From patchwork Mon Feb 17 06:33:34 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuai Xue X-Patchwork-Id: 13977159 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) (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 A1ED218BC1D; Mon, 17 Feb 2025 06:33:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.100 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739774028; cv=none; b=gfumYF96HjqSIHXUJdBXlYKd3Y+HsjLb3JwLdk77x6gm6iWLptr6xgeM/pEfMR5QQgAz3k2BjWS1wup/tvBuotSRg+tlypBsxHI+96YCODjDtefTW0Czwnrx9H5LXvaAz3RUNb7Coe/Kc4i/s53L+6+tVvtG9aElhwy6hqTve3A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739774028; c=relaxed/simple; bh=tyeqZc+X0WuP8uiwjOV0n9F+Fr+cwMxePx3EJVi8JHY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jEd+XihoGJg1ZSjLXxXGwSr8cv5RUKkGKn3j0X39OviTVnblfFUblsNBL1AOMfe1xFwPVEnPPAwhWHWNmEy49lPG6CqVFuhz1TUOg6+LhJbBFkuSmftOAUDRWeWtNjcMRCb0FJhUHJatbxj0P5EUm8LQ3dYMqvrOsXkJ79VKmCo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=CUttw4BX; arc=none smtp.client-ip=115.124.30.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="CUttw4BX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1739774023; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=vvMi8bcBgppidelzMl/TigrL5YZhFRFfYcEROd+lYRc=; b=CUttw4BX2Tfeg8MVmM77B3AvtOGqbsysc202/jGw7+0lMGAs/ut0QlyEP+jfnWrmeztmtBTNvagnKqNgGnBzTxKM7/NIUykck9+jpTI8dzoxLVa61qXmKOV+Znyronry3e/R5qs2SxKm3uDc1UGQbABKeSOCumXvsy1iiuqTyPQ= Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0WPb1mQP_1739774021 cluster:ay36) by smtp.aliyun-inc.com; Mon, 17 Feb 2025 14:33:41 +0800 From: Shuai Xue To: tony.luck@intel.com, bp@alien8.de, nao.horiguchi@gmail.com Cc: tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linmiaohe@huawei.com, akpm@linux-foundation.org, peterz@infradead.org, jpoimboe@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, baolin.wang@linux.alibaba.com, tianruidong@linux.alibaba.com Subject: [PATCH v2 4/5] mm/hwpoison: Fix incorrect "not recovered" report for recovered clean pages Date: Mon, 17 Feb 2025 14:33:34 +0800 Message-ID: <20250217063335.22257-5-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20250217063335.22257-1-xueshuai@linux.alibaba.com> References: <20250217063335.22257-1-xueshuai@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-edac@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When an uncorrected memory error is consumed there is a race between the CMCI from the memory controller reporting an uncorrected error with a UCNA signature, and the core reporting and SRAR signature machine check when the data is about to be consumed. If the CMCI wins that race, the page is marked poisoned when uc_decode_notifier() calls memory_failure(). For dirty pages, memory_failure() invokes try_to_unmap() with the TTU_HWPOISON flag, converting the PTE to a hwpoison entry. As a result, kill_accessing_process(): - call walk_page_range() and return 1 regardless of whether try_to_unmap() succeeds or fails, - call kill_proc() to make sure a SIGBUS is sent - return -EHWPOISON to indicate that SIGBUS is already sent to the process and kill_me_maybe() doesn't have to send it again. However, for clean pages, the TTU_HWPOISON flag is cleared, leaving the PTE unchanged and not converted to a hwpoison entry. Conversely, for clean pages where PTE entries are not marked as hwpoison, kill_accessing_process() returns -EFAULT, causing kill_me_maybe() to send a SIGBUS. Console log looks like this: Memory failure: 0x827ca68: corrupted page was clean: dropped without side effects Memory failure: 0x827ca68: recovery action for clean LRU page: Recovered Memory failure: 0x827ca68: already hardware poisoned mce: Memory error not recovered To fix it, return 0 for "corrupted page was clean", preventing an unnecessary SIGBUS. Fixes: 046545a661af ("mm/hwpoison: fix error page recovered but reported "not recovered"") Signed-off-by: Shuai Xue Cc: stable@vger.kernel.org --- mm/memory-failure.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 995a15eb67e2..b037952565be 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -881,12 +881,17 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn, mmap_read_lock(p->mm); ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwpoison_walk_ops, (void *)&priv); + /* + * ret = 1 when CMCI wins, regardless of whether try_to_unmap() + * succeeds or fails, then kill the process with SIGBUS. + * ret = 0 when poison page is a clean page and it's dropped, no + * SIGBUS is needed. + */ if (ret == 1 && priv.tk.addr) kill_proc(&priv.tk, pfn, flags); - else - ret = 0; mmap_read_unlock(p->mm); - return ret > 0 ? -EHWPOISON : -EFAULT; + + return ret > 0 ? -EHWPOISON : 0; } /*