X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=probes%2Flttng-kretprobes.c;h=49b7de82d86e32ed0a9afd81d971159f43d80aa4;hb=a8f2d0c75c9cc179fc9e7f7ca17ea3b3b3b5af41;hp=d71090a2bc321edcac3695c774508c1d0d025655;hpb=13ab8b0a749053960f81a4924a3ed27775518f94;p=lttng-modules.git

diff --git a/probes/lttng-kretprobes.c b/probes/lttng-kretprobes.c
index d71090a2..49b7de82 100644
--- a/probes/lttng-kretprobes.c
+++ b/probes/lttng-kretprobes.c
@@ -1,5 +1,5 @@
 /*
- * probes/lttng-kretprobes.c
+* probes/lttng-kretprobes.c
  *
  * LTTng kretprobes integration module.
  *
@@ -24,10 +24,11 @@
 #include <linux/kprobes.h>
 #include <linux/slab.h>
 #include <linux/kref.h>
-#include "../lttng-events.h"
-#include "../wrapper/ringbuffer/frontend_types.h"
-#include "../wrapper/vmalloc.h"
-#include "../lttng-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <wrapper/irqflags.h>
+#include <lttng-tracer.h>
 
 enum lttng_kretprobe_type {
 	EVENT_ENTRY = 0,
@@ -50,6 +51,10 @@ int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
 		container_of(krpi->rp, struct lttng_krp, krp);
 	struct lttng_event *event =
 		lttng_krp->event[type];
+	struct lttng_probe_ctx lttng_probe_ctx = {
+		.event = event,
+		.interruptible = !lttng_regs_irqs_disabled(regs),
+	};
 	struct lttng_channel *chan = event->chan;
 	struct lib_ring_buffer_ctx ctx;
 	int ret;
@@ -58,17 +63,17 @@ int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
 		unsigned long parent_ip;
 	} payload;
 
-	if (unlikely(!ACCESS_ONCE(chan->session->active)))
+	if (unlikely(!READ_ONCE(chan->session->active)))
 		return 0;
-	if (unlikely(!ACCESS_ONCE(chan->enabled)))
+	if (unlikely(!READ_ONCE(chan->enabled)))
 		return 0;
-	if (unlikely(!ACCESS_ONCE(event->enabled)))
+	if (unlikely(!READ_ONCE(event->enabled)))
 		return 0;
 
 	payload.ip = (unsigned long) krpi->rp->kp.addr;
 	payload.parent_ip = (unsigned long) krpi->ret_addr;
 
-	lib_ring_buffer_ctx_init(&ctx, chan->chan, event, sizeof(payload),
+	lib_ring_buffer_ctx_init(&ctx, chan->chan, &lttng_probe_ctx, sizeof(payload),
 				 lttng_alignof(payload), -1);
 	ret = chan->ops->event_reserve(&ctx, event->id);
 	if (ret < 0)
@@ -219,9 +224,9 @@ int lttng_kretprobes_register(const char *name,
 	 * unregistered. Same for memory allocation.
 	 */
 	kref_init(&lttng_krp->kref_alloc);
-	kref_get(&lttng_krp->kref_alloc);	/* inc refcount to 2 */
+	kref_get(&lttng_krp->kref_alloc);	/* inc refcount to 2, no overflow. */
 	kref_init(&lttng_krp->kref_register);
-	kref_get(&lttng_krp->kref_register);	/* inc refcount to 2 */
+	kref_get(&lttng_krp->kref_register);	/* inc refcount to 2, no overflow. */
 
 	/*
 	 * Ensure the memory we just allocated don't trigger page faults.
@@ -285,6 +290,26 @@ void lttng_kretprobes_destroy_private(struct lttng_event *event)
 }
 EXPORT_SYMBOL_GPL(lttng_kretprobes_destroy_private);
 
+int lttng_kretprobes_event_enable_state(struct lttng_event *event,
+		int enable)
+{
+	struct lttng_event *event_return;
+	struct lttng_krp *lttng_krp;
+
+	if (event->instrumentation != LTTNG_KERNEL_KRETPROBE) {
+		return -EINVAL;
+	}
+	if (event->enabled == enable) {
+		return -EBUSY;
+	}
+	lttng_krp = event->u.kretprobe.lttng_krp;
+	event_return = lttng_krp->event[EVENT_RETURN];
+	WRITE_ONCE(event->enabled, enable);
+	WRITE_ONCE(event_return->enabled, enable);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_kretprobes_event_enable_state);
+
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");
 MODULE_DESCRIPTION("Linux Trace Toolkit Kretprobes Support");