From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967306AbdCXTgM (ORCPT ); Fri, 24 Mar 2017 15:36:12 -0400 Received: from mail-wm0-f54.google.com ([74.125.82.54]:38061 "EHLO mail-wm0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967013AbdCXTcy (ORCPT ); Fri, 24 Mar 2017 15:32:54 -0400 From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrey Konovalov Subject: [PATCH v4 1/9] kasan: introduce helper functions for determining bug type Date: Fri, 24 Mar 2017 20:32:27 +0100 Message-Id: <69485dff9439fca82343965d3746b52c36716d91.1490383597.git.andreyknvl@google.com> X-Mailer: git-send-email 2.12.1.578.ge9c3154ca4-goog In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce get_shadow_bug_type() function, which determines bug type based on the shadow value for a particular kernel address. Introduce get_wild_bug_type() function, which determines bug type for addresses which don't have a corresponding shadow value. Signed-off-by: Andrey Konovalov --- mm/kasan/report.c | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index f479365530b6..e3af37b7a74c 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -49,7 +49,13 @@ static const void *find_first_bad_addr(const void *addr, size_t size) return first_bad_addr; } -static void print_error_description(struct kasan_access_info *info) +static bool addr_has_shadow(struct kasan_access_info *info) +{ + return (info->access_addr >= + kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); +} + +static const char *get_shadow_bug_type(struct kasan_access_info *info) { const char *bug_type = "unknown-crash"; u8 *shadow_addr; @@ -96,6 +102,27 @@ static void print_error_description(struct kasan_access_info *info) break; } + return bug_type; +} + +static const char *get_wild_bug_type(struct kasan_access_info *info) +{ + const char *bug_type; + + if ((unsigned long)info->access_addr < PAGE_SIZE) + bug_type = "null-ptr-deref"; + else if ((unsigned long)info->access_addr < TASK_SIZE) + bug_type = "user-memory-access"; + else + bug_type = "wild-memory-access"; + + return bug_type; +} + +static void print_error_description(struct kasan_access_info *info) +{ + const char *bug_type = get_shadow_bug_type(info); + pr_err("BUG: KASAN: %s in %pS at addr %p\n", bug_type, (void *)info->ip, info->access_addr); @@ -265,18 +292,11 @@ static void print_shadow_for_address(const void *addr) static void kasan_report_error(struct kasan_access_info *info) { unsigned long flags; - const char *bug_type; kasan_start_report(&flags); - if (info->access_addr < - kasan_shadow_to_mem((void *)KASAN_SHADOW_START)) { - if ((unsigned long)info->access_addr < PAGE_SIZE) - bug_type = "null-ptr-deref"; - else if ((unsigned long)info->access_addr < TASK_SIZE) - bug_type = "user-memory-access"; - else - bug_type = "wild-memory-access"; + if (!addr_has_shadow(info)) { + const char *bug_type = get_wild_bug_type(info); pr_err("BUG: KASAN: %s on address %p\n", bug_type, info->access_addr); pr_err("%s of size %zu by task %s/%d\n", -- 2.12.1.578.ge9c3154ca4-goog