-/*
- * (C) Copyright 2009-2011 -
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
+ * probes/lttng-ftrace.c
*
* LTTng function tracer integration module.
*
- * Dual LGPL v2.1/GPL v2 license.
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
/*
* 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>
#include <linux/ftrace.h>
#include <linux/slab.h>
-#include "../ltt-events.h"
-#include "../wrapper/ringbuffer/frontend_types.h"
-#include "../wrapper/ftrace.h"
-#include "../wrapper/vmalloc.h"
-#include "../ltt-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/ftrace.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
+static
+void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void *data)
+{
+ struct lttng_event *event = data;
+ struct lttng_probe_ctx lttng_probe_ctx = {
+ .event = event,
+ .interruptible = !irqs_disabled(),
+ };
+ struct lttng_channel *chan = event->chan;
+ struct lib_ring_buffer_ctx ctx;
+ struct {
+ unsigned long ip;
+ unsigned long parent_ip;
+ } payload;
+ int ret;
+
+ if (unlikely(!READ_ONCE(chan->session->active)))
+ return;
+ if (unlikely(!READ_ONCE(chan->enabled)))
+ return;
+ if (unlikely(!READ_ONCE(event->enabled)))
+ return;
+
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx,
+ sizeof(payload), lttng_alignof(payload), -1);
+ ret = chan->ops->event_reserve(&ctx, event->id);
+ if (ret < 0)
+ return;
+ payload.ip = ip;
+ payload.parent_ip = parent_ip;
+ lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload));
+ chan->ops->event_write(&ctx, &payload, sizeof(payload));
+ chan->ops->event_commit(&ctx);
+ return;
+}
+#else
static
void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data)
{
- struct ltt_event *event = *data;
- struct ltt_channel *chan = event->chan;
+ struct lttng_event *event = *data;
+ struct lttng_probe_ctx lttng_probe_ctx = {
+ .event = event,
+ .interruptible = !irqs_disabled(),
+ };
+ struct lttng_channel *chan = event->chan;
struct lib_ring_buffer_ctx ctx;
struct {
unsigned long ip;
} payload;
int ret;
- if (!ACCESS_ONCE(chan->session->active))
+ if (unlikely(!READ_ONCE(chan->session->active)))
+ return;
+ if (unlikely(!READ_ONCE(chan->enabled)))
+ return;
+ if (unlikely(!READ_ONCE(event->enabled)))
return;
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL,
- sizeof(payload), ltt_alignof(payload), -1);
- ret = chan->ops->event_reserve(&ctx);
+
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx,
+ sizeof(payload), lttng_alignof(payload), -1);
+ ret = chan->ops->event_reserve(&ctx, event->id);
if (ret < 0)
return;
payload.ip = ip;
payload.parent_ip = parent_ip;
- lib_ring_buffer_align_ctx(&ctx, ltt_alignof(payload));
+ lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload));
chan->ops->event_write(&ctx, &payload, sizeof(payload));
chan->ops->event_commit(&ctx);
return;
}
+#endif
/*
* Create event description
*/
static
-int lttng_create_ftrace_event(const char *name, struct ltt_event *event)
+int lttng_create_ftrace_event(const char *name, struct lttng_event *event)
{
struct lttng_event_field *fields;
struct lttng_event_desc *desc;
desc->nr_fields = 2;
desc->fields = fields =
kzalloc(2 * sizeof(struct lttng_event_field), GFP_KERNEL);
+ if (!desc->fields) {
+ ret = -ENOMEM;
+ goto error_fields;
+ }
fields[0].name = "ip";
fields[0].type.atype = atype_integer;
- fields[0].type.u.basic.integer.size = sizeof(unsigned long);
- fields[0].type.u.basic.integer.alignment = ltt_alignof(unsigned long);
- fields[0].type.u.basic.integer.signedness = 0;
+ fields[0].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT;
+ fields[0].type.u.basic.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT;
+ fields[0].type.u.basic.integer.signedness = lttng_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;
fields[1].name = "parent_ip";
fields[1].type.atype = atype_integer;
- fields[1].type.u.basic.integer.size = sizeof(unsigned long);
- fields[1].type.u.basic.integer.alignment = ltt_alignof(unsigned long);
- fields[1].type.u.basic.integer.signedness = 0;
+ fields[1].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT;
+ fields[1].type.u.basic.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT;
+ fields[1].type.u.basic.integer.signedness = lttng_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;
+error_fields:
+ kfree(desc->name);
error_str:
kfree(desc);
return ret;
int lttng_ftrace_register(const char *name,
const char *symbol_name,
- struct ltt_event *event)
+ struct lttng_event *event)
{
int ret;
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;
ret = wrapper_register_ftrace_function_probe(event->u.ftrace.symbol_name,
<tng_ftrace_ops, event);
- if (ret)
+ if (ret < 0)
goto register_error;
return 0;
}
EXPORT_SYMBOL_GPL(lttng_ftrace_register);
-void lttng_ftrace_unregister(struct ltt_event *event)
+void lttng_ftrace_unregister(struct lttng_event *event)
{
wrapper_unregister_ftrace_function_probe(event->u.ftrace.symbol_name,
<tng_ftrace_ops, event);
+}
+EXPORT_SYMBOL_GPL(lttng_ftrace_unregister);
+
+void lttng_ftrace_destroy_private(struct lttng_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();
}
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");
+MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
+MODULE_DESCRIPTION("LTTng ftrace probes");
+MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
+ __stringify(LTTNG_MODULES_MINOR_VERSION) "."
+ __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+ LTTNG_MODULES_EXTRAVERSION);
projects / lttng-modules.git / blobdiff