#include <linux/syscalls.h>
#include <linux/ptrace.h>
#include <linux/signal.h>
+#include <linux/signalfd.h>
#include <linux/capability.h>
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
-fastcall void recalc_sigpending_tsk(struct task_struct *t)
+static int recalc_sigpending_tsk(struct task_struct *t)
{
if (t->signal->group_stop_count > 0 ||
(freezing(t)) ||
PENDING(&t->pending, &t->blocked) ||
- PENDING(&t->signal->shared_pending, &t->blocked))
+ PENDING(&t->signal->shared_pending, &t->blocked)) {
set_tsk_thread_flag(t, TIF_SIGPENDING);
- else
- clear_tsk_thread_flag(t, TIF_SIGPENDING);
+ return 1;
+ }
+ /*
+ * We must never clear the flag in another thread, or in current
+ * when it's possible the current syscall is returning -ERESTART*.
+ * So we don't clear it here, and only callers who know they should do.
+ */
+ return 0;
+}
+
+/*
+ * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
+ * This is superfluous when called on current, the wakeup is a harmless no-op.
+ */
+void recalc_sigpending_and_wake(struct task_struct *t)
+{
+ if (recalc_sigpending_tsk(t))
+ signal_wake_up(t, 0);
}
void recalc_sigpending(void)
{
- recalc_sigpending_tsk(current);
+ if (!recalc_sigpending_tsk(current))
+ clear_thread_flag(TIF_SIGPENDING);
+
}
/* Given the mask, find the first available signal that should be serviced. */
-static int
-next_signal(struct sigpending *pending, sigset_t *mask)
+int next_signal(struct sigpending *pending, sigset_t *mask)
{
unsigned long i, *s, *m, x;
int sig = 0;
}
}
}
- recalc_sigpending_tsk(tsk);
+ if (likely(tsk == current))
+ recalc_sigpending();
if (signr && unlikely(sig_kernel_stop(signr))) {
/*
* Set a marker that we have dequeued a stop signal. Our
int error = -EINVAL;
if (!valid_signal(sig))
return error;
+
+ error = audit_signal_info(sig, t); /* Let audit system see the signal */
+ if (error)
+ return error;
+
error = -EPERM;
if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
&& ((sig != SIGCONT) ||
&& !capable(CAP_KILL))
return error;
- error = security_task_kill(t, info, sig, 0);
- if (!error)
- audit_signal_info(sig, t); /* Let audit system see the signal */
- return error;
+ return security_task_kill(t, info, sig, 0);
}
/* forward decl */
struct sigqueue * q = NULL;
int ret = 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.
action->sa.sa_handler = SIG_DFL;
if (blocked) {
sigdelset(&t->blocked, sig);
- recalc_sigpending_tsk(t);
+ recalc_sigpending_and_wake(t);
}
}
ret = specific_send_sig_info(sig, info, t);
ret = 1;
goto out;
}
+ /*
+ * Deliver the signal to listening signalfds. This must be called
+ * with the sighand lock held.
+ */
+ signalfd_notify(p, sig);
list_add_tail(&q->list, &p->pending.list);
sigaddset(&p->pending.signal, sig);
q->info.si_overrun++;
goto out;
}
+ /*
+ * Deliver the signal to listening signalfds. This must be called
+ * with the sighand lock held.
+ */
+ signalfd_notify(p, sig);
/*
* Put this signal on the shared-pending queue.
/*
* Queued signals ignored us while we were stopped for tracing.
* So check for any that we should take before resuming user mode.
+ * This sets TIF_SIGPENDING, but never clears it.
*/
- recalc_sigpending();
+ recalc_sigpending_tsk(current);
}
void ptrace_notify(int exit_code)
/*
* If you change siginfo_t structure, please be sure
* this code is fixed accordingly.
+ * Please remember to update the signalfd_copyinfo() function
+ * inside fs/signalfd.c too, in case siginfo_t changes.
* It should never copy any pad contained in the structure
* to avoid security leaks, but must copy the generic
* 3 ints plus the relevant union member.
rm_from_queue_full(&mask, &t->signal->shared_pending);
do {
rm_from_queue_full(&mask, &t->pending);
- recalc_sigpending_tsk(t);
+ recalc_sigpending_and_wake(t);
t = next_thread(t);
} while (t != current);
}