docs/core-api/mm: fix return value descriptions in mm/

Many kernel-doc comments in mm/ have the return value descriptions
either misformatted or omitted at all which makes kernel-doc script
unhappy:

$ make V=1 htmldocs
...
./mm/util.c:36: info: Scanning doc for kstrdup
./mm/util.c:41: warning: No description found for return value of 'kstrdup'
./mm/util.c:57: info: Scanning doc for kstrdup_const
./mm/util.c:66: warning: No description found for return value of 'kstrdup_const'
./mm/util.c:75: info: Scanning doc for kstrndup
./mm/util.c:83: warning: No description found for return value of 'kstrndup'
...

Fixing the formatting and adding the missing return value descriptions
eliminates ~100 such warnings.

Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index cd75b8985707..03eeb8b7b4b1 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -939,6 +939,8 @@ EXPORT_SYMBOL(kmem_cache_destroy);
  *
  * Releases as many slabs as possible for a cache.
  * To help debugging, a zero exit status indicates all slabs were released.
+ *
+ * Return: %0 if all slabs were released, non-zero otherwise
  */
 int kmem_cache_shrink(struct kmem_cache *cachep)
 {
@@ -1528,6 +1530,8 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size,
  * 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)
 {
@@ -1549,6 +1553,8 @@ EXPORT_SYMBOL(__krealloc);
  * lesser of the new and old sizes.  If @p is %NULL, krealloc()
  * behaves exactly like kmalloc().  If @new_size is 0 and @p is not a
  * %NULL pointer, the object pointed to is freed.
+ *
+ * Return: pointer to the allocated memory or %NULL in case of error
  */
 void *krealloc(const void *p, size_t new_size, gfp_t flags)
 {