1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index d70adc394f62..b8246a8df7d2 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1285,9 +1285,13 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      Return 0 if permission is granted.
  *
  * @secid_to_secctx:
- *      Convert secid to security context.
+ *      Convert secid to security context.  If secdata is NULL the length of
+ *      the result will be returned in seclen, but no secdata will be returned.
+ *      This does mean that the length could change between calls to check the
+ *      length and the next call which actually allocates and returns the secdata.
  *      @secid contains the security ID.
  *      @secdata contains the pointer that stores the converted security context.
+ *      @seclen pointer which contains the length of the data
  * @secctx_to_secid:
  *      Convert security context to secid.
  *      @secid contains the pointer to the generated security ID.