X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ltt-events.c;h=28f7bdb44ec687e720920acc8c07e38b37dae4b6;hb=71c1d8431c8b94c34332cf2fbdbd7c9dc5f1489a;hp=40e8e459183efacae2744fcc6a6071bd9625e5b1;hpb=24cedcfefbfe781af5430e07a327030cc7caddfc;p=lttng-modules.git diff --git a/ltt-events.c b/ltt-events.c index 40e8e459..28f7bdb4 100644 --- a/ltt-events.c +++ b/ltt-events.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include "wrapper/uuid.h" #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ #include "ltt-events.h" #include "ltt-tracer.h" @@ -34,8 +34,6 @@ int _ltt_event_metadata_statedump(struct ltt_session *session, static int _ltt_session_metadata_statedump(struct ltt_session *session); - -static void synchronize_trace(void) { synchronize_sched(); @@ -82,7 +80,7 @@ void ltt_session_destroy(struct ltt_session *session) kfree(session); } -int ltt_session_start(struct ltt_session *session) +int ltt_session_enable(struct ltt_session *session) { int ret = 0; struct ltt_channel *chan; @@ -108,18 +106,15 @@ int ltt_session_start(struct ltt_session *session) ACCESS_ONCE(session->active) = 1; ACCESS_ONCE(session->been_active) = 1; - synchronize_trace(); /* Wait for in-flight events to complete */ ret = _ltt_session_metadata_statedump(session); - if (ret) { + if (ret) ACCESS_ONCE(session->active) = 0; - synchronize_trace(); /* Wait for in-flight events to complete */ - } end: mutex_unlock(&sessions_mutex); return ret; } -int ltt_session_stop(struct ltt_session *session) +int ltt_session_disable(struct ltt_session *session) { int ret = 0; @@ -129,12 +124,59 @@ int ltt_session_stop(struct ltt_session *session) goto end; } ACCESS_ONCE(session->active) = 0; - synchronize_trace(); /* Wait for in-flight events to complete */ end: mutex_unlock(&sessions_mutex); return ret; } +int ltt_channel_enable(struct ltt_channel *channel) +{ + int old; + + if (channel == channel->session->metadata) + return -EPERM; + old = xchg(&channel->enabled, 1); + if (old) + return -EEXIST; + return 0; +} + +int ltt_channel_disable(struct ltt_channel *channel) +{ + int old; + + if (channel == channel->session->metadata) + return -EPERM; + old = xchg(&channel->enabled, 0); + if (!old) + return -EEXIST; + return 0; +} + +int ltt_event_enable(struct ltt_event *event) +{ + int old; + + if (event->chan == event->chan->session->metadata) + return -EPERM; + old = xchg(&event->enabled, 1); + if (old) + return -EEXIST; + return 0; +} + +int ltt_event_disable(struct ltt_event *event) +{ + int old; + + if (event->chan == event->chan->session->metadata) + return -EPERM; + old = xchg(&event->enabled, 0); + if (!old) + return -EEXIST; + return 0; +} + static struct ltt_transport *ltt_transport_find(const char *name) { struct ltt_transport *transport; @@ -154,7 +196,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session, unsigned int read_timer_interval) { struct ltt_channel *chan; - struct ltt_transport *transport; + struct ltt_transport *transport = NULL; mutex_lock(&sessions_mutex); if (session->been_active) @@ -165,6 +207,10 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session, transport_name); goto notransport; } + if (!try_module_get(transport->owner)) { + printk(KERN_WARNING "LTT : Can't lock transport module.\n"); + goto notransport; + } chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL); if (!chan) goto nomem; @@ -180,7 +226,9 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session, read_timer_interval); if (!chan->chan) goto create_error; + chan->enabled = 1; chan->ops = &transport->ops; + chan->transport = transport; list_add(&chan->list, &session->chan); mutex_unlock(&sessions_mutex); return chan; @@ -188,6 +236,8 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session, create_error: kfree(chan); nomem: + if (transport) + module_put(transport->owner); notransport: active: mutex_unlock(&sessions_mutex); @@ -201,6 +251,7 @@ static void _ltt_channel_destroy(struct ltt_channel *chan) { chan->ops->channel_destroy(chan->chan); + module_put(chan->transport->owner); list_del(&chan->list); lttng_destroy_context(chan->ctx); kfree(chan); @@ -232,6 +283,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, event->chan = chan; event->filter = filter; event->id = chan->free_event_id++; + event->enabled = 1; event->instrumentation = event_param->instrumentation; /* Populate ltt_event structure before tracepoint registration. */ smp_wmb(); @@ -257,6 +309,49 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, ret = try_module_get(event->desc->owner); WARN_ON_ONCE(!ret); break; + case LTTNG_KERNEL_KRETPROBE: + { + struct ltt_event *event_return; + + /* kretprobe defines 2 events */ + event_return = + kmem_cache_zalloc(event_cache, GFP_KERNEL); + if (!event_return) + goto register_error; + event_return->chan = chan; + event_return->filter = filter; + event_return->id = chan->free_event_id++; + event_return->enabled = 1; + event_return->instrumentation = event_param->instrumentation; + /* + * Populate ltt_event structure before kretprobe registration. + */ + smp_wmb(); + ret = lttng_kretprobes_register(event_param->name, + event_param->u.kretprobe.symbol_name, + event_param->u.kretprobe.offset, + event_param->u.kretprobe.addr, + event, event_return); + if (ret) { + kmem_cache_free(event_cache, event_return); + goto register_error; + } + /* Take 2 refs on the module: one per event. */ + ret = try_module_get(event->desc->owner); + WARN_ON_ONCE(!ret); + ret = try_module_get(event->desc->owner); + WARN_ON_ONCE(!ret); + ret = _ltt_event_metadata_statedump(chan->session, chan, + event_return); + if (ret) { + kmem_cache_free(event_cache, event_return); + module_put(event->desc->owner); + module_put(event->desc->owner); + goto statedump_error; + } + list_add(&event_return->list, &chan->session->events); + break; + } case LTTNG_KERNEL_FUNCTION: ret = lttng_ftrace_register(event_param->name, event_param->u.ftrace.symbol_name, @@ -309,6 +404,10 @@ int _ltt_event_unregister(struct ltt_event *event) lttng_kprobes_unregister(event); ret = 0; break; + case LTTNG_KERNEL_KRETPROBE: + lttng_kretprobes_unregister(event); + ret = 0; + break; case LTTNG_KERNEL_FUNCTION: lttng_ftrace_unregister(event); ret = 0; @@ -333,6 +432,10 @@ void _ltt_event_destroy(struct ltt_event *event) module_put(event->desc->owner); lttng_kprobes_destroy_private(event); break; + case LTTNG_KERNEL_KRETPROBE: + module_put(event->desc->owner); + lttng_kretprobes_destroy_private(event); + break; case LTTNG_KERNEL_FUNCTION: module_put(event->desc->owner); lttng_ftrace_destroy_private(event); @@ -384,7 +487,7 @@ int lttng_metadata_printf(struct ltt_session *session, * we need to bail out after timeout or being * interrupted. */ - waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan->chan), + waitret = wait_event_interruptible_timeout(*chan->ops->get_writer_buf_wait_queue(chan->chan, -1), ({ ret = chan->ops->event_reserve(&ctx, 0); ret != -ENOBUFS || !ret;