pid: use pid_has_task() in pidfd_open() (1e1d0f0b) · Commits · 戴 / test

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

kernel/pid.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -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;
		}

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