[PATCH v2 1/2] mm, kasan: don't call kasan_krealloc() from ksize().

From: Alexander Potapenko
Date: Wed Apr 13 2016 - 07:20:35 EST


Instead of calling kasan_krealloc(), which replaces the memory allocation
stack ID (if stack depot is used), just unpoison the whole memory chunk.

Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
v2: - splitted v1 into two patches
---
mm/slab.c | 2 +-
mm/slub.c | 5 +++--
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 17e2848..de46319 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4324,7 +4324,7 @@ size_t ksize(const void *objp)
/* We assume that ksize callers could use the whole allocated area,
* so we need to unpoison this area.
*/
- kasan_krealloc(objp, size, GFP_NOWAIT);
+ kasan_unpoison_shadow(objp, size);

return size;
}
diff --git a/mm/slub.c b/mm/slub.c
index 4dbb109e..62194e2 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3635,8 +3635,9 @@ size_t ksize(const void *object)
{
size_t size = __ksize(object);
/* We assume that ksize callers could use whole allocated area,
- so we need unpoison this area. */
- kasan_krealloc(object, size, GFP_NOWAIT);
+ * so we need to unpoison this area.
+ */
+ kasan_unpoison_shadow(object, size);
return size;
}
EXPORT_SYMBOL(ksize);
--
2.8.0.rc3.226.g39d4020