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Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c98
1 files changed, 72 insertions, 26 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 8d8a940422a8..cfa9d10e731a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -172,6 +172,17 @@ void recalc_sigpending(void)
}
+void calculate_sigpending(void)
+{
+ /* Have any signals or users of TIF_SIGPENDING been delayed
+ * until after fork?
+ */
+ spin_lock_irq(&current->sighand->siglock);
+ set_tsk_thread_flag(current, TIF_SIGPENDING);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+}
+
/* Given the mask, find the first available signal that should be serviced. */
#define SYNCHRONOUS_MASK \
@@ -362,6 +373,20 @@ static bool task_participate_group_stop(struct task_struct *task)
return false;
}
+void task_join_group_stop(struct task_struct *task)
+{
+ /* Have the new thread join an on-going signal group stop */
+ unsigned long jobctl = current->jobctl;
+ if (jobctl & JOBCTL_STOP_PENDING) {
+ struct signal_struct *sig = current->signal;
+ unsigned long signr = jobctl & JOBCTL_STOP_SIGMASK;
+ unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
+ if (task_set_jobctl_pending(task, signr | gstop)) {
+ sig->group_stop_count++;
+ }
+ }
+}
+
/*
* allocate a new signal queue record
* - this may be called without locks if and only if t == current, otherwise an
@@ -895,7 +920,7 @@ static inline int wants_signal(int sig, struct task_struct *p)
return task_curr(p) || !signal_pending(p);
}
-static void complete_signal(int sig, struct task_struct *p, int group)
+static void complete_signal(int sig, struct task_struct *p, enum pid_type type)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
@@ -908,7 +933,7 @@ static void complete_signal(int sig, struct task_struct *p, int group)
*/
if (wants_signal(sig, p))
t = p;
- else if (!group || thread_group_empty(p))
+ else if ((type == PIDTYPE_PID) || 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.
@@ -998,7 +1023,7 @@ static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_str
#endif
static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
- int group, int from_ancestor_ns)
+ enum pid_type type, int from_ancestor_ns)
{
struct sigpending *pending;
struct sigqueue *q;
@@ -1012,7 +1037,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
from_ancestor_ns || (info == SEND_SIG_FORCED)))
goto ret;
- pending = group ? &t->signal->shared_pending : &t->pending;
+ pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending;
/*
* Short-circuit ignored signals and support queuing
* exactly one non-rt signal, so that we can get more
@@ -1096,14 +1121,29 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
out_set:
signalfd_notify(t, sig);
sigaddset(&pending->signal, sig);
- complete_signal(sig, t, group);
+
+ /* Let multiprocess signals appear after on-going forks */
+ if (type > PIDTYPE_TGID) {
+ struct multiprocess_signals *delayed;
+ hlist_for_each_entry(delayed, &t->signal->multiprocess, node) {
+ sigset_t *signal = &delayed->signal;
+ /* Can't queue both a stop and a continue signal */
+ if (sig == SIGCONT)
+ sigdelsetmask(signal, SIG_KERNEL_STOP_MASK);
+ else if (sig_kernel_stop(sig))
+ sigdelset(signal, SIGCONT);
+ sigaddset(signal, sig);
+ }
+ }
+
+ complete_signal(sig, t, type);
ret:
- trace_signal_generate(sig, info, t, group, result);
+ trace_signal_generate(sig, info, t, type != PIDTYPE_PID, result);
return ret;
}
static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
- int group)
+ enum pid_type type)
{
int from_ancestor_ns = 0;
@@ -1112,7 +1152,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
!task_pid_nr_ns(current, task_active_pid_ns(t));
#endif
- return __send_signal(sig, info, t, group, from_ancestor_ns);
+ return __send_signal(sig, info, t, type, from_ancestor_ns);
}
static void print_fatal_signal(int signr)
@@ -1151,23 +1191,23 @@ __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);
+ return send_signal(sig, info, p, PIDTYPE_TGID);
}
static int
specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
{
- return send_signal(sig, info, t, 0);
+ return send_signal(sig, info, t, PIDTYPE_PID);
}
int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
- bool group)
+ enum pid_type type)
{
unsigned long flags;
int ret = -ESRCH;
if (lock_task_sighand(p, &flags)) {
- ret = send_signal(sig, info, p, group);
+ ret = send_signal(sig, info, p, type);
unlock_task_sighand(p, &flags);
}
@@ -1274,7 +1314,8 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
/*
* send signal info to all the members of a group
*/
-int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
+int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
+ enum pid_type type)
{
int ret;
@@ -1283,7 +1324,7 @@ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
rcu_read_unlock();
if (!ret && sig)
- ret = do_send_sig_info(sig, info, p, true);
+ ret = do_send_sig_info(sig, info, p, type);
return ret;
}
@@ -1301,7 +1342,7 @@ int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp)
success = 0;
retval = -ESRCH;
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
- int err = group_send_sig_info(sig, info, p);
+ int err = group_send_sig_info(sig, info, p, PIDTYPE_PGID);
success |= !err;
retval = err;
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
@@ -1317,7 +1358,7 @@ int kill_pid_info(int sig, struct siginfo *info, struct pid *pid)
rcu_read_lock();
p = pid_task(pid, PIDTYPE_PID);
if (p)
- error = group_send_sig_info(sig, info, p);
+ error = group_send_sig_info(sig, info, p, PIDTYPE_TGID);
rcu_read_unlock();
if (likely(!p || error != -ESRCH))
return error;
@@ -1376,7 +1417,7 @@ int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid,
if (sig) {
if (lock_task_sighand(p, &flags)) {
- ret = __send_signal(sig, info, p, 1, 0);
+ ret = __send_signal(sig, info, p, PIDTYPE_TGID, 0);
unlock_task_sighand(p, &flags);
} else
ret = -ESRCH;
@@ -1420,7 +1461,8 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
for_each_process(p) {
if (task_pid_vnr(p) > 1 &&
!same_thread_group(p, current)) {
- int err = group_send_sig_info(sig, info, p);
+ int err = group_send_sig_info(sig, info, p,
+ PIDTYPE_MAX);
++count;
if (err != -EPERM)
retval = err;
@@ -1446,7 +1488,7 @@ int send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
if (!valid_signal(sig))
return -EINVAL;
- return do_send_sig_info(sig, info, p, false);
+ return do_send_sig_info(sig, info, p, PIDTYPE_PID);
}
#define __si_special(priv) \
@@ -1664,17 +1706,20 @@ void sigqueue_free(struct sigqueue *q)
__sigqueue_free(q);
}
-int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
+int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
{
int sig = q->info.si_signo;
struct sigpending *pending;
+ struct task_struct *t;
unsigned long flags;
int ret, result;
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
ret = -1;
- if (!likely(lock_task_sighand(t, &flags)))
+ rcu_read_lock();
+ t = pid_task(pid, type);
+ if (!t || !likely(lock_task_sighand(t, &flags)))
goto ret;
ret = 1; /* the signal is ignored */
@@ -1696,15 +1741,16 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
q->info.si_overrun = 0;
signalfd_notify(t, sig);
- pending = group ? &t->signal->shared_pending : &t->pending;
+ pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending;
list_add_tail(&q->list, &pending->list);
sigaddset(&pending->signal, sig);
- complete_signal(sig, t, group);
+ complete_signal(sig, t, type);
result = TRACE_SIGNAL_DELIVERED;
out:
- trace_signal_generate(sig, &q->info, t, group, result);
+ trace_signal_generate(sig, &q->info, t, type != PIDTYPE_PID, result);
unlock_task_sighand(t, &flags);
ret:
+ rcu_read_unlock();
return ret;
}
@@ -3193,7 +3239,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
* probe. No signal is actually delivered.
*/
if (!error && sig) {
- error = do_send_sig_info(sig, info, p, false);
+ error = do_send_sig_info(sig, info, p, PIDTYPE_PID);
/*
* If lock_task_sighand() failed we pretend the task
* dies after receiving the signal. The window is tiny,
@@ -3960,7 +4006,7 @@ void kdb_send_sig(struct task_struct *t, int sig)
"the deadlock.\n");
return;
}
- ret = send_signal(sig, SEND_SIG_PRIV, t, false);
+ ret = send_signal(sig, SEND_SIG_PRIV, t, PIDTYPE_PID);
spin_unlock(&t->sighand->siglock);
if (ret)
kdb_printf("Fail to deliver Signal %d to process %d.\n",
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-27 13:01:04 +0000