[PATCH 3/5] Add TASK_WAKEKILL

From: Matthew Wilcox
Date: Sat Sep 01 2007 - 22:47:54 EST


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 <matthew@xxxxxx>
---
include/linux/sched.h | 22 ++++++++++++++--------
kernel/signal.c | 8 ++++----
2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index ea509e9..6769179 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -167,28 +167,34 @@ 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_NONINTERACTIVE 64
#define TASK_DEAD 128
+#define TASK_WAKEKILL 256
+
+/* 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 is_task_traced(task) ((task->state & TASK_TRACED) != 0)
-#define is_task_stopped(task) ((task->state & TASK_STOPPED) != 0)
+#define is_task_traced(task) ((task->state & __TASK_TRACED) != 0)
+#define is_task_stopped(task) ((task->state & __TASK_STOPPED) != 0)
#define is_task_stopped_or_traced(task) \
- ((task->state & (TASK_STOPPED | TASK_TRACED)) != 0)
+ ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define is_task_loadavg(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0)

#define __set_task_state(tsk, state_value) \
diff --git a/kernel/signal.c b/kernel/signal.c
index 53cbac4..986ba10 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -459,15 +459,15 @@ 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);
}
@@ -623,7 +623,7 @@ 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;
--
1.4.4.2

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