Add kprobes support

[lttng-modules.git] / probes / lttng-kprobes.c

diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c
new file mode 100644 (file)
index 0000000..eb6e16a
--- /dev/null
+++ b/probes/lttng-kprobes.c
@@ -0,0 +1,40 @@
+/*
+ * (C) Copyright       2009-2011 -
+ *             Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng kprobes integration module.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include <linux/kprobes.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)
+{
+       struct ltt_event *event =
+               container_of(p, struct ltt_event, u.kprobe.kp);
+       struct ltt_channel *chan = event->chan;
+       struct lib_ring_buffer_ctx ctx;
+       int ret;
+       unsigned long data = (unsigned long) p->addr;
+
+       if (!ACCESS_ONCE(chan->session->active))
+               return;
+       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;
+       lib_ring_buffer_align_ctx(&ctx, ltt_alignof(data));
+       chan->ops->event_write(&ctx, &data, sizeof(data));
+       chan->ops->event_commit(&ctx);
+}
+EXPORT_SYMBOL_GPL(lttng_kprobes_handler_pre);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Linux Trace Toolkit Kprobes Support");