X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=probes%2Flttng-kprobes.c;h=9d9fb5b9a759fd6445f70478c907657736f1f082;hb=e3de3ddef85fe03b67578e124d6af84d51198bb6;hp=eb6e16a0c129e1afb9fc366c36ae2d39c6c36ace;hpb=d6d808f3780d0b519aaf966e66df501730db7d13;p=lttng-modules.git

diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c
index eb6e16a0..9d9fb5b9 100644
--- a/probes/lttng-kprobes.c
+++ b/probes/lttng-kprobes.c
@@ -9,11 +9,13 @@
 
 #include <linux/module.h>
 #include <linux/kprobes.h>
+#include <linux/slab.h>
 #include "../ltt-events.h"
 #include "../wrapper/ringbuffer/frontend_types.h"
 #include "../ltt-tracer.h"
 
-void lttng_kprobes_handler_pre(struct kprobe *p, struct pt_regs *regs)
+static
+int lttng_kprobes_handler_pre(struct kprobe *p, struct pt_regs *regs)
 {
 	struct ltt_event *event =
 		container_of(p, struct ltt_event, u.kprobe.kp);
@@ -23,17 +25,105 @@ void lttng_kprobes_handler_pre(struct kprobe *p, struct pt_regs *regs)
 	unsigned long data = (unsigned long) p->addr;
 
 	if (!ACCESS_ONCE(chan->session->active))
-		return;
+		return 0;
 	lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, sizeof(data),
 				 ltt_alignof(data), -1);
 	ret = chan->ops->event_reserve(&ctx);
 	if (ret < 0)
-		return;
+		return 0;
 	lib_ring_buffer_align_ctx(&ctx, ltt_alignof(data));
 	chan->ops->event_write(&ctx, &data, sizeof(data));
 	chan->ops->event_commit(&ctx);
+	return 0;
 }
-EXPORT_SYMBOL_GPL(lttng_kprobes_handler_pre);
+
+/*
+ * Create event description
+ */
+static
+int lttng_create_kprobe_event(const char *name, struct ltt_event *event)
+{
+	struct lttng_event_field *field;
+	struct lttng_event_desc *desc;
+	int ret;
+
+	desc = kzalloc(sizeof(*event->desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+	desc->name = kstrdup(name, GFP_KERNEL);
+	if (!desc->name) {
+		ret = -ENOMEM;
+		goto error_str;
+	}
+	desc->nr_fields = 1;
+	desc->fields = field =
+		kzalloc(1 * sizeof(struct lttng_event_field), GFP_KERNEL);
+	field->name = "ip";
+	field->type.atype = atype_integer;
+	field->type.u.basic.integer.size = sizeof(unsigned long);
+	field->type.u.basic.integer.alignment = ltt_alignof(unsigned long);
+	field->type.u.basic.integer.signedness = 0;
+	field->type.u.basic.integer.reverse_byte_order = 0;
+	field->type.u.basic.integer.base = 16;
+	field->type.u.basic.integer.encoding = lttng_encode_none;
+	event->desc = desc;
+
+	return 0;
+
+error_str:
+	kfree(desc);
+	return ret;
+}
+
+int lttng_kprobes_register(const char *name,
+			   const char *symbol_name,
+			   uint64_t offset,
+			   uint64_t addr,
+			   struct ltt_event *event)
+{
+	int ret;
+
+	ret = lttng_create_kprobe_event(name, event);
+	if (ret)
+		goto error;
+	memset(&event->u.kprobe.kp, 0, sizeof(event->u.kprobe.kp));
+	event->u.kprobe.kp.pre_handler = lttng_kprobes_handler_pre;
+	event->u.kprobe.symbol_name =
+		kzalloc(LTTNG_SYM_NAME_LEN * sizeof(char),
+			GFP_KERNEL);
+	if (!event->u.kprobe.symbol_name) {
+		ret = -ENOMEM;
+		goto name_error;
+	}
+	memcpy(event->u.kprobe.symbol_name, symbol_name,
+	       LTTNG_SYM_NAME_LEN * sizeof(char));
+	event->u.kprobe.kp.symbol_name =
+		event->u.kprobe.symbol_name;
+	event->u.kprobe.kp.offset = offset;
+	event->u.kprobe.kp.addr = (void *) addr;
+	ret = register_kprobe(&event->u.kprobe.kp);
+	if (ret)
+		goto register_error;
+	return 0;
+
+register_error:
+	kfree(event->u.kprobe.symbol_name);
+name_error:
+	kfree(event->desc->name);
+	kfree(event->desc);
+error:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(lttng_kprobes_register);
+
+void lttng_kprobes_unregister(struct ltt_event *event)
+{
+	unregister_kprobe(&event->u.kprobe.kp);
+	kfree(event->u.kprobe.symbol_name);
+	kfree(event->desc->name);
+	kfree(event->desc);
+}
+EXPORT_SYMBOL_GPL(lttng_kprobes_unregister);
 
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");