diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 83 |
1 files changed, 38 insertions, 45 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index d282fea8113..4980a073237 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. |