pid: use pid_has_task() in pidfd_open()
Use the new pid_has_task() helper in pidfd_open(). This simplifies the
code and avoids taking rcu_read_{lock,unlock}() and leads to overall
nicer code.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20191017101832.5985-5-christian.brauner@ubuntu.com
diff --git a/kernel/pid.c b/kernel/pid.c
index 124d40b..7b5f6c9 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -497,7 +497,7 @@ static int pidfd_create(struct pid *pid)
*/
SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
{
- int fd, ret;
+ int fd;
struct pid *p;
if (flags)
@@ -510,13 +510,11 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
if (!p)
return -ESRCH;
- ret = 0;
- rcu_read_lock();
- if (!pid_task(p, PIDTYPE_TGID))
- ret = -EINVAL;
- rcu_read_unlock();
+ if (pid_has_task(p, PIDTYPE_TGID))
+ fd = pidfd_create(p);
+ else
+ fd = -EINVAL;
- fd = ret ?: pidfd_create(p);
put_pid(p);
return fd;
}
