. See [0]. It doesn't do anything wrong, it just doesn't fix the problem for every case. I suggested a re-roll of this patch based on top of my cleanup patches [1], since I think with those the end result is a bit nicer. I suppose we have 3 options: 1. Take this patch in hotfixes and leave kho_restore_pages() path unfixed. The fix the rest next merge window. 2. Do a new version of this patch fixing kho_restore_pages() with the current code, and then re-roll the clean up series to fix conflicts for next merge window. 3. Pull in the cleanups in hotfixes too, and then do a new revision of this patch on top. I don't think the end result of option 2 is too horrible, so I think that is probably the best option, but do let me know what you'd prefer. [0] https://lore.kernel.org/linux-mm/2vxzpl7chw8d.fsf@kernel.org/ [1] https://lore.kernel.org/linux-mm/20260116112217.915803-1-pratyush@kernel.org/T/#u > > ------------------------------------------------------ > From: Ran Xiaokai > Subject: kho: init alloc tags when restoring pages from reserved memory > Date: Fri, 9 Jan 2026 10:42:51 +0000 > > Memblock pages (including reserved memory) should have their allocation > tags initialized to CODETAG_EMPTY via clear_page_tag_ref() before being > released to the page allocator. When kho restores pages through > kho_restore_page(), missing this call causes mismatched > allocation/deallocation tracking and below warning message: > > alloc_tag was not set > WARNING: include/linux/alloc_tag.h:164 at ___free_pages+0xb8/0x260, CPU#1: swapper/0/1 > RIP: 0010:___free_pages+0xb8/0x260 > kho_restore_vmalloc+0x187/0x2e0 > kho_test_init+0x3c4/0xa30 > do_one_initcall+0x62/0x2b0 > kernel_init_freeable+0x25b/0x480 > kernel_init+0x1a/0x1c0 > ret_from_fork+0x2d1/0x360 > > Add missing clear_page_tag_ref() annotation in kho_restore_page() to > fix this. > > Link: https://lkml.kernel.org/r/20260113033403.161869-1-ranxiaokai627@163.com > Link: https://lkml.kernel.org/r/20260109104251.157767-1-ranxiaokai627@163.com > Fixes: fc33e4b44b27 ("kexec: enable KHO support for memory preservation") > Signed-off-by: Ran Xiaokai > Reviewed-by: Mike Rapoport (Microsoft) > Reviewed-by: Suren Baghdasaryan > Reviewed-by: Pasha Tatashin > Cc: Alexander Graf > Cc: Pratyush Yadav > Cc: > Signed-off-by: Andrew Morton > --- > > kernel/liveupdate/kexec_handover.c | 1 + > 1 file changed, 1 insertion(+) > > --- a/kernel/liveupdate/kexec_handover.c~kho-init-alloc-tags-when-restoring-pages-from-reserved-memory > +++ a/kernel/liveupdate/kexec_handover.c > @@ -255,6 +255,7 @@ static struct page *kho_restore_page(phy > if (is_folio && info.order) > prep_compound_page(page, info.order); > > + clear_page_tag_ref(page); > adjust_managed_page_count(page, nr_pages); > return page; > } > _ > > Patches currently in -mm which might be from ran.xiaokai@zte.com.cn are > > alloc_tag-fix-rw-permission-issue-when-handling-boot-parameter.patch > -- Regards, Pratyush Yadav