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 BC7AC2DFA4D; Mon, 14 Apr 2025 14:37:26 +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=1744641449; cv=none; b=Zmqdz+MtSvFJlrV5BGBF6vs0B2rLPe+3wS86euBiX5pM2GUJsAKnUDMUJrO4MH5RsMSRhQwFFodvhwJ59wmgO5w0ed9YWYUsCbcnpwVNSDJ/0vFDZn95HVH/EZEXkv53VtF+4ohQlRj3z9emeZbLh9TQNBB/NKE1IQOZF/oaQmU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744641449; c=relaxed/simple; bh=/RyjC2iNOfnZm2jgaWulSid9/ozmjHgS3tJdqrDAXDw=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=JdVGoCMGczJwP5iUM+cIgTJGZvv3SbhHNUlVSpz4gK89fbwdIhm6VMkjntLjC+pF9xq87EmqVo/DM8pDraBGYtTRt2kVdT/RiK0ksMTgi5BjKgzfW8ADCO7gMS1807xmxHZ9B7NQ8cTq2s/fkeDuLkiPcTRWaKj5ixL+vgNFfCo= 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 4ZbqY14QMGzHrDV; Mon, 14 Apr 2025 22:33:57 +0800 (CST) Received: from dggpemf500002.china.huawei.com (unknown [7.185.36.57]) by mail.maildlp.com (Postfix) with ESMTPS id 53FEC1401F4; Mon, 14 Apr 2025 22:37:23 +0800 (CST) Received: from [10.174.178.247] (10.174.178.247) by dggpemf500002.china.huawei.com (7.185.36.57) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 14 Apr 2025 22:37:21 +0800 Subject: Re: [RESEND PATCH v18 1/2] ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered To: Shuai Xue , , , , , , , , , , , , , , , , , , , , , , , CC: , , , , , , , , , , , , , , , , , References: <20250404112050.42040-1-xueshuai@linux.alibaba.com> <20250404112050.42040-2-xueshuai@linux.alibaba.com> From: Hanjun Guo Message-ID: <0c0bc332-0323-4e43-a96b-dd5f5957ecc9@huawei.com> Date: Mon, 14 Apr 2025 22:37:21 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 Precedence: bulk X-Mailing-List: linux-edac@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20250404112050.42040-2-xueshuai@linux.alibaba.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemf500002.china.huawei.com (7.185.36.57) On 2025/4/4 19:20, Shuai Xue wrote: > Synchronous error was detected as a result of user-space process accessing > a 2-bit uncorrected error. The CPU will take a synchronous error exception > such as Synchronous External Abort (SEA) on Arm64. The kernel will queue a > memory_failure() work which poisons the related page, unmaps the page, and > then sends a SIGBUS to the process, so that a system wide panic can be > avoided. > > However, no memory_failure() work will be queued when abnormal synchronous > errors occur. These errors can include situations such as invalid PA, > unexpected severity, no memory failure config support, invalid GUID > section, etc. In such case, the user-space process will trigger SEA again. > This loop can potentially exceed the platform firmware threshold or even > trigger a kernel hard lockup, leading to a system reboot. > > Fix it by performing a force kill if no memory_failure() work is queued > for synchronous errors. > > Signed-off-by: Shuai Xue > Reviewed-by: Jarkko Sakkinen > Reviewed-by: Jonathan Cameron > Reviewed-by: Yazen Ghannam > Reviewed-by: Jane Chu > --- > drivers/acpi/apei/ghes.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index b72772494655..50e4d924aa8b 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -799,6 +799,17 @@ static bool ghes_do_proc(struct ghes *ghes, > } > } > > + /* > + * If no memory failure work is queued for abnormal synchronous > + * errors, do a force kill. > + */ > + if (sync && !queued) { > + dev_err(ghes->dev, > + HW_ERR GHES_PFX "%s:%d: synchronous unrecoverable error (SIGBUS)\n", > + current->comm, task_pid_nr(current)); > + force_sig(SIGBUS); > + } I think it's reasonable to send a force kill to the task when the synchronous memory error is not recovered. But I hope this code will not trigger some legacy firmware issues, let's be careful for this, so can we just introduce arch specific callbacks for this? Thanks Hanjun