[PATCH] wait4-fix-2.5.34-B2, BK-curr

This fixes a number of bugs that broke ptrace:

 - wait4 must not inhibit TASK_STOPPED processes even for thread group
   leaders.

 - do_notify_parent() should not delay the notification of parents if
   the thread in question is ptraced.

strace now works as expected for CLONE_THREAD applications as well.

kernel/exit.c

@@ -770,11 +770,6 @@ asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struc
 			if (!ret)
 				continue;
 			flag = 1;
-			/*
-			 * Eligible but we cannot release it yet:
-			 */
-			if (ret == 2)
-				continue;
 
 			switch (p->state) {
 			case TASK_STOPPED:
@@ -798,6 +793,11 @@ asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struc
 				}
 				goto end_wait4;
 			case TASK_ZOMBIE:
+				/*
+				 * Eligible but we cannot release it yet:
+				 */
+				if (ret == 2)
+					continue;
 				read_unlock(&tasklist_lock);
 				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
 				if (!retval && stat_addr) {

kernel/signal.c

@@ -1105,7 +1105,7 @@ void do_notify_parent(struct task_struct *tsk, int sig)
 	struct siginfo info;
 	int why, status;
 
-	if (delay_group_leader(tsk))
+	if (!tsk->ptrace && delay_group_leader(tsk))
 		return;
 	if (sig == -1)
 		BUG();