On 17.06.20 00:54, William Kucharski wrote:
> Other mm routines such as kfree() and kzfree() silently do the right
> thing if passed a NULL pointer, so ksize() should do the same.
> 
> Signed-off-by: William Kucharski <william.kuchar...@oracle.com>
> ---
>  mm/slab_common.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 9e72ba224175..2bff01ad94d8 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -1660,10 +1660,9 @@ static __always_inline void *__do_krealloc(const void 
> *p, size_t new_size,
>                                          gfp_t flags)
>  {
>       void *ret;
> -     size_t ks = 0;
> +     size_t ks;
>  
> -     if (p)
> -             ks = ksize(p);
> +     ks = ksize(p);
>  
>       if (ks >= new_size) {
>               p = kasan_krealloc((void *)p, new_size, flags);
> @@ -1723,10 +1722,9 @@ void kzfree(const void *p)
>       size_t ks;
>       void *mem = (void *)p;
>  
> -     if (unlikely(ZERO_OR_NULL_PTR(mem)))
> -             return;
>       ks = ksize(mem);
> -     memset(mem, 0, ks);
> +     if (ks)
> +             memset(mem, 0, ks);
>       kfree(mem);
>  }
>  EXPORT_SYMBOL(kzfree);
> @@ -1749,8 +1747,6 @@ size_t ksize(const void *objp)
>  {
>       size_t size;
>  
> -     if (WARN_ON_ONCE(!objp))
> -             return 0;
>       /*
>        * We need to check that the pointed to object is valid, and only then
>        * unpoison the shadow memory below. We use __kasan_check_read(), to
> @@ -1764,7 +1760,7 @@ size_t ksize(const void *objp)
>        * We want to perform the check before __ksize(), to avoid potentially
>        * crashing in __ksize() due to accessing invalid metadata.
>        */
> -     if (unlikely(objp == ZERO_SIZE_PTR) || !__kasan_check_read(objp, 1))
> +     if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1))
>               return 0;
>  
>       size = __ksize(objp);
> 

Reviewed-by: David Hildenbrand <da...@redhat.com>

-- 
Thanks,

David / dhildenb

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