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authorAndrey Konovalov <andreyknvl@google.com>2017-05-04 00:56:34 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-04 01:52:12 +0300
commitdb429f16e0b472292000fd53b63ebd7221a9856e (patch)
tree620b88b09d6fda9530222fc93fa1dd5e163ac229
parentb6b72f4919c121bee5890732e0b8de2ab99c8dbc (diff)
downloadlinux-db429f16e0b472292000fd53b63ebd7221a9856e.tar.xz
kasan: simplify address description logic
Simplify logic for describing a memory address. Add addr_to_page() helper function. Makes the code easier to follow. Link: http://lkml.kernel.org/r/20170302134851.101218-5-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/kasan/report.c37
1 files changed, 21 insertions, 16 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 7d24363edd66..a82d6896062b 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -190,11 +190,18 @@ static void print_track(struct kasan_track *track, const char *prefix)
}
}
-static void kasan_object_err(struct kmem_cache *cache, void *object)
+static struct page *addr_to_page(const void *addr)
+{
+ if ((addr >= (void *)PAGE_OFFSET) &&
+ (addr < high_memory))
+ return virt_to_head_page(addr);
+ return NULL;
+}
+
+static void describe_object(struct kmem_cache *cache, void *object)
{
struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object);
- dump_stack();
pr_err("Object at %p, in cache %s size: %d\n", object, cache->name,
cache->object_size);
@@ -213,34 +220,32 @@ void kasan_report_double_free(struct kmem_cache *cache, void *object,
kasan_start_report(&flags);
pr_err("BUG: Double free or freeing an invalid pointer\n");
pr_err("Unexpected shadow byte: 0x%hhX\n", shadow);
- kasan_object_err(cache, object);
+ dump_stack();
+ describe_object(cache, object);
kasan_end_report(&flags);
}
static void print_address_description(struct kasan_access_info *info)
{
const void *addr = info->access_addr;
+ struct page *page = addr_to_page(addr);
- if ((addr >= (void *)PAGE_OFFSET) &&
- (addr < high_memory)) {
- struct page *page = virt_to_head_page(addr);
-
- if (PageSlab(page)) {
- void *object;
- struct kmem_cache *cache = page->slab_cache;
- object = nearest_obj(cache, page,
- (void *)info->access_addr);
- kasan_object_err(cache, object);
- return;
- }
+ if (page)
dump_page(page, "kasan: bad access detected");
+
+ dump_stack();
+
+ if (page && PageSlab(page)) {
+ struct kmem_cache *cache = page->slab_cache;
+ void *object = nearest_obj(cache, page, (void *)addr);
+
+ describe_object(cache, object);
}
if (kernel_or_module_addr(addr)) {
if (!init_task_stack_addr(addr))
pr_err("Address belongs to variable %pS\n", addr);
}
- dump_stack();
}
static bool row_is_guilty(const void *row, const void *guilty)