Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds

[~andy/linux] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index fe08008133dad06e0acd6efdc98db25c64367565..1814e68e4de38297d0fcf1a8d2c1caa6056354d3 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -28,7 +28,8 @@
 #include <linux/freezer.h>
 #include <linux/pid_namespace.h>
 #include <linux/nsproxy.h>
-#include <trace/events/sched.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/signal.h>
 
 #include <asm/param.h>
 #include <asm/uaccess.h>
@@ -422,7 +423,7 @@ still_pending:
                 */
                info->si_signo = sig;
                info->si_errno = 0;
-               info->si_code = 0;
+               info->si_code = SI_USER;
                info->si_pid = 0;
                info->si_uid = 0;
        }
@@ -606,6 +607,17 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s)
        return 1;
 }
 
+static inline int is_si_special(const struct siginfo *info)
+{
+       return info <= SEND_SIG_FORCED;
+}
+
+static inline bool si_fromuser(const struct siginfo *info)
+{
+       return info == SEND_SIG_NOINFO ||
+               (!is_si_special(info) && SI_FROMUSER(info));
+}
+
 /*
  * Bad permissions for sending the signal
  * - the caller must hold at least the RCU read lock
@@ -620,7 +632,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
        if (!valid_signal(sig))
                return -EINVAL;
 
-       if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
+       if (!si_fromuser(info))
                return 0;
 
        error = audit_signal_info(sig, t); /* Let audit system see the signal */
@@ -856,7 +868,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
        struct sigqueue *q;
        int override_rlimit;
 
-       trace_sched_signal_send(sig, t);
+       trace_signal_generate(sig, info, t);
 
        assert_spin_locked(&t->sighand->siglock);
 
@@ -918,12 +930,21 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
                        break;
                }
        } else if (!is_si_special(info)) {
-               if (sig >= SIGRTMIN && info->si_code != SI_USER)
-               /*
-                * Queue overflow, abort.  We may abort if the signal was rt
-                * and sent by user using something other than kill().
-                */
+               if (sig >= SIGRTMIN && info->si_code != SI_USER) {
+                       /*
+                        * Queue overflow, abort.  We may abort if the
+                        * signal was rt and sent by user using something
+                        * other than kill().
+                        */
+                       trace_signal_overflow_fail(sig, group, info);
                        return -EAGAIN;
+               } else {
+                       /*
+                        * This is a silent loss of information.  We still
+                        * send the signal, but the *info bits are lost.
+                        */
+                       trace_signal_lose_info(sig, group, info);
+               }
        }
 
 out_set:
@@ -939,9 +960,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
        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;
+       from_ancestor_ns = si_fromuser(info) &&
+                          !task_pid_nr_ns(current, task_active_pid_ns(t));
 #endif
 
        return __send_signal(sig, info, t, group, from_ancestor_ns);
@@ -1042,12 +1062,6 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
        return ret;
 }
 
-void
-force_sig_specific(int sig, struct task_struct *t)
-{
-       force_sig_info(sig, SEND_SIG_FORCED, t);
-}
-
 /*
  * Nuke all other threads in the group.
  */
@@ -1176,8 +1190,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid,
                goto out_unlock;
        }
        pcred = __task_cred(p);
-       if ((info == SEND_SIG_NOINFO ||
-            (!is_si_special(info) && SI_FROMUSER(info))) &&
+       if (si_fromuser(info) &&
            euid != pcred->suid && euid != pcred->uid &&
            uid  != pcred->suid && uid  != pcred->uid) {
                ret = -EPERM;
@@ -1827,11 +1840,6 @@ relock:
 
        for (;;) {
                struct k_sigaction *ka;
-
-               if (unlikely(signal->group_stop_count > 0) &&
-                   do_signal_stop(0))
-                       goto relock;
-
                /*
                 * Tracing can induce an artifical signal and choose sigaction.
                 * The return value in @signr determines the default action,
@@ -1843,6 +1851,10 @@ relock:
                if (unlikely(signr != 0))
                        ka = return_ka;
                else {
+                       if (unlikely(signal->group_stop_count > 0) &&
+                           do_signal_stop(0))
+                               goto relock;
+
                        signr = dequeue_signal(current, &current->blocked,
                                               info);
 
@@ -1859,6 +1871,9 @@ relock:
                        ka = &sighand->action[signr-1];
                }
 
+               /* Trace actually delivered signals. */
+               trace_signal_deliver(signr, info, ka);
+
                if (ka->sa.sa_handler == SIG_IGN) /* Do nothing.  */
                        continue;
                if (ka->sa.sa_handler != SIG_DFL) {