X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ftracepoint.c;h=af8c85664882c992d962c0ff8809f889ccadd65d;hb=6209344f5a3795d34b7f2c0061f49802283b6bdd;hp=db39961a0d0377cf6e1d52edf14bb2949d2e79a2;hpb=ca2db6cf30d6a45798b7a760d0c4f7735b16799d;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index db39961a0d0..af8c8566488 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -131,6 +131,9 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe)
 
 	old = entry->funcs;
 
+	if (!old)
+		return NULL;
+
 	debug_print_probes(entry);
 	/* (N -> M), (N > 1, M >= 0) probes */
 	for (nr_probes = 0; old[nr_probes]; nr_probes++) {
@@ -356,6 +359,8 @@ int tracepoint_probe_register(const char *name, void *probe)
 	mutex_lock(&tracepoints_mutex);
 	entry = get_tracepoint(name);
 	WARN_ON(!entry);
+	if (entry->rcu_pending)
+		rcu_barrier_sched();
 	tracepoint_entry_free_old(entry, old);
 end:
 	mutex_unlock(&tracepoints_mutex);
@@ -386,12 +391,19 @@ int tracepoint_probe_unregister(const char *name, void *probe)
 	if (entry->rcu_pending)
 		rcu_barrier_sched();
 	old = tracepoint_entry_remove_probe(entry, probe);
+	if (!old) {
+		printk(KERN_WARNING "Warning: Trying to unregister a probe"
+				    "that doesn't exist\n");
+		goto end;
+	}
 	mutex_unlock(&tracepoints_mutex);
 	tracepoint_update_probes();		/* may update entry */
 	mutex_lock(&tracepoints_mutex);
 	entry = get_tracepoint(name);
 	if (!entry)
 		goto end;
+	if (entry->rcu_pending)
+		rcu_barrier_sched();
 	tracepoint_entry_free_old(entry, old);
 	remove_tracepoint(name);	/* Ignore busy error message */
 	ret = 0;