From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752350AbdK1Ht7 (ORCPT ); Tue, 28 Nov 2017 02:49:59 -0500 Received: from mail-pg0-f67.google.com ([74.125.83.67]:43965 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752261AbdK1Hty (ORCPT ); Tue, 28 Nov 2017 02:49:54 -0500 X-Google-Smtp-Source: AGs4zMaEOzwKPnP9V5SQgfYAOEXuIYdyQDEa6Wg2Yo7jflPrN1ECfDmcZgKzeyAX04z444Dn2mszPg== From: js1304@gmail.com X-Google-Original-From: iamjoonsoo.kim@lge.com To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Namhyung Kim , Wengang Wang , Joonsoo Kim Subject: [PATCH 10/18] vchecker: Use __GFP_ATOMIC to save stacktrace Date: Tue, 28 Nov 2017 16:48:45 +0900 Message-Id: <1511855333-3570-11-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Namhyung Kim Since we're finding a cause of broken data, it'd be desired not to miss any suspects. It doesn't use GFP_ATOMIC since it includes __GFP_HIGH which is for system making forward progress. It also adds a WARN_ON whenever it fails to allocate pages even with __GFP_ATOMIC. Signed-off-by: Namhyung Kim Signed-off-by: Joonsoo Kim --- mm/kasan/vchecker.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/kasan/vchecker.c b/mm/kasan/vchecker.c index 6b3824f..df480d5 100644 --- a/mm/kasan/vchecker.c +++ b/mm/kasan/vchecker.c @@ -301,13 +301,20 @@ static noinline depot_stack_handle_t save_stack(int skip, bool *is_new) .max_entries = VCHECKER_STACK_DEPTH, .skip = skip, }; + depot_stack_handle_t handle; save_stack_trace(&trace); if (trace.nr_entries != 0 && trace.entries[trace.nr_entries-1] == ULONG_MAX) trace.nr_entries--; - return depot_save_stack(NULL, &trace, GFP_NOWAIT, is_new); + if (trace.nr_entries == 0) + return 0; + + handle = depot_save_stack(NULL, &trace, __GFP_ATOMIC, is_new); + WARN_ON(!handle); + + return handle; } static ssize_t vchecker_type_write(struct file *filp, const char __user *ubuf, -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 064FF6B0298 for ; Tue, 28 Nov 2017 02:49:55 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id t76so20411939pfk.7 for ; Mon, 27 Nov 2017 23:49:54 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id h88sor9466669pfk.10.2017.11.27.23.49.53 for (Google Transport Security); Mon, 27 Nov 2017 23:49:54 -0800 (PST) From: js1304@gmail.com Subject: [PATCH 10/18] vchecker: Use __GFP_ATOMIC to save stacktrace Date: Tue, 28 Nov 2017 16:48:45 +0900 Message-Id: <1511855333-3570-11-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Namhyung Kim , Wengang Wang , Joonsoo Kim From: Namhyung Kim Since we're finding a cause of broken data, it'd be desired not to miss any suspects. It doesn't use GFP_ATOMIC since it includes __GFP_HIGH which is for system making forward progress. It also adds a WARN_ON whenever it fails to allocate pages even with __GFP_ATOMIC. Signed-off-by: Namhyung Kim Signed-off-by: Joonsoo Kim --- mm/kasan/vchecker.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/kasan/vchecker.c b/mm/kasan/vchecker.c index 6b3824f..df480d5 100644 --- a/mm/kasan/vchecker.c +++ b/mm/kasan/vchecker.c @@ -301,13 +301,20 @@ static noinline depot_stack_handle_t save_stack(int skip, bool *is_new) .max_entries = VCHECKER_STACK_DEPTH, .skip = skip, }; + depot_stack_handle_t handle; save_stack_trace(&trace); if (trace.nr_entries != 0 && trace.entries[trace.nr_entries-1] == ULONG_MAX) trace.nr_entries--; - return depot_save_stack(NULL, &trace, GFP_NOWAIT, is_new); + if (trace.nr_entries == 0) + return 0; + + handle = depot_save_stack(NULL, &trace, __GFP_ATOMIC, is_new); + WARN_ON(!handle); + + return handle; } static ssize_t vchecker_type_write(struct file *filp, const char __user *ubuf, -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org