X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=probes%2Flttng-ftrace.c;h=b8bd344749b201ecec08b6e93ebcba2715fb08f7;hb=d01202ff1f043dd04f62ab77aacea3c26cb65eb3;hp=7c4fc9f55d78f5fc98898cd45af8a630b37e90ae;hpb=4e1f08f47c1837b09af74712c299c5169496591a;p=lttng-modules.git

diff --git a/probes/lttng-ftrace.c b/probes/lttng-ftrace.c
index 7c4fc9f5..b8bd3447 100644
--- a/probes/lttng-ftrace.c
+++ b/probes/lttng-ftrace.c
@@ -11,6 +11,10 @@
  * Ftrace function tracer does not seem to provide synchronization between probe
  * teardown and callback execution. Therefore, we make this module permanently
  * loaded (unloadable).
+ *
+ * TODO: Move to register_ftrace_function() (which is exported for
+ * modules) for Linux >= 3.0. It is faster (only enables the selected
+ * functions), and will stay there.
  */
 
 #include <linux/module.h>
@@ -36,7 +40,7 @@ void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data
 
 	if (!ACCESS_ONCE(chan->session->active))
 		return;
-	lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL,
+	lib_ring_buffer_ctx_init(&ctx, chan->chan, event,
 				 sizeof(payload), ltt_alignof(payload), -1);
 	ret = chan->ops->event_reserve(&ctx, event->id);
 	if (ret < 0)
@@ -78,7 +82,7 @@ int lttng_create_ftrace_event(const char *name, struct ltt_event *event)
 	fields[0].type.atype = atype_integer;
 	fields[0].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT;
 	fields[0].type.u.basic.integer.alignment = ltt_alignof(unsigned long) * CHAR_BIT;
-	fields[0].type.u.basic.integer.signedness = 0;
+	fields[0].type.u.basic.integer.signedness = is_signed_type(unsigned long);
 	fields[0].type.u.basic.integer.reverse_byte_order = 0;
 	fields[0].type.u.basic.integer.base = 16;
 	fields[0].type.u.basic.integer.encoding = lttng_encode_none;
@@ -87,11 +91,12 @@ int lttng_create_ftrace_event(const char *name, struct ltt_event *event)
 	fields[1].type.atype = atype_integer;
 	fields[1].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT;
 	fields[1].type.u.basic.integer.alignment = ltt_alignof(unsigned long) * CHAR_BIT;
-	fields[1].type.u.basic.integer.signedness = 0;
+	fields[1].type.u.basic.integer.signedness = is_signed_type(unsigned long);
 	fields[1].type.u.basic.integer.reverse_byte_order = 0;
 	fields[1].type.u.basic.integer.base = 16;
 	fields[1].type.u.basic.integer.encoding = lttng_encode_none;
 
+	desc->owner = THIS_MODULE;
 	event->desc = desc;
 
 	return 0;
@@ -118,7 +123,7 @@ int lttng_ftrace_register(const char *name,
 	if (ret)
 		goto error;
 
-	event->u.ftrace.symbol_name = kstrdup(name, GFP_KERNEL);
+	event->u.ftrace.symbol_name = kstrdup(symbol_name, GFP_KERNEL);
 	if (!event->u.ftrace.symbol_name)
 		goto name_error;
 
@@ -127,7 +132,7 @@ int lttng_ftrace_register(const char *name,
 
 	ret = wrapper_register_ftrace_function_probe(event->u.ftrace.symbol_name,
 			&lttng_ftrace_ops, event);
-	if (ret)
+	if (ret < 0)
 		goto register_error;
 	return 0;
 
@@ -145,14 +150,18 @@ void lttng_ftrace_unregister(struct ltt_event *event)
 {
 	wrapper_unregister_ftrace_function_probe(event->u.ftrace.symbol_name,
 			&lttng_ftrace_ops, event);
+}
+EXPORT_SYMBOL_GPL(lttng_ftrace_unregister);
+
+void lttng_ftrace_destroy_private(struct ltt_event *event)
+{
 	kfree(event->u.ftrace.symbol_name);
 	kfree(event->desc->fields);
 	kfree(event->desc->name);
 	kfree(event->desc);
 }
-EXPORT_SYMBOL_GPL(lttng_ftrace_unregister);
+EXPORT_SYMBOL_GPL(lttng_ftrace_destroy_private);
 
-/* This module is permanent. */
 int lttng_ftrace_init(void)
 {
 	wrapper_vmalloc_sync_all();
@@ -160,6 +169,15 @@ int lttng_ftrace_init(void)
 }
 module_init(lttng_ftrace_init)
 
+/*
+ * Ftrace takes care of waiting for a grace period (RCU sched) at probe
+ * unregistration, and disables preemption around probe call.
+ */
+void lttng_ftrace_exit(void)
+{
+}
+module_exit(lttng_ftrace_exit)
+
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");
 MODULE_DESCRIPTION("Linux Trace Toolkit Ftrace Support");