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 6D5C2143757; Wed, 19 Jun 2024 13:24:08 +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=1718803448; cv=none; b=TsOvk01rXhFNvfKzfyG2saNihnBaWB6xhRa36WAyDouI/XJ5rL8OIh2BXkhPgJaHj7nAjqjIMLzwXJzRxtYHyExfOYwMfUXMSAXylpOGMJxKDgv619hrN4RI1ODZvmyp01L0/XBYW75q96kSYAu5r1UX+9xGASmNp4Ny+zmv4bE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718803448; c=relaxed/simple; bh=LWeLbB6iwTlaw0u5ADgWgXOROnEQebARrqwOgoiTxko=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aCPefRxCURlf2qUo4TKyYkC7VJyJtNEgwMz0OKOHn1EI8NN/XMSHZYdH5ImlU/AQcpaRwWJzHqBcZwr1uXHC52B0mSgLNkvoSfyZc8p9iVEWKmSrOux90bV4yk70tlsCh5Mz3AACRMpi6dL3LyK51CSA05TLxVOwLEdq005pKOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MyxT8W8L; 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="MyxT8W8L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2D99C2BBFC; Wed, 19 Jun 2024 13:24:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718803448; bh=LWeLbB6iwTlaw0u5ADgWgXOROnEQebARrqwOgoiTxko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MyxT8W8LSdJrx1L6l618284e8LKLjlpyOakVTxClE3DrYpM5nbmv0W83LWjqWM8OW 6IHAIs/SoJ2DXwkaxwoGcaE9TB9tTWaK2h0aPDNbyWIoq9NrIIvfQXWtFwCc/wI30S DDXGEyabxoGw09VcBa6USI6qtOlqkHL/5OUbeyvY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Miaohe Lin , David Hildenbrand , Yang Shi , Oscar Salvador , Anshuman Khandual , Naoya Horiguchi , Xu Yu , Andrew Morton Subject: [PATCH 6.9 270/281] mm/huge_memory: dont unpoison huge_zero_folio Date: Wed, 19 Jun 2024 14:57:09 +0200 Message-ID: <20240619125620.371139654@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125609.836313103@linuxfoundation.org> References: <20240619125609.836313103@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miaohe Lin commit fe6f86f4b40855a130a19aa589f9ba7f650423f4 upstream. 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 Signed-off-by: Miaohe Lin Signed-off-by: Greg Kroah-Hartman --- mm/memory-failure.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2550,6 +2550,13 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } + if (is_huge_zero_page(&folio->page)) { + 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);