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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 33EABD3EE66 for ; Thu, 22 Jan 2026 13:35:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gh4XtAj9AB3rY76cV8CWTGYjLU/b8KyOlaB0cJ3cxrw=; b=cL17/BCnHzhhw64tNX5ukCI9IH xBXqzANWMHCc5FdhVopn1Y9vJz0JJstctPaCxDryGNLVderSPaPpfZPi1i3sBHDn1M4vM2rM3s8Nu Uzhy5ux0iDysFd4kc8A9GGF4m9ttlwue8hzSVq1wizeMdDD45r14imY6wIiXj0+ihpcRthQ0wLIRS rV3YyJhyIXUNG5frceCl1tMxXKlCBcOqMpbXydWCwCX7eApeNdntqyFXVx99qeiVt0fuicEwHyS2C djajEtwAn7xVYN9TMFFavgxu11Gyi0UfaYBxdDhLV94mqM/UnqUEQ1IZpSeD89qM0zL3ll89Ryhv+ 0Ni55Isw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1viuqh-00000007A4j-0qOT; Thu, 22 Jan 2026 13:35:47 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1viuqg-00000007A4a-0H03 for kexec@lists.infradead.org; Thu, 22 Jan 2026 13:35:46 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 5034B600C4; Thu, 22 Jan 2026 13:35:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4CE5C116C6; Thu, 22 Jan 2026 13:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769088945; bh=wED3dXV0kHkiBnPWNUBgYlSUdtgP2fArJ/kzjZEMltI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=mrM43KnIhyHDnc8ivUCX5HTrM9Pl42GBN8gXbejQ3Jl7OGoZ6s6TYv7Q9f+Ds41mV +atyWBT9K1XOmZr0pF5xVDisRvZ3G+sA0qlf+8xqzuMhEvZp4UEln1+29gf3zF8UIM hDr0aYGQEDqiPxMYnxspQa3y7BzZqMUsjuoGrP0jIAK+PgK0D2VLGCIn2k5S95TWLs uieNDly2PL9lHs2HFOjsXJgRHIrcw5486a5jYlh+T2wfAUhDov1hXXSAUo6cTbh/uZ yD8mWEN/VEDP5hyMTo/uckvNJclqUK7clMtEpzkS9kYenRw3CDQY2ZRB1Qh1ai61Ql pXhD2DGjTqOBQ== From: Pratyush Yadav To: ranxiaokai627@163.com Cc: pratyush@kernel.org, surenb@google.com, akpm@linux-foundation.org, pasha.tatashin@soleen.com, kent.overstreet@linux.dev, rppt@kernel.org, graf@amazon.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, ran.xiaokai@zte.com.cn, stable@vger.kernel.org Subject: Re: [PATCH RESEND v3] kho: init alloc tags when restoring pages from reserved memory In-Reply-To: <20260122132740.176468-1-ranxiaokai627@163.com> (ranxiaokai's message of "Thu, 22 Jan 2026 13:27:40 +0000") References: <20260122132740.176468-1-ranxiaokai627@163.com> Date: Thu, 22 Jan 2026 14:35:41 +0100 Message-ID: <2vxzcy31bwia.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Thu, Jan 22 2026, ranxiaokai627@163.com wrote: > From: Ran Xiaokai > > 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. > > Fixes: fc33e4b44b27 ("kexec: enable KHO support for memory preservation") > Cc: > Signed-off-by: Ran Xiaokai > --- > > v2 -> v3: > - also call clear_page_tag_ref() for non-compound order-0 tail pages > > kernel/liveupdate/kexec_handover.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c > index d4482b6e3cae..96767b106cac 100644 > --- a/kernel/liveupdate/kexec_handover.c > +++ b/kernel/liveupdate/kexec_handover.c > @@ -255,6 +255,14 @@ static struct page *kho_restore_page(phys_addr_t phys, bool is_folio) > if (is_folio && info.order) > 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); > + } > + I think it would be a little bit better if we just did this in the loop above instead of looping again. But I think it is fine for now. I can fix it up in the next release. Reviewed-by: Pratyush Yadav > adjust_managed_page_count(page, nr_pages); > return page; > } -- Regards, Pratyush Yadav