Fix tsk->exit_state usage

tsk->exit_state can only be 0, EXIT_ZOMBIE, or EXIT_DEAD.  A non-zero test
is the same as tsk->exit_state & (EXIT_ZOMBIE | EXIT_DEAD), so just testing
tsk->exit_state is sufficient.

Signed-off-by: Eugene Teo <eugeneteo@kernel.sg>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 3 insertions, 4 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 04b689f3288f..7a34571203bc 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -146,8 +146,7 @@ static inline const char *get_task_state(struct task_struct *tsk)
                                             TASK_UNINTERRUPTIBLE |
                                             TASK_STOPPED |
                                             TASK_TRACED)) |
-                        (tsk->exit_state & (EXIT_ZOMBIE |
-                                            EXIT_DEAD));
+                                           tsk->exit_state;
         const char **p = &task_state_array[0];
 
         while (state) {
diff --git a/kernel/fork.c b/kernel/fork.c
index a794bfcf6003..240aa6601f5b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -117,7 +117,7 @@ EXPORT_SYMBOL(free_task);
 
 void __put_task_struct(struct task_struct *tsk)
 {
-        WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE)));
+        WARN_ON(!tsk->exit_state);
         WARN_ON(atomic_read(&tsk->usage));
         WARN_ON(tsk == current);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 72a809a54d5b..9d458504e3a6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5279,7 +5279,7 @@ static void migrate_dead(unsigned int dead_cpu, struct task_struct *p)
         struct rq *rq = cpu_rq(dead_cpu);
 
         /* Must be exiting, otherwise would be on tasklist. */
-        BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD);
+        BUG_ON(!p->exit_state);
 
         /* Cannot have done final schedule yet: would have vanished. */
         BUG_ON(p->state == TASK_DEAD);