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 7BA0B3B961C for ; Wed, 4 Feb 2026 09:59:31 +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=1770199171; cv=none; b=H4yVCkTwTp79o5ggsDY3t/IFPgVIsTu0ZgCo8c12k2Kv+zyuraWNms7rHL9FAKQB0MJBp0+rMgSh3wmk9VZazxv8lfm+AeChN1QZSNOIrzXq3ibtVTfjQRl3B6cPZFz0RJTtM3VROP3jKZ2xboTXlzR9/SDCbDZ8k9xrgkPtpLA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770199171; c=relaxed/simple; bh=KdqlhGM1C3SBt7l/NwTZdCohrrG7+C7dLW2/rn4U1FQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TM3pRI9KiwltTUTAQ92OoZ/lmJFeYcJrAqyqNUwSbeMDKqBgenipCSwUBRZEpvT7W2bEWeNSm8BkeJ6GCS5FEzMVJMOc26TV/XafNlvtl5nflPLI9AzLgOoEx44Yi8iYeagZI4QGPU7H/+IuaBefoSmg6yALWLwLxYLdeI0gfdE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Es+rZFy9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Es+rZFy9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91A47C4CEF7; Wed, 4 Feb 2026 09:59:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770199171; bh=KdqlhGM1C3SBt7l/NwTZdCohrrG7+C7dLW2/rn4U1FQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Es+rZFy9le2O5peXo82eJ4YY2D8p83WrLIC/CIe+cTnZpYKYMyNvC2KMT+3DMBYF3 vy3042Peeu19afmwZOpJmMF7TfWRrC/ShSStxchNi7NmkSQATzhkYxgM3wmoricgsz dKafo+prc+gdDQCdsIwg6Yyjrfn+srlSna/BfZnI= Date: Wed, 4 Feb 2026 10:59:27 +0100 From: Greg KH To: Sasha Levin Cc: stable@vger.kernel.org, Ran Xiaokai , Pratyush Yadav , Pasha Tatashin , "Mike Rapoport (Microsoft)" , Alexander Graf , Kent Overstreet , Suren Baghdasaryan , Andrew Morton Subject: Re: [PATCH 6.18.y] kho: init alloc tags when restoring pages from reserved memory Message-ID: <2026020419-extortion-swinging-6394@gregkh> References: <2026020303-drippy-appliance-a74c@gregkh> <20260204002654.1462558-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260204002654.1462558-1-sashal@kernel.org> On Tue, Feb 03, 2026 at 07:26:54PM -0500, Sasha Levin wrote: > From: Ran Xiaokai > > [ Upstream commit e86436ad0ad2a9aaf88802d69b68f02cbd1f04a9 ] > > 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/20260122132740.176468-1-ranxiaokai627@163.com > Fixes: fc33e4b44b27 ("kexec: enable KHO support for memory preservation") > Signed-off-by: Ran Xiaokai > Reviewed-by: Pratyush Yadav > Reviewed-by: Pasha Tatashin > Reviewed-by: Mike Rapoport (Microsoft) > Cc: Alexander Graf > Cc: Kent Overstreet > Cc: Suren Baghdasaryan > Cc: > Signed-off-by: Andrew Morton > Signed-off-by: Sasha Levin > --- > kernel/kexec_handover.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c > index 03d12e27189fc..db08c1a2e1f80 100644 > --- a/kernel/kexec_handover.c > +++ b/kernel/kexec_handover.c > @@ -260,6 +260,14 @@ static struct page *kho_restore_page(phys_addr_t phys) > if (info.order > 0) > prep_compound_page(page, info.order); > > + /* Always mark headpage's codetag as empty to avoid accounting mismatch */ > + clear_page_tag_ref(page); > + if (!is_folio) { > + /* Also do that for the non-compound tail pages */ > + for (unsigned int i = 1; i < nr_pages; i++) > + clear_page_tag_ref(page + i); > + } > + Breaks the build :(