[PATCH] slab: warning if total alloc size overflow

[Yang Bai <hamo.by@xxxxxxxxx>]

Before, if the total alloc size is overflow,
we just return NULL like alloc fail. But they
are two different type problems. The former looks
more like a programming problem. So add a warning
here.

Signed-off-by: Yang Bai <hamo.by@xxxxxxxxx>
---
 include/linux/slab.h |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 573c809..5865237 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -242,8 +242,10 @@ size_t ksize(const void *);
  */
 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 {
-	if (size != 0 && n > ULONG_MAX / size)
+	if (size != 0 && n > ULONG_MAX / size) {
+		WARN(1, "Alloc memory size (%lu * %lu) overflow.", n, size);
 		return NULL;
+	}
 	return __kmalloc(n * size, flags | __GFP_ZERO);
 }
 
-- 
1.7.9

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