cred_guard_mutex: do not return -EINTR to user-space

do_execve() and ptrace_attach() return -EINTR if
mutex_lock_interruptible(->cred_guard_mutex) fails.

This is not right, change the code to return ERESTARTNOINTR.

Perhaps we should also change proc_pid_attr_write().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 61c78b2c07ba..082c320e4dbf 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -181,8 +181,8 @@ int ptrace_attach(struct task_struct *task)
          * interference; SUID, SGID and LSM creds get determined differently
          * under ptrace.
          */
-        retval = mutex_lock_interruptible(&task->cred_guard_mutex);
-        if (retval < 0)
+        retval = -ERESTARTNOINTR;
+        if (mutex_lock_interruptible(&task->cred_guard_mutex))
                 goto out;
 
         task_lock(task);