handler = sig_handler(t, sig);
+ /* SIGKILL and SIGSTOP may not be sent to the global init */
+ if (unlikely(is_global_init(t) && sig_kernel_only(sig)))
+ return true;
+
if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
handler == SIG_DFL && !(force && sig_kernel_only(sig)))
return 1;
kick_process(t);
}
+static int dequeue_synchronous_signal(siginfo_t *info)
+{
+ struct task_struct *tsk = current;
+ struct sigpending *pending = &tsk->pending;
+ struct sigqueue *q, *sync = NULL;
+
+ /*
+ * Might a synchronous signal be in the queue?
+ */
+ if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK))
+ return 0;
+
+ /*
+ * Return the first synchronous signal in the queue.
+ */
+ list_for_each_entry(q, &pending->list, list) {
+ /* Synchronous signals have a postive si_code */
+ if ((q->info.si_code > SI_USER) &&
+ (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
+ sync = q;
+ goto next;
+ }
+ }
+ return 0;
+next:
+ /*
+ * Check if there is another siginfo for the same signal.
+ */
+ list_for_each_entry_continue(q, &pending->list, list) {
+ if (q->info.si_signo == sync->info.si_signo)
+ goto still_pending;
+ }
+
+ sigdelset(&pending->signal, sync->info.si_signo);
+ recalc_sigpending();
+still_pending:
+ list_del_init(&sync->list);
+ copy_siginfo(info, &sync->info);
+ __sigqueue_free(sync);
+ return info->si_signo;
+}
+
/*
* Remove signals in mask from the pending set and queue.
* Returns 1 if any signals were found.
result = TRACE_SIGNAL_IGNORED;
if (!prepare_signal(sig, t,
- from_ancestor_ns || (info == SEND_SIG_FORCED)))
+ from_ancestor_ns || (info == SEND_SIG_PRIV) || (info == SEND_SIG_FORCED)))
goto ret;
pending = group ? &t->signal->shared_pending : &t->pending;
return;
}
+ set_special_state(TASK_TRACED);
+
/*
* We're committing to trapping. TRACED should be visible before
* TRAPPING is cleared; otherwise, the tracer might fail do_wait().
* Also, transition to TRACED and updates to ->jobctl should be
* atomic with respect to siglock and should be done after the arch
* hook as siglock is released and regrabbed across it.
+ *
+ * TRACER TRACEE
+ *
+ * ptrace_attach()
+ * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED)
+ * do_wait()
+ * set_current_state() smp_wmb();
+ * ptrace_do_wait()
+ * wait_task_stopped()
+ * task_stopped_code()
+ * [L] task_is_traced() [S] task_clear_jobctl_trapping();
*/
- set_current_state(TASK_TRACED);
+ smp_wmb();
current->last_siginfo = info;
current->exit_code = exit_code;
if (task_participate_group_stop(current))
notify = CLD_STOPPED;
- __set_current_state(TASK_STOPPED);
+ set_special_state(TASK_STOPPED);
spin_unlock_irq(¤t->sighand->siglock);
/*
goto relock;
}
+ /* Has this task already been marked for death? */
+ if (signal_group_exit(signal)) {
+ ksig->info.si_signo = signr = SIGKILL;
+ sigdelset(¤t->pending.signal, SIGKILL);
+ trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+ &sighand->action[SIGKILL - 1]);
+ recalc_sigpending();
+ goto fatal;
+ }
+
for (;;) {
struct k_sigaction *ka;
goto relock;
}
- signr = dequeue_signal(current, ¤t->blocked, &ksig->info);
+ /*
+ * Signals generated by the execution of an instruction
+ * need to be delivered before any other pending signals
+ * so that the instruction pointer in the signal stack
+ * frame points to the faulting instruction.
+ */
+ signr = dequeue_synchronous_signal(&ksig->info);
+ if (!signr)
+ signr = dequeue_signal(current, ¤t->blocked, &ksig->info);
if (!signr)
break; /* will return 0 */
continue;
}
+ fatal:
spin_unlock_irq(&sighand->siglock);
/*
}
#endif
-enum siginfo_layout siginfo_layout(int sig, int si_code)
+enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
{
enum siginfo_layout layout = SIL_KILL;
if ((si_code > SI_USER) && (si_code < SI_KERNEL)) {
}
static int
-do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp)
+do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp,
+ size_t min_ss_size)
{
struct task_struct *t = current;
ss_size = 0;
ss_sp = NULL;
} else {
- if (unlikely(ss_size < MINSIGSTKSZ))
+ if (unlikely(ss_size < min_ss_size))
return -ENOMEM;
}
if (uss && copy_from_user(&new, uss, sizeof(stack_t)))
return -EFAULT;
err = do_sigaltstack(uss ? &new : NULL, uoss ? &old : NULL,
- current_user_stack_pointer());
+ current_user_stack_pointer(),
+ MINSIGSTKSZ);
if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t)))
err = -EFAULT;
return err;
stack_t new;
if (copy_from_user(&new, uss, sizeof(stack_t)))
return -EFAULT;
- (void)do_sigaltstack(&new, NULL, current_user_stack_pointer());
+ (void)do_sigaltstack(&new, NULL, current_user_stack_pointer(),
+ MINSIGSTKSZ);
/* squash all but EFAULT for now */
return 0;
}
uss.ss_size = uss32.ss_size;
}
ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss,
- compat_user_stack_pointer());
+ compat_user_stack_pointer(),
+ COMPAT_MINSIGSTKSZ);
if (ret >= 0 && uoss_ptr) {
compat_stack_t old;
memset(&old, 0, sizeof(old));