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authorOleg Nesterov <oleg@redhat.com>2013-01-21 20:47:41 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-01-22 08:50:08 -0800
commit910ffdb18a6408e14febbb6e4b6840fd2c928c82 (patch)
tree258a215685f2ca2bb11dcd92582e0adafbd83f7b
parent9a9284153d965a57edc7162a8e57c14c97f3a935 (diff)
downloadlinaro-lsk-910ffdb18a6408e14febbb6e4b6840fd2c928c82.tar.gz
ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()
Cleanup and preparation for the next change. signal_wake_up(resume => true) is overused. None of ptrace/jctl callers actually want to wakeup a TASK_WAKEKILL task, but they can't specify the necessary mask. Turn signal_wake_up() into signal_wake_up_state(state), reintroduce signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up() which adds __TASK_TRACED. This way ptrace_signal_wake_up() can work "inside" ptrace_request() even if the tracee doesn't have the TASK_WAKEKILL bit set. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/sched.h11
-rw-r--r--kernel/ptrace.c8
-rw-r--r--kernel/signal.c14
3 files changed, 18 insertions, 15 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6fc8f45de4e..d2112477ff5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2714,7 +2714,16 @@ static inline void thread_group_cputime_init(struct signal_struct *sig)
extern void recalc_sigpending_and_wake(struct task_struct *t);
extern void recalc_sigpending(void);
-extern void signal_wake_up(struct task_struct *t, int resume_stopped);
+extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
+
+static inline void signal_wake_up(struct task_struct *t, bool resume)
+{
+ signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
+}
+static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
+{
+ signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
+}
/*
* Wrappers for p->thread_info->cpu access. No-op on UP.
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 612a5612685..62f7c2774b1 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -117,7 +117,7 @@ void __ptrace_unlink(struct task_struct *child)
* TASK_KILLABLE sleeps.
*/
if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
- signal_wake_up(child, task_is_traced(child));
+ ptrace_signal_wake_up(child, true);
spin_unlock(&child->sighand->siglock);
}
@@ -317,7 +317,7 @@ static int ptrace_attach(struct task_struct *task, long request,
*/
if (task_is_stopped(task) &&
task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
- signal_wake_up(task, 1);
+ signal_wake_up_state(task, __TASK_STOPPED);
spin_unlock(&task->sighand->siglock);
@@ -737,7 +737,7 @@ int ptrace_request(struct task_struct *child, long request,
* tracee into STOP.
*/
if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
- signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
+ ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
unlock_task_sighand(child, &flags);
ret = 0;
@@ -763,7 +763,7 @@ int ptrace_request(struct task_struct *child, long request,
* start of this trap and now. Trigger re-trap.
*/
if (child->jobctl & JOBCTL_TRAP_NOTIFY)
- signal_wake_up(child, true);
+ ptrace_signal_wake_up(child, true);
ret = 0;
}
unlock_task_sighand(child, &flags);
diff --git a/kernel/signal.c b/kernel/signal.c
index 53cd5c4d117..6e97aa6fa32 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -680,23 +680,17 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
* No need to set need_resched since signal event passing
* goes through ->blocked
*/
-void signal_wake_up(struct task_struct *t, int resume)
+void signal_wake_up_state(struct task_struct *t, unsigned int state)
{
- unsigned int mask;
-
set_tsk_thread_flag(t, TIF_SIGPENDING);
-
/*
- * For SIGKILL, we want to wake it up in the stopped/traced/killable
+ * TASK_WAKEKILL also means 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_WAKEKILL;
- if (!wake_up_state(t, mask))
+ if (!wake_up_state(t, state | TASK_INTERRUPTIBLE))
kick_process(t);
}
@@ -844,7 +838,7 @@ static void ptrace_trap_notify(struct task_struct *t)
assert_spin_locked(&t->sighand->siglock);
task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY);
- signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
+ ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
}
/*