#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/signalfd.h>
+#include <linux/tracehook.h>
#include <linux/capability.h>
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
+#include <trace/sched.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)
+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)
{
- /*
- * Tracers always want to know about signals..
- */
- if (t->ptrace & PT_PTRACED)
- return 0;
+ void __user *handler;
/*
* Blocked signals are never ignored, since the
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- return __sig_ignored(t, sig);
+ handler = sig_handler(t, sig);
+ if (!sig_handler_ignored(handler, sig))
+ return 0;
+
+ /*
+ * Tracers may want to know about even ignored signals.
+ */
+ return !tracehook_consider_ignored_signal(t, sig, handler);
}
/*
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);
}
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, handler);
}
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) {
/*
static int check_kill_permission(int sig, struct siginfo *info,
struct task_struct *t)
{
+ 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;
+ 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);
}
-/* 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)
{
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 finish_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;
}
}
+
+ return !sig_ignored(p, sig);
}
/*
* 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_GROUP_EXIT) &&
+ if (sig_fatal(p, sig) &&
+ !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
!sigismember(&t->real_blocked, sig) &&
- (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
+ (sig == SIGKILL ||
+ !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
/*
* This signal will be fatal to the whole group.
*/
struct sigpending *pending;
struct sigqueue *q;
+ trace_sched_signal_send(sig, t);
+
assert_spin_locked(&t->sighand->siglock);
- handle_stop_signal(sig, t);
+ if (!prepare_signal(sig, t))
+ return 0;
pending = group ? &t->signal->shared_pending : &t->pending;
/*
* 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(pending, 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.
}
out_set:
+ signalfd_notify(t, sig);
sigaddset(&pending->signal, sig);
complete_signal(sig, t, group);
return 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);
* 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;
}
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
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);
}
int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
if (!likely(lock_task_sighand(t, &flags)))
goto ret;
- handle_stop_signal(sig, t);
-
- ret = 1;
- if (sig_ignored(t, sig))
+ ret = 1; /* the signal is ignored */
+ if (!prepare_signal(sig, t))
goto out;
ret = 0;
q->info.si_overrun++;
goto out;
}
+ q->info.si_overrun = 0;
signalfd_notify(t, sig);
pending = group ? &t->signal->shared_pending : &t->pending;
/*
* 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;
+ struct task_cputime cputime;
+ int ret = sig;
BUG_ON(sig == -1);
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));
+ thread_group_cputime(tsk, &cputime);
+ info.si_utime = cputime_to_jiffies(cputime.utime);
+ info.si_stime = cputime_to_jiffies(cputime.stime);
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)
* 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)
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) {
* 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);
read_unlock(&tasklist_lock);
schedule();
* 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)) {
+ if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
read_lock(&tasklist_lock);
do_notify_parent_cldstop(current, CLD_STOPPED);
read_unlock(&tasklist_lock);
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;
spin_unlock_irq(&sighand->siglock);
+ if (unlikely(!tracehook_notify_jctl(1, why)))
+ goto relock;
+
read_lock(&tasklist_lock);
do_notify_parent_cldstop(current->group_leader, why);
read_unlock(&tasklist_lock);
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];
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)) {
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);
out:
spin_unlock_irq(&tsk->sighand->siglock);
- if (unlikely(group_stop)) {
+ if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) {
read_lock(&tasklist_lock);
do_notify_parent_cldstop(tsk, CLD_STOPPED);
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);
}
asmlinkage long
-sys_kill(int pid, int sig)
+sys_kill(pid_t pid, int sig)
{
struct siginfo info;
return kill_something_info(sig, &info, pid);
}
-static int do_tkill(int tgid, int pid, int sig)
+static int do_tkill(pid_t tgid, pid_t pid, int sig)
{
int error;
struct siginfo info;
* 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)
+asmlinkage long sys_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)
+sys_tkill(pid_t pid, int sig)
{
/* This is only valid for single tasks */
if (pid <= 0)
}
asmlinkage long
-sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo)
+sys_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t __user *uinfo)
{
siginfo_t info;
* (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);
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