X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Fsignal.c;h=72bb4f51f9634c448ad6eb4986d8ed7f35deb1f1;hb=c3921ab71507b108d51a0f1ee960f80cd668a93d;hp=8423867f7d8f0c3b1eb8be57657a55d0c0a1612f;hpb=021e1ae3d85a76ce962a300c96813f04ae50c87c;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/signal.c b/kernel/signal.c
index 8423867..72bb4f5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -533,6 +533,7 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s)
 static int check_kill_permission(int sig, struct siginfo *info,
 				 struct task_struct *t)
 {
+	struct pid *sid;
 	int error;
 
 	if (!valid_signal(sig))
@@ -545,11 +546,22 @@ static int check_kill_permission(int sig, struct siginfo *info,
 	if (error)
 		return error;
 
-	if (((sig != SIGCONT) || (task_session_nr(current) != task_session_nr(t)))
-	    && (current->euid ^ t->suid) && (current->euid ^ t->uid)
-	    && (current->uid ^ t->suid) && (current->uid ^ t->uid)
-	    && !capable(CAP_KILL))
-		return -EPERM;
+	if ((current->euid ^ t->suid) && (current->euid ^ t->uid) &&
+	    (current->uid  ^ t->suid) && (current->uid  ^ t->uid) &&
+	    !capable(CAP_KILL)) {
+		switch (sig) {
+		case SIGCONT:
+			sid = task_session(t);
+			/*
+			 * We don't return the error if sid == NULL. The
+			 * task was unhashed, the caller must notice this.
+			 */
+			if (!sid || sid == task_session(current))
+				break;
+		default:
+			return -EPERM;
+		}
+	}
 
 	return security_task_kill(t, info, sig, 0);
 }
@@ -716,7 +728,8 @@ static void complete_signal(int sig, struct task_struct *p, int group)
 	 * Found a killable thread.  If the signal will be fatal,
 	 * then start taking the whole group down immediately.
 	 */
-	if (sig_fatal(p, sig) && !(signal->flags & SIGNAL_GROUP_EXIT) &&
+	if (sig_fatal(p, sig) &&
+	    !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
 	    !sigismember(&t->real_blocked, sig) &&
 	    (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
 		/*
@@ -772,13 +785,6 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	 */
 	if (legacy_queue(pending, sig))
 		return 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.
@@ -828,6 +834,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	}
 
 out_set:
+	signalfd_notify(t, sig);
 	sigaddset(&pending->signal, sig);
 	complete_signal(sig, t, group);
 	return 0;
@@ -885,7 +892,8 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
  * since we do not want to have a signal handler that was blocked
  * be invoked when user space had explicitly blocked it.
  *
- * We don't want to have recursive SIGSEGV's etc, for example.
+ * We don't want to have recursive SIGSEGV's etc, for example,
+ * that is why we also clear SIGNAL_UNKILLABLE.
  */
 int
 force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
@@ -905,6 +913,8 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 			recalc_sigpending_and_wake(t);
 		}
 	}
+	if (action->sa.sa_handler == SIG_DFL)
+		t->signal->flags &= ~SIGNAL_UNKILLABLE;
 	ret = specific_send_sig_info(sig, info, t);
 	spin_unlock_irqrestore(&t->sighand->siglock, flags);
 
@@ -1609,7 +1619,8 @@ static int do_signal_stop(int signr)
 	} else {
 		struct task_struct *t;
 
-		if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
+		if (unlikely((sig->flags & (SIGNAL_STOP_DEQUEUED | SIGNAL_UNKILLABLE))
+					 != SIGNAL_STOP_DEQUEUED) ||
 		    unlikely(signal_group_exit(sig)))
 			return 0;
 		/*
@@ -1755,7 +1766,8 @@ relock:
 		/*
 		 * Global init gets no signals it doesn't want.
 		 */
-		if (is_global_init(current))
+		if (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
+		    !signal_group_exit(signal))
 			continue;
 
 		if (sig_kernel_stop(signr)) {
@@ -2529,7 +2541,7 @@ asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();
-	set_thread_flag(TIF_RESTORE_SIGMASK);
+	set_restore_sigmask();
 	return -ERESTARTNOHAND;
 }
 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */