X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fsignal.c;h=50c992643771e033c3833e42066fd3218f812d27;hb=ba9b543d5bec0a7605952e2ba501fb8b0f3b6407;hp=ca1186eef9380cd5e633f644a0891d1dacc5bd16;hpb=b857c730d4e960d1876ff56ce5c4bd81ea9ff5ae;p=linux-2.6

diff --git a/kernel/signal.c b/kernel/signal.c
index ca1186eef9..50c9926437 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) &&
@@ -678,7 +679,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 
 /* forward decl */
 static void do_notify_parent_cldstop(struct task_struct *tsk,
-				     struct task_struct *parent,
+				     int to_self,
 				     int why);
 
 /*
@@ -692,7 +693,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
 {
 	struct task_struct *t;
 
-	if (p->flags & SIGNAL_GROUP_EXIT)
+	if (p->signal->flags & SIGNAL_GROUP_EXIT)
 		/*
 		 * The process is in the middle of dying already.
 		 */
@@ -729,14 +730,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
 			p->signal->group_stop_count = 0;
 			p->signal->flags = SIGNAL_STOP_CONTINUED;
 			spin_unlock(&p->sighand->siglock);
-			if (p->ptrace & PT_PTRACED)
-				do_notify_parent_cldstop(p, p->parent,
-							 CLD_STOPPED);
-			else
-				do_notify_parent_cldstop(
-					p->group_leader,
-					p->group_leader->real_parent,
-							 CLD_STOPPED);
+			do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_STOPPED);
 			spin_lock(&p->sighand->siglock);
 		}
 		rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
@@ -777,14 +771,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
 			p->signal->flags = SIGNAL_STOP_CONTINUED;
 			p->signal->group_exit_code = 0;
 			spin_unlock(&p->sighand->siglock);
-			if (p->ptrace & PT_PTRACED)
-				do_notify_parent_cldstop(p, p->parent,
-							 CLD_CONTINUED);
-			else
-				do_notify_parent_cldstop(
-					p->group_leader,
-					p->group_leader->real_parent,
-							 CLD_CONTINUED);
+			do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_CONTINUED);
 			spin_lock(&p->sighand->siglock);
 		} else {
 			/*
@@ -950,34 +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))
 		/*
@@ -995,7 +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)
 				/*
@@ -1209,6 +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).
@@ -1380,16 +1398,16 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
 	unsigned long flags;
 	int ret = 0;
 
-	/*
-	 * We need the tasklist lock even for the specific
-	 * thread case (when we don't need to follow the group
-	 * lists) in order to avoid races with "p->sighand"
-	 * going away or changing from under us.
-	 */
 	BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
-	read_lock(&tasklist_lock);  
+	read_lock(&tasklist_lock);
+
+	if (unlikely(p->flags & PF_EXITING)) {
+		ret = -1;
+		goto out_err;
+	}
+
 	spin_lock_irqsave(&p->sighand->siglock, flags);
-	
+
 	if (unlikely(!list_empty(&q->list))) {
 		/*
 		 * If an SI_TIMER entry is already queue just increment
@@ -1399,7 +1417,7 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
 			BUG();
 		q->info.si_overrun++;
 		goto out;
-	} 
+	}
 	/* Short-circuit ignored signals.  */
 	if (sig_ignored(p, sig)) {
 		ret = 1;
@@ -1414,8 +1432,10 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
 
 out:
 	spin_unlock_irqrestore(&p->sighand->siglock, flags);
+out_err:
 	read_unlock(&tasklist_lock);
-	return(ret);
+
+	return ret;
 }
 
 int
@@ -1542,14 +1562,20 @@ void do_notify_parent(struct task_struct *tsk, int sig)
 	spin_unlock_irqrestore(&psig->siglock, flags);
 }
 
-static void
-do_notify_parent_cldstop(struct task_struct *tsk, struct task_struct *parent,
-			 int why)
+static void do_notify_parent_cldstop(struct task_struct *tsk, int to_self, int why)
 {
 	struct siginfo info;
 	unsigned long flags;
+	struct task_struct *parent;
 	struct sighand_struct *sighand;
 
+	if (to_self)
+		parent = tsk->parent;
+	else {
+		tsk = tsk->group_leader;
+		parent = tsk->real_parent;
+	}
+
 	info.si_signo = SIGCHLD;
 	info.si_errno = 0;
 	info.si_pid = tsk->pid;
@@ -1618,8 +1644,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
 		   !(current->ptrace & PT_ATTACHED)) &&
 	    (likely(current->parent->signal != current->signal) ||
 	     !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) {
-		do_notify_parent_cldstop(current, current->parent,
-					 CLD_TRAPPED);
+		do_notify_parent_cldstop(current, 1, CLD_TRAPPED);
 		read_unlock(&tasklist_lock);
 		schedule();
 	} else {
@@ -1668,25 +1693,25 @@ void ptrace_notify(int exit_code)
 static void
 finish_stop(int stop_count)
 {
+	int to_self;
+
 	/*
 	 * If there are no other threads in the group, or if there is
 	 * a group stop in progress and we are the last to stop,
 	 * report to the parent.  When ptraced, every thread reports itself.
 	 */
-	if (stop_count < 0 || (current->ptrace & PT_PTRACED)) {
-		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(current, current->parent,
-					 CLD_STOPPED);
-		read_unlock(&tasklist_lock);
-	}
-	else if (stop_count == 0) {
-		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(current->group_leader,
-					 current->group_leader->real_parent,
-					 CLD_STOPPED);
-		read_unlock(&tasklist_lock);
-	}
+	if (stop_count < 0 || (current->ptrace & PT_PTRACED))
+		to_self = 1;
+	else if (stop_count == 0)
+		to_self = 0;
+	else
+		goto out;
 
+	read_lock(&tasklist_lock);
+	do_notify_parent_cldstop(current, to_self, CLD_STOPPED);
+	read_unlock(&tasklist_lock);
+
+out:
 	schedule();
 	/*
 	 * Now we don't run again until continued.
@@ -1773,7 +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);
 				}
@@ -2228,8 +2254,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese,
 			recalc_sigpending();
 			spin_unlock_irq(&current->sighand->siglock);
 
-			current->state = TASK_INTERRUPTIBLE;
-			timeout = schedule_timeout(timeout);
+			timeout = schedule_timeout_interruptible(timeout);
 
 			try_to_freeze();
 			spin_lock_irq(&current->sighand->siglock);