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-rw-r--r--kernel/signal.c83
1 files changed, 38 insertions, 45 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index d282fea81138..4980a073237f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -678,7 +678,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
/* forward decl */
static void do_notify_parent_cldstop(struct task_struct *tsk,
- struct task_struct *parent,
+ int to_self,
int why);
/*
@@ -729,14 +729,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
p->signal->group_stop_count = 0;
p->signal->flags = SIGNAL_STOP_CONTINUED;
spin_unlock(&p->sighand->siglock);
- if (p->ptrace & PT_PTRACED)
- do_notify_parent_cldstop(p, p->parent,
- CLD_STOPPED);
- else
- do_notify_parent_cldstop(
- p->group_leader,
- p->group_leader->real_parent,
- CLD_STOPPED);
+ do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_STOPPED);
spin_lock(&p->sighand->siglock);
}
rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
@@ -777,14 +770,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
p->signal->flags = SIGNAL_STOP_CONTINUED;
p->signal->group_exit_code = 0;
spin_unlock(&p->sighand->siglock);
- if (p->ptrace & PT_PTRACED)
- do_notify_parent_cldstop(p, p->parent,
- CLD_CONTINUED);
- else
- do_notify_parent_cldstop(
- p->group_leader,
- p->group_leader->real_parent,
- CLD_CONTINUED);
+ do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_CONTINUED);
spin_lock(&p->sighand->siglock);
} else {
/*
@@ -1380,16 +1366,16 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
unsigned long flags;
int ret = 0;
- /*
- * We need the tasklist lock even for the specific
- * thread case (when we don't need to follow the group
- * lists) in order to avoid races with "p->sighand"
- * going away or changing from under us.
- */
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
- read_lock(&tasklist_lock);
+ read_lock(&tasklist_lock);
+
+ if (unlikely(p->flags & PF_EXITING)) {
+ ret = -1;
+ goto out_err;
+ }
+
spin_lock_irqsave(&p->sighand->siglock, flags);
-
+
if (unlikely(!list_empty(&q->list))) {
/*
* If an SI_TIMER entry is already queue just increment
@@ -1399,7 +1385,7 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
BUG();
q->info.si_overrun++;
goto out;
- }
+ }
/* Short-circuit ignored signals. */
if (sig_ignored(p, sig)) {
ret = 1;
@@ -1414,8 +1400,10 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
out:
spin_unlock_irqrestore(&p->sighand->siglock, flags);
+out_err:
read_unlock(&tasklist_lock);
- return(ret);
+
+ return ret;
}
int
@@ -1542,14 +1530,20 @@ void do_notify_parent(struct task_struct *tsk, int sig)
spin_unlock_irqrestore(&psig->siglock, flags);
}
-static void
-do_notify_parent_cldstop(struct task_struct *tsk, struct task_struct *parent,
- int why)
+static void do_notify_parent_cldstop(struct task_struct *tsk, int to_self, int why)
{
struct siginfo info;
unsigned long flags;
+ struct task_struct *parent;
struct sighand_struct *sighand;
+ if (to_self)
+ parent = tsk->parent;
+ else {
+ tsk = tsk->group_leader;
+ parent = tsk->real_parent;
+ }
+
info.si_signo = SIGCHLD;
info.si_errno = 0;
info.si_pid = tsk->pid;
@@ -1618,8 +1612,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
!(current->ptrace & PT_ATTACHED)) &&
(likely(current->parent->signal != current->signal) ||
!unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) {
- do_notify_parent_cldstop(current, current->parent,
- CLD_TRAPPED);
+ do_notify_parent_cldstop(current, 1, CLD_TRAPPED);
read_unlock(&tasklist_lock);
schedule();
} else {
@@ -1668,25 +1661,25 @@ void ptrace_notify(int exit_code)
static void
finish_stop(int stop_count)
{
+ int to_self;
+
/*
* If there are no other threads in the group, or if there is
* a group stop in progress and we are the last to stop,
* report to the parent. When ptraced, every thread reports itself.
*/
- if (stop_count < 0 || (current->ptrace & PT_PTRACED)) {
- read_lock(&tasklist_lock);
- do_notify_parent_cldstop(current, current->parent,
- CLD_STOPPED);
- read_unlock(&tasklist_lock);
- }
- else if (stop_count == 0) {
- read_lock(&tasklist_lock);
- do_notify_parent_cldstop(current->group_leader,
- current->group_leader->real_parent,
- CLD_STOPPED);
- read_unlock(&tasklist_lock);
- }
+ if (stop_count < 0 || (current->ptrace & PT_PTRACED))
+ to_self = 1;
+ else if (stop_count == 0)
+ to_self = 0;
+ else
+ goto out;
+ read_lock(&tasklist_lock);
+ do_notify_parent_cldstop(current, to_self, CLD_STOPPED);
+ read_unlock(&tasklist_lock);
+
+out:
schedule();
/*
* Now we don't run again until continued.