Add TASK_WAKEKILL

Set TASK_WAKEKILL for TASK_STOPPED and TASK_TRACED, add TASK_KILLABLE and
use TASK_WAKEKILL in signal_wake_up()

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

2 files changed, 18 insertions, 12 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 69233c7fe28d..70d87f2fd23e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -170,27 +170,33 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 #define TASK_RUNNING            0
 #define TASK_INTERRUPTIBLE      1
 #define TASK_UNINTERRUPTIBLE    2
-#define TASK_STOPPED            4
-#define TASK_TRACED             8
+#define __TASK_STOPPED          4
+#define __TASK_TRACED           8
 /* in tsk->exit_state */
 #define EXIT_ZOMBIE             16
 #define EXIT_DEAD               32
 /* in tsk->state again */
 #define TASK_DEAD               64
+#define TASK_WAKEKILL           128
+
+/* Convenience macros for the sake of set_task_state */
+#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
+#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
+#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 
 /* Convenience macros for the sake of wake_up */
 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
-#define TASK_ALL                (TASK_NORMAL | TASK_STOPPED | TASK_TRACED)
+#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 
 /* get_task_state() */
 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
-                                 TASK_UNINTERRUPTIBLE | TASK_STOPPED | \
-                                 TASK_TRACED)
+                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
+                                 __TASK_TRACED)
 
-#define task_is_traced(task)    ((task->state & TASK_TRACED) != 0)
-#define task_is_stopped(task)   ((task->state & TASK_STOPPED) != 0)
+#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
+#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 #define task_is_stopped_or_traced(task) \
-                        ((task->state & (TASK_STOPPED | TASK_TRACED)) != 0)
+                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 #define task_contributes_to_load(task)  \
                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0)
 
diff --git a/kernel/signal.c b/kernel/signal.c
index c5a401aa715c..fd4797f30628 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -456,15 +456,15 @@ void signal_wake_up(struct task_struct *t, int resume)
         set_tsk_thread_flag(t, TIF_SIGPENDING);
 
         /*
-         * For SIGKILL, we want to wake it up in the stopped/traced case.
-         * We don't check t->state here because there is a race with it
+         * For SIGKILL, we want to wake it up in the stopped/traced/killable
+         * case. We don't check t->state here because there is a race with it
          * executing another processor and just now entering stopped state.
          * By using wake_up_state, we ensure the process will wake up and
          * handle its death signal.
          */
         mask = TASK_INTERRUPTIBLE;
         if (resume)
-                mask |= TASK_STOPPED | TASK_TRACED;
+                mask |= TASK_WAKEKILL;
         if (!wake_up_state(t, mask))
                 kick_process(t);
 }
@@ -620,7 +620,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                          * Wake up the stopped thread _after_ setting
                          * TIF_SIGPENDING
                          */
-                        state = TASK_STOPPED;
+                        state = __TASK_STOPPED;
                         if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) {
                                 set_tsk_thread_flag(t, TIF_SIGPENDING);
                                 state |= TASK_INTERRUPTIBLE;