}
/*
- * kill_pgrp_info() sends a signal to a process group: this is what the tty
+ * __kill_pgrp_info() sends a signal to a process group: this is what the tty
* control characters do (^C, ^Z etc)
*/
return success ? 0 : retval;
}
-int kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp)
-{
- int retval;
-
- read_lock(&tasklist_lock);
- retval = __kill_pgrp_info(sig, info, pgrp);
- read_unlock(&tasklist_lock);
-
- return retval;
-}
-
int kill_pid_info(int sig, struct siginfo *info, struct pid *pid)
{
- int error;
+ int error = -ESRCH;
struct task_struct *p;
rcu_read_lock();
if (unlikely(sig_needs_tasklist(sig)))
read_lock(&tasklist_lock);
+retry:
p = pid_task(pid, PIDTYPE_PID);
- error = -ESRCH;
- if (p)
+ if (p) {
error = group_send_sig_info(sig, info, p);
+ if (unlikely(error == -ESRCH))
+ /*
+ * The task was unhashed in between, try again.
+ * If it is dead, pid_task() will return NULL,
+ * if we race with de_thread() it will find the
+ * new leader.
+ */
+ goto retry;
+ }
if (unlikely(sig_needs_tasklist(sig)))
read_unlock(&tasklist_lock);
static int kill_something_info(int sig, struct siginfo *info, int pid)
{
int ret;
- rcu_read_lock();
- if (!pid) {
- ret = kill_pgrp_info(sig, info, task_pgrp(current));
- } else if (pid == -1) {
+
+ if (pid > 0) {
+ rcu_read_lock();
+ ret = kill_pid_info(sig, info, find_vpid(pid));
+ rcu_read_unlock();
+ return ret;
+ }
+
+ read_lock(&tasklist_lock);
+ if (pid != -1) {
+ ret = __kill_pgrp_info(sig, info,
+ pid ? find_vpid(-pid) : task_pgrp(current));
+ } else {
int retval = 0, count = 0;
struct task_struct * p;
- read_lock(&tasklist_lock);
for_each_process(p) {
if (p->pid > 1 && !same_thread_group(p, current)) {
int err = group_send_sig_info(sig, info, p);
retval = err;
}
}
- read_unlock(&tasklist_lock);
ret = count ? retval : -ESRCH;
- } else if (pid < 0) {
- ret = kill_pgrp_info(sig, info, find_vpid(-pid));
- } else {
- ret = kill_pid_info(sig, info, find_vpid(pid));
}
- rcu_read_unlock();
+ read_unlock(&tasklist_lock);
+
return ret;
}
return send_sig_info(sig, __si_special(priv), p);
}
-/*
- * This is the entry point for "process-wide" signals.
- * They will go to an appropriate thread in the thread group.
- */
-int
-send_group_sig_info(int sig, struct siginfo *info, struct task_struct *p)
-{
- int ret;
- read_lock(&tasklist_lock);
- ret = group_send_sig_info(sig, info, p);
- read_unlock(&tasklist_lock);
- return ret;
-}
-
void
force_sig(int sig, struct task_struct *p)
{
int kill_pgrp(struct pid *pid, int sig, int priv)
{
- return kill_pgrp_info(sig, __si_special(priv), pid);
+ int ret;
+
+ read_lock(&tasklist_lock);
+ ret = __kill_pgrp_info(sig, __si_special(priv), pid);
+ read_unlock(&tasklist_lock);
+
+ return ret;
}
EXPORT_SYMBOL(kill_pgrp);