From: Andrey Konovalov <andreyknvl@google.com>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Cc: Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v3 1/9] kasan: introduce helper functions for determining bug type
Date: Mon, 6 Mar 2017 17:00:01 +0100 [thread overview]
Message-ID: <1f1fa8b358f8bb24bc80d585c654a7b2b33b318b.1488815789.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1488815789.git.andreyknvl@google.com>
In-Reply-To: <cover.1488815789.git.andreyknvl@google.com>
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 <andreyknvl@google.com>
---
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",
--
2.12.0.rc1.440.g5b76565f74-goog
--
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next prev parent reply other threads:[~2017-03-06 16:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-06 16:00 [PATCH v3 0/9] kasan: improve error reports Andrey Konovalov
2017-03-06 16:00 ` Andrey Konovalov [this message]
2017-03-06 16:00 ` [PATCH v3 2/9] kasan: unify report headers Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 3/9] kasan: change allocation and freeing stack traces headers Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 4/9] kasan: simplify address description logic Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 5/9] kasan: change report header Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 6/9] kasan: improve slab object description Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 7/9] kasan: print page description after stacks Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 8/9] kasan: improve double-free report format Andrey Konovalov
2017-03-06 16:00 ` [PATCH v3 9/9] kasan: separate report parts by empty lines Andrey Konovalov
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