From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756127AbdKCMCV (ORCPT ); Fri, 3 Nov 2017 08:02:21 -0400 Received: from mail.skyhub.de ([5.9.137.197]:37566 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750857AbdKCMCT (ORCPT ); Fri, 3 Nov 2017 08:02:19 -0400 Date: Fri, 3 Nov 2017 13:02:08 +0100 From: Borislav Petkov To: Yazen Ghannam Cc: linux-edac@vger.kernel.org, Tony Luck , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] x86/MCE/AMD: Always give PANIC severity for UC errors IN_KERNEL context Message-ID: <20171103120208.pdnalo4tmwnh6rb2@pd.tnic> References: <1509562746-6313-1-git-send-email-Yazen.Ghannam@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1509562746-6313-1-git-send-email-Yazen.Ghannam@amd.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 01, 2017 at 01:59:06PM -0500, Yazen Ghannam wrote: > From: Yazen Ghannam > > The AMD severity grading function was introduced in v4.1 and has remained > logically unchanged with the exception of a separate SMCA severity grading > function for SMCA systems. The current logic can possibly give > MCE_AR_SEVERITY for uncorrectable errors in kernel context. The system may > then get stuck in a loop as memory_failure() will try to handle the bad > kernel memory and find it busy. > > Return MCE_PANIC_SEVERITY for all UC errors IN_KERNEL context on AMD > systems. > > After: > > b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries") > > was accepted in v4.6, this issue was masked because of the tail-end attempt > at kernel mode recovery in the #MC handler. > > However, uncorrectable errors IN_KERNEL context should always be considered > unrecoverable and cause a panic. > > Fixes: bf80bbd7dcf5 (x86/mce: Add an AMD severities-grading function) > > Signed-off-by: Yazen Ghannam > [ This needs to be reworked to apply to v4.1 and v4.4 stable branches.] > Cc: # 4.9.x > --- > Link: > https://lkml.kernel.org/r/1505830031-9630-1-git-send-email-Yazen.Ghannam@amd.com > > v1->v2: > * Update commit message. > > arch/x86/kernel/cpu/mcheck/mce-severity.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) Applied, thanks. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v2] x86/MCE/AMD: Always give PANIC severity for UC errors IN_KERNEL context From: Borislav Petkov Message-Id: <20171103120208.pdnalo4tmwnh6rb2@pd.tnic> Date: Fri, 3 Nov 2017 13:02:08 +0100 To: Yazen Ghannam Cc: linux-edac@vger.kernel.org, Tony Luck , x86@kernel.org, linux-kernel@vger.kernel.org List-ID: T24gV2VkLCBOb3YgMDEsIDIwMTcgYXQgMDE6NTk6MDZQTSAtMDUwMCwgWWF6ZW4gR2hhbm5hbSB3 cm90ZToKPiBGcm9tOiBZYXplbiBHaGFubmFtIDx5YXplbi5naGFubmFtQGFtZC5jb20+Cj4gCj4g VGhlIEFNRCBzZXZlcml0eSBncmFkaW5nIGZ1bmN0aW9uIHdhcyBpbnRyb2R1Y2VkIGluIHY0LjEg YW5kIGhhcyByZW1haW5lZAo+IGxvZ2ljYWxseSB1bmNoYW5nZWQgd2l0aCB0aGUgZXhjZXB0aW9u IG9mIGEgc2VwYXJhdGUgU01DQSBzZXZlcml0eSBncmFkaW5nCj4gZnVuY3Rpb24gZm9yIFNNQ0Eg c3lzdGVtcy4gVGhlIGN1cnJlbnQgbG9naWMgY2FuIHBvc3NpYmx5IGdpdmUKPiBNQ0VfQVJfU0VW RVJJVFkgZm9yIHVuY29ycmVjdGFibGUgZXJyb3JzIGluIGtlcm5lbCBjb250ZXh0LiBUaGUgc3lz dGVtIG1heQo+IHRoZW4gZ2V0IHN0dWNrIGluIGEgbG9vcCBhcyBtZW1vcnlfZmFpbHVyZSgpIHdp bGwgdHJ5IHRvIGhhbmRsZSB0aGUgYmFkCj4ga2VybmVsIG1lbW9yeSBhbmQgZmluZCBpdCBidXN5 Lgo+IAo+IFJldHVybiBNQ0VfUEFOSUNfU0VWRVJJVFkgZm9yIGFsbCBVQyBlcnJvcnMgSU5fS0VS TkVMIGNvbnRleHQgb24gQU1ECj4gc3lzdGVtcy4KPiAKPiBBZnRlcjoKPiAKPiAgIGIyZjlkNjc4 ZTI4YyAoIng4Ni9tY2U6IENoZWNrIGZvciBmYXVsdHMgdGFnZ2VkIGluIEVYVEFCTEVfQ0xBU1Nf RkFVTFQgZXhjZXB0aW9uIHRhYmxlIGVudHJpZXMiKQo+IAo+IHdhcyBhY2NlcHRlZCBpbiB2NC42 LCB0aGlzIGlzc3VlIHdhcyBtYXNrZWQgYmVjYXVzZSBvZiB0aGUgdGFpbC1lbmQgYXR0ZW1wdAo+ IGF0IGtlcm5lbCBtb2RlIHJlY292ZXJ5IGluIHRoZSAjTUMgaGFuZGxlci4KPiAKPiBIb3dldmVy LCB1bmNvcnJlY3RhYmxlIGVycm9ycyBJTl9LRVJORUwgY29udGV4dCBzaG91bGQgYWx3YXlzIGJl IGNvbnNpZGVyZWQKPiB1bnJlY292ZXJhYmxlIGFuZCBjYXVzZSBhIHBhbmljLgo+IAo+IEZpeGVz OiBiZjgwYmJkN2RjZjUgKHg4Ni9tY2U6IEFkZCBhbiBBTUQgc2V2ZXJpdGllcy1ncmFkaW5nIGZ1 bmN0aW9uKQo+IAo+IFNpZ25lZC1vZmYtYnk6IFlhemVuIEdoYW5uYW0gPHlhemVuLmdoYW5uYW1A YW1kLmNvbT4KPiBbIFRoaXMgbmVlZHMgdG8gYmUgcmV3b3JrZWQgdG8gYXBwbHkgdG8gdjQuMSBh bmQgdjQuNCBzdGFibGUgYnJhbmNoZXMuXQo+IENjOiA8c3RhYmxlQHZnZXIua2VybmVsLm9yZz4g IyA0LjkueAo+IC0tLQo+IExpbms6Cj4gaHR0cHM6Ly9sa21sLmtlcm5lbC5vcmcvci8xNTA1ODMw MDMxLTk2MzAtMS1naXQtc2VuZC1lbWFpbC1ZYXplbi5HaGFubmFtQGFtZC5jb20KPiAKPiB2MS0+ djI6Cj4gKiBVcGRhdGUgY29tbWl0IG1lc3NhZ2UuCj4gCj4gIGFyY2gveDg2L2tlcm5lbC9jcHUv bWNoZWNrL21jZS1zZXZlcml0eS5jIHwgNyArKystLS0tCj4gIDEgZmlsZSBjaGFuZ2VkLCAzIGlu c2VydGlvbnMoKyksIDQgZGVsZXRpb25zKC0pCgpBcHBsaWVkLCB0aGFua3MuCg==