handler = sig_handler(t, sig);
if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
- handler == SIG_DFL && !force)
+ handler == SIG_DFL && !(force && sig_kernel_only(sig)))
return 1;
return sig_handler_ignored(handler, sig);
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- if (!sig_task_ignored(t, sig, force))
- return 0;
-
/*
- * Tracers may want to know about even ignored signals.
+ * Tracers may want to know about even ignored signal unless it
+ * is SIGKILL which can't be reported anyway but can be ignored
+ * by SIGNAL_UNKILLABLE task.
*/
- return !t->ptrace;
+ if (t->ptrace && sig != SIGKILL)
+ return 0;
+
+ return sig_task_ignored(t, sig, force);
}
/*
* fresh group stop. Read comment in do_signal_stop() for details.
*/
if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) {
- sig->flags = SIGNAL_STOP_STOPPED;
+ signal_set_stop_flags(sig, SIGNAL_STOP_STOPPED);
return true;
}
return false;
(!is_si_special(info) && SI_FROMUSER(info));
}
+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;
+}
+
/*
* called with RCU read lock from check_kill_permission()
*/
* will take ->siglock, notice SIGNAL_CLD_MASK, and
* notify its parent. See get_signal_to_deliver().
*/
- signal->flags = why | SIGNAL_STOP_CONTINUED;
+ signal_set_stop_flags(signal, why | SIGNAL_STOP_CONTINUED);
signal->group_stop_count = 0;
signal->group_exit_code = 0;
}
* then start taking the whole group down immediately.
*/
if (sig_fatal(p, sig) &&
- !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
+ !(signal->flags & SIGNAL_GROUP_EXIT) &&
!sigismember(&t->real_blocked, sig) &&
- (sig == SIGKILL || !t->ptrace)) {
+ (sig == SIGKILL || !p->ptrace)) {
/*
* This signal will be fatal to the whole group.
*/
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 ret;
}
+ /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */
+ if (pid == INT_MIN)
+ return -ESRCH;
+
read_lock(&tasklist_lock);
if (pid != -1) {
ret = __kill_pgrp_info(sig, info,
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);
/*
{
struct task_struct *tsk = current;
+ /*
+ * In case the signal mask hasn't changed, there is nothing we need
+ * to do. The current->blocked shouldn't be modified by other task.
+ */
+ if (sigequalsets(&tsk->blocked, newset))
+ return;
+
spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, newset);
spin_unlock_irq(&tsk->sighand->siglock);
}
static int
-do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp)
+do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp,
+ size_t min_ss_size)
{
stack_t oss;
int error;
ss_size = 0;
ss_sp = NULL;
} else {
- error = -ENOMEM;
- if (ss_size < MINSIGSTKSZ)
- goto out;
+ if (unlikely(ss_size < min_ss_size))
+ return -ENOMEM;
}
current->sas_ss_sp = (unsigned long) ss_sp;
}
SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)
{
- return do_sigaltstack(uss, uoss, current_user_stack_pointer());
+ return do_sigaltstack(uss, uoss, current_user_stack_pointer(),
+ MINSIGSTKSZ);
}
int restore_altstack(const stack_t __user *uss)
{
- int err = do_sigaltstack(uss, NULL, current_user_stack_pointer());
+ int err = do_sigaltstack(uss, NULL, current_user_stack_pointer(),
+ MINSIGSTKSZ);
/* squash all but EFAULT for now */
return err == -EFAULT ? err : 0;
}
set_fs(KERNEL_DS);
ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
(stack_t __force __user *) &uoss,
- compat_user_stack_pointer());
+ compat_user_stack_pointer(),
+ COMPAT_MINSIGSTKSZ);
set_fs(seg);
if (ret >= 0 && uoss_ptr) {
if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) ||