From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 5F9421E89C for ; Mon, 15 Jul 2024 06:23:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721024630; cv=none; b=RxoEXvYXduxMJO8ahQLbYudL5bMJnw+oMKSV06fwsUS/u2UroUH05iW0tNsuIYFPa9zQwZq+UrvPbjTQD42ZWI0qS7p8lCCXD9AnWvE4S0mk3wU/7aS2t2Cxum6VNE07rwDvzbk7aHpgN9mv1u2Eg4TzkjlU6mGgP0jPSM8OM80= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721024630; c=relaxed/simple; bh=XXCUXGWPSSzklNSCq2m8DSQ0Hyy3sM2PBwlUqsyAC4k=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=f+uTmdK3dAWklpx6ddovsNMe+eHusV+g7zi2R30SA4IFdXuqQuLf0hVhWGyCsa1Yl2Of/323d+h3wtELYO/j+BkrwTP2P1yJvOqN7qO6V8C0t9kCiVUM4sTIHq5gtM2H/6dh8USroFtnYqPr/i1eiSBsoZpGfcngOFVs69x7tlY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4WMsVc3nDhzQllW; Mon, 15 Jul 2024 14:19:36 +0800 (CST) Received: from kwepemd200019.china.huawei.com (unknown [7.221.188.193]) by mail.maildlp.com (Postfix) with ESMTPS id 9E195140158; Mon, 15 Jul 2024 14:23:37 +0800 (CST) Received: from [10.173.127.72] (10.173.127.72) by kwepemd200019.china.huawei.com (7.221.188.193) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 15 Jul 2024 14:23:37 +0800 Subject: Re: [PATCH] mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory To: Andrew Morton CC: , , References: <20240712064249.3882707-1-linmiaohe@huawei.com> <20240712140921.9aa90b18d22e67417d59dfc1@linux-foundation.org> From: Miaohe Lin Message-ID: <8fe349f9-d3d3-65ab-6045-da0bd19249ea@huawei.com> Date: Mon, 15 Jul 2024 14:23:36 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240712140921.9aa90b18d22e67417d59dfc1@linux-foundation.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200019.china.huawei.com (7.221.188.193) On 2024/7/13 5:09, Andrew Morton wrote: > On Fri, 12 Jul 2024 14:42:49 +0800 Miaohe Lin wrote: > >> When I did memory failure tests recently, below panic occurs: >> >> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >> kernel BUG at include/linux/page-flags.h:616! >> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >> RIP: 0010:unpoison_memory+0x2f3/0x590 >> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >> Call Trace: >> >> unpoison_memory+0x2f3/0x590 >> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >> debugfs_attr_write+0x42/0x60 >> full_proxy_write+0x5b/0x80 >> vfs_write+0xd5/0x540 >> ksys_write+0x64/0xe0 >> do_syscall_64+0xb9/0x1d0 >> entry_SYSCALL_64_after_hwframe+0x77/0x7f >> RIP: 0033:0x7f08f0314887 >> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >> >> Modules linked in: hwpoison_inject >> ---[ end trace 0000000000000000 ]--- >> RIP: 0010:unpoison_memory+0x2f3/0x590 >> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >> Kernel panic - not syncing: Fatal exception >> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >> ---[ end Kernel panic - not syncing: Fatal exception ]--- >> >> The root cause is that unpoison_memory() tries to check the PG_HWPoison >> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >> triggered. > > I'm not seeing the call path. Is this BUG happening via > > static __always_inline void __ClearPage##uname(struct page *page) \ > { \ > VM_BUG_ON_PAGE(!Page##uname(page), page); \ > page->page_type |= PG_##lname; \ > } > > ? > > If so, where's the callsite? It is BUG on PF_ANY(): PAGEFLAG(HWPoison, hwpoison, PF_ANY) #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) #define PF_POISONED_CHECK(page) ({ \ VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ page; }) #define PAGE_POISON_PATTERN -1l static inline int PagePoisoned(const struct page *page) { return READ_ONCE(page->flags) == PAGE_POISON_PATTERN; } The offlined pages will have page->flags set to PAGE_POISON_PATTERN while pfn is still valid: offline_pages remove_pfn_range_from_zone page_init_poison memset(page, PAGE_POISON_PATTERN, size); > >> This can be reproduced by below steps: >> 1.Offline memory block: >> echo offline > /sys/devices/system/memory/memory12/state >> 2.Get offlined memory pfn: >> page-types -b n -rlN >> 3.Write pfn to unpoison-pfn >> echo > /sys/kernel/debug/hwpoison/unpoison-pfn >> > > I guess cc:stable. It looks old? Can you help to identify the Fixes: > target? Since memory unpoison is only used for testing and users usually won't pass in a offlined pfn (memory offline itself should be rare too). So I think this doesn't deserve cc statble. But If a Fixes tag is required, I think it should be: Fixes: f165b378bbdf ("mm: uninitialized struct page poisoning sanity checking") Thanks. .