From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: Re: [PATCH V8 06/10] acpi: apei: panic OS with fatal error status block Date: Wed, 15 Feb 2017 12:13:09 +0000 Message-ID: <58A445D5.7030501@arm.com> References: <1485969413-23577-1-git-send-email-tbaicar@codeaurora.org> <1485969413-23577-7-git-send-email-tbaicar@codeaurora.org> <589C490A.9080109@arm.com> <5b06372d-e389-5157-ccb4-a7b023990d4d@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5b06372d-e389-5157-ccb4-a7b023990d4d-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Baicar, Tyler" , zjzhang-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org Cc: christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org, robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, lv.zheng-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, nkaje-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, eun.taik.lee-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, sandeepa.s.prabhu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, labbott-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, shijie.huang-5wv7dgnIgG8@public.gmane.org, rruigrok-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, tn-nYOzD4b6Jr9Wk0Htik3J/w@public.gmane.org, fu.wei-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, bristot-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-E0kO6a4B6psdnm+yROfE0A@public.gmane.org, Suzuki.Poulose-5wv7dgnIgG8@public.gmane.org, punit.agr List-Id: linux-efi@vger.kernel.org Hi Tyler, On 13/02/17 22:45, Baicar, Tyler wrote: > On 2/9/2017 3:48 AM, James Morse wrote: >> 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. [...] >>> 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. I don't think the queued stuff is relevant, isn't that just for x86-NMI messages that it doesn't print out directly? A quick grep shows arm64 doesn't have oops_begin(), you may have to add some equivalent mechanism. Lets try and avoid that rabbit hole! Given __ghes_panic() calls __ghes_print_estatus() too, you could try moving that into your new __ghes_call_panic().... or whatever results in the least lines changed! Thanks, James