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 D05C541C76; Fri, 24 May 2024 18:55:46 +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=1716576946; cv=none; b=onA3lqCHvoqTye90RmjW0Pkka//zEtJI3s/Jyv+mHb+CoTbiuBspdj6/gntjbCDlCLU2VA64mhUU7iR+jkLWbkOsuCdgFK2QmoeZ3tjq5nJPPCcMT7u7JDvmmXhe5I+g2ICeLd651mTqQQ8L15E+ttgmF7Lw+dD/J16sikc4PnQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716576946; c=relaxed/simple; bh=RMre9fC63IjFwuGQhInISVE12OgpAuJTLPOBZFtQSiw=; h=Date:To:From:Subject:Message-Id; b=Iwb+eqgiEOiJhg+F5yAC5OIWOC6Ls8X5o1yZXrc8oQAmQp+Nk3zzSSe+XCAKdttUEHQCERvX7dtWdNQnkC3NXc1m9jxkWutY8i11mx01K7aHob+I7lnDe+SKXXqa6lqnJc7XXV5jxzEIOc5XjWzQmTXoM6U7KsDAc8kvvSEIYlM= 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=amasuGHq; 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="amasuGHq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 559BDC2BD11; Fri, 24 May 2024 18:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1716576946; bh=RMre9fC63IjFwuGQhInISVE12OgpAuJTLPOBZFtQSiw=; h=Date:To:From:Subject:From; b=amasuGHq9UsZihxKlpac6MsnBmN4SKFl02RzfAk/b0Gzr1aKJ5uPYQg+inlk+xn0M tkv+sNT/iFTMjy8Px62+8hDwQTtAcVolQI1TFSp0IL+wHb8xREkaU5PxIuAUiZVdVM zSYxKpbH9CD1zz82fOhhd8cq3WMdzeC+8AOPZmuc= Date: Fri, 24 May 2024 11:55:45 -0700 To: mm-commits@vger.kernel.org,xuyu@linux.alibaba.com,stable@vger.kernel.org,shy828301@gmail.com,osalvador@suse.de,nao.horiguchi@gmail.com,david@redhat.com,anshuman.khandual@arm.com,linmiaohe@huawei.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-huge_memory-dont-unpoison-huge_zero_folio.patch removed from -mm tree Message-Id: <20240524185546.559BDC2BD11@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/huge_memory: don't unpoison huge_zero_folio has been removed from the -mm tree. Its filename was mm-huge_memory-dont-unpoison-huge_zero_folio.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 ------------------------------------------------------ From: Miaohe Lin Subject: mm/huge_memory: don't unpoison huge_zero_folio Date: Thu, 16 May 2024 20:26:08 +0800 When I did memory failure tests recently, below panic occurs: kernel BUG at include/linux/mm.h:1135! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 Call Trace: do_shrink_slab+0x14f/0x6a0 shrink_slab+0xca/0x8c0 shrink_node+0x2d0/0x7d0 balance_pgdat+0x33a/0x720 kswapd+0x1f3/0x410 kthread+0xd5/0x100 ret_from_fork+0x2f/0x50 ret_from_fork_asm+0x1a/0x30 Modules linked in: mce_inject hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 The root cause is that HWPoison flag will be set for huge_zero_folio without increasing the folio refcnt. But then unpoison_memory() will decrease the folio refcnt unexpectedly as it appears like a successfully hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when releasing huge_zero_folio. Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. We're not prepared to unpoison huge_zero_folio yet. Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") Signed-off-by: Miaohe Lin Acked-by: David Hildenbrand Reviewed-by: Yang Shi Reviewed-by: Oscar Salvador Reviewed-by: Anshuman Khandual Cc: Naoya Horiguchi Cc: Xu Yu Cc: Signed-off-by: Andrew Morton --- mm/memory-failure.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/mm/memory-failure.c~mm-huge_memory-dont-unpoison-huge_zero_folio +++ a/mm/memory-failure.c @@ -2546,6 +2546,13 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } + if (is_huge_zero_folio(folio)) { + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", + pfn, &unpoison_rs); + ret = -EOPNOTSUPP; + goto unlock_mutex; + } + if (!PageHWPoison(p)) { unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", pfn, &unpoison_rs); _ Patches currently in -mm which might be from linmiaohe@huawei.com are