static struct kmem_cache *sigqueue_cachep;
+static int __sig_ignored(struct task_struct *t, int sig)
+{
+ void __user *handler;
+
+ /* Is it explicitly or implicitly ignored? */
+
+ handler = t->sighand->action[sig - 1].sa.sa_handler;
+ return handler == SIG_IGN ||
+ (handler == SIG_DFL && sig_kernel_ignore(sig));
+}
static int sig_ignored(struct task_struct *t, int sig)
{
- void __user * handler;
-
/*
* Tracers always want to know about signals..
*/
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- /* Is it explicitly or implicitly ignored? */
- handler = t->sighand->action[sig-1].sa.sa_handler;
- return handler == SIG_IGN ||
- (handler == SIG_DFL && sig_kernel_ignore(sig));
+ return __sig_ignored(t, sig);
}
/*
*/
int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
{
- int signr = 0;
+ int signr;
/* We only dequeue private signals from ourselves, we don't let
* signalfd steal them
}
}
}
+
recalc_sigpending();
- if (signr && unlikely(sig_kernel_stop(signr))) {
+ if (!signr)
+ return 0;
+
+ if (unlikely(sig_kernel_stop(signr))) {
/*
* Set a marker that we have dequeued a stop signal. Our
* caller might release the siglock and then the pending
if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
}
- if (signr &&
- ((info->si_code & __SI_MASK) == __SI_TIMER) &&
- info->si_sys_private) {
+ if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
/*
* Release the siglock to ensure proper locking order
* of timer locks outside of siglocks. Note, we leave
static int check_kill_permission(int sig, struct siginfo *info,
struct task_struct *t)
{
- int error = -EINVAL;
+ struct pid *sid;
+ int error;
+
if (!valid_signal(sig))
- return error;
+ return -EINVAL;
- if (info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) {
- error = audit_signal_info(sig, t); /* Let audit system see the signal */
- if (error)
- return error;
- error = -EPERM;
- if (((sig != SIGCONT) ||
- (task_session_nr(current) != task_session_nr(t)))
- && (current->euid ^ t->suid) && (current->euid ^ t->uid)
- && (current->uid ^ t->suid) && (current->uid ^ t->uid)
- && !capable(CAP_KILL))
+ if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
+ return 0;
+
+ error = audit_signal_info(sig, t); /* Let audit system see the signal */
+ if (error)
return error;
+
+ if ((current->euid ^ t->suid) && (current->euid ^ t->uid) &&
+ (current->uid ^ t->suid) && (current->uid ^ t->uid) &&
+ !capable(CAP_KILL)) {
+ switch (sig) {
+ case SIGCONT:
+ sid = task_session(t);
+ /*
+ * We don't return the error if sid == NULL. The
+ * task was unhashed, the caller must notice this.
+ */
+ if (!sid || sid == task_session(current))
+ break;
+ default:
+ return -EPERM;
+ }
}
return security_task_kill(t, info, sig, 0);
static void do_notify_parent_cldstop(struct task_struct *tsk, int why);
/*
- * Handle magic process-wide effects of stop/continue signals.
- * Unlike the signal actions, these happen immediately at signal-generation
+ * Handle magic process-wide effects of stop/continue signals. Unlike
+ * the signal actions, these happen immediately at signal-generation
* time regardless of blocking, ignoring, or handling. This does the
* actual continuing for SIGCONT, but not the actual stopping for stop
- * signals. The process stop is done as a signal action for SIG_DFL.
+ * signals. The process stop is done as a signal action for SIG_DFL.
+ *
+ * Returns true if the signal should be actually delivered, otherwise
+ * it should be dropped.
*/
-static void handle_stop_signal(int sig, struct task_struct *p)
+static int prepare_signal(int sig, struct task_struct *p)
{
+ struct signal_struct *signal = p->signal;
struct task_struct *t;
- if (p->signal->flags & SIGNAL_GROUP_EXIT)
+ if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) {
/*
- * The process is in the middle of dying already.
+ * The process is in the middle of dying, nothing to do.
*/
- return;
-
- if (sig_kernel_stop(sig)) {
+ } else if (sig_kernel_stop(sig)) {
/*
* This is a stop signal. Remove SIGCONT from all queues.
*/
- rm_from_queue(sigmask(SIGCONT), &p->signal->shared_pending);
+ rm_from_queue(sigmask(SIGCONT), &signal->shared_pending);
t = p;
do {
rm_from_queue(sigmask(SIGCONT), &t->pending);
- t = next_thread(t);
- } while (t != p);
+ } while_each_thread(p, t);
} else if (sig == SIGCONT) {
+ unsigned int why;
/*
* Remove all stop signals from all queues,
* and wake all threads.
*/
- if (unlikely(p->signal->group_stop_count > 0)) {
- /*
- * There was a group stop in progress. We'll
- * pretend it finished before we got here. We are
- * obliged to report it to the parent: if the
- * SIGSTOP happened "after" this SIGCONT, then it
- * would have cleared this pending SIGCONT. If it
- * happened "before" this SIGCONT, then the parent
- * got the SIGCHLD about the stop finishing before
- * the continue happened. We do the notification
- * now, and it's as if the stop had finished and
- * the SIGCHLD was pending on entry to this kill.
- */
- p->signal->group_stop_count = 0;
- p->signal->flags = SIGNAL_STOP_CONTINUED;
- spin_unlock(&p->sighand->siglock);
- do_notify_parent_cldstop(p, CLD_STOPPED);
- spin_lock(&p->sighand->siglock);
- }
- rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
+ rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending);
t = p;
do {
unsigned int state;
rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
-
/*
* If there is a handler for SIGCONT, we must make
* sure that no thread returns to user mode before
* running the handler. With the TIF_SIGPENDING
* flag set, the thread will pause and acquire the
* siglock that we hold now and until we've queued
- * the pending signal.
+ * the pending signal.
*
* Wake up the stopped thread _after_ setting
* TIF_SIGPENDING
state |= TASK_INTERRUPTIBLE;
}
wake_up_state(t, state);
+ } while_each_thread(p, t);
- t = next_thread(t);
- } while (t != p);
+ /*
+ * Notify the parent with CLD_CONTINUED if we were stopped.
+ *
+ * If we were in the middle of a group stop, we pretend it
+ * was already finished, and then continued. Since SIGCHLD
+ * doesn't queue we report only CLD_STOPPED, as if the next
+ * CLD_CONTINUED was dropped.
+ */
+ why = 0;
+ if (signal->flags & SIGNAL_STOP_STOPPED)
+ why |= SIGNAL_CLD_CONTINUED;
+ else if (signal->group_stop_count)
+ why |= SIGNAL_CLD_STOPPED;
- if (p->signal->flags & SIGNAL_STOP_STOPPED) {
+ if (why) {
/*
- * We were in fact stopped, and are now continued.
- * Notify the parent with CLD_CONTINUED.
+ * The first thread which returns from finish_stop()
+ * will take ->siglock, notice SIGNAL_CLD_MASK, and
+ * notify its parent. See get_signal_to_deliver().
*/
- p->signal->flags = SIGNAL_STOP_CONTINUED;
- p->signal->group_exit_code = 0;
- spin_unlock(&p->sighand->siglock);
- do_notify_parent_cldstop(p, CLD_CONTINUED);
- spin_lock(&p->sighand->siglock);
+ signal->flags = why | SIGNAL_STOP_CONTINUED;
+ signal->group_stop_count = 0;
+ signal->group_exit_code = 0;
} else {
/*
* We are not stopped, but there could be a stop
* signal in the middle of being processed after
* being removed from the queue. Clear that too.
*/
- p->signal->flags = 0;
+ signal->flags &= ~SIGNAL_STOP_DEQUEUED;
+ }
+ }
+
+ return !sig_ignored(p, sig);
+}
+
+/*
+ * Test if P wants to take SIG. After we've checked all threads with this,
+ * it's equivalent to finding no threads not blocking SIG. Any threads not
+ * blocking SIG were ruled out because they are not running and already
+ * have pending signals. Such threads will dequeue from the shared queue
+ * as soon as they're available, so putting the signal on the shared queue
+ * will be equivalent to sending it to one such thread.
+ */
+static inline int wants_signal(int sig, struct task_struct *p)
+{
+ if (sigismember(&p->blocked, sig))
+ return 0;
+ if (p->flags & PF_EXITING)
+ return 0;
+ if (sig == SIGKILL)
+ return 1;
+ if (task_is_stopped_or_traced(p))
+ return 0;
+ return task_curr(p) || !signal_pending(p);
+}
+
+static void complete_signal(int sig, struct task_struct *p, int group)
+{
+ struct signal_struct *signal = p->signal;
+ struct task_struct *t;
+
+ /*
+ * Now find a thread we can wake up to take the signal off the queue.
+ *
+ * If the main thread wants the signal, it gets first crack.
+ * Probably the least surprising to the average bear.
+ */
+ if (wants_signal(sig, p))
+ t = p;
+ else if (!group || thread_group_empty(p))
+ /*
+ * There is just one thread and it does not need to be woken.
+ * It will dequeue unblocked signals before it runs again.
+ */
+ return;
+ else {
+ /*
+ * Otherwise try to find a suitable thread.
+ */
+ t = signal->curr_target;
+ while (!wants_signal(sig, t)) {
+ t = next_thread(t);
+ if (t == signal->curr_target)
+ /*
+ * No thread needs to be woken.
+ * Any eligible threads will see
+ * the signal in the queue soon.
+ */
+ return;
}
- } else if (sig == SIGKILL) {
+ signal->curr_target = t;
+ }
+
+ /*
+ * Found a killable thread. If the signal will be fatal,
+ * then start taking the whole group down immediately.
+ */
+ if (sig_fatal(p, sig) &&
+ !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
+ !sigismember(&t->real_blocked, sig) &&
+ (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
/*
- * Make sure that any pending stop signal already dequeued
- * is undone by the wakeup for SIGKILL.
+ * This signal will be fatal to the whole group.
*/
- p->signal->flags = 0;
+ if (!sig_kernel_coredump(sig)) {
+ /*
+ * Start a group exit and wake everybody up.
+ * This way we don't have other threads
+ * running and doing things after a slower
+ * thread has the fatal signal pending.
+ */
+ signal->flags = SIGNAL_GROUP_EXIT;
+ signal->group_exit_code = sig;
+ signal->group_stop_count = 0;
+ t = p;
+ do {
+ sigaddset(&t->pending.signal, SIGKILL);
+ signal_wake_up(t, 1);
+ } while_each_thread(p, t);
+ return;
+ }
}
+
+ /*
+ * The signal is already in the shared-pending queue.
+ * Tell the chosen thread to wake up and dequeue it.
+ */
+ signal_wake_up(t, sig == SIGKILL);
+ return;
+}
+
+static inline int legacy_queue(struct sigpending *signals, int sig)
+{
+ return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
- struct sigpending *signals)
+ int group)
{
- struct sigqueue * q = NULL;
+ struct sigpending *pending;
+ struct sigqueue *q;
+
+ assert_spin_locked(&t->sighand->siglock);
+ if (!prepare_signal(sig, t))
+ return 0;
+ pending = group ? &t->signal->shared_pending : &t->pending;
/*
- * Deliver the signal to listening signalfds. This must be called
- * with the sighand lock held.
+ * Short-circuit ignored signals and support queuing
+ * exactly one non-rt signal, so that we can get more
+ * detailed information about the cause of the signal.
*/
- signalfd_notify(t, sig);
-
+ if (legacy_queue(pending, sig))
+ return 0;
/*
* fast-pathed signals for kernel-internal things like SIGSTOP
* or SIGKILL.
(is_si_special(info) ||
info->si_code >= 0)));
if (q) {
- list_add_tail(&q->list, &signals->list);
+ list_add_tail(&q->list, &pending->list);
switch ((unsigned long) info) {
case (unsigned long) SEND_SIG_NOINFO:
q->info.si_signo = sig;
}
out_set:
- sigaddset(&signals->signal, sig);
+ signalfd_notify(t, sig);
+ sigaddset(&pending->signal, sig);
+ complete_signal(sig, t, group);
return 0;
}
-#define LEGACY_QUEUE(sigptr, sig) \
- (((sig) < SIGRTMIN) && sigismember(&(sigptr)->signal, (sig)))
-
int print_fatal_signals;
static void print_fatal_signal(struct pt_regs *regs, int signr)
__setup("print-fatal-signals=", setup_print_fatal_signals);
+int
+__group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
+{
+ return send_signal(sig, info, p, 1);
+}
+
static int
specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
{
- int ret = 0;
-
- BUG_ON(!irqs_disabled());
- assert_spin_locked(&t->sighand->siglock);
-
- /* Short-circuit ignored signals. */
- if (sig_ignored(t, sig))
- goto out;
-
- /* Support queueing exactly one non-rt signal, so that we
- can get more detailed information about the cause of
- the signal. */
- if (LEGACY_QUEUE(&t->pending, sig))
- goto out;
-
- ret = send_signal(sig, info, t, &t->pending);
- if (!ret && !sigismember(&t->blocked, sig))
- signal_wake_up(t, sig == SIGKILL);
-out:
- return ret;
+ return send_signal(sig, info, t, 0);
}
/*
* since we do not want to have a signal handler that was blocked
* be invoked when user space had explicitly blocked it.
*
- * We don't want to have recursive SIGSEGV's etc, for example.
+ * We don't want to have recursive SIGSEGV's etc, for example,
+ * that is why we also clear SIGNAL_UNKILLABLE.
*/
int
force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
recalc_sigpending_and_wake(t);
}
}
+ if (action->sa.sa_handler == SIG_DFL)
+ t->signal->flags &= ~SIGNAL_UNKILLABLE;
ret = specific_send_sig_info(sig, info, t);
spin_unlock_irqrestore(&t->sighand->siglock, flags);
force_sig_info(sig, SEND_SIG_FORCED, t);
}
-/*
- * Test if P wants to take SIG. After we've checked all threads with this,
- * it's equivalent to finding no threads not blocking SIG. Any threads not
- * blocking SIG were ruled out because they are not running and already
- * have pending signals. Such threads will dequeue from the shared queue
- * as soon as they're available, so putting the signal on the shared queue
- * will be equivalent to sending it to one such thread.
- */
-static inline int wants_signal(int sig, struct task_struct *p)
-{
- if (sigismember(&p->blocked, sig))
- return 0;
- if (p->flags & PF_EXITING)
- return 0;
- if (sig == SIGKILL)
- return 1;
- if (task_is_stopped_or_traced(p))
- return 0;
- return task_curr(p) || !signal_pending(p);
-}
-
-static void
-__group_complete_signal(int sig, struct task_struct *p)
-{
- struct task_struct *t;
-
- /*
- * Now find a thread we can wake up to take the signal off the queue.
- *
- * If the main thread wants the signal, it gets first crack.
- * Probably the least surprising to the average bear.
- */
- if (wants_signal(sig, p))
- t = p;
- else if (thread_group_empty(p))
- /*
- * There is just one thread and it does not need to be woken.
- * It will dequeue unblocked signals before it runs again.
- */
- return;
- else {
- /*
- * Otherwise try to find a suitable thread.
- */
- t = p->signal->curr_target;
- if (t == NULL)
- /* restart balancing at this thread */
- t = p->signal->curr_target = p;
-
- while (!wants_signal(sig, t)) {
- t = next_thread(t);
- if (t == p->signal->curr_target)
- /*
- * No thread needs to be woken.
- * Any eligible threads will see
- * the signal in the queue soon.
- */
- return;
- }
- p->signal->curr_target = t;
- }
-
- /*
- * Found a killable thread. If the signal will be fatal,
- * then start taking the whole group down immediately.
- */
- if (sig_fatal(p, sig) && !(p->signal->flags & SIGNAL_GROUP_EXIT) &&
- !sigismember(&t->real_blocked, sig) &&
- (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
- /*
- * This signal will be fatal to the whole group.
- */
- if (!sig_kernel_coredump(sig)) {
- /*
- * Start a group exit and wake everybody up.
- * This way we don't have other threads
- * running and doing things after a slower
- * thread has the fatal signal pending.
- */
- p->signal->flags = SIGNAL_GROUP_EXIT;
- p->signal->group_exit_code = sig;
- p->signal->group_stop_count = 0;
- t = p;
- do {
- sigaddset(&t->pending.signal, SIGKILL);
- signal_wake_up(t, 1);
- } while_each_thread(p, t);
- return;
- }
- }
-
- /*
- * The signal is already in the shared-pending queue.
- * Tell the chosen thread to wake up and dequeue it.
- */
- signal_wake_up(t, sig == SIGKILL);
- return;
-}
-
-int
-__group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
-{
- int ret = 0;
-
- assert_spin_locked(&p->sighand->siglock);
- handle_stop_signal(sig, p);
-
- /* Short-circuit ignored signals. */
- if (sig_ignored(p, sig))
- return ret;
-
- if (LEGACY_QUEUE(&p->signal->shared_pending, sig))
- /* This is a non-RT signal and we already have one queued. */
- return ret;
-
- /*
- * Put this signal on the shared-pending queue, or fail with EAGAIN.
- * We always use the shared queue for process-wide signals,
- * to avoid several races.
- */
- ret = send_signal(sig, info, p, &p->signal->shared_pending);
- if (unlikely(ret))
- return ret;
-
- __group_complete_signal(sig, p);
- return 0;
-}
-
/*
* Nuke all other threads in the group.
*/
}
EXPORT_SYMBOL(__fatal_signal_pending);
-/*
- * Must be called under rcu_read_lock() or with tasklist_lock read-held.
- */
struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
{
struct sighand_struct *sighand;
+ rcu_read_lock();
for (;;) {
sighand = rcu_dereference(tsk->sighand);
if (unlikely(sighand == NULL))
break;
spin_unlock_irqrestore(&sighand->siglock, *flags);
}
+ rcu_read_unlock();
return sighand;
}
struct task_struct *p;
rcu_read_lock();
- if (unlikely(sig_needs_tasklist(sig)))
- read_lock(&tasklist_lock);
-
retry:
p = pid_task(pid, PIDTYPE_PID);
if (p) {
*/
goto retry;
}
-
- if (unlikely(sig_needs_tasklist(sig)))
- read_unlock(&tasklist_lock);
rcu_read_unlock();
+
return error;
}
*/
/*
- * These two are the most common entry points. They send a signal
- * just to the specific thread.
+ * The caller must ensure the task can't exit.
*/
int
send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
if (!valid_signal(sig))
return -EINVAL;
- /*
- * 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.
- */
- read_lock(&tasklist_lock);
spin_lock_irqsave(&p->sighand->siglock, flags);
ret = specific_send_sig_info(sig, info, p);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
- read_unlock(&tasklist_lock);
return ret;
}
__sigqueue_free(q);
}
-int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
+int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
{
+ int sig = q->info.si_signo;
+ struct sigpending *pending;
unsigned long flags;
- int ret = 0;
+ int ret;
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
- /*
- * The rcu based delayed sighand destroy makes it possible to
- * run this without tasklist lock held. The task struct itself
- * cannot go away as create_timer did get_task_struct().
- *
- * We return -1, when the task is marked exiting, so
- * posix_timer_event can redirect it to the group leader
- */
- rcu_read_lock();
+ ret = -1;
+ if (!likely(lock_task_sighand(t, &flags)))
+ goto ret;
- if (!likely(lock_task_sighand(p, &flags))) {
- ret = -1;
- goto out_err;
- }
+ ret = 1; /* the signal is ignored */
+ if (!prepare_signal(sig, t))
+ goto out;
+ ret = 0;
if (unlikely(!list_empty(&q->list))) {
/*
* If an SI_TIMER entry is already queue just increment
q->info.si_overrun++;
goto out;
}
- /* Short-circuit ignored signals. */
- if (sig_ignored(p, sig)) {
- ret = 1;
- goto out;
- }
- /*
- * Deliver the signal to listening signalfds. This must be called
- * with the sighand lock held.
- */
- signalfd_notify(p, sig);
-
- list_add_tail(&q->list, &p->pending.list);
- sigaddset(&p->pending.signal, sig);
- if (!sigismember(&p->blocked, sig))
- signal_wake_up(p, sig == SIGKILL);
-
-out:
- unlock_task_sighand(p, &flags);
-out_err:
- rcu_read_unlock();
-
- return ret;
-}
-
-int
-send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
-{
- unsigned long flags;
- int ret = 0;
-
- BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
-
- read_lock(&tasklist_lock);
- /* Since it_lock is held, p->sighand cannot be NULL. */
- spin_lock_irqsave(&p->sighand->siglock, flags);
- handle_stop_signal(sig, p);
-
- /* Short-circuit ignored signals. */
- if (sig_ignored(p, sig)) {
- ret = 1;
- goto out;
- }
- if (unlikely(!list_empty(&q->list))) {
- /*
- * If an SI_TIMER entry is already queue just increment
- * the overrun count. Other uses should not try to
- * send the signal multiple times.
- */
- BUG_ON(q->info.si_code != SI_TIMER);
- q->info.si_overrun++;
- goto out;
- }
- /*
- * Deliver the signal to listening signalfds. This must be called
- * with the sighand lock held.
- */
- signalfd_notify(p, sig);
-
- /*
- * Put this signal on the shared-pending queue.
- * We always use the shared queue for process-wide signals,
- * to avoid several races.
- */
- list_add_tail(&q->list, &p->signal->shared_pending.list);
- sigaddset(&p->signal->shared_pending.signal, sig);
-
- __group_complete_signal(sig, p);
+ signalfd_notify(t, sig);
+ pending = group ? &t->signal->shared_pending : &t->pending;
+ list_add_tail(&q->list, &pending->list);
+ sigaddset(&pending->signal, sig);
+ complete_signal(sig, t, group);
out:
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- read_unlock(&tasklist_lock);
+ unlock_task_sighand(t, &flags);
+ret:
return ret;
}
} else {
struct task_struct *t;
- if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
- unlikely(sig->group_exit_task))
+ if (unlikely((sig->flags & (SIGNAL_STOP_DEQUEUED | SIGNAL_UNKILLABLE))
+ != SIGNAL_STOP_DEQUEUED) ||
+ unlikely(signal_group_exit(sig)))
return 0;
/*
* There is no group stop already in progress.
int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
struct pt_regs *regs, void *cookie)
{
- sigset_t *mask = ¤t->blocked;
- int signr = 0;
+ struct sighand_struct *sighand = current->sighand;
+ struct signal_struct *signal = current->signal;
+ int signr;
relock:
/*
*/
try_to_freeze();
- spin_lock_irq(¤t->sighand->siglock);
+ spin_lock_irq(&sighand->siglock);
+ /*
+ * Every stopped thread goes here after wakeup. Check to see if
+ * we should notify the parent, prepare_signal(SIGCONT) encodes
+ * the CLD_ si_code into SIGNAL_CLD_MASK bits.
+ */
+ if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
+ int why = (signal->flags & SIGNAL_STOP_CONTINUED)
+ ? CLD_CONTINUED : CLD_STOPPED;
+ signal->flags &= ~SIGNAL_CLD_MASK;
+ spin_unlock_irq(&sighand->siglock);
+
+ read_lock(&tasklist_lock);
+ do_notify_parent_cldstop(current->group_leader, why);
+ read_unlock(&tasklist_lock);
+ goto relock;
+ }
+
for (;;) {
struct k_sigaction *ka;
- if (unlikely(current->signal->group_stop_count > 0) &&
+ if (unlikely(signal->group_stop_count > 0) &&
do_signal_stop(0))
goto relock;
- signr = dequeue_signal(current, mask, info);
-
+ signr = dequeue_signal(current, ¤t->blocked, info);
if (!signr)
break; /* will return 0 */
continue;
}
- ka = ¤t->sighand->action[signr-1];
+ ka = &sighand->action[signr-1];
if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */
continue;
if (ka->sa.sa_handler != SIG_DFL) {
/*
* Global init gets no signals it doesn't want.
*/
- if (is_global_init(current))
+ if (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
+ !signal_group_exit(signal))
continue;
if (sig_kernel_stop(signr)) {
* We need to check for that and bail out if necessary.
*/
if (signr != SIGSTOP) {
- spin_unlock_irq(¤t->sighand->siglock);
+ spin_unlock_irq(&sighand->siglock);
/* signals can be posted during this window */
if (is_current_pgrp_orphaned())
goto relock;
- spin_lock_irq(¤t->sighand->siglock);
+ spin_lock_irq(&sighand->siglock);
}
if (likely(do_signal_stop(signr))) {
continue;
}
- spin_unlock_irq(¤t->sighand->siglock);
+ spin_unlock_irq(&sighand->siglock);
/*
* Anything else is fatal, maybe with a core dump.
*/
current->flags |= PF_SIGNALED;
- if ((signr != SIGKILL) && print_fatal_signals)
- print_fatal_signal(regs, signr);
+
if (sig_kernel_coredump(signr)) {
+ if (print_fatal_signals)
+ print_fatal_signal(regs, signr);
/*
* If it was able to dump core, this kills all
* other threads in the group and synchronizes with
do_group_exit(signr);
/* NOTREACHED */
}
- spin_unlock_irq(¤t->sighand->siglock);
+ spin_unlock_irq(&sighand->siglock);
return signr;
}
int error;
struct siginfo info;
struct task_struct *p;
+ unsigned long flags;
error = -ESRCH;
info.si_signo = sig;
info.si_pid = task_tgid_vnr(current);
info.si_uid = current->uid;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_task_by_vpid(pid);
if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) {
error = check_kill_permission(sig, &info, p);
/*
* The null signal is a permissions and process existence
* probe. No signal is actually delivered.
+ *
+ * If lock_task_sighand() fails we pretend the task dies
+ * after receiving the signal. The window is tiny, and the
+ * signal is private anyway.
*/
- if (!error && sig && p->sighand) {
- spin_lock_irq(&p->sighand->siglock);
- handle_stop_signal(sig, p);
+ if (!error && sig && lock_task_sighand(p, &flags)) {
error = specific_send_sig_info(sig, &info, p);
- spin_unlock_irq(&p->sighand->siglock);
+ unlock_task_sighand(p, &flags);
}
}
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return error;
}
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
+ struct task_struct *t = current;
struct k_sigaction *k;
sigset_t mask;
if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig)))
return -EINVAL;
- k = ¤t->sighand->action[sig-1];
+ k = &t->sighand->action[sig-1];
spin_lock_irq(¤t->sighand->siglock);
if (oact)
* (for example, SIGCHLD), shall cause the pending signal to
* be discarded, whether or not it is blocked"
*/
- if (act->sa.sa_handler == SIG_IGN ||
- (act->sa.sa_handler == SIG_DFL && sig_kernel_ignore(sig))) {
- struct task_struct *t = current;
+ if (__sig_ignored(t, sig)) {
sigemptyset(&mask);
sigaddset(&mask, sig);
rm_from_queue_full(&mask, &t->signal->shared_pending);
current->state = TASK_INTERRUPTIBLE;
schedule();
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
return -ERESTARTNOHAND;
}
#endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
git.samba.org / sfrench / cifs-2.6.git / blobdiff