[PATCH] Fix do_wait race

Only set the flag in the cases when the exit state is not either
TASK_DEAD or TASK_ZOMBIE.

(TASK_DEAD or TASK_ZOMBIE will either race or we'll return the 
information, so no need to note them).

I confirmed that this fixes the problem and I also ran some LTP tests
Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/exit.c

@@ -1335,14 +1335,15 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 			ret = eligible_child(pid, options, p);
 			if (!ret)
 				continue;
-			flag = 1;
 
 			switch (p->state) {
 			case TASK_TRACED:
+				flag = 1;
 				if (!my_ptrace_child(p))
 					continue;
 				/*FALLTHROUGH*/
 			case TASK_STOPPED:
+				flag = 1;
 				if (!(options & WUNTRACED) &&
 				    !my_ptrace_child(p))
 					continue;
@@ -1377,6 +1378,7 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 						goto end;
 					break;
 				}
+				flag = 1;
 check_continued:
 				if (!unlikely(options & WCONTINUED))
 					continue;