From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751525AbdBMWpx (ORCPT ); Mon, 13 Feb 2017 17:45:53 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:54556 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbdBMWpu (ORCPT ); Mon, 13 Feb 2017 17:45:50 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 430A060C78 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=tbaicar@codeaurora.org Subject: Re: [PATCH V8 06/10] acpi: apei: panic OS with fatal error status block To: James Morse , zjzhang@codeaurora.org References: <1485969413-23577-1-git-send-email-tbaicar@codeaurora.org> <1485969413-23577-7-git-send-email-tbaicar@codeaurora.org> <589C490A.9080109@arm.com> Cc: christoffer.dall@linaro.org, marc.zyngier@arm.com, pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, matt@codeblueprint.co.uk, robert.moore@intel.com, lv.zheng@intel.com, nkaje@codeaurora.org, mark.rutland@arm.com, akpm@linux-foundation.org, eun.taik.lee@samsung.com, sandeepa.s.prabhu@gmail.com, labbott@redhat.com, shijie.huang@arm.com, rruigrok@codeaurora.org, paul.gortmaker@windriver.com, tn@semihalf.com, fu.wei@linaro.org, rostedt@goodmis.org, bristot@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org, devel@acpica.org, Suzuki.Poulose@arm.com, punit.agrawal@arm.com, astone@redhat.com, harba@codeaurora.org, hanjun.guo@linaro.org, john.garry@huawei.com, shiju.jose@huawei.com From: "Baicar, Tyler" Message-ID: <5b06372d-e389-5157-ccb4-a7b023990d4d@codeaurora.org> Date: Mon, 13 Feb 2017 15:45:44 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <589C490A.9080109@arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello James, On 2/9/2017 3:48 AM, James Morse wrote: > Hi Jonathan, Tyler, > > On 01/02/17 17:16, Tyler Baicar wrote: >> From: "Jonathan (Zhixiong) Zhang" >> >> Even if an error status block's severity is fatal, the kernel does not >> honor the severity level and panic. >> >> With the firmware first model, the platform could inform the OS about a >> fatal hardware error through the non-NMI GHES notification type. The OS >> should panic when a hardware error record is received with this >> severity. >> >> Call panic() after CPER data in error status block is printed if >> severity is fatal, before each error section is handled. >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c >> index 8756172..86c1f15 100644 >> --- a/drivers/acpi/apei/ghes.c >> +++ b/drivers/acpi/apei/ghes.c >> @@ -687,6 +689,13 @@ static int ghes_ack_error(struct acpi_hest_generic_v2 *generic_v2) >> return rc; >> } >> >> +static void __ghes_call_panic(void) >> +{ >> + if (panic_timeout == 0) >> + panic_timeout = ghes_panic_timeout; >> + panic("Fatal hardware error!"); >> +} >> + > __ghes_panic() also has: >> __ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus); > Which prints this estatus regardless of rate limiting and cache-ing. > > [ ... ] > >> @@ -698,6 +707,10 @@ static int ghes_proc(struct ghes *ghes) >> if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus)) > ghes_print_estatus() uses some custom rate limiting '2 messages every 5 > seconds', GHES_SEV_PANIC shares the same limit as GHES_SEV_RECOVERABLE. > > I think its possible to get 2 recoverable messages, then a panic in a 5 second > window. The rate limit will kick in to stop the panic estatus block being > printed, but we still go on to call panic() without the real reason being printed... > > (the caching thing only seems to consider identical messages, given we would > never see two panic messages, I don't think that will cause any problems.) > >> ghes_estatus_cache_add(ghes->generic, ghes->estatus); >> } >> + if (ghes_severity(ghes->estatus->error_severity) >= GHES_SEV_PANIC) { >> + __ghes_call_panic(); >> + } >> + > I think this ghes_severity() then panic() should go above the: >> if (!ghes_estatus_cached(ghes->estatus)) { > and we should call __ghes_print_estatus() here too, to make sure the message > definitely got out! Okay, that makes sense. If we move this up, is there a problem with calling __ghes_panic() instead of making the __ghes_print_estatus() and __ghes_call_panic() calls here? It looks like that will just add a call to oops_begin() and ghes_print_queued_estatus() as well, but this is what ghes_notify_nmi() does if the severity is panic. Thanks, Tyler > With that, > Reviewed-by: James Morse > > > Thanks, > > James -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.