mm: remove __krealloc

Since 5.5-rc1 the last user of this function is gone, so remove the
functionality.

See commit
2ad9d7747c ("netfilter: conntrack: free extension area immediately")
for details.

Link: http://lkml.kernel.org/r/20191212223442.22141-1-fw@strlen.de
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/slab.h

@@ -184,7 +184,6 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *);
 /*
  * Common kmalloc functions provided by all allocators
  */
-void * __must_check __krealloc(const void *, size_t, gfp_t);
 void * __must_check krealloc(const void *, size_t, gfp_t);
 void kfree(const void *);
 void kzfree(const void *);

mm/slab_common.c

@@ -1676,28 +1676,6 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size,
 	return ret;
 }
 
-/**
- * __krealloc - like krealloc() but don't free @p.
- * @p: object to reallocate memory for.
- * @new_size: how many bytes of memory are required.
- * @flags: the type of memory to allocate.
- *
- * This function is like krealloc() except it never frees the originally
- * allocated buffer. Use this if you don't want to free the buffer immediately
- * like, for example, with RCU.
- *
- * Return: pointer to the allocated memory or %NULL in case of error
- */
-void *__krealloc(const void *p, size_t new_size, gfp_t flags)
-{
-	if (unlikely(!new_size))
-		return ZERO_SIZE_PTR;
-
-	return __do_krealloc(p, new_size, flags);
-
-}
-EXPORT_SYMBOL(__krealloc);
-
 /**
  * krealloc - reallocate memory. The contents will remain unchanged.
  * @p: object to reallocate memory for.

scripts/coccinelle/free/devm_free.cocci

@@ -90,8 +90,6 @@ position p;
  kfree@p(x)
 |
  kzfree@p(x)
-|
- __krealloc@p(x, ...)
 |
  krealloc@p(x, ...)
 |
@@ -116,8 +114,6 @@ position p != safe.p;
 |
 * kzfree@p(x)
 |
-* __krealloc@p(x, ...)
-|
 * krealloc@p(x, ...)
 |
 * free_pages@p(x, ...)