1 files changed, 53 insertions, 20 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index b92c3c9f8b9a..50c992643771 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -262,7 +262,7 @@ next_signal(struct sigpending *pending, sigset_t *mask)
         return sig;
 }
 
-static struct sigqueue *__sigqueue_alloc(struct task_struct *t, unsigned int __nocast flags,
+static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
                                          int override_rlimit)
 {
         struct sigqueue *q = NULL;
@@ -578,7 +578,8 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
                  * is to alert stop-signal processing code when another
                  * processor has come along and cleared the flag.
                  */
-                tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+                if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
+                        tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
         }
         if ( signr &&
              ((info->si_code & __SI_MASK) == __SI_TIMER) &&
@@ -936,34 +937,31 @@ force_sig_specific(int sig, struct task_struct *t)
  * as soon as they're available, so putting the signal on the shared queue
  * will be equivalent to sending it to one such thread.
  */
-#define wants_signal(sig, p, mask)                      \
-        (!sigismember(&(p)->blocked, sig)               \
-         && !((p)->state & mask)                        \
-         && !((p)->flags & PF_EXITING)                  \
-         && (task_curr(p) || !signal_pending(p)))
-
+static inline int wants_signal(int sig, struct task_struct *p)
+{
+        if (sigismember(&p->blocked, sig))
+                return 0;
+        if (p->flags & PF_EXITING)
+                return 0;
+        if (sig == SIGKILL)
+                return 1;
+        if (p->state & (TASK_STOPPED | TASK_TRACED))
+                return 0;
+        return task_curr(p) || !signal_pending(p);
+}
 
 static void
 __group_complete_signal(int sig, struct task_struct *p)
 {
-        unsigned int mask;
         struct task_struct *t;
 
         /*
-         * Don't bother traced and stopped tasks (but
-         * SIGKILL will punch through that).
-         */
-        mask = TASK_STOPPED | TASK_TRACED;
-        if (sig == SIGKILL)
-                mask = 0;
-
-        /*
          * Now find a thread we can wake up to take the signal off the queue.
          *
          * If the main thread wants the signal, it gets first crack.
          * Probably the least surprising to the average bear.
          */
-        if (wants_signal(sig, p, mask))
+        if (wants_signal(sig, p))
                 t = p;
         else if (thread_group_empty(p))
                 /*
@@ -981,7 +979,7 @@ __group_complete_signal(int sig, struct task_struct *p)
                         t = p->signal->curr_target = p;
                 BUG_ON(t->tgid != p->tgid);
 
-                while (!wants_signal(sig, t, mask)) {
+                while (!wants_signal(sig, t)) {
                         t = next_thread(t);
                         if (t == p->signal->curr_target)
                                 /*
@@ -1195,6 +1193,40 @@ kill_proc_info(int sig, struct siginfo *info, pid_t pid)
         return error;
 }
 
+/* like kill_proc_info(), but doesn't use uid/euid of "current" */
+int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid,
+                      uid_t uid, uid_t euid)
+{
+        int ret = -EINVAL;
+        struct task_struct *p;
+
+        if (!valid_signal(sig))
+                return ret;
+
+        read_lock(&tasklist_lock);
+        p = find_task_by_pid(pid);
+        if (!p) {
+                ret = -ESRCH;
+                goto out_unlock;
+        }
+        if ((!info || ((unsigned long)info != 1 &&
+                        (unsigned long)info != 2 && SI_FROMUSER(info)))
+            && (euid != p->suid) && (euid != p->uid)
+            && (uid != p->suid) && (uid != p->uid)) {
+                ret = -EPERM;
+                goto out_unlock;
+        }
+        if (sig && p->sighand) {
+                unsigned long flags;
+                spin_lock_irqsave(&p->sighand->siglock, flags);
+                ret = __group_send_sig_info(sig, info, p);
+                spin_unlock_irqrestore(&p->sighand->siglock, flags);
+        }
+out_unlock:
+        read_unlock(&tasklist_lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(kill_proc_info_as_uid);
 
 /*
  * kill_something_info() interprets pid in interesting ways just like kill(2).
@@ -1766,7 +1798,8 @@ do_signal_stop(int signr)
                                  * stop is always done with the siglock held,
                                  * so this check has no races.
                                  */
-                                if (t->state < TASK_STOPPED) {
+                                if (!t->exit_state &&
+                                    !(t->state & (TASK_STOPPED|TASK_TRACED))) {
                                         stop_count++;
                                         signal_wake_up(t, 0);
                                 }