1 files changed, 91 insertions, 89 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 6c0958e52ea7..c539f60c6f41 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -22,6 +22,7 @@
 #include <linux/ptrace.h>
 #include <linux/signal.h>
 #include <linux/signalfd.h>
+#include <linux/tracehook.h>
 #include <linux/capability.h>
 #include <linux/freezer.h>
 #include <linux/pid_namespace.h>
@@ -39,24 +40,21 @@
 
 static struct kmem_cache *sigqueue_cachep;
 
-static int __sig_ignored(struct task_struct *t, int sig)
+static void __user *sig_handler(struct task_struct *t, int sig)
 {
-        void __user *handler;
+        return t->sighand->action[sig - 1].sa.sa_handler;
+}
 
+static int sig_handler_ignored(void __user *handler, int sig)
+{
         /* Is it explicitly or implicitly ignored? */
-
-        handler = t->sighand->action[sig - 1].sa.sa_handler;
         return handler == SIG_IGN ||
                 (handler == SIG_DFL && sig_kernel_ignore(sig));
 }
 
 static int sig_ignored(struct task_struct *t, int sig)
 {
-        /*
-         * Tracers always want to know about signals..
-         */
-        if (t->ptrace & PT_PTRACED)
-                return 0;
+        void __user *handler;
 
         /*
          * Blocked signals are never ignored, since the
@@ -66,7 +64,14 @@ static int sig_ignored(struct task_struct *t, int sig)
         if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
                 return 0;
 
-        return __sig_ignored(t, sig);
+        handler = sig_handler(t, sig);
+        if (!sig_handler_ignored(handler, sig))
+                return 0;
+
+        /*
+         * Tracers may want to know about even ignored signals.
+         */
+        return !tracehook_consider_ignored_signal(t, sig, handler);
 }
 
 /*
@@ -129,7 +134,9 @@ void recalc_sigpending_and_wake(struct task_struct *t)
 
 void recalc_sigpending(void)
 {
-        if (!recalc_sigpending_tsk(current) && !freezing(current))
+        if (unlikely(tracehook_force_sigpending()))
+                set_thread_flag(TIF_SIGPENDING);
+        else if (!recalc_sigpending_tsk(current) && !freezing(current))
                 clear_thread_flag(TIF_SIGPENDING);
 
 }
@@ -295,12 +302,12 @@ flush_signal_handlers(struct task_struct *t, int force_default)
 
 int unhandled_signal(struct task_struct *tsk, int sig)
 {
+        void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler;
         if (is_global_init(tsk))
                 return 1;
-        if (tsk->ptrace & PT_PTRACED)
+        if (handler != SIG_IGN && handler != SIG_DFL)
                 return 0;
-        return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
-                (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
+        return !tracehook_consider_fatal_signal(tsk, sig, handler);
 }
 
 
@@ -338,13 +345,9 @@ unblock_all_signals(void)
         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 }
 
-static int collect_signal(int sig, struct sigpending *list, siginfo_t *info)
+static void collect_signal(int sig, struct sigpending *list, siginfo_t *info)
 {
         struct sigqueue *q, *first = NULL;
-        int still_pending = 0;
-
-        if (unlikely(!sigismember(&list->signal, sig)))
-                return 0;
 
         /*
          * Collect the siginfo appropriate to this signal.  Check if
@@ -352,33 +355,30 @@ static int collect_signal(int sig, struct sigpending *list, siginfo_t *info)
         */
         list_for_each_entry(q, &list->list, list) {
                 if (q->info.si_signo == sig) {
-                        if (first) {
-                                still_pending = 1;
-                                break;
-                        }
+                        if (first)
+                                goto still_pending;
                         first = q;
                 }
         }
+
+        sigdelset(&list->signal, sig);
+
         if (first) {
+still_pending:
                 list_del_init(&first->list);
                 copy_siginfo(info, &first->info);
                 __sigqueue_free(first);
-                if (!still_pending)
-                        sigdelset(&list->signal, sig);
         } else {
-
                 /* Ok, it wasn't in the queue.  This must be
                    a fast-pathed signal or we must have been
                    out of queue space.  So zero out the info.
                  */
-                sigdelset(&list->signal, sig);
                 info->si_signo = sig;
                 info->si_errno = 0;
                 info->si_code = 0;
                 info->si_pid = 0;
                 info->si_uid = 0;
         }
-        return 1;
 }
 
 static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
@@ -396,8 +396,7 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
                         }
                 }
 
-                if (!collect_signal(sig, pending, info))
-                        sig = 0;
+                collect_signal(sig, pending, info);
         }
 
         return sig;
@@ -462,8 +461,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
                  * is to alert stop-signal processing code when another
                  * processor has come along and cleared the flag.
                  */
-                if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
-                        tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+                tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
         }
         if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
                 /*
@@ -600,9 +598,6 @@ static int check_kill_permission(int sig, struct siginfo *info,
         return security_task_kill(t, info, sig, 0);
 }
 
-/* forward decl */
-static void do_notify_parent_cldstop(struct task_struct *tsk, int why);
-
 /*
  * Handle magic process-wide effects of stop/continue signals. Unlike
  * the signal actions, these happen immediately at signal-generation
@@ -765,7 +760,8 @@ static void complete_signal(int sig, struct task_struct *p, int group)
         if (sig_fatal(p, sig) &&
             !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
             !sigismember(&t->real_blocked, sig) &&
-            (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
+            (sig == SIGKILL ||
+             !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
                 /*
                  * This signal will be fatal to the whole group.
                  */
@@ -1125,7 +1121,7 @@ EXPORT_SYMBOL_GPL(kill_pid_info_as_uid);
  * is probably wrong.  Should make it like BSD or SYSV.
  */
 
-static int kill_something_info(int sig, struct siginfo *info, int pid)
+static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
 {
         int ret;
 
@@ -1237,17 +1233,6 @@ int kill_pid(struct pid *pid, int sig, int priv)
 }
 EXPORT_SYMBOL(kill_pid);
 
-int
-kill_proc(pid_t pid, int sig, int priv)
-{
-        int ret;
-
-        rcu_read_lock();
-        ret = kill_pid_info(sig, __si_special(priv), find_pid(pid));
-        rcu_read_unlock();
-        return ret;
-}
-
 /*
  * These functions support sending signals using preallocated sigqueue
  * structures.  This is needed "because realtime applications cannot
@@ -1319,6 +1304,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
                 q->info.si_overrun++;
                 goto out;
         }
+        q->info.si_overrun = 0;
 
         signalfd_notify(t, sig);
         pending = group ? &t->signal->shared_pending : &t->pending;
@@ -1343,9 +1329,11 @@ static inline void __wake_up_parent(struct task_struct *p,
 /*
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
+ *
+ * Returns -1 if our parent ignored us and so we've switched to
+ * self-reaping, or else @sig.
  */
-
-void do_notify_parent(struct task_struct *tsk, int sig)
+int do_notify_parent(struct task_struct *tsk, int sig)
 {
         struct siginfo info;
         unsigned long flags;
@@ -1379,10 +1367,9 @@ void do_notify_parent(struct task_struct *tsk, int sig)
 
         info.si_uid = tsk->uid;
 
-        /* FIXME: find out whether or not this is supposed to be c*time. */
-        info.si_utime = cputime_to_jiffies(cputime_add(tsk->utime,
+        info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
                                                        tsk->signal->utime));
-        info.si_stime = cputime_to_jiffies(cputime_add(tsk->stime,
+        info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
                                                        tsk->signal->stime));
 
         info.si_status = tsk->exit_code & 0x7f;
@@ -1417,12 +1404,14 @@ void do_notify_parent(struct task_struct *tsk, int sig)
                  */
                 tsk->exit_signal = -1;
                 if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
-                        sig = 0;
+                        sig = -1;
         }
         if (valid_signal(sig) && sig > 0)
                 __group_send_sig_info(sig, &info, tsk->parent);
         __wake_up_parent(tsk, tsk->parent);
         spin_unlock_irqrestore(&psig->siglock, flags);
+
+        return sig;
 }
 
 static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
@@ -1450,9 +1439,8 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
 
         info.si_uid = tsk->uid;
 
-        /* FIXME: find out whether or not this is supposed to be c*time. */
-        info.si_utime = cputime_to_jiffies(tsk->utime);
-        info.si_stime = cputime_to_jiffies(tsk->stime);
+        info.si_utime = cputime_to_clock_t(tsk->utime);
+        info.si_stime = cputime_to_clock_t(tsk->stime);
 
         info.si_code = why;
         switch (why) {
@@ -1491,10 +1479,10 @@ static inline int may_ptrace_stop(void)
          * is a deadlock situation, and pointless because our tracer
          * is dead so don't allow us to stop.
          * If SIGKILL was already sent before the caller unlocked
-         * ->siglock we must see ->core_waiters != 0. Otherwise it
+         * ->siglock we must see ->core_state != NULL. Otherwise it
          * is safe to enter schedule().
          */
-        if (unlikely(current->mm->core_waiters) &&
+        if (unlikely(current->mm->core_state) &&
             unlikely(current->mm == current->parent->mm))
                 return 0;
 
@@ -1507,9 +1495,8 @@ static inline int may_ptrace_stop(void)
  */
 static int sigkill_pending(struct task_struct *tsk)
 {
-        return ((sigismember(&tsk->pending.signal, SIGKILL) ||
-                 sigismember(&tsk->signal->shared_pending.signal, SIGKILL)) &&
-                !unlikely(sigismember(&tsk->blocked, SIGKILL)));
+        return  sigismember(&tsk->pending.signal, SIGKILL) ||
+                sigismember(&tsk->signal->shared_pending.signal, SIGKILL);
 }
 
 /*
@@ -1525,8 +1512,6 @@ static int sigkill_pending(struct task_struct *tsk)
  */
 static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 {
-        int killed = 0;
-
         if (arch_ptrace_stop_needed(exit_code, info)) {
                 /*
                  * The arch code has something special to do before a
@@ -1542,7 +1527,8 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
                 spin_unlock_irq(&current->sighand->siglock);
                 arch_ptrace_stop(exit_code, info);
                 spin_lock_irq(&current->sighand->siglock);
-                killed = sigkill_pending(current);
+                if (sigkill_pending(current))
+                        return;
         }
 
         /*
@@ -1559,7 +1545,7 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
         __set_current_state(TASK_TRACED);
         spin_unlock_irq(&current->sighand->siglock);
         read_lock(&tasklist_lock);
-        if (!unlikely(killed) && may_ptrace_stop()) {
+        if (may_ptrace_stop()) {
                 do_notify_parent_cldstop(current, CLD_TRAPPED);
                 read_unlock(&tasklist_lock);
                 schedule();
@@ -1623,7 +1609,7 @@ finish_stop(int stop_count)
          * a group stop in progress and we are the last to stop,
          * report to the parent.  When ptraced, every thread reports itself.
          */
-        if (stop_count == 0 || (current->ptrace & PT_PTRACED)) {
+        if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
                 read_lock(&tasklist_lock);
                 do_notify_parent_cldstop(current, CLD_STOPPED);
                 read_unlock(&tasklist_lock);
@@ -1658,8 +1644,7 @@ static int do_signal_stop(int signr)
         } else {
                 struct task_struct *t;
 
-                if (unlikely((sig->flags & (SIGNAL_STOP_DEQUEUED | SIGNAL_UNKILLABLE))
-                                         != SIGNAL_STOP_DEQUEUED) ||
+                if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
                     unlikely(signal_group_exit(sig)))
                         return 0;
                 /*
@@ -1760,6 +1745,9 @@ relock:
                 signal->flags &= ~SIGNAL_CLD_MASK;
                 spin_unlock_irq(&sighand->siglock);
 
+                if (unlikely(!tracehook_notify_jctl(1, why)))
+                        goto relock;
+
                 read_lock(&tasklist_lock);
                 do_notify_parent_cldstop(current->group_leader, why);
                 read_unlock(&tasklist_lock);
@@ -1773,17 +1761,33 @@ relock:
                     do_signal_stop(0))
                         goto relock;
 
-                signr = dequeue_signal(current, &current->blocked, info);
-                if (!signr)
-                        break; /* will return 0 */
+                /*
+                 * Tracing can induce an artifical signal and choose sigaction.
+                 * The return value in @signr determines the default action,
+                 * but @info->si_signo is the signal number we will report.
+                 */
+                signr = tracehook_get_signal(current, regs, info, return_ka);
+                if (unlikely(signr < 0))
+                        goto relock;
+                if (unlikely(signr != 0))
+                        ka = return_ka;
+                else {
+                        signr = dequeue_signal(current, &current->blocked,
+                                               info);
 
-                if (signr != SIGKILL) {
-                        signr = ptrace_signal(signr, info, regs, cookie);
                         if (!signr)
-                                continue;
+                                break; /* will return 0 */
+
+                        if (signr != SIGKILL) {
+                                signr = ptrace_signal(signr, info,
+                                                      regs, cookie);
+                                if (!signr)
+                                        continue;
+                        }
+
+                        ka = &sighand->action[signr-1];
                 }
 
-                ka = &sighand->action[signr-1];
                 if (ka->sa.sa_handler == SIG_IGN) /* Do nothing.  */
                         continue;
                 if (ka->sa.sa_handler != SIG_DFL) {
@@ -1831,7 +1835,7 @@ relock:
                                 spin_lock_irq(&sighand->siglock);
                         }
 
-                        if (likely(do_signal_stop(signr))) {
+                        if (likely(do_signal_stop(info->si_signo))) {
                                 /* It released the siglock.  */
                                 goto relock;
                         }
@@ -1852,7 +1856,7 @@ relock:
 
                 if (sig_kernel_coredump(signr)) {
                         if (print_fatal_signals)
-                                print_fatal_signal(regs, signr);
+                                print_fatal_signal(regs, info->si_signo);
                         /*
                          * If it was able to dump core, this kills all
                          * other threads in the group and synchronizes with
@@ -1861,13 +1865,13 @@ relock:
                          * first and our do_group_exit call below will use
                          * that value and ignore the one we pass it.
                          */
-                        do_coredump((long)signr, signr, regs);
+                        do_coredump(info->si_signo, info->si_signo, regs);
                 }
 
                 /*
                  * Death signals, no core dump.
                  */
-                do_group_exit(signr);
+                do_group_exit(info->si_signo);
                 /* NOTREACHED */
         }
         spin_unlock_irq(&sighand->siglock);
@@ -1909,7 +1913,7 @@ void exit_signals(struct task_struct *tsk)
 out:
         spin_unlock_irq(&tsk->sighand->siglock);
 
-        if (unlikely(group_stop)) {
+        if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) {
                 read_lock(&tasklist_lock);
                 do_notify_parent_cldstop(tsk, CLD_STOPPED);
                 read_unlock(&tasklist_lock);
@@ -1920,8 +1924,6 @@ EXPORT_SYMBOL(recalc_sigpending);
 EXPORT_SYMBOL_GPL(dequeue_signal);
 EXPORT_SYMBOL(flush_signals);
 EXPORT_SYMBOL(force_sig);
-EXPORT_SYMBOL(kill_proc);
-EXPORT_SYMBOL(ptrace_notify);
 EXPORT_SYMBOL(send_sig);
 EXPORT_SYMBOL(send_sig_info);
 EXPORT_SYMBOL(sigprocmask);
@@ -2196,7 +2198,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese,
 }
 
 asmlinkage long
-sys_kill(int pid, int sig)
+sys_kill(pid_t pid, int sig)
 {
         struct siginfo info;
 
@@ -2209,7 +2211,7 @@ sys_kill(int pid, int sig)
         return kill_something_info(sig, &info, pid);
 }
 
-static int do_tkill(int tgid, int pid, int sig)
+static int do_tkill(pid_t tgid, pid_t pid, int sig)
 {
         int error;
         struct siginfo info;
@@ -2255,7 +2257,7 @@ static int do_tkill(int tgid, int pid, int sig)
  *  exists but it's not belonging to the target process anymore. This
  *  method solves the problem of threads exiting and PIDs getting reused.
  */
-asmlinkage long sys_tgkill(int tgid, int pid, int sig)
+asmlinkage long sys_tgkill(pid_t tgid, pid_t pid, int sig)
 {
         /* This is only valid for single tasks */
         if (pid <= 0 || tgid <= 0)
@@ -2268,7 +2270,7 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig)
  *  Send a signal to only one task, even if it's a CLONE_THREAD task.
  */
 asmlinkage long
-sys_tkill(int pid, int sig)
+sys_tkill(pid_t pid, int sig)
 {
         /* This is only valid for single tasks */
         if (pid <= 0)
@@ -2278,7 +2280,7 @@ sys_tkill(int pid, int sig)
 }
 
 asmlinkage long
-sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo)
+sys_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t __user *uinfo)
 {
         siginfo_t info;
 
@@ -2325,7 +2327,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
                  *   (for example, SIGCHLD), shall cause the pending signal to
                  *   be discarded, whether or not it is blocked"
                  */
-                if (__sig_ignored(t, sig)) {
+                if (sig_handler_ignored(sig_handler(t, sig), sig)) {
                         sigemptyset(&mask);
                         sigaddset(&mask, sig);
                         rm_from_queue_full(&mask, &t->signal->shared_pending);