make SysRq-T show all tasks again

show_state() (SysRq-T) developed the buggy habbit of not showing
TASK_RUNNING tasks.  This was due to the mistaken belief that state_filter
== -1 would be a pass-through filter - while in reality it did not let
TASK_RUNNING == 0 p->state values through.

Fix this by restoring the original '!state_filter means all tasks'
special-case i had in the original version.  Test-built and test-booted on
i686, SysRq-T now works as intended.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 49fe2997a016..a1707583de49 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -196,13 +196,13 @@ extern void init_idle(struct task_struct *idle, int cpu);
 extern cpumask_t nohz_cpu_mask;
 
 /*
- * Only dump TASK_* tasks. (-1 for all tasks)
+ * Only dump TASK_* tasks. (0 for all tasks)
  */
 extern void show_state_filter(unsigned long state_filter);
 
 static inline void show_state(void)
 {
-        show_state_filter(-1);
+        show_state_filter(0);
 }
 
 extern void show_regs(struct pt_regs *);
diff --git a/kernel/sched.c b/kernel/sched.c
index b9a683730148..960d7c5fca39 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4746,7 +4746,7 @@ void show_state_filter(unsigned long state_filter)
                  * console might take alot of time:
                  */
                 touch_nmi_watchdog();
-                if (p->state & state_filter)
+                if (!state_filter || (p->state & state_filter))
                         show_task(p);
         } while_each_thread(g, p);