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: [4.13,18/28] x86/MCE/AMD: Always give panic severity for UC errors in kernel context From: Greg Kroah-Hartman Message-Id: <20171119144312.511384056@linuxfoundation.org> Date: Sun, 19 Nov 2017 15:44:05 +0100 To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yazen Ghannam , Borislav Petkov , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Tony Luck , linux-edac , Ingo Molnar List-ID: NC4xMy1zdGFibGUgcmV2aWV3IHBhdGNoLiAgSWYgYW55b25lIGhhcyBhbnkgb2JqZWN0aW9ucywg cGxlYXNlIGxldCBtZSBrbm93LgoKLS0tLS0tLS0tLS0tLS0tLS0tCgpGcm9tOiBZYXplbiBHaGFu bmFtIDx5YXplbi5naGFubmFtQGFtZC5jb20+Cgpjb21taXQgZDY1ZGZjODFiYjM4OTRmZGI2OGNi Yzc0YmJmNWZiNDhkMjM1NDA3MSB1cHN0cmVhbS4KClRoZSBBTUQgc2V2ZXJpdHkgZ3JhZGluZyBm dW5jdGlvbiB3YXMgaW50cm9kdWNlZCBpbiBrZXJuZWwgNC4xLiBUaGUKY3VycmVudCBsb2dpYyBj YW4gcG9zc2libHkgZ2l2ZSBNQ0VfQVJfU0VWRVJJVFkgZm9yIHVuY29ycmVjdGFibGUKZXJyb3Jz IGluIGtlcm5lbCBjb250ZXh0LiBUaGUgc3lzdGVtIG1heSB0aGVuIGdldCBzdHVjayBpbiBhIGxv b3AgYXMKbWVtb3J5X2ZhaWx1cmUoKSB3aWxsIHRyeSB0byBoYW5kbGUgdGhlIGJhZCBrZXJuZWwg bWVtb3J5IGFuZCBmaW5kIGl0CmJ1c3kuCgpSZXR1cm4gTUNFX1BBTklDX1NFVkVSSVRZIGZvciBh bGwgVUMgZXJyb3JzIElOX0tFUk5FTCBjb250ZXh0IG9uIEFNRApzeXN0ZW1zLgoKQWZ0ZXI6Cgog IGIyZjlkNjc4ZTI4YyAoIng4Ni9tY2U6IENoZWNrIGZvciBmYXVsdHMgdGFnZ2VkIGluIEVYVEFC TEVfQ0xBU1NfRkFVTFQgZXhjZXB0aW9uIHRhYmxlIGVudHJpZXMiKQoKd2FzIGFjY2VwdGVkIGlu IHY0LjYsIHRoaXMgaXNzdWUgd2FzIG1hc2tlZCBiZWNhdXNlIG9mIHRoZSB0YWlsLWVuZCBhdHRl bXB0CmF0IGtlcm5lbCBtb2RlIHJlY292ZXJ5IGluIHRoZSAjTUMgaGFuZGxlci4KCkhvd2V2ZXIs IHVuY29ycmVjdGFibGUgZXJyb3JzIElOX0tFUk5FTCBjb250ZXh0IHNob3VsZCBhbHdheXMgYmUg Y29uc2lkZXJlZAp1bnJlY292ZXJhYmxlIGFuZCBjYXVzZSBhIHBhbmljLgoKU2lnbmVkLW9mZi1i eTogWWF6ZW4gR2hhbm5hbSA8eWF6ZW4uZ2hhbm5hbUBhbWQuY29tPgpTaWduZWQtb2ZmLWJ5OiBC b3Jpc2xhdiBQZXRrb3YgPGJwQHN1c2UuZGU+CkNjOiBMaW51cyBUb3J2YWxkcyA8dG9ydmFsZHNA bGludXgtZm91bmRhdGlvbi5vcmc+CkNjOiBQZXRlciBaaWpsc3RyYSA8cGV0ZXJ6QGluZnJhZGVh ZC5vcmc+CkNjOiBUaG9tYXMgR2xlaXhuZXIgPHRnbHhAbGludXRyb25peC5kZT4KQ2M6IFRvbnkg THVjayA8dG9ueS5sdWNrQGludGVsLmNvbT4KQ2M6IGxpbnV4LWVkYWMgPGxpbnV4LWVkYWNAdmdl ci5rZXJuZWwub3JnPgpGaXhlczogYmY4MGJiZDdkY2Y1ICh4ODYvbWNlOiBBZGQgYW4gQU1EIHNl dmVyaXRpZXMtZ3JhZGluZyBmdW5jdGlvbikKTGluazogaHR0cDovL2xrbWwua2VybmVsLm9yZy9y LzIwMTcxMTA2MTc0NjMzLjEzNTc2LTEtYnBAYWxpZW44LmRlClNpZ25lZC1vZmYtYnk6IEluZ28g TW9sbmFyIDxtaW5nb0BrZXJuZWwub3JnPgpTaWduZWQtb2ZmLWJ5OiBHcmVnIEtyb2FoLUhhcnRt YW4gPGdyZWdraEBsaW51eGZvdW5kYXRpb24ub3JnPgotLS0KIGFyY2gveDg2L2tlcm5lbC9jcHUv bWNoZWNrL21jZS1zZXZlcml0eS5jIHwgICAgNyArKystLS0tCiAxIGZpbGUgY2hhbmdlZCwgMyBp bnNlcnRpb25zKCspLCA0IGRlbGV0aW9ucygtKQoKCgotLQpUbyB1bnN1YnNjcmliZSBmcm9tIHRo aXMgbGlzdDogc2VuZCB0aGUgbGluZSAidW5zdWJzY3JpYmUgbGludXgtZWRhYyIgaW4KdGhlIGJv ZHkgb2YgYSBtZXNzYWdlIHRvIG1ham9yZG9tb0B2Z2VyLmtlcm5lbC5vcmcKTW9yZSBtYWpvcmRv bW8gaW5mbyBhdCAgaHR0cDovL3ZnZXIua2VybmVsLm9yZy9tYWpvcmRvbW8taW5mby5odG1sCgot LS0gYS9hcmNoL3g4Ni9rZXJuZWwvY3B1L21jaGVjay9tY2Utc2V2ZXJpdHkuYworKysgYi9hcmNo L3g4Ni9rZXJuZWwvY3B1L21jaGVjay9tY2Utc2V2ZXJpdHkuYwpAQCAtMjQ1LDYgKzI0NSw5IEBA IHN0YXRpYyBpbnQgbWNlX3NldmVyaXR5X2FtZChzdHJ1Y3QgbWNlICoKIAogCWlmIChtLT5zdGF0 dXMgJiBNQ0lfU1RBVFVTX1VDKSB7CiAKKwkJaWYgKGN0eCA9PSBJTl9LRVJORUwpCisJCQlyZXR1 cm4gTUNFX1BBTklDX1NFVkVSSVRZOworCiAJCS8qCiAJCSAqIE9uIG9sZGVyIHN5c3RlbXMgd2hl cmUgb3ZlcmZsb3dfcmVjb3YgZmxhZyBpcyBub3QgcHJlc2VudCwgd2UKIAkJICogc2hvdWxkIHNp bXBseSBwYW5pYyBpZiBhbiBlcnJvciBvdmVyZmxvdyBvY2N1cnMuIElmCkBAIC0yNTUsMTAgKzI1 OCw2IEBAIHN0YXRpYyBpbnQgbWNlX3NldmVyaXR5X2FtZChzdHJ1Y3QgbWNlICoKIAkJCWlmICht Y2VfZmxhZ3Muc21jYSkKIAkJCQlyZXR1cm4gbWNlX3NldmVyaXR5X2FtZF9zbWNhKG0sIGN0eCk7 CiAKLQkJCS8qIHNvZnR3YXJlIGNhbiB0cnkgdG8gY29udGFpbiAqLwotCQkJaWYgKCEobS0+bWNn c3RhdHVzICYgTUNHX1NUQVRVU19SSVBWKSAmJiAoY3R4ID09IElOX0tFUk5FTCkpCi0JCQkJcmV0 dXJuIE1DRV9QQU5JQ19TRVZFUklUWTsKLQogCQkJLyoga2lsbCBjdXJyZW50IHByb2Nlc3MgKi8K IAkJCXJldHVybiBNQ0VfQVJfU0VWRVJJVFk7CiAJCX0gZWxzZSB7Cg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753483AbdKSOoq (ORCPT ); Sun, 19 Nov 2017 09:44:46 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53536 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753480AbdKSOom (ORCPT ); Sun, 19 Nov 2017 09:44:42 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yazen Ghannam , Borislav Petkov , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Tony Luck , linux-edac , Ingo Molnar Subject: [PATCH 4.13 18/28] x86/MCE/AMD: Always give panic severity for UC errors in kernel context Date: Sun, 19 Nov 2017 15:44:05 +0100 Message-Id: <20171119144312.511384056@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171119144311.441716251@linuxfoundation.org> References: <20171119144311.441716251@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yazen Ghannam commit d65dfc81bb3894fdb68cbc74bbf5fb48d2354071 upstream. The AMD severity grading function was introduced in kernel 4.1. 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. Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-edac Fixes: bf80bbd7dcf5 (x86/mce: Add an AMD severities-grading function) Link: http://lkml.kernel.org/r/20171106174633.13576-1-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mcheck/mce-severity.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -245,6 +245,9 @@ static int mce_severity_amd(struct mce * if (m->status & MCI_STATUS_UC) { + if (ctx == IN_KERNEL) + return MCE_PANIC_SEVERITY; + /* * On older systems where overflow_recov flag is not present, we * should simply panic if an error overflow occurs. If @@ -255,10 +258,6 @@ static int mce_severity_amd(struct mce * if (mce_flags.smca) return mce_severity_amd_smca(m, ctx); - /* software can try to contain */ - if (!(m->mcgstatus & MCG_STATUS_RIPV) && (ctx == IN_KERNEL)) - return MCE_PANIC_SEVERITY; - /* kill current process */ return MCE_AR_SEVERITY; } else {