提交 7cf7db8d 编写于 作者: T Thomas Gleixner

signals: Fix more rcu assumptions

1) Remove the misleading comment in __sigqueue_alloc() which claims
   that holding a spinlock is equivalent to rcu_read_lock().

2) Add a rcu_read_lock/unlock around the __task_cred() access
   in __sigqueue_alloc()

This needs to be revisited to remove the remaining users of
read_lock(&tasklist_lock) but that's outside the scope of this patch.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091210004703.269843657@linutronix.de>
上级 14d8c9f3
......@@ -218,13 +218,13 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimi
struct user_struct *user;
/*
* We won't get problems with the target's UID changing under us
* because changing it requires RCU be used, and if t != current, the
* caller must be holding the RCU readlock (by way of a spinlock) and
* we use RCU protection here
* Protect access to @t credentials. This can go away when all
* callers hold rcu read lock.
*/
rcu_read_lock();
user = get_uid(__task_cred(t)->user);
atomic_inc(&user->sigpending);
rcu_read_unlock();
if (override_rlimit ||
atomic_read(&user->sigpending) <=
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册