#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
-#include <trace/sched.h>
+#include <trace/events/sched.h>
#include <asm/param.h>
#include <asm/uaccess.h>
static struct kmem_cache *sigqueue_cachep;
-DEFINE_TRACE(sched_signal_send);
-
static void __user *sig_handler(struct task_struct *t, int sig)
{
return t->sighand->action[sig - 1].sa.sa_handler;
(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)
{
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;
- handler = sig_handler(t, sig);
- if (!sig_handler_ignored(handler, 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, handler);
+ return !tracehook_consider_ignored_signal(t, sig);
}
/*
/*
* 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);
}
return 1;
if (handler != SIG_IGN && handler != SIG_DFL)
return 0;
- return !tracehook_consider_fatal_signal(tsk, sig, handler);
+ return !tracehook_consider_fatal_signal(tsk, sig);
}
* Returns true if the signal should be actually delivered, otherwise
* it should be dropped.
*/
-static int prepare_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 (why) {
/*
- * The first thread which returns from finish_stop()
+ * 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().
*/
}
}
- return !sig_ignored(p, sig);
+ return !sig_ignored(p, sig, from_ancestor_ns);
}
/*
!(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
!sigismember(&t->real_blocked, sig) &&
(sig == SIGKILL ||
- !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
+ !tracehook_consider_fatal_signal(t, sig))) {
/*
* This signal will be fatal to the whole group.
*/
return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
-static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
- int group)
+static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
+ int group, int from_ancestor_ns)
{
struct sigpending *pending;
struct sigqueue *q;
+ int override_rlimit;
trace_sched_signal_send(sig, t);
assert_spin_locked(&t->sighand->siglock);
- if (!prepare_signal(sig, t))
+
+ if (!prepare_signal(sig, t, from_ancestor_ns))
return 0;
pending = group ? &t->signal->shared_pending : &t->pending;
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(t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE,
+ override_rlimit);
if (q) {
list_add_tail(&q->list, &pending->list);
switch ((unsigned long) info) {
break;
default:
copy_siginfo(&q->info, info);
+ if (from_ancestor_ns)
+ q->info.si_pid = 0;
break;
}
} else if (!is_si_special(info)) {
return 0;
}
+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);
+}
+
int print_fatal_signals;
static void print_fatal_signal(struct pt_regs *regs, int signr)
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);
+ }
+
+ 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.
}
}
-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;
*/
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;
}
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:
* These are for backward compatibility with the rest of the kernel source.
*/
-/*
- * The caller must ensure the task can't exit.
- */
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;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- ret = specific_send_sig_info(sig, info, p);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- return ret;
+ return do_send_sig_info(sig, info, p, false);
}
#define __si_special(priv) \
goto ret;
ret = 1; /* the signal is ignored */
- if (!prepare_signal(sig, t))
+ if (!prepare_signal(sig, t, 0))
goto out;
ret = 0;
}
/*
- * 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.
*
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
- struct task_cputime cputime;
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;
info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
- thread_group_cputime(tsk, &cputime);
- info.si_utime = cputime_to_jiffies(cputime.utime);
- info.si_stime = cputime_to_jiffies(cputime.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))) {
/*
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();
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?
read_lock(&tasklist_lock);
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 {
/*
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 (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
- 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 (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());
- if (stop_count == 0)
- sig->flags = SIGNAL_STOP_STOPPED;
- current->exit_code = sig->group_exit_code;
- __set_current_state(TASK_STOPPED);
+ 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);
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;
+ 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;
}
/*
* 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 (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
- !signal_group_exit(signal))
+ !sig_kernel_only(signr))
continue;
if (sig_kernel_stop(signr)) {
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) && tracehook_notify_jctl(1, CLD_STOPPED)) {
+ 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);
}
}
return kill_something_info(sig, &info, pid);
}
-static int do_tkill(pid_t tgid, pid_t 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;
- unsigned long flags;
-
- 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();
+ int error = -ESRCH;
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 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 && lock_task_sighand(p, &flags)) {
- error = specific_send_sig_info(sig, &info, p);
- unlock_task_sighand(p, &flags);
+ 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;
}
}
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
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;
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;
}