From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout11.his.huawei.com (canpmsgout11.his.huawei.com [113.46.200.226]) (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 467D119E819; Thu, 28 May 2026 01:48:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.226 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779932936; cv=none; b=Sy1lWeqU4MAI6v8IZuFcTz/xLKrt6IxmOZqSQnXPhRZ+ZhyJR9N1Yqf6BWl0dwY2WYw+P48FNg7DLUwDw9r0anB4QyahdFm+aQardsSIfxQ6ejElD8jfneAVLBVYMIjhx8PMKrS/7/wrjyjOKT/6fy5jBL3aZ0v9+tq8XHaXXfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779932936; c=relaxed/simple; bh=Iaj4GspoZ6TmHSGBSlUoa6GHOAxS0ZdF81vbej3S4IU=; h=Message-ID:Date:MIME-Version:CC:Subject:To:References:From: In-Reply-To:Content-Type; b=N5Dfok2gDUCRKoHVBJ65Vcqcrb6YDiiulnrgJ1jEoICbyAWL719mlYDVYtHHDSojmifOVdf9LXNkfsUCOQQ0wflsYt1b/SXxf0z2VaHgXrXJxReyXq4MVVtwRweiSbIa3hgfTdWHA6D5uzs1CmM8pwGbvLEwOwg0LeHTo+ZBmTk= 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; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=P5Aj2Fok; arc=none smtp.client-ip=113.46.200.226 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="P5Aj2Fok" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=45Oce1pquAJ/ph1CD+IV4tnCpI3/A8JF18u5iSlgQ6E=; b=P5Aj2Foka2SXI/yWFmcQVzF1p22oxugSORQnKUOEP2x/dor1NhdJJ2UqHztZg+IzD5lNnLkD7 5iAOY8EZvz3CY7St37xpVMSCCQbk4aBRWwKUpA6Q83biZWzrZZsG2hUVYFKd1vk51mhoNjSqyP9 SJTzAkrZV3rzV1MmnO2piEg= Received: from mail.maildlp.com (unknown [172.19.163.15]) by canpmsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4gQq2N5whqzKm98; Thu, 28 May 2026 09:41:00 +0800 (CST) Received: from kwepemj100016.china.huawei.com (unknown [7.202.194.10]) by mail.maildlp.com (Postfix) with ESMTPS id 5C43E40571; Thu, 28 May 2026 09:48:49 +0800 (CST) Received: from [10.174.177.15] (10.174.177.15) by kwepemj100016.china.huawei.com (7.202.194.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 28 May 2026 09:48:48 +0800 Message-ID: Date: Thu, 28 May 2026 09:48:47 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird CC: , , , , , , , , Subject: Re: [PATCH v2] ACPI: APEI: Handle repeated SEA error storms To: , , , , , , , , , , References: <20260527082707.2013499-1-hejunhao3@h-partners.com> From: mawupeng In-Reply-To: <20260527082707.2013499-1-hejunhao3@h-partners.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemj100016.china.huawei.com (7.202.194.10) On 周三 2026-5-27 16:27, Junhao He wrote: > When hardware memory corruption occurs and a user process accesses the > corrupted page, the CPU triggers a Synchronous External Abort (SEA). > The kernel invokes do_sea() to handle the exception, which calls > memory_failure() to handle the faulty page. > > Scenario 1: Memory Error Interrupt First, then SEA > The page is already poisoned by the memory error interrupt path. The > subsequent SEA handler sends a SIGBUS to the task, which accesses the > poisoned page. This flow is correct. > > Scenario 2: SEA first, then memory error interrupt (problematic scenario) > If a user task directly accesses corrupted memory through a PFNMAP-style > mapping (e.g., devmem), the page may still be in the free-buddy state when > SEA is handled. In this case, memory_failure() will poison the page without > invoking kill_accessing_process(), and then takes the free-buddy recovery > path. > > After the CPU returns to the task context, the task re-enters the SEA > handler due to the same access. However, ghes_estatus_cached() suppresses > all subsequent entries during the 10-second window, preventing > ghes_do_proc() from being called. This suppression blocks the > MF_ACTION_REQUIRED-based SIGBUS delivery, causing the kernel to fail to > kill the task immediately. Consequently, the process keeps re-entering > the SEA handler, leading to an SEA storm. Later, the memory error > interrupt path also cannot kill the task, leaving the system stuck in > this repeated loop. > > The following error logs are explained using the devmem process: > NOTICE: SEA Handle > [Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 9 > [Hardware Error]: event severity: recoverable > [Hardware Error]: section_type: ARM processor error > [Hardware Error]: physical fault address: 0x0000001000093c00 > [T54990] Memory failure: 0x1000093: recovery action for free buddy page: Recovered > [ T9955] EDAC MC0: 1 UE Multi-bit ECC on unknown memory > (page:0x1000093 offset:0xc00 grain:1 - APEI location: ...) > NOTICE: SEA Handle > NOTICE: SEA Handle > ... > ... ---> SEA storm > ... > NOTICE: SEA Handle > [ T9955] Memory failure: 0x1000093: already hardware poisoned > ghes_print_estatus: 1 callbacks suppressed > [Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 9 > [Hardware Error]: event severity: recoverable > [Hardware Error]: section_type: ARM processor error > [Hardware Error]: physical fault address: 0x0000001000093c00 > [T54990] Memory failure: 0x1000093: already hardware poisoned > [T54990] 0x1000093: Sending SIGBUS to devmem:54990 due to hardware memory corruption > > To resolve this, return an error when encountering the same SEA again. > The subsequent SEA handler invocation uses arm64_notify_die() to send a > SIGBUS signal to the task, which terminates the process and prevents it > from re-entering the handler loop. > > Signed-off-by: Junhao He Reviewed-by: Wupeng Ma