#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/signalfd.h>
+#include <linux/ratelimit.h>
+#include <linux/tracehook.h>
#include <linux/capability.h>
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/signal.h>
#include <asm/param.h>
#include <asm/uaccess.h>
static struct kmem_cache *sigqueue_cachep;
-static int __sig_ignored(struct task_struct *t, int sig)
+int print_fatal_signals __read_mostly;
+
+static void __user *sig_handler(struct task_struct *t, int sig)
{
- void __user *handler;
+ return t->sighand->action[sig - 1].sa.sa_handler;
+}
+static int sig_handler_ignored(void __user *handler, int sig)
+{
/* 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)
+static int sig_task_ignored(struct task_struct *t, int sig,
+ int from_ancestor_ns)
{
- /*
- * Tracers always want to know about signals..
- */
- if (t->ptrace & PT_PTRACED)
- return 0;
+ void __user *handler;
+ handler = sig_handler(t, sig);
+
+ if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
+ handler == SIG_DFL && !from_ancestor_ns)
+ return 1;
+
+ return sig_handler_ignored(handler, sig);
+}
+
+static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
+{
/*
* Blocked signals are never ignored, since the
* signal handler may change by the time it is
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- return __sig_ignored(t, sig);
+ if (!sig_task_ignored(t, sig, from_ancestor_ns))
+ return 0;
+
+ /*
+ * Tracers may want to know about even ignored signals.
+ */
+ return !tracehook_consider_ignored_signal(t, sig);
}
/*
void recalc_sigpending(void)
{
- if (!recalc_sigpending_tsk(current) && !freezing(current))
+ if (unlikely(tracehook_force_sigpending()))
+ set_thread_flag(TIF_SIGPENDING);
+ else if (!recalc_sigpending_tsk(current) && !freezing(current))
clear_thread_flag(TIF_SIGPENDING);
}
{
unsigned long i, *s, *m, x;
int sig = 0;
-
+
s = pending->signal.sig;
m = mask->sig;
switch (_NSIG_WORDS) {
sig = ffz(~x) + 1;
break;
}
-
+
return sig;
}
-static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
- int override_rlimit)
+static inline void print_dropped_signal(int sig)
+{
+ static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+ if (!print_fatal_signals)
+ return;
+
+ if (!__ratelimit(&ratelimit_state))
+ return;
+
+ printk(KERN_INFO "%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n",
+ current->comm, current->pid, sig);
+}
+
+/*
+ * allocate a new signal queue record
+ * - this may be called without locks if and only if t == current, otherwise an
+ * appopriate lock must be held to stop the target task from exiting
+ */
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
{
struct sigqueue *q = NULL;
struct user_struct *user;
/*
- * In order to avoid problems with "switch_user()", we want to make
- * sure that the compiler doesn't re-load "t->user"
+ * We won't get problems with the target's UID changing under us
+ * because changing it requires RCU be used, and if t != current, the
+ * caller must be holding the RCU readlock (by way of a spinlock) and
+ * we use RCU protection here
*/
- user = t->user;
- barrier();
+ user = get_uid(__task_cred(t)->user);
atomic_inc(&user->sigpending);
+
if (override_rlimit ||
atomic_read(&user->sigpending) <=
- t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur)
+ t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) {
q = kmem_cache_alloc(sigqueue_cachep, flags);
+ } else {
+ print_dropped_signal(sig);
+ }
+
if (unlikely(q == NULL)) {
atomic_dec(&user->sigpending);
+ free_uid(user);
} else {
INIT_LIST_HEAD(&q->list);
q->flags = 0;
- q->user = get_uid(user);
+ q->user = user;
}
- return(q);
+
+ return q;
}
static void __sigqueue_free(struct sigqueue *q)
/*
* Flush all pending signals for a task.
*/
+void __flush_signals(struct task_struct *t)
+{
+ clear_tsk_thread_flag(t, TIF_SIGPENDING);
+ flush_sigqueue(&t->pending);
+ flush_sigqueue(&t->signal->shared_pending);
+}
+
void flush_signals(struct task_struct *t)
{
unsigned long flags;
spin_lock_irqsave(&t->sighand->siglock, flags);
- clear_tsk_thread_flag(t, TIF_SIGPENDING);
- flush_sigqueue(&t->pending);
- flush_sigqueue(&t->signal->shared_pending);
+ __flush_signals(t);
spin_unlock_irqrestore(&t->sighand->siglock, flags);
}
+static void __flush_itimer_signals(struct sigpending *pending)
+{
+ sigset_t signal, retain;
+ struct sigqueue *q, *n;
+
+ signal = pending->signal;
+ sigemptyset(&retain);
+
+ list_for_each_entry_safe(q, n, &pending->list, list) {
+ int sig = q->info.si_signo;
+
+ if (likely(q->info.si_code != SI_TIMER)) {
+ sigaddset(&retain, sig);
+ } else {
+ sigdelset(&signal, sig);
+ list_del_init(&q->list);
+ __sigqueue_free(q);
+ }
+ }
+
+ sigorsets(&pending->signal, &signal, &retain);
+}
+
+void flush_itimer_signals(void)
+{
+ struct task_struct *tsk = current;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tsk->sighand->siglock, flags);
+ __flush_itimer_signals(&tsk->pending);
+ __flush_itimer_signals(&tsk->signal->shared_pending);
+ spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+}
+
void ignore_signals(struct task_struct *t)
{
int i;
int unhandled_signal(struct task_struct *tsk, int sig)
{
+ void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler;
if (is_global_init(tsk))
return 1;
- if (tsk->ptrace & PT_PTRACED)
+ if (handler != SIG_IGN && handler != SIG_DFL)
return 0;
- return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
- (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
+ return !tracehook_consider_fatal_signal(tsk, sig);
}
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
}
-static int collect_signal(int sig, struct sigpending *list, siginfo_t *info)
+static void collect_signal(int sig, struct sigpending *list, siginfo_t *info)
{
struct sigqueue *q, *first = NULL;
- int still_pending = 0;
-
- if (unlikely(!sigismember(&list->signal, sig)))
- return 0;
/*
* Collect the siginfo appropriate to this signal. Check if
*/
list_for_each_entry(q, &list->list, list) {
if (q->info.si_signo == sig) {
- if (first) {
- still_pending = 1;
- break;
- }
+ if (first)
+ goto still_pending;
first = q;
}
}
+
+ sigdelset(&list->signal, sig);
+
if (first) {
+still_pending:
list_del_init(&first->list);
copy_siginfo(info, &first->info);
__sigqueue_free(first);
- if (!still_pending)
- sigdelset(&list->signal, sig);
} else {
-
/* Ok, it wasn't in the queue. This must be
a fast-pathed signal or we must have been
out of queue space. So zero out the info.
*/
- sigdelset(&list->signal, sig);
info->si_signo = sig;
info->si_errno = 0;
info->si_code = 0;
info->si_pid = 0;
info->si_uid = 0;
}
- return 1;
}
static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
}
}
- if (!collect_signal(sig, pending, info))
- sig = 0;
+ collect_signal(sig, pending, info);
}
return sig;
* is to alert stop-signal processing code when another
* processor has come along and cleared the flag.
*/
- if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
- tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+ tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
}
if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
/*
/*
* Bad permissions for sending the signal
+ * - the caller must hold at least the RCU read lock
*/
static int check_kill_permission(int sig, struct siginfo *info,
struct task_struct *t)
{
+ const struct cred *cred = current_cred(), *tcred;
+ struct pid *sid;
int error;
if (!valid_signal(sig))
if (error)
return error;
- 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))
- return -EPERM;
+ tcred = __task_cred(t);
+ if ((cred->euid ^ tcred->suid) &&
+ (cred->euid ^ tcred->uid) &&
+ (cred->uid ^ tcred->suid) &&
+ (cred->uid ^ tcred->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);
}
-/* forward decl */
-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, int from_ancestor_ns)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
- if (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.
*/
why |= SIGNAL_CLD_STOPPED;
if (why) {
+ /*
+ * The first thread which returns from do_signal_stop()
+ * will take ->siglock, notice SIGNAL_CLD_MASK, and
+ * notify its parent. See get_signal_to_deliver().
+ */
signal->flags = why | SIGNAL_STOP_CONTINUED;
signal->group_stop_count = 0;
signal->group_exit_code = 0;
*/
signal->flags &= ~SIGNAL_STOP_DEQUEUED;
}
- } else if (sig == SIGKILL) {
+ }
+
+ return !sig_ignored(p, sig, from_ancestor_ns);
+}
+
+/*
+ * 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))
/*
- * Make sure that any pending stop signal already dequeued
- * is undone by the wakeup for SIGKILL.
+ * There is just one thread and it does not need to be woken.
+ * It will dequeue unblocked signals before it runs again.
*/
- signal->flags &= ~SIGNAL_STOP_DEQUEUED;
+ 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;
+ }
+ 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 ||
+ !tracehook_consider_fatal_signal(t, sig))) {
+ /*
+ * 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.
+ */
+ 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)
+static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
+ int group, int from_ancestor_ns)
{
- struct sigqueue * q = NULL;
+ struct sigpending *pending;
+ struct sigqueue *q;
+ int override_rlimit;
+
+ trace_signal_generate(sig, info, t);
+
+ assert_spin_locked(&t->sighand->siglock);
+ if (!prepare_signal(sig, t, from_ancestor_ns))
+ return 0;
+
+ pending = group ? &t->signal->shared_pending : &t->pending;
/*
* 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.
*/
- if (sig_ignored(t, sig) || legacy_queue(signals, sig))
+ if (legacy_queue(pending, sig))
return 0;
-
- /*
- * Deliver the signal to listening signalfds. This must be called
- * with the sighand lock held.
- */
- signalfd_notify(t, sig);
-
/*
* fast-pathed signals for kernel-internal things like SIGSTOP
* or SIGKILL.
make sure at least one signal gets delivered and don't
pass on the info struct. */
- q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
- (is_si_special(info) ||
- info->si_code >= 0)));
+ if (sig < SIGRTMIN)
+ override_rlimit = (is_si_special(info) || info->si_code >= 0);
+ else
+ override_rlimit = 0;
+
+ q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE,
+ override_rlimit);
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;
q->info.si_errno = 0;
q->info.si_code = SI_USER;
- q->info.si_pid = task_pid_vnr(current);
- q->info.si_uid = current->uid;
+ q->info.si_pid = task_tgid_nr_ns(current,
+ task_active_pid_ns(t));
+ q->info.si_uid = current_uid();
break;
case (unsigned long) SEND_SIG_PRIV:
q->info.si_signo = sig;
break;
default:
copy_siginfo(&q->info, info);
+ if (from_ancestor_ns)
+ q->info.si_pid = 0;
break;
}
} else if (!is_si_special(info)) {
- if (sig >= SIGRTMIN && info->si_code != SI_USER)
- /*
- * Queue overflow, abort. We may abort if the signal was rt
- * and sent by user using something other than kill().
- */
+ if (sig >= SIGRTMIN && info->si_code != SI_USER) {
+ /*
+ * Queue overflow, abort. We may abort if the
+ * signal was rt and sent by user using something
+ * other than kill().
+ */
+ trace_signal_overflow_fail(sig, group, info);
return -EAGAIN;
+ } else {
+ /*
+ * This is a silent loss of information. We still
+ * send the signal, but the *info bits are lost.
+ */
+ trace_signal_lose_info(sig, group, info);
+ }
}
out_set:
- sigaddset(&signals->signal, sig);
- return 1;
+ signalfd_notify(t, sig);
+ sigaddset(&pending->signal, sig);
+ complete_signal(sig, t, group);
+ return 0;
}
-int print_fatal_signals;
+static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
+ int group)
+{
+ int from_ancestor_ns = 0;
+
+#ifdef CONFIG_PID_NS
+ if (!is_si_special(info) && SI_FROMUSER(info) &&
+ task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0)
+ from_ancestor_ns = 1;
+#endif
+
+ return __send_signal(sig, info, t, group, from_ancestor_ns);
+}
static void print_fatal_signal(struct pt_regs *regs, int signr)
{
}
#endif
printk("\n");
+ preempt_disable();
show_regs(regs);
+ preempt_enable();
}
static int __init setup_print_fatal_signals(char *str)
__setup("print-fatal-signals=", setup_print_fatal_signals);
-static int
-specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
-{
- int ret;
-
- BUG_ON(!irqs_disabled());
- assert_spin_locked(&t->sighand->siglock);
-
- ret = send_signal(sig, info, t, &t->pending);
- if (ret <= 0)
- return ret;
-
- if (!sigismember(&t->blocked, sig))
- signal_wake_up(t, sig == SIGKILL);
- return 0;
-}
-
-/*
- * Force a signal that the process can't ignore: if necessary
- * we unblock the signal and change any SIG_IGN to SIG_DFL.
- *
- * Note: If we unblock the signal, we always reset it to SIG_DFL,
- * 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.
- */
int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
-{
- unsigned long int flags;
- int ret, blocked, ignored;
- struct k_sigaction *action;
-
- spin_lock_irqsave(&t->sighand->siglock, flags);
- action = &t->sighand->action[sig-1];
- ignored = action->sa.sa_handler == SIG_IGN;
- blocked = sigismember(&t->blocked, sig);
- if (blocked || ignored) {
- action->sa.sa_handler = SIG_DFL;
- if (blocked) {
- sigdelset(&t->blocked, sig);
- recalc_sigpending_and_wake(t);
- }
- }
- ret = specific_send_sig_info(sig, info, t);
- spin_unlock_irqrestore(&t->sighand->siglock, flags);
-
- return ret;
-}
-
-void
-force_sig_specific(int sig, struct task_struct *t)
-{
- 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)
+__group_send_sig_info(int sig, struct siginfo *info, 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;
- }
+ return send_signal(sig, info, p, 1);
+}
+
+static int
+specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+{
+ return send_signal(sig, info, t, 0);
+}
+
+int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
+ bool group)
+{
+ unsigned long flags;
+ int ret = -ESRCH;
+
+ if (lock_task_sighand(p, &flags)) {
+ ret = send_signal(sig, info, p, group);
+ unlock_task_sighand(p, &flags);
}
- /*
- * 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;
+ return ret;
}
+/*
+ * Force a signal that the process can't ignore: if necessary
+ * we unblock the signal and change any SIG_IGN to SIG_DFL.
+ *
+ * Note: If we unblock the signal, we always reset it to SIG_DFL,
+ * 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,
+ * that is why we also clear SIGNAL_UNKILLABLE.
+ */
int
-__group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
+force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
{
- int ret;
+ unsigned long int flags;
+ int ret, blocked, ignored;
+ struct k_sigaction *action;
- assert_spin_locked(&p->sighand->siglock);
- handle_stop_signal(sig, p);
+ spin_lock_irqsave(&t->sighand->siglock, flags);
+ action = &t->sighand->action[sig-1];
+ ignored = action->sa.sa_handler == SIG_IGN;
+ blocked = sigismember(&t->blocked, sig);
+ if (blocked || ignored) {
+ action->sa.sa_handler = SIG_DFL;
+ if (blocked) {
+ sigdelset(&t->blocked, sig);
+ 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);
- /*
- * 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 (ret <= 0)
- return ret;
+ return ret;
+}
- __group_complete_signal(sig, p);
- return 0;
+void
+force_sig_specific(int sig, struct task_struct *t)
+{
+ force_sig_info(sig, SEND_SIG_FORCED, t);
}
/*
}
}
-int __fatal_signal_pending(struct task_struct *tsk)
-{
- return sigismember(&tsk->pending.signal, SIGKILL);
-}
-EXPORT_SYMBOL(__fatal_signal_pending);
-
struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
{
struct sighand_struct *sighand;
return sighand;
}
+/*
+ * send signal info to all the members of a group
+ * - the caller must hold the RCU read lock at least
+ */
int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
{
- unsigned long flags;
- int ret;
+ int ret = check_kill_permission(sig, info, p);
- ret = check_kill_permission(sig, info, p);
-
- if (!ret && sig) {
- ret = -ESRCH;
- if (lock_task_sighand(p, &flags)) {
- ret = __group_send_sig_info(sig, info, p);
- unlock_task_sighand(p, &flags);
- }
- }
+ if (!ret && sig)
+ ret = do_send_sig_info(sig, info, p, true);
return ret;
}
/*
* __kill_pgrp_info() sends a signal to a process group: this is what the tty
* control characters do (^C, ^Z etc)
+ * - the caller must hold at least a readlock on tasklist_lock
*/
-
int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp)
{
struct task_struct *p = NULL;
{
int ret = -EINVAL;
struct task_struct *p;
+ const struct cred *pcred;
if (!valid_signal(sig))
return ret;
ret = -ESRCH;
goto out_unlock;
}
- if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
- && (euid != p->suid) && (euid != p->uid)
- && (uid != p->suid) && (uid != p->uid)) {
+ pcred = __task_cred(p);
+ if ((info == SEND_SIG_NOINFO ||
+ (!is_si_special(info) && SI_FROMUSER(info))) &&
+ euid != pcred->suid && euid != pcred->uid &&
+ uid != pcred->suid && uid != pcred->uid) {
ret = -EPERM;
goto out_unlock;
}
if (sig && p->sighand) {
unsigned long flags;
spin_lock_irqsave(&p->sighand->siglock, flags);
- ret = __group_send_sig_info(sig, info, p);
+ ret = __send_signal(sig, info, p, 1, 0);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
out_unlock:
* is probably wrong. Should make it like BSD or SYSV.
*/
-static int kill_something_info(int sig, struct siginfo *info, int pid)
+static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
{
int ret;
struct task_struct * p;
for_each_process(p) {
- if (p->pid > 1 && !same_thread_group(p, current)) {
+ if (task_pid_vnr(p) > 1 &&
+ !same_thread_group(p, current)) {
int err = group_send_sig_info(sig, info, p);
++count;
if (err != -EPERM)
* These are for backward compatibility with the rest of the kernel source.
*/
-/*
- * These two are the most common entry points. They send a signal
- * just to the specific thread.
- */
int
send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
{
- int ret;
- unsigned long flags;
-
/*
* Make sure legacy kernel users don't send in bad values
* (normal paths check this in check_kill_permission).
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;
+ return do_send_sig_info(sig, info, p, false);
}
#define __si_special(priv) \
}
EXPORT_SYMBOL(kill_pid);
-int
-kill_proc(pid_t pid, int sig, int priv)
-{
- int ret;
-
- rcu_read_lock();
- ret = kill_pid_info(sig, __si_special(priv), find_pid(pid));
- rcu_read_unlock();
- return ret;
-}
-
/*
* These functions support sending signals using preallocated sigqueue
* structures. This is needed "because realtime applications cannot
* afford to lose notifications of asynchronous events, like timer
- * expirations or I/O completions". In the case of Posix Timers
+ * expirations or I/O completions". In the case of Posix Timers
* we allocate the sigqueue structure from the timer_create. If this
* allocation fails we are able to report the failure to the application
* with an EAGAIN error.
*/
-
struct sigqueue *sigqueue_alloc(void)
{
- struct sigqueue *q;
+ struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
- if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0)))
+ if (q)
q->flags |= SIGQUEUE_PREALLOC;
- return(q);
+
+ return q;
}
void sigqueue_free(struct sigqueue *q)
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
/*
- * If the signal is still pending remove it from the
- * pending queue. We must hold ->siglock while testing
- * q->list to serialize with collect_signal().
+ * We must hold ->siglock while testing q->list
+ * to serialize with collect_signal() or with
+ * __exit_signal()->flush_sigqueue().
*/
spin_lock_irqsave(lock, flags);
+ q->flags &= ~SIGQUEUE_PREALLOC;
+ /*
+ * If it is queued it will be freed when dequeued,
+ * like the "regular" sigqueue.
+ */
if (!list_empty(&q->list))
- list_del_init(&q->list);
+ q = NULL;
spin_unlock_irqrestore(lock, flags);
- q->flags &= ~SIGQUEUE_PREALLOC;
- __sigqueue_free(q);
+ if (q)
+ __sigqueue_free(q);
}
-static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t,
- struct sigpending *pending)
+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;
+
+ BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
+
+ ret = -1;
+ if (!likely(lock_task_sighand(t, &flags)))
+ goto ret;
+
+ ret = 1; /* the signal is ignored */
+ if (!prepare_signal(sig, t, 0))
+ goto out;
+
+ ret = 0;
if (unlikely(!list_empty(&q->list))) {
/*
* If an SI_TIMER entry is already queue just increment
* the overrun count.
*/
-
BUG_ON(q->info.si_code != SI_TIMER);
q->info.si_overrun++;
- return 0;
+ goto out;
}
-
- if (sig_ignored(t, sig))
- return 1;
+ q->info.si_overrun = 0;
signalfd_notify(t, sig);
+ pending = group ? &t->signal->shared_pending : &t->pending;
list_add_tail(&q->list, &pending->list);
sigaddset(&pending->signal, sig);
- return 0;
-}
-
-int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
-{
- unsigned long flags;
- int ret = -1;
-
- 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
- */
- if (!likely(lock_task_sighand(p, &flags)))
- goto out_err;
-
- ret = do_send_sigqueue(sig, q, p, &p->pending);
-
- if (!sigismember(&p->blocked, sig))
- signal_wake_up(p, sig == SIGKILL);
-
- unlock_task_sighand(p, &flags);
-out_err:
- return ret;
-}
-
-int
-send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
-{
- unsigned long flags;
- int ret;
-
- 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);
-
- ret = do_send_sigqueue(sig, q, p, &p->signal->shared_pending);
-
- __group_complete_signal(sig, p);
-
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- read_unlock(&tasklist_lock);
+ complete_signal(sig, t, group);
+out:
+ unlock_task_sighand(t, &flags);
+ret:
return ret;
}
/*
- * Wake up any threads in the parent blocked in wait* syscalls.
- */
-static inline void __wake_up_parent(struct task_struct *p,
- struct task_struct *parent)
-{
- wake_up_interruptible_sync(&parent->signal->wait_chldexit);
-}
-
-/*
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
+ *
+ * Returns -1 if our parent ignored us and so we've switched to
+ * self-reaping, or else @sig.
*/
-
-void do_notify_parent(struct task_struct *tsk, int sig)
+int do_notify_parent(struct task_struct *tsk, int sig)
{
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
+ int ret = sig;
BUG_ON(sig == -1);
/* do_notify_parent_cldstop should have been called instead. */
BUG_ON(task_is_stopped_or_traced(tsk));
- BUG_ON(!tsk->ptrace &&
+ BUG_ON(!task_ptrace(tsk) &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
info.si_signo = sig;
*/
rcu_read_lock();
info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns);
+ info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
- info.si_uid = tsk->uid;
-
- /* FIXME: find out whether or not this is supposed to be c*time. */
- info.si_utime = cputime_to_jiffies(cputime_add(tsk->utime,
- tsk->signal->utime));
- info.si_stime = cputime_to_jiffies(cputime_add(tsk->stime,
- tsk->signal->stime));
+ info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
+ tsk->signal->utime));
+ info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
+ tsk->signal->stime));
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)
psig = tsk->parent->sighand;
spin_lock_irqsave(&psig->siglock, flags);
- if (!tsk->ptrace && sig == SIGCHLD &&
+ if (!task_ptrace(tsk) && sig == SIGCHLD &&
(psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
(psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
/*
* is implementation-defined: we do (if you don't want
* it, just use SIG_IGN instead).
*/
- tsk->exit_signal = -1;
+ ret = tsk->exit_signal = -1;
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
- sig = 0;
+ sig = -1;
}
if (valid_signal(sig) && sig > 0)
__group_send_sig_info(sig, &info, tsk->parent);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
+
+ return ret;
}
static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
struct task_struct *parent;
struct sighand_struct *sighand;
- if (tsk->ptrace & PT_PTRACED)
+ if (task_ptrace(tsk))
parent = tsk->parent;
else {
tsk = tsk->group_leader;
* see comment in do_notify_parent() abot the following 3 lines
*/
rcu_read_lock();
- info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns);
+ info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
+ info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
- info.si_uid = tsk->uid;
-
- /* FIXME: find out whether or not this is supposed to be c*time. */
- info.si_utime = cputime_to_jiffies(tsk->utime);
- info.si_stime = cputime_to_jiffies(tsk->stime);
+ info.si_utime = cputime_to_clock_t(tsk->utime);
+ info.si_stime = cputime_to_clock_t(tsk->stime);
info.si_code = why;
switch (why) {
static inline int may_ptrace_stop(void)
{
- if (!likely(current->ptrace & PT_PTRACED))
+ if (!likely(task_ptrace(current)))
return 0;
/*
* Are we in the middle of do_coredump?
* is a deadlock situation, and pointless because our tracer
* is dead so don't allow us to stop.
* If SIGKILL was already sent before the caller unlocked
- * ->siglock we must see ->core_waiters != 0. Otherwise it
+ * ->siglock we must see ->core_state != NULL. Otherwise it
* is safe to enter schedule().
*/
- if (unlikely(current->mm->core_waiters) &&
+ if (unlikely(current->mm->core_state) &&
unlikely(current->mm == current->parent->mm))
return 0;
*/
static int sigkill_pending(struct task_struct *tsk)
{
- return ((sigismember(&tsk->pending.signal, SIGKILL) ||
- sigismember(&tsk->signal->shared_pending.signal, SIGKILL)) &&
- !unlikely(sigismember(&tsk->blocked, SIGKILL)));
+ return sigismember(&tsk->pending.signal, SIGKILL) ||
+ sigismember(&tsk->signal->shared_pending.signal, SIGKILL);
}
/*
*/
static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
{
- int killed = 0;
-
if (arch_ptrace_stop_needed(exit_code, info)) {
/*
* The arch code has something special to do before a
spin_unlock_irq(¤t->sighand->siglock);
arch_ptrace_stop(exit_code, info);
spin_lock_irq(¤t->sighand->siglock);
- killed = sigkill_pending(current);
+ if (sigkill_pending(current))
+ return;
}
/*
__set_current_state(TASK_TRACED);
spin_unlock_irq(¤t->sighand->siglock);
read_lock(&tasklist_lock);
- if (!unlikely(killed) && may_ptrace_stop()) {
+ if (may_ptrace_stop()) {
do_notify_parent_cldstop(current, CLD_TRAPPED);
+ /*
+ * Don't want to allow preemption here, because
+ * sys_ptrace() needs this task to be inactive.
+ *
+ * XXX: implement read_unlock_no_resched().
+ */
+ preempt_disable();
read_unlock(&tasklist_lock);
+ preempt_enable_no_resched();
schedule();
} else {
/*
info.si_signo = SIGTRAP;
info.si_code = exit_code;
info.si_pid = task_pid_vnr(current);
- info.si_uid = current->uid;
+ info.si_uid = current_uid();
/* Let the debugger run. */
spin_lock_irq(¤t->sighand->siglock);
spin_unlock_irq(¤t->sighand->siglock);
}
-static void
-finish_stop(int stop_count)
-{
- /*
- * 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, CLD_STOPPED);
- read_unlock(&tasklist_lock);
- }
-
- do {
- schedule();
- } while (try_to_freeze());
- /*
- * Now we don't run again until continued.
- */
- current->exit_code = 0;
-}
-
/*
* This performs the stopping for SIGSTOP and other stop signals.
* We have to stop all threads in the thread group.
static int do_signal_stop(int signr)
{
struct signal_struct *sig = current->signal;
- int stop_count;
+ int notify;
- if (sig->group_stop_count > 0) {
- /*
- * There is a group stop in progress. We don't need to
- * start another one.
- */
- stop_count = --sig->group_stop_count;
- } else {
+ if (!sig->group_stop_count) {
struct task_struct *t;
if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
*/
sig->group_exit_code = signr;
- stop_count = 0;
+ sig->group_stop_count = 1;
for (t = next_thread(current); t != current; t = next_thread(t))
/*
* Setting state to TASK_STOPPED for a group
*/
if (!(t->flags & PF_EXITING) &&
!task_is_stopped_or_traced(t)) {
- stop_count++;
+ sig->group_stop_count++;
signal_wake_up(t, 0);
}
- sig->group_stop_count = stop_count;
}
+ /*
+ * 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.
+ */
+ notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0;
+ notify = tracehook_notify_jctl(notify, CLD_STOPPED);
+ /*
+ * tracehook_notify_jctl() can drop and reacquire siglock, so
+ * we keep ->group_stop_count != 0 before the call. If SIGCONT
+ * or SIGKILL comes in between ->group_stop_count == 0.
+ */
+ if (sig->group_stop_count) {
+ if (!--sig->group_stop_count)
+ sig->flags = SIGNAL_STOP_STOPPED;
+ current->exit_code = sig->group_exit_code;
+ __set_current_state(TASK_STOPPED);
+ }
+ spin_unlock_irq(¤t->sighand->siglock);
- if (stop_count == 0)
- sig->flags = SIGNAL_STOP_STOPPED;
- current->exit_code = sig->group_exit_code;
- __set_current_state(TASK_STOPPED);
+ if (notify) {
+ read_lock(&tasklist_lock);
+ do_notify_parent_cldstop(current, notify);
+ read_unlock(&tasklist_lock);
+ }
+
+ /* Now we don't run again until woken by SIGCONT or SIGKILL */
+ do {
+ schedule();
+ } while (try_to_freeze());
+
+ tracehook_finish_jctl();
+ current->exit_code = 0;
- spin_unlock_irq(¤t->sighand->siglock);
- finish_stop(stop_count);
return 1;
}
static int ptrace_signal(int signr, siginfo_t *info,
struct pt_regs *regs, void *cookie)
{
- if (!(current->ptrace & PT_PTRACED))
+ if (!task_ptrace(current))
return signr;
ptrace_signal_deliver(regs, cookie);
info->si_errno = 0;
info->si_code = SI_USER;
info->si_pid = task_pid_vnr(current->parent);
- info->si_uid = current->parent->uid;
+ info->si_uid = task_uid(current->parent);
}
/* If the (new) signal is now blocked, requeue it. */
try_to_freeze();
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;
+
+ why = tracehook_notify_jctl(why, CLD_CONTINUED);
spin_unlock_irq(&sighand->siglock);
- read_lock(&tasklist_lock);
- do_notify_parent_cldstop(current->group_leader, why);
- read_unlock(&tasklist_lock);
+ if (why) {
+ read_lock(&tasklist_lock);
+ do_notify_parent_cldstop(current->group_leader, why);
+ read_unlock(&tasklist_lock);
+ }
goto relock;
}
do_signal_stop(0))
goto relock;
- signr = dequeue_signal(current, ¤t->blocked, info);
- if (!signr)
- break; /* will return 0 */
+ /*
+ * Tracing can induce an artifical signal and choose sigaction.
+ * The return value in @signr determines the default action,
+ * but @info->si_signo is the signal number we will report.
+ */
+ signr = tracehook_get_signal(current, regs, info, return_ka);
+ if (unlikely(signr < 0))
+ goto relock;
+ if (unlikely(signr != 0))
+ ka = return_ka;
+ else {
+ signr = dequeue_signal(current, ¤t->blocked,
+ info);
- if (signr != SIGKILL) {
- signr = ptrace_signal(signr, info, regs, cookie);
if (!signr)
- continue;
+ break; /* will return 0 */
+
+ if (signr != SIGKILL) {
+ signr = ptrace_signal(signr, info,
+ regs, cookie);
+ if (!signr)
+ continue;
+ }
+
+ ka = &sighand->action[signr-1];
}
- ka = &sighand->action[signr-1];
+ /* Trace actually delivered signals. */
+ trace_signal_deliver(signr, info, ka);
+
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.
+ * Container-init gets no signals it doesn't want from same
+ * container.
+ *
+ * Note that if global/container-init sees a sig_kernel_only()
+ * signal here, the signal must have been generated internally
+ * or must have come from an ancestor namespace. In either
+ * case, the signal cannot be dropped.
*/
- if (is_global_init(current))
+ if (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
+ !sig_kernel_only(signr))
continue;
if (sig_kernel_stop(signr)) {
spin_lock_irq(&sighand->siglock);
}
- if (likely(do_signal_stop(signr))) {
+ if (likely(do_signal_stop(info->si_signo))) {
/* It released the siglock. */
goto relock;
}
* 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, info->si_signo);
/*
* If it was able to dump core, this kills all
* other threads in the group and synchronizes with
* first and our do_group_exit call below will use
* that value and ignore the one we pass it.
*/
- do_coredump((long)signr, signr, regs);
+ do_coredump(info->si_signo, info->si_signo, regs);
}
/*
* Death signals, no core dump.
*/
- do_group_exit(signr);
+ do_group_exit(info->si_signo);
/* NOTREACHED */
}
spin_unlock_irq(&sighand->siglock);
if (unlikely(tsk->signal->group_stop_count) &&
!--tsk->signal->group_stop_count) {
tsk->signal->flags = SIGNAL_STOP_STOPPED;
- group_stop = 1;
+ group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED);
}
out:
spin_unlock_irq(&tsk->sighand->siglock);
if (unlikely(group_stop)) {
read_lock(&tasklist_lock);
- do_notify_parent_cldstop(tsk, CLD_STOPPED);
+ do_notify_parent_cldstop(tsk, group_stop);
read_unlock(&tasklist_lock);
}
}
EXPORT_SYMBOL_GPL(dequeue_signal);
EXPORT_SYMBOL(flush_signals);
EXPORT_SYMBOL(force_sig);
-EXPORT_SYMBOL(kill_proc);
-EXPORT_SYMBOL(ptrace_notify);
EXPORT_SYMBOL(send_sig);
EXPORT_SYMBOL(send_sig_info);
EXPORT_SYMBOL(sigprocmask);
* System call entry points.
*/
-asmlinkage long sys_restart_syscall(void)
+SYSCALL_DEFINE0(restart_syscall)
{
struct restart_block *restart = ¤t_thread_info()->restart_block;
return restart->fn(restart);
return error;
}
-asmlinkage long
-sys_rt_sigprocmask(int how, sigset_t __user *set, sigset_t __user *oset, size_t sigsetsize)
+SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, set,
+ sigset_t __user *, oset, size_t, sigsetsize)
{
int error = -EINVAL;
sigset_t old_set, new_set;
return error;
}
-asmlinkage long
-sys_rt_sigpending(sigset_t __user *set, size_t sigsetsize)
+SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize)
{
return do_sigpending(set, sigsetsize);
}
#endif
-asmlinkage long
-sys_rt_sigtimedwait(const sigset_t __user *uthese,
- siginfo_t __user *uinfo,
- const struct timespec __user *uts,
- size_t sigsetsize)
+SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
+ siginfo_t __user *, uinfo, const struct timespec __user *, uts,
+ size_t, sigsetsize)
{
int ret, sig;
sigset_t these;
return ret;
}
-asmlinkage long
-sys_kill(int pid, int sig)
+SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
{
struct siginfo info;
info.si_errno = 0;
info.si_code = SI_USER;
info.si_pid = task_tgid_vnr(current);
- info.si_uid = current->uid;
+ info.si_uid = current_uid();
return kill_something_info(sig, &info, pid);
}
-static int do_tkill(int tgid, int pid, int sig)
+static int
+do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
{
- int error;
- struct siginfo info;
struct task_struct *p;
+ int error = -ESRCH;
- error = -ESRCH;
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = SI_TKILL;
- 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);
+ error = check_kill_permission(sig, info, p);
/*
* The null signal is a permissions and process existence
* probe. No signal is actually delivered.
*/
- if (!error && sig && p->sighand) {
- spin_lock_irq(&p->sighand->siglock);
- handle_stop_signal(sig, p);
- error = specific_send_sig_info(sig, &info, p);
- spin_unlock_irq(&p->sighand->siglock);
+ if (!error && sig) {
+ error = do_send_sig_info(sig, info, p, false);
+ /*
+ * If lock_task_sighand() failed we pretend the task
+ * dies after receiving the signal. The window is tiny,
+ * and the signal is private anyway.
+ */
+ if (unlikely(error == -ESRCH))
+ error = 0;
}
}
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return error;
}
+static int do_tkill(pid_t tgid, pid_t pid, int sig)
+{
+ struct siginfo info;
+
+ info.si_signo = sig;
+ info.si_errno = 0;
+ info.si_code = SI_TKILL;
+ info.si_pid = task_tgid_vnr(current);
+ info.si_uid = current_uid();
+
+ return do_send_specific(tgid, pid, sig, &info);
+}
+
/**
* sys_tgkill - send signal to one specific thread
* @tgid: the thread group ID of the thread
* exists but it's not belonging to the target process anymore. This
* method solves the problem of threads exiting and PIDs getting reused.
*/
-asmlinkage long sys_tgkill(int tgid, int pid, int sig)
+SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig)
{
/* This is only valid for single tasks */
if (pid <= 0 || tgid <= 0)
/*
* Send a signal to only one task, even if it's a CLONE_THREAD task.
*/
-asmlinkage long
-sys_tkill(int pid, int sig)
+SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig)
{
/* This is only valid for single tasks */
if (pid <= 0)
return do_tkill(0, pid, sig);
}
-asmlinkage long
-sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo)
+SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig,
+ siginfo_t __user *, uinfo)
{
siginfo_t info;
return kill_proc_info(sig, &info, pid);
}
+long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
+{
+ /* This is only valid for single tasks */
+ if (pid <= 0 || tgid <= 0)
+ return -EINVAL;
+
+ /* Not even root can pretend to send signals from the kernel.
+ Nor can they impersonate a kill(), which adds source info. */
+ if (info->si_code >= 0)
+ return -EPERM;
+ info->si_signo = sig;
+
+ return do_send_specific(tgid, pid, sig, info);
+}
+
+SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig,
+ siginfo_t __user *, uinfo)
+{
+ siginfo_t info;
+
+ if (copy_from_user(&info, uinfo, sizeof(siginfo_t)))
+ return -EFAULT;
+
+ return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
+}
+
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
struct task_struct *t = current;
* (for example, SIGCHLD), shall cause the pending signal to
* be discarded, whether or not it is blocked"
*/
- if (__sig_ignored(t, sig)) {
+ if (sig_handler_ignored(sig_handler(t, sig), sig)) {
sigemptyset(&mask);
sigaddset(&mask, sig);
rm_from_queue_full(&mask, &t->signal->shared_pending);
stack_t oss;
int error;
- if (uoss) {
- oss.ss_sp = (void __user *) current->sas_ss_sp;
- oss.ss_size = current->sas_ss_size;
- oss.ss_flags = sas_ss_flags(sp);
- }
+ oss.ss_sp = (void __user *) current->sas_ss_sp;
+ oss.ss_size = current->sas_ss_size;
+ oss.ss_flags = sas_ss_flags(sp);
if (uss) {
void __user *ss_sp;
int ss_flags;
error = -EFAULT;
- if (!access_ok(VERIFY_READ, uss, sizeof(*uss))
- || __get_user(ss_sp, &uss->ss_sp)
- || __get_user(ss_flags, &uss->ss_flags)
- || __get_user(ss_size, &uss->ss_size))
+ if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
+ goto out;
+ error = __get_user(ss_sp, &uss->ss_sp) |
+ __get_user(ss_flags, &uss->ss_flags) |
+ __get_user(ss_size, &uss->ss_size);
+ if (error)
goto out;
error = -EPERM;
current->sas_ss_size = ss_size;
}
+ error = 0;
if (uoss) {
error = -EFAULT;
- if (copy_to_user(uoss, &oss, sizeof(oss)))
+ if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
goto out;
+ error = __put_user(oss.ss_sp, &uoss->ss_sp) |
+ __put_user(oss.ss_size, &uoss->ss_size) |
+ __put_user(oss.ss_flags, &uoss->ss_flags);
}
- error = 0;
out:
return error;
}
#ifdef __ARCH_WANT_SYS_SIGPENDING
-asmlinkage long
-sys_sigpending(old_sigset_t __user *set)
+SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
{
return do_sigpending(set, sizeof(*set));
}
/* Some platforms have their own version with special arguments others
support only sys_rt_sigprocmask. */
-asmlinkage long
-sys_sigprocmask(int how, old_sigset_t __user *set, old_sigset_t __user *oset)
+SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set,
+ old_sigset_t __user *, oset)
{
int error;
old_sigset_t old_set, new_set;
#endif /* __ARCH_WANT_SYS_SIGPROCMASK */
#ifdef __ARCH_WANT_SYS_RT_SIGACTION
-asmlinkage long
-sys_rt_sigaction(int sig,
- const struct sigaction __user *act,
- struct sigaction __user *oact,
- size_t sigsetsize)
+SYSCALL_DEFINE4(rt_sigaction, int, sig,
+ const struct sigaction __user *, act,
+ struct sigaction __user *, oact,
+ size_t, sigsetsize)
{
struct k_sigaction new_sa, old_sa;
int ret = -EINVAL;
/*
* For backwards compatibility. Functionality superseded by sigprocmask.
*/
-asmlinkage long
-sys_sgetmask(void)
+SYSCALL_DEFINE0(sgetmask)
{
/* SMP safe */
return current->blocked.sig[0];
}
-asmlinkage long
-sys_ssetmask(int newmask)
+SYSCALL_DEFINE1(ssetmask, int, newmask)
{
int old;
/*
* For backwards compatibility. Functionality superseded by sigaction.
*/
-asmlinkage unsigned long
-sys_signal(int sig, __sighandler_t handler)
+SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler)
{
struct k_sigaction new_sa, old_sa;
int ret;
#ifdef __ARCH_WANT_SYS_PAUSE
-asmlinkage long
-sys_pause(void)
+SYSCALL_DEFINE0(pause)
{
current->state = TASK_INTERRUPTIBLE;
schedule();
#endif
#ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
-asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
+SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
{
sigset_t newset;
current->state = TASK_INTERRUPTIBLE;
schedule();
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
return -ERESTARTNOHAND;
}
#endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff