X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fsignal.c;h=d1258729a5f9cdf6674b897b273036e1dee29291;hb=72414d3f1d22fc3e311b162fca95c430048d38ce;hp=e6567d7f2b623b53e5a73e168054b042ab89ac10;hpb=6cae60feb6709dea4cb94da93d4d2ea039aee59d;p=linux-2.6

diff --git a/kernel/signal.c b/kernel/signal.c
index e6567d7f2b..d1258729a5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -23,6 +23,8 @@
 #include <linux/syscalls.h>
 #include <linux/ptrace.h>
 #include <linux/posix-timers.h>
+#include <linux/signal.h>
+#include <linux/audit.h>
 #include <asm/param.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -211,6 +213,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked)
 fastcall void recalc_sigpending_tsk(struct task_struct *t)
 {
 	if (t->signal->group_stop_count > 0 ||
+	    (t->flags & PF_FREEZE) ||
 	    PENDING(&t->pending, &t->blocked) ||
 	    PENDING(&t->signal->shared_pending, &t->blocked))
 		set_tsk_thread_flag(t, TIF_SIGPENDING);
@@ -521,7 +524,16 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
 {
 	int sig = 0;
 
-	sig = next_signal(pending, mask);
+	/* SIGKILL must have priority, otherwise it is quite easy
+	 * to create an unkillable process, sending sig < SIGKILL
+	 * to self */
+	if (unlikely(sigismember(&pending->signal, SIGKILL))) {
+		if (!sigismember(mask, SIGKILL))
+			sig = SIGKILL;
+	}
+
+	if (likely(!sig))
+		sig = next_signal(pending, mask);
 	if (sig) {
 		if (current->notifier) {
 			if (sigismember(current->notifier_mask, sig)) {
@@ -646,7 +658,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 				 struct task_struct *t)
 {
 	int error = -EINVAL;
-	if (sig < 0 || sig > _NSIG)
+	if (!valid_signal(sig))
 		return error;
 	error = -EPERM;
 	if ((!info || ((unsigned long)info != 1 &&
@@ -657,7 +669,11 @@ static int check_kill_permission(int sig, struct siginfo *info,
 	    && (current->uid ^ t->suid) && (current->uid ^ t->uid)
 	    && !capable(CAP_KILL))
 		return error;
-	return security_task_kill(t, info, sig);
+
+	error = security_task_kill(t, info, sig);
+	if (!error)
+		audit_signal_info(sig, t); /* Let audit system see the signal */
+	return error;
 }
 
 /* forward decl */
@@ -1245,7 +1261,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 	 * Make sure legacy kernel users don't send in bad values
 	 * (normal paths check this in check_kill_permission).
 	 */
-	if (sig < 0 || sig > _NSIG)
+	if (!valid_signal(sig))
 		return -EINVAL;
 
 	/*
@@ -1520,7 +1536,7 @@ void do_notify_parent(struct task_struct *tsk, int sig)
 		if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
 			sig = 0;
 	}
-	if (sig > 0 && sig <= _NSIG)
+	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);
@@ -2364,7 +2380,7 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
 {
 	struct k_sigaction *k;
 
-	if (sig < 1 || sig > _NSIG || (act && sig_kernel_only(sig)))
+	if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig)))
 		return -EINVAL;
 
 	k = &current->sighand->action[sig-1];