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Subject[PATCH 1/8] mm: slab: provide krealloc_array()
Date
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

When allocating an array of elements, users should check for
multiplication overflow or preferably use one of the provided helpers
like: kmalloc_array().

There's no krealloc_array() counterpart but there are many users who use
regular krealloc() to reallocate arrays. Let's provide an actual
krealloc_array() implementation.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
include/linux/slab.h | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index dd6897f62010..0e6683affee7 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -592,6 +592,17 @@ static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
return __kmalloc(bytes, flags);
}

+static __must_check inline void *
+krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t flags)
+{
+ size_t bytes;
+
+ if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
+ return NULL;
+
+ return krealloc(p, bytes, flags);
+}
+
/**
* kcalloc - allocate memory for an array. The memory is set to zero.
* @n: number of elements.
--
2.29.1
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