kasan: introduce kasan_get_alloc_track

Add a kasan_get_alloc_track() helper that fetches alloc_track for a slab
object and use this helper in the common reporting code.

For now, the implementations of this helper are the same for the Generic
and tag-based modes, but they will diverge later in the series.

This change hides references to alloc_meta from the common reporting code.
This is desired as only the Generic mode will be using per-object
metadata after this series.

Link: https://lkml.kernel.org/r/0c365a35f4a833fff46f9d42c3212b32f7166556.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 98c451a3b01f8387e741398eb5007d1c5c72319c..f212b9ae57b597510ca6530c0a0158ec727b345d 100644 (file)
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -381,8 +381,20 @@ void kasan_save_free_info(struct kmem_cache *cache,
        *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK;
 }
 
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+                                               void *object)
+{
+       struct kasan_alloc_meta *alloc_meta;
+
+       alloc_meta = kasan_get_alloc_meta(cache, object);
+       if (!alloc_meta)
+               return NULL;
+
+       return &alloc_meta->alloc_track;
+}
+
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-                               void *object, u8 tag)
+                                               void *object, u8 tag)
 {
        if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREETRACK)
                return NULL;

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 30ff341b6d35e9517ec0fbf9f1a0a57574e2f160..b65a51349c51b86aa047e09de7f5806b7bdaae67 100644 (file)
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -283,8 +283,10 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
 void kasan_set_track(struct kasan_track *track, gfp_t flags);
 void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
 void kasan_save_free_info(struct kmem_cache *cache, void *object, u8 tag);
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+                                               void *object);
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-                               void *object, u8 tag);
+                                               void *object, u8 tag);
 
 #if defined(CONFIG_KASAN_GENERIC) && \
        (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index cd9f5c7fc6db1e5d7dbce344c71a3a1ac47792d3..5d225d7d9c4c783cf579cf263d4932f97ed94185 100644 (file)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -255,12 +255,12 @@ static void describe_object_addr(struct kmem_cache *cache, void *object,
 static void describe_object_stacks(struct kmem_cache *cache, void *object,
                                        const void *addr, u8 tag)
 {
-       struct kasan_alloc_meta *alloc_meta;
+       struct kasan_track *alloc_track;
        struct kasan_track *free_track;
 
-       alloc_meta = kasan_get_alloc_meta(cache, object);
-       if (alloc_meta) {
-               print_track(&alloc_meta->alloc_track, "Allocated");
+       alloc_track = kasan_get_alloc_track(cache, object);
+       if (alloc_track) {
+               print_track(alloc_track, "Allocated");
                pr_err("\n");
        }
 

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index e0e5de8ce834d0c6e0298ee0ba64e0475fec1205..7b1fc8e7c99c9f07b70999945e3e6bf408f3e45f 100644 (file)
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -38,8 +38,20 @@ void kasan_save_free_info(struct kmem_cache *cache,
        kasan_set_track(&alloc_meta->free_track, GFP_NOWAIT);
 }
 
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+                                               void *object)
+{
+       struct kasan_alloc_meta *alloc_meta;
+
+       alloc_meta = kasan_get_alloc_meta(cache, object);
+       if (!alloc_meta)
+               return NULL;
+
+       return &alloc_meta->alloc_track;
+}
+
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-                               void *object, u8 tag)
+                                               void *object, u8 tag)
 {
        struct kasan_alloc_meta *alloc_meta;