1 files changed, 53 insertions, 97 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index f2b96b08fb44..1bf3c39d6109 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -277,7 +277,6 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
         } else {
                 INIT_LIST_HEAD(&q->list);
                 q->flags = 0;
-                q->lock = NULL;
                 q->user = get_uid(t->user);
         }
         return(q);
@@ -406,6 +405,8 @@ void __exit_signal(struct task_struct *tsk)
 
 void exit_signal(struct task_struct *tsk)
 {
+        atomic_dec(&tsk->signal->live);
+
         write_lock_irq(&tasklist_lock);
         __exit_signal(tsk);
         write_unlock_irq(&tasklist_lock);
@@ -650,8 +651,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
         if (!valid_signal(sig))
                 return error;
         error = -EPERM;
-        if ((!info || ((unsigned long)info != 1 &&
-                        (unsigned long)info != 2 && SI_FROMUSER(info)))
+        if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
             && ((sig != SIGCONT) ||
                 (current->signal->session != t->signal->session))
             && (current->euid ^ t->suid) && (current->euid ^ t->uid)
@@ -788,7 +788,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
          * fast-pathed signals for kernel-internal things like SIGSTOP
          * or SIGKILL.
          */
-        if ((unsigned long)info == 2)
+        if (info == SEND_SIG_FORCED)
                 goto out_set;
 
         /* Real-time signals must be queued if sent by sigqueue, or
@@ -800,19 +800,19 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
            pass on the info struct.  */
 
         q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
-                                             ((unsigned long) info < 2 ||
+                                             (is_si_special(info) ||
                                               info->si_code >= 0)));
         if (q) {
                 list_add_tail(&q->list, &signals->list);
                 switch ((unsigned long) info) {
-                case 0:
+                case (unsigned long) SEND_SIG_NOINFO:
                         q->info.si_signo = sig;
                         q->info.si_errno = 0;
                         q->info.si_code = SI_USER;
                         q->info.si_pid = current->pid;
                         q->info.si_uid = current->uid;
                         break;
-                case 1:
+                case (unsigned long) SEND_SIG_PRIV:
                         q->info.si_signo = sig;
                         q->info.si_errno = 0;
                         q->info.si_code = SI_KERNEL;
@@ -823,20 +823,13 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
                         copy_siginfo(&q->info, info);
                         break;
                 }
-        } else {
-                if (sig >= SIGRTMIN && info && (unsigned long)info != 1
-                   && info->si_code != SI_USER)
+        } 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().
                  */
                         return -EAGAIN;
-                if (((unsigned long)info > 1) && (info->si_code == SI_TIMER))
-                        /*
-                         * Set up a return to indicate that we dropped 
-                         * the signal.
-                         */
-                        ret = info->si_sys_private;
         }
 
 out_set:
@@ -857,12 +850,6 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
                 BUG();
         assert_spin_locked(&t->sighand->siglock);
 
-        if (((unsigned long)info > 2) && (info->si_code == SI_TIMER))
-                /*
-                 * Set up a return to indicate that we dropped the signal.
-                 */
-                ret = info->si_sys_private;
-
         /* Short-circuit ignored signals.  */
         if (sig_ignored(t, sig))
                 goto out;
@@ -892,11 +879,13 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
         int ret;
 
         spin_lock_irqsave(&t->sighand->siglock, flags);
-        if (sigismember(&t->blocked, sig) || t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) {
+        if (t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) {
                 t->sighand->action[sig-1].sa.sa_handler = SIG_DFL;
+        }
+        if (sigismember(&t->blocked, sig)) {
                 sigdelset(&t->blocked, sig);
-                recalc_sigpending_tsk(t);
         }
+        recalc_sigpending_tsk(t);
         ret = specific_send_sig_info(sig, info, t);
         spin_unlock_irqrestore(&t->sighand->siglock, flags);
 
@@ -906,15 +895,7 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 void
 force_sig_specific(int sig, struct task_struct *t)
 {
-        unsigned long int flags;
-
-        spin_lock_irqsave(&t->sighand->siglock, flags);
-        if (t->sighand->action[sig-1].sa.sa_handler == SIG_IGN)
-                t->sighand->action[sig-1].sa.sa_handler = SIG_DFL;
-        sigdelset(&t->blocked, sig);
-        recalc_sigpending_tsk(t);
-        specific_send_sig_info(sig, (void *)2, t);
-        spin_unlock_irqrestore(&t->sighand->siglock, flags);
+        force_sig_info(sig, SEND_SIG_FORCED, t);
 }
 
 /*
@@ -1049,12 +1030,6 @@ __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
         assert_spin_locked(&p->sighand->siglock);
         handle_stop_signal(sig, p);
 
-        if (((unsigned long)info > 2) && (info->si_code == SI_TIMER))
-                /*
-                 * Set up a return to indicate that we dropped the signal.
-                 */
-                ret = info->si_sys_private;
-
         /* Short-circuit ignored signals.  */
         if (sig_ignored(p, sig))
                 return ret;
@@ -1107,8 +1082,8 @@ void zap_other_threads(struct task_struct *p)
                 if (t != p->group_leader)
                         t->exit_signal = -1;
 
+                /* SIGKILL will be handled before any pending SIGSTOP */
                 sigaddset(&t->pending.signal, SIGKILL);
-                rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
                 signal_wake_up(t, 1);
         }
 }
@@ -1284,10 +1259,13 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
         return ret;
 }
 
+#define __si_special(priv) \
+        ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
+
 int
 send_sig(int sig, struct task_struct *p, int priv)
 {
-        return send_sig_info(sig, (void*)(long)(priv != 0), p);
+        return send_sig_info(sig, __si_special(priv), p);
 }
 
 /*
@@ -1307,7 +1285,7 @@ send_group_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 void
 force_sig(int sig, struct task_struct *p)
 {
-        force_sig_info(sig, (void*)1L, p);
+        force_sig_info(sig, SEND_SIG_PRIV, p);
 }
 
 /*
@@ -1332,13 +1310,13 @@ force_sigsegv(int sig, struct task_struct *p)
 int
 kill_pg(pid_t pgrp, int sig, int priv)
 {
-        return kill_pg_info(sig, (void *)(long)(priv != 0), pgrp);
+        return kill_pg_info(sig, __si_special(priv), pgrp);
 }
 
 int
 kill_proc(pid_t pid, int sig, int priv)
 {
-        return kill_proc_info(sig, (void *)(long)(priv != 0), pid);
+        return kill_proc_info(sig, __si_special(priv), pid);
 }
 
 /*
@@ -1369,11 +1347,12 @@ void sigqueue_free(struct sigqueue *q)
          * pending queue.
          */
         if (unlikely(!list_empty(&q->list))) {
-                read_lock(&tasklist_lock);  
-                spin_lock_irqsave(q->lock, flags);
+                spinlock_t *lock = &current->sighand->siglock;
+                read_lock(&tasklist_lock);
+                spin_lock_irqsave(lock, flags);
                 if (!list_empty(&q->list))
                         list_del_init(&q->list);
-                spin_unlock_irqrestore(q->lock, flags);
+                spin_unlock_irqrestore(lock, flags);
                 read_unlock(&tasklist_lock);
         }
         q->flags &= ~SIGQUEUE_PREALLOC;
@@ -1412,7 +1391,6 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
                 goto out;
         }
 
-        q->lock = &p->sighand->siglock;
         list_add_tail(&q->list, &p->pending.list);
         sigaddset(&p->pending.signal, sig);
         if (!sigismember(&p->blocked, sig))
@@ -1460,7 +1438,6 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
          * We always use the shared queue for process-wide signals,
          * to avoid several races.
          */
-        q->lock = &p->sighand->siglock;
         list_add_tail(&q->list, &p->signal->shared_pending.list);
         sigaddset(&p->signal->shared_pending.signal, sig);
 
@@ -1879,9 +1856,9 @@ relock:
                         /* Let the debugger run.  */
                         ptrace_stop(signr, signr, info);
 
-                        /* We're back.  Did the debugger cancel the sig?  */
+                        /* We're back.  Did the debugger cancel the sig or group_exit? */
                         signr = current->exit_code;
-                        if (signr == 0)
+                        if (signr == 0 || current->signal->flags & SIGNAL_GROUP_EXIT)
                                 continue;
 
                         current->exit_code = 0;
@@ -2283,26 +2260,13 @@ sys_kill(int pid, int sig)
         return kill_something_info(sig, &info, pid);
 }
 
-/**
- *  sys_tgkill - send signal to one specific thread
- *  @tgid: the thread group ID of the thread
- *  @pid: the PID of the thread
- *  @sig: signal to be sent
- *
- *  This syscall also checks the tgid and returns -ESRCH even if the PID
- *  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)
+static int do_tkill(int tgid, int pid, int sig)
 {
-        struct siginfo info;
         int error;
+        struct siginfo info;
         struct task_struct *p;
 
-        /* This is only valid for single tasks */
-        if (pid <= 0 || tgid <= 0)
-                return -EINVAL;
-
+        error = -ESRCH;
         info.si_signo = sig;
         info.si_errno = 0;
         info.si_code = SI_TKILL;
@@ -2311,8 +2275,7 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig)
 
         read_lock(&tasklist_lock);
         p = find_task_by_pid(pid);
-        error = -ESRCH;
-        if (p && (p->tgid == tgid)) {
+        if (p && (tgid <= 0 || p->tgid == tgid)) {
                 error = check_kill_permission(sig, &info, p);
                 /*
                  * The null signal is a permissions and process existence
@@ -2326,47 +2289,40 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig)
                 }
         }
         read_unlock(&tasklist_lock);
+
         return error;
 }
 
+/**
+ *  sys_tgkill - send signal to one specific thread
+ *  @tgid: the thread group ID of the thread
+ *  @pid: the PID of the thread
+ *  @sig: signal to be sent
+ *
+ *  This syscall also checks the tgid and returns -ESRCH even if the PID
+ *  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)
+{
+        /* This is only valid for single tasks */
+        if (pid <= 0 || tgid <= 0)
+                return -EINVAL;
+
+        return do_tkill(tgid, pid, sig);
+}
+
 /*
  *  Send a signal to only one task, even if it's a CLONE_THREAD task.
  */
 asmlinkage long
 sys_tkill(int pid, int sig)
 {
-        struct siginfo info;
-        int error;
-        struct task_struct *p;
-
         /* This is only valid for single tasks */
         if (pid <= 0)
                 return -EINVAL;
 
-        info.si_signo = sig;
-        info.si_errno = 0;
-        info.si_code = SI_TKILL;
-        info.si_pid = current->tgid;
-        info.si_uid = current->uid;
-
-        read_lock(&tasklist_lock);
-        p = find_task_by_pid(pid);
-        error = -ESRCH;
-        if (p) {
-                error = check_kill_permission(sig, &info, p);
-                /*
-                 * The null signal is a permissions and process existence
-                 * probe.  No signal is actually delivered.
-                 */
-                if (!error && sig && p->sighand) {
-                        spin_lock_irq(&p->sighand->siglock);
-                        handle_stop_signal(sig, p);
-                        error = specific_send_sig_info(sig, &info, p);
-                        spin_unlock_irq(&p->sighand->siglock);
-                }
-        }
-        read_unlock(&tasklist_lock);
-        return error;
+        return do_tkill(0, pid, sig);
 }
 
 asmlinkage long