X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-events.c;h=2820a0e4d1f9045017dd772d08b7f9325be85cc9;hb=4f3a1efed1d8fed72595489d8ca18f7e4249bae6;hp=97d82a297b911d9ad945cc6b88e484d87d2d8fb3;hpb=abc0446a8da1fe7cc09a546389cbcc932b265520;p=lttng-modules.git diff --git a/lttng-events.c b/lttng-events.c index 97d82a29..2820a0e4 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -20,6 +20,12 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +/* + * This page_alloc.h wrapper needs to be included before gfpflags.h because it + * overrides a function with a define. + */ +#include "wrapper/page_alloc.h" + #include #include #include @@ -98,6 +104,8 @@ 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; @@ -368,7 +376,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, mutex_lock(&sessions_mutex); if (chan->free_event_id == -1U) { - event = ERR_PTR(-EMFILE); + ret = -EMFILE; goto full; } /* @@ -377,13 +385,19 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, */ list_for_each_entry(event, &chan->session->events, list) { if (!strcmp(event->desc->name, event_param->name)) { - event = ERR_PTR(-EEXIST); - goto exist; + /* + * Allow events with the same name to appear in + * different channels. + */ + if (event->chan == chan) { + ret = -EEXIST; + goto exist; + } } } event = kmem_cache_zalloc(event_cache, GFP_KERNEL); if (!event) { - event = ERR_PTR(-ENOMEM); + ret = -ENOMEM; goto cache_error; } event->chan = chan; @@ -397,14 +411,14 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, case LTTNG_KERNEL_TRACEPOINT: event->desc = lttng_event_get(event_param->name); if (!event->desc) { - event = ERR_PTR(-ENOENT); + ret = -ENOENT; goto register_error; } - ret = kabi_2635_tracepoint_probe_register(event_param->name, + ret = lttng_wrapper_tracepoint_probe_register(event->desc->kname, event->desc->probe_callback, event); if (ret) { - event = ERR_PTR(-EINVAL); + ret = -EINVAL; goto register_error; } break; @@ -415,7 +429,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, event_param->u.kprobe.addr, event); if (ret) { - event = ERR_PTR(-EINVAL); + ret = -EINVAL; goto register_error; } ret = try_module_get(event->desc->owner); @@ -429,7 +443,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, event_return = kmem_cache_zalloc(event_cache, GFP_KERNEL); if (!event_return) { - event = ERR_PTR(-ENOMEM); + ret = -ENOMEM; goto register_error; } event_return->chan = chan; @@ -448,7 +462,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, event, event_return); if (ret) { kmem_cache_free(event_cache, event_return); - event = ERR_PTR(-EINVAL); + ret = -EINVAL; goto register_error; } /* Take 2 refs on the module: one per event. */ @@ -463,7 +477,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, kmem_cache_free(event_cache, event_return); module_put(event->desc->owner); module_put(event->desc->owner); - event = ERR_PTR(ret); goto statedump_error; } list_add(&event_return->list, &chan->session->events); @@ -474,7 +487,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, event_param->u.ftrace.symbol_name, event); if (ret) { - event = ERR_PTR(ret); goto register_error; } ret = try_module_get(event->desc->owner); @@ -483,19 +495,18 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, case LTTNG_KERNEL_NOOP: event->desc = internal_desc; if (!event->desc) { - event = ERR_PTR(-EINVAL); + ret = -EINVAL; goto register_error; } break; default: WARN_ON_ONCE(1); - event = ERR_PTR(-EINVAL); + ret = -EINVAL; goto register_error; } ret = _lttng_event_metadata_statedump(chan->session, chan, event); WARN_ON_ONCE(ret > 0); if (ret) { - event = ERR_PTR(ret); goto statedump_error; } list_add(&event->list, &chan->session->events); @@ -510,7 +521,7 @@ cache_error: exist: full: mutex_unlock(&sessions_mutex); - return event; + return ERR_PTR(ret); } /* @@ -522,7 +533,7 @@ int _lttng_event_unregister(struct lttng_event *event) switch (event->instrumentation) { case LTTNG_KERNEL_TRACEPOINT: - ret = kabi_2635_tracepoint_probe_unregister(event->desc->name, + ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname, event->desc->probe_callback, event); if (ret) @@ -600,16 +611,20 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, /* * 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, stream->transport->ops.packet_avail_size(chan), len); @@ -631,6 +646,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, ret = reserve_len; end: + mutex_unlock(&stream->lock); return ret; } @@ -1258,15 +1274,34 @@ static int __init lttng_events_init(void) { int ret; + ret = wrapper_lttng_fixup_sig(THIS_MODULE); + if (ret) + return ret; + ret = wrapper_get_pfnblock_flags_mask_init(); + if (ret) + return ret; + ret = lttng_tracepoint_init(); + if (ret) + return ret; event_cache = KMEM_CACHE(lttng_event, 0); - if (!event_cache) - return -ENOMEM; + if (!event_cache) { + ret = -ENOMEM; + goto error_kmem; + } ret = lttng_abi_init(); if (ret) goto error_abi; + ret = lttng_logger_init(); + if (ret) + goto error_logger; return 0; + +error_logger: + lttng_abi_exit(); error_abi: kmem_cache_destroy(event_cache); +error_kmem: + lttng_tracepoint_exit(); return ret; } @@ -1276,10 +1311,12 @@ static void __exit lttng_events_exit(void) { struct lttng_session *session, *tmpsession; + lttng_logger_exit(); lttng_abi_exit(); list_for_each_entry_safe(session, tmpsession, &sessions, list) lttng_session_destroy(session); kmem_cache_destroy(event_cache); + lttng_tracepoint_exit(); } module_exit(lttng_events_exit); @@ -1289,4 +1326,5 @@ MODULE_AUTHOR("Mathieu Desnoyers "); MODULE_DESCRIPTION("LTTng Events"); MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." __stringify(LTTNG_MODULES_MINOR_VERSION) "." - __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)); + __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION) + LTTNG_MODULES_EXTRAVERSION);