[PATCH] kernel/signal: Modify the comment of function check_kill_permission

[zhouchuangao]

Maybe it's easier for us to understand the function of
check_kill_permission().

Signed-off-by: zhouchuangao <zhouchuangao@xxxxxxxx>
---
 kernel/signal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 66e8864..8335f17 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -861,8 +861,10 @@ static bool kill_ok_by_cred(struct task_struct *t)
 }
 
 /*
- * Bad permissions for sending the signal
- * - the caller must hold the RCU read lock
+ * Check whether the caller has permissions to send the signal.
+ * - The caller must hold the RCU read lock;
+ * - Return 0 means permission is allowed, otherwise returns the
+ *   corresponding error number.
  */
 static int check_kill_permission(int sig, struct kernel_siginfo *info,
 				 struct task_struct *t)
-- 
2.7.4