#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/utsname.h>
+#include <linux/err.h>
#include "wrapper/uuid.h"
#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
#include "wrapper/random.h"
#include "wrapper/tracepoint.h"
+#include "lttng-kernel-version.h"
#include "lttng-events.h"
#include "lttng-tracer.h"
#include "lttng-abi-old.h"
void synchronize_trace(void)
{
synchronize_sched();
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0))
+#ifdef CONFIG_PREEMPT_RT_FULL
+ synchronize_rcu();
+#endif
+#else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
#ifdef CONFIG_PREEMPT_RT
synchronize_rcu();
#endif
+#endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
}
struct lttng_session *lttng_session_create(void)
kref_init(&metadata_cache->refcount);
session->metadata_cache = metadata_cache;
INIT_LIST_HEAD(&metadata_cache->metadata_stream);
+ memcpy(&metadata_cache->uuid, &session->uuid,
+ sizeof(metadata_cache->uuid));
list_add(&session->list, &sessions);
mutex_unlock(&sessions_mutex);
return session;
goto nomem;
chan->session = session;
chan->id = session->free_chan_id++;
+ chan->ops = &transport->ops;
/*
* Note: the channel creation op already writes into the packet
* headers. Therefore the "chan" information used as input
if (!chan->chan)
goto create_error;
chan->enabled = 1;
- chan->ops = &transport->ops;
chan->transport = transport;
chan->channel_type = channel_type;
list_add(&chan->list, &session->chan);
int ret;
mutex_lock(&sessions_mutex);
- if (chan->free_event_id == -1U)
+ if (chan->free_event_id == -1U) {
+ ret = -EMFILE;
goto full;
+ }
/*
* This is O(n^2) (for each event, the loop is called at event
* creation). Might require a hash if we have lots of events.
*/
- list_for_each_entry(event, &chan->session->events, list)
- if (!strcmp(event->desc->name, event_param->name))
+ list_for_each_entry(event, &chan->session->events, list) {
+ if (!strcmp(event->desc->name, event_param->name)) {
+ ret = -EEXIST;
goto exist;
+ }
+ }
event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
- if (!event)
+ if (!event) {
+ ret = -ENOMEM;
goto cache_error;
+ }
event->chan = chan;
event->filter = filter;
event->id = chan->free_event_id++;
switch (event_param->instrumentation) {
case LTTNG_KERNEL_TRACEPOINT:
event->desc = lttng_event_get(event_param->name);
- if (!event->desc)
+ if (!event->desc) {
+ ret = -ENOENT;
goto register_error;
- ret = kabi_2635_tracepoint_probe_register(event_param->name,
+ }
+ ret = kabi_2635_tracepoint_probe_register(event->desc->kname,
event->desc->probe_callback,
event);
- if (ret)
+ if (ret) {
+ ret = -EINVAL;
goto register_error;
+ }
break;
case LTTNG_KERNEL_KPROBE:
ret = lttng_kprobes_register(event_param->name,
event_param->u.kprobe.offset,
event_param->u.kprobe.addr,
event);
- if (ret)
+ if (ret) {
+ ret = -EINVAL;
goto register_error;
+ }
ret = try_module_get(event->desc->owner);
WARN_ON_ONCE(!ret);
break;
/* kretprobe defines 2 events */
event_return =
kmem_cache_zalloc(event_cache, GFP_KERNEL);
- if (!event_return)
+ if (!event_return) {
+ ret = -ENOMEM;
goto register_error;
+ }
event_return->chan = chan;
event_return->filter = filter;
event_return->id = chan->free_event_id++;
event, event_return);
if (ret) {
kmem_cache_free(event_cache, event_return);
+ ret = -EINVAL;
goto register_error;
}
/* Take 2 refs on the module: one per event. */
WARN_ON_ONCE(!ret);
ret = _lttng_event_metadata_statedump(chan->session, chan,
event_return);
+ WARN_ON_ONCE(ret > 0);
if (ret) {
kmem_cache_free(event_cache, event_return);
module_put(event->desc->owner);
ret = lttng_ftrace_register(event_param->name,
event_param->u.ftrace.symbol_name,
event);
- if (ret)
+ if (ret) {
goto register_error;
+ }
ret = try_module_get(event->desc->owner);
WARN_ON_ONCE(!ret);
break;
case LTTNG_KERNEL_NOOP:
event->desc = internal_desc;
- if (!event->desc)
+ if (!event->desc) {
+ ret = -EINVAL;
goto register_error;
+ }
break;
default:
WARN_ON_ONCE(1);
+ ret = -EINVAL;
+ goto register_error;
}
ret = _lttng_event_metadata_statedump(chan->session, chan, event);
- if (ret)
+ WARN_ON_ONCE(ret > 0);
+ if (ret) {
goto statedump_error;
+ }
list_add(&event->list, &chan->session->events);
mutex_unlock(&sessions_mutex);
return event;
exist:
full:
mutex_unlock(&sessions_mutex);
- return NULL;
+ return ERR_PTR(ret);
}
/*
switch (event->instrumentation) {
case LTTNG_KERNEL_TRACEPOINT:
- ret = kabi_2635_tracepoint_probe_unregister(event->desc->name,
+ ret = kabi_2635_tracepoint_probe_unregister(event->desc->kname,
event->desc->probe_callback,
event);
if (ret)
* sessions_mutex), so we can do racy operations such as looking for
* remaining space left in packet and write, since mutual exclusion
* protects us from concurrent writes.
+ * Returns the number of bytes written in the channel, 0 if no data
+ * was written and a negative value on error.
*/
-int lttng_metadata_output_channel(struct lttng_channel *chan,
- struct lttng_metadata_stream *stream)
+int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
+ struct channel *chan)
{
struct lib_ring_buffer_ctx ctx;
int ret = 0;
/*
* Ensure we support mutiple get_next / put sequences followed
- * by put_next.
+ * by put_next. The metadata stream lock internally protects
+ * reading the metadata cache. It can indeed be read
+ * concurrently by "get_next_subbuf" and "flush" operations on
+ * the buffer invoked by different processes.
*/
+ mutex_lock(&stream->lock);
WARN_ON(stream->metadata_in < stream->metadata_out);
if (stream->metadata_in != stream->metadata_out)
- return 0;
+ goto end;
len = stream->metadata_cache->metadata_written -
stream->metadata_in;
if (!len)
- return 0;
+ goto end;
reserve_len = min_t(size_t,
- chan->ops->packet_avail_size(chan->chan),
+ stream->transport->ops.packet_avail_size(chan),
len);
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+ lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len,
sizeof(char), -1);
/*
* If reservation failed, return an error to the caller.
*/
- ret = chan->ops->event_reserve(&ctx, 0);
+ ret = stream->transport->ops.event_reserve(&ctx, 0);
if (ret != 0) {
printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
goto end;
}
- chan->ops->event_write(&ctx,
+ stream->transport->ops.event_write(&ctx,
stream->metadata_cache->data + stream->metadata_in,
reserve_len);
- chan->ops->event_commit(&ctx);
+ stream->transport->ops.event_commit(&ctx);
stream->metadata_in += reserve_len;
ret = reserve_len;
end:
+ mutex_unlock(&stream->lock);
return ret;
}
ret = lttng_metadata_printf(session,
"event {\n"
- " name = %s;\n"
+ " name = \"%s\";\n"
" id = %u;\n"
" stream_id = %u;\n",
event->desc->name,
MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
MODULE_DESCRIPTION("LTTng Events");
+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