]> err.no Git - linux-2.6/blobdiff - kernel/signal.c
[PATCH] do_notify_parent_cldstop: remove 'to_self' param
[linux-2.6] / kernel / signal.c
index 6ea49f742a2f1fb777379d633302710cdc479f2e..0528a959daa9d612ea48e7f12034c17e301213ea 100644 (file)
@@ -146,8 +146,7 @@ static kmem_cache_t *sigqueue_cachep;
 #define sig_kernel_stop(sig) \
                (((sig) < SIGRTMIN)  && T(sig, SIG_KERNEL_STOP_MASK))
 
-#define sig_needs_tasklist(sig) \
-               (((sig) < SIGRTMIN)  && T(sig, SIG_KERNEL_STOP_MASK | M(SIGCONT)))
+#define sig_needs_tasklist(sig)        ((sig) == SIGCONT)
 
 #define sig_user_defined(t, signr) \
        (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&  \
@@ -592,9 +591,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 }
 
 /* forward decl */
-static void do_notify_parent_cldstop(struct task_struct *tsk,
-                                    int to_self,
-                                    int why);
+static void do_notify_parent_cldstop(struct task_struct *tsk, int why);
 
 /*
  * Handle magic process-wide effects of stop/continue signals.
@@ -644,7 +641,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                        p->signal->group_stop_count = 0;
                        p->signal->flags = SIGNAL_STOP_CONTINUED;
                        spin_unlock(&p->sighand->siglock);
-                       do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_STOPPED);
+                       do_notify_parent_cldstop(p, CLD_STOPPED);
                        spin_lock(&p->sighand->siglock);
                }
                rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
@@ -685,7 +682,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                        p->signal->flags = SIGNAL_STOP_CONTINUED;
                        p->signal->group_exit_code = 0;
                        spin_unlock(&p->sighand->siglock);
-                       do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_CONTINUED);
+                       do_notify_parent_cldstop(p, CLD_CONTINUED);
                        spin_lock(&p->sighand->siglock);
                } else {
                        /*
@@ -1520,14 +1517,14 @@ void do_notify_parent(struct task_struct *tsk, int sig)
        spin_unlock_irqrestore(&psig->siglock, flags);
 }
 
-static void do_notify_parent_cldstop(struct task_struct *tsk, int to_self, int why)
+static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
 {
        struct siginfo info;
        unsigned long flags;
        struct task_struct *parent;
        struct sighand_struct *sighand;
 
-       if (to_self)
+       if (tsk->ptrace & PT_PTRACED)
                parent = tsk->parent;
        else {
                tsk = tsk->group_leader;
@@ -1602,7 +1599,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
                   !(current->ptrace & PT_ATTACHED)) &&
            (likely(current->parent->signal != current->signal) ||
             !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) {
-               do_notify_parent_cldstop(current, 1, CLD_TRAPPED);
+               do_notify_parent_cldstop(current, CLD_TRAPPED);
                read_unlock(&tasklist_lock);
                schedule();
        } else {
@@ -1651,25 +1648,17 @@ void ptrace_notify(int exit_code)
 static void
 finish_stop(int stop_count)
 {
-       int to_self;
-
        /*
         * If there are no other threads in the group, or if there is
         * 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))
-               to_self = 1;
-       else if (stop_count == 0)
-               to_self = 0;
-       else
-               goto out;
-
-       read_lock(&tasklist_lock);
-       do_notify_parent_cldstop(current, to_self, CLD_STOPPED);
-       read_unlock(&tasklist_lock);
+       if (stop_count == 0 || (current->ptrace & PT_PTRACED)) {
+               read_lock(&tasklist_lock);
+               do_notify_parent_cldstop(current, CLD_STOPPED);
+               read_unlock(&tasklist_lock);
+       }
 
-out:
        schedule();
        /*
         * Now we don't run again until continued.
@@ -1683,12 +1672,10 @@ out:
  * Returns nonzero if we've actually stopped and released the siglock.
  * Returns zero if we didn't stop and still hold the siglock.
  */
-static int
-do_signal_stop(int signr)
+static int do_signal_stop(int signr)
 {
        struct signal_struct *sig = current->signal;
-       struct sighand_struct *sighand = current->sighand;
-       int stop_count = -1;
+       int stop_count;
 
        if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED))
                return 0;
@@ -1698,86 +1685,37 @@ do_signal_stop(int signr)
                 * There is a group stop in progress.  We don't need to
                 * start another one.
                 */
-               signr = sig->group_exit_code;
                stop_count = --sig->group_stop_count;
-               current->exit_code = signr;
-               set_current_state(TASK_STOPPED);
-               if (stop_count == 0)
-                       sig->flags = SIGNAL_STOP_STOPPED;
-               spin_unlock_irq(&sighand->siglock);
-       }
-       else if (thread_group_empty(current)) {
-               /*
-                * Lock must be held through transition to stopped state.
-                */
-               current->exit_code = current->signal->group_exit_code = signr;
-               set_current_state(TASK_STOPPED);
-               sig->flags = SIGNAL_STOP_STOPPED;
-               spin_unlock_irq(&sighand->siglock);
-       }
-       else {
+       } else {
                /*
                 * There is no group stop already in progress.
-                * We must initiate one now, but that requires
-                * dropping siglock to get both the tasklist lock
-                * and siglock again in the proper order.  Note that
-                * this allows an intervening SIGCONT to be posted.
-                * We need to check for that and bail out if necessary.
+                * We must initiate one now.
                 */
                struct task_struct *t;
 
-               spin_unlock_irq(&sighand->siglock);
-
-               /* signals can be posted during this window */
-
-               read_lock(&tasklist_lock);
-               spin_lock_irq(&sighand->siglock);
+               sig->group_exit_code = signr;
 
-               if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED)) {
+               stop_count = 0;
+               for (t = next_thread(current); t != current; t = next_thread(t))
                        /*
-                        * Another stop or continue happened while we
-                        * didn't have the lock.  We can just swallow this
-                        * signal now.  If we raced with a SIGCONT, that
-                        * should have just cleared it now.  If we raced
-                        * with another processor delivering a stop signal,
-                        * then the SIGCONT that wakes us up should clear it.
+                        * Setting state to TASK_STOPPED for a group
+                        * stop is always done with the siglock held,
+                        * so this check has no races.
                         */
-                       read_unlock(&tasklist_lock);
-                       return 0;
-               }
-
-               if (sig->group_stop_count == 0) {
-                       sig->group_exit_code = signr;
-                       stop_count = 0;
-                       for (t = next_thread(current); t != current;
-                            t = next_thread(t))
-                               /*
-                                * Setting state to TASK_STOPPED for a group
-                                * stop is always done with the siglock held,
-                                * so this check has no races.
-                                */
-                               if (!t->exit_state &&
-                                   !(t->state & (TASK_STOPPED|TASK_TRACED))) {
-                                       stop_count++;
-                                       signal_wake_up(t, 0);
-                               }
-                       sig->group_stop_count = stop_count;
-               }
-               else {
-                       /* A race with another thread while unlocked.  */
-                       signr = sig->group_exit_code;
-                       stop_count = --sig->group_stop_count;
-               }
-
-               current->exit_code = signr;
-               set_current_state(TASK_STOPPED);
-               if (stop_count == 0)
-                       sig->flags = SIGNAL_STOP_STOPPED;
-
-               spin_unlock_irq(&sighand->siglock);
-               read_unlock(&tasklist_lock);
+                       if (!t->exit_state &&
+                           !(t->state & (TASK_STOPPED|TASK_TRACED))) {
+                               stop_count++;
+                               signal_wake_up(t, 0);
+                       }
+               sig->group_stop_count = stop_count;
        }
 
+       if (stop_count == 0)
+               sig->flags = SIGNAL_STOP_STOPPED;
+       current->exit_code = sig->group_exit_code;
+       __set_current_state(TASK_STOPPED);
+
+       spin_unlock_irq(&current->sighand->siglock);
        finish_stop(stop_count);
        return 1;
 }
@@ -2337,8 +2275,7 @@ sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo)
        return kill_proc_info(sig, &info, pid);
 }
 
-int
-do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
+int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 {
        struct k_sigaction *k;
        sigset_t mask;
@@ -2364,6 +2301,7 @@ do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
        if (act) {
                sigdelsetmask(&act->sa.sa_mask,
                              sigmask(SIGKILL) | sigmask(SIGSTOP));
+               *k = *act;
                /*
                 * POSIX 3.3.1.3:
                 *  "Setting a signal action to SIG_IGN for a signal that is
@@ -2376,19 +2314,8 @@ do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
                 *   be discarded, whether or not it is blocked"
                 */
                if (act->sa.sa_handler == SIG_IGN ||
-                   (act->sa.sa_handler == SIG_DFL &&
-                    sig_kernel_ignore(sig))) {
-                       /*
-                        * This is a fairly rare case, so we only take the
-                        * tasklist_lock once we're sure we'll need it.
-                        * Now we must do this little unlock and relock
-                        * dance to maintain the lock hierarchy.
-                        */
+                  (act->sa.sa_handler == SIG_DFL && sig_kernel_ignore(sig))) {
                        struct task_struct *t = current;
-                       spin_unlock_irq(&t->sighand->siglock);
-                       read_lock(&tasklist_lock);
-                       spin_lock_irq(&t->sighand->siglock);
-                       *k = *act;
                        sigemptyset(&mask);
                        sigaddset(&mask, sig);
                        rm_from_queue_full(&mask, &t->signal->shared_pending);
@@ -2397,12 +2324,7 @@ do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
                                recalc_sigpending_tsk(t);
                                t = next_thread(t);
                        } while (t != current);
-                       spin_unlock_irq(&current->sighand->siglock);
-                       read_unlock(&tasklist_lock);
-                       return 0;
                }
-
-               *k = *act;
        }
 
        spin_unlock_irq(&current->sighand->siglock);