X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=lttng-events.c;h=cfe2a3529de33efb0184409d4dbdbd105eb93b8a;hb=fd3d2e7837394550f2600f17833ed8e4a699730b;hp=cc932bf61643d04095c5d198e297a153d2fbd7f7;hpb=ae457be2b1c81f72e8eef057203d67089ab96372;p=lttng-modules.git diff --git a/lttng-events.c b/lttng-events.c index cc932bf6..cfe2a352 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -27,10 +27,10 @@ #include #include #include -#include #include -#include /* for wrapper_vmalloc_sync_all() */ +#include +#include /* for wrapper_vmalloc_sync_mappings() */ #include #include #include @@ -130,7 +130,7 @@ struct lttng_session *lttng_session_create(void) goto err; INIT_LIST_HEAD(&session->chan); INIT_LIST_HEAD(&session->events); - uuid_le_gen(&session->uuid); + lttng_guid_gen(&session->uuid); metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache), GFP_KERNEL); @@ -416,7 +416,6 @@ int lttng_event_enable(struct lttng_event *event) ret = -EINVAL; break; case LTTNG_KERNEL_KPROBE: - case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_UPROBE: case LTTNG_KERNEL_NOOP: WRITE_ONCE(event->enabled, 1); @@ -424,6 +423,7 @@ int lttng_event_enable(struct lttng_event *event) case LTTNG_KERNEL_KRETPROBE: ret = lttng_kretprobes_event_enable_state(event, 1); break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through. */ default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -452,7 +452,6 @@ int lttng_event_disable(struct lttng_event *event) ret = -EINVAL; break; case LTTNG_KERNEL_KPROBE: - case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_UPROBE: case LTTNG_KERNEL_NOOP: WRITE_ONCE(event->enabled, 0); @@ -460,6 +459,7 @@ int lttng_event_disable(struct lttng_event *event) case LTTNG_KERNEL_KRETPROBE: ret = lttng_kretprobes_event_enable_state(event, 0); break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through. */ default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -602,11 +602,11 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: case LTTNG_KERNEL_KRETPROBE: - case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_SYSCALL: event_name = event_param->name; break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through. */ default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -729,27 +729,6 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, list_add(&event_return->list, &chan->session->events); break; } - case LTTNG_KERNEL_FUNCTION: - /* - * Needs to be explicitly enabled after creation, since - * we may want to apply filters. - */ - event->enabled = 0; - event->registered = 1; - /* - * Populate lttng_event structure before event - * registration. - */ - smp_wmb(); - ret = lttng_ftrace_register(event_name, - event_param->u.ftrace.symbol_name, - event); - if (ret) { - goto register_error; - } - ret = try_module_get(event->desc->owner); - WARN_ON_ONCE(!ret); - break; case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_SYSCALL: /* @@ -786,6 +765,7 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, ret = try_module_get(event->desc->owner); WARN_ON_ONCE(!ret); break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ default: WARN_ON_ONCE(1); ret = -EINVAL; @@ -850,10 +830,10 @@ void register_event(struct lttng_event *event) case LTTNG_KERNEL_KPROBE: case LTTNG_KERNEL_UPROBE: case LTTNG_KERNEL_KRETPROBE: - case LTTNG_KERNEL_FUNCTION: case LTTNG_KERNEL_NOOP: ret = 0; break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ default: WARN_ON_ONCE(1); } @@ -887,10 +867,6 @@ int _lttng_event_unregister(struct lttng_event *event) lttng_kretprobes_unregister(event); ret = 0; break; - case LTTNG_KERNEL_FUNCTION: - lttng_ftrace_unregister(event); - ret = 0; - break; case LTTNG_KERNEL_SYSCALL: ret = lttng_syscall_filter_disable(event->chan, desc->name); @@ -902,6 +878,7 @@ int _lttng_event_unregister(struct lttng_event *event) lttng_uprobes_unregister(event); ret = 0; break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ default: WARN_ON_ONCE(1); } @@ -928,10 +905,6 @@ void _lttng_event_destroy(struct lttng_event *event) 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); - break; case LTTNG_KERNEL_NOOP: case LTTNG_KERNEL_SYSCALL: break; @@ -939,6 +912,7 @@ void _lttng_event_destroy(struct lttng_event *event) module_put(event->desc->owner); lttng_uprobes_destroy_private(event); break; + case LTTNG_KERNEL_FUNCTION: /* Fall-through */ default: WARN_ON_ONCE(1); } @@ -1648,7 +1622,7 @@ void lttng_session_lazy_sync_enablers(struct lttng_session *session) * was written and a negative value on error. */ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, - struct channel *chan) + struct channel *chan, bool *coherent) { struct lib_ring_buffer_ctx ctx; int ret = 0; @@ -1687,6 +1661,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, ret = stream->transport->ops.event_reserve(&ctx, 0); if (ret != 0) { printk(KERN_WARNING "LTTng: Metadata event reservation failed\n"); + stream->coherent = false; goto end; } stream->transport->ops.event_write(&ctx, @@ -1694,18 +1669,43 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, reserve_len); stream->transport->ops.event_commit(&ctx); stream->metadata_in += reserve_len; + if (reserve_len < len || stream->metadata_cache->producing != 0) + stream->coherent = false; + else + stream->coherent = true; ret = reserve_len; end: + if (coherent) + *coherent = stream->coherent; mutex_unlock(&stream->metadata_cache->lock); return ret; } +static +void lttng_metadata_begin(struct lttng_session *session) +{ + mutex_lock(&session->metadata_cache->lock); + session->metadata_cache->producing++; + mutex_unlock(&session->metadata_cache->lock); +} + +static +void lttng_metadata_end(struct lttng_session *session) +{ + mutex_lock(&session->metadata_cache->lock); + WARN_ON_ONCE(!session->metadata_cache->producing); + session->metadata_cache->producing--; + mutex_unlock(&session->metadata_cache->lock); +} + /* * Write the metadata to the metadata cache. * Must be called with sessions_mutex held. * The metadata cache lock protects us from concurrent read access from * thread outputting metadata content to ring buffer. + * The content of the printf is printed as a single atomic metadata + * transaction. */ int lttng_metadata_printf(struct lttng_session *session, const char *fmt, ...) @@ -1725,6 +1725,7 @@ int lttng_metadata_printf(struct lttng_session *session, len = strlen(str); mutex_lock(&session->metadata_cache->lock); + session->metadata_cache->producing++; if (session->metadata_cache->metadata_written + len > session->metadata_cache->cache_alloc) { char *tmp_cache_realloc; @@ -1750,6 +1751,7 @@ int lttng_metadata_printf(struct lttng_session *session, session->metadata_cache->metadata_written, str, len); session->metadata_cache->metadata_written += len; + session->metadata_cache->producing--; mutex_unlock(&session->metadata_cache->lock); kfree(str); @@ -1759,6 +1761,7 @@ int lttng_metadata_printf(struct lttng_session *session, return 0; err: + session->metadata_cache->producing--; mutex_unlock(&session->metadata_cache->lock); kfree(str); return -ENOMEM; @@ -2296,6 +2299,8 @@ int _lttng_fields_metadata_statedump(struct lttng_session *session, /* * Must be called with sessions_mutex held. + * The entire event metadata is printed as a single atomic metadata + * transaction. */ static int _lttng_event_metadata_statedump(struct lttng_session *session, @@ -2309,6 +2314,8 @@ int _lttng_event_metadata_statedump(struct lttng_session *session, if (chan->channel_type == METADATA_CHANNEL) return 0; + lttng_metadata_begin(session); + ret = lttng_metadata_printf(session, "event {\n" " name = \"%s\";\n" @@ -2358,12 +2365,15 @@ int _lttng_event_metadata_statedump(struct lttng_session *session, event->metadata_dumped = 1; end: + lttng_metadata_end(session); return ret; } /* * Must be called with sessions_mutex held. + * The entire channel metadata is printed as a single atomic metadata + * transaction. */ static int _lttng_channel_metadata_statedump(struct lttng_session *session, @@ -2377,6 +2387,8 @@ int _lttng_channel_metadata_statedump(struct lttng_session *session, if (chan->channel_type == METADATA_CHANNEL) return 0; + lttng_metadata_begin(session); + WARN_ON_ONCE(!chan->header_type); ret = lttng_metadata_printf(session, "stream {\n" @@ -2410,6 +2422,7 @@ int _lttng_channel_metadata_statedump(struct lttng_session *session, chan->metadata_dumped = 1; end: + lttng_metadata_end(session); return ret; } @@ -2597,6 +2610,9 @@ int _lttng_session_metadata_statedump(struct lttng_session *session) if (!READ_ONCE(session->active)) return 0; + + lttng_metadata_begin(session); + if (session->metadata_dumped) goto skip_session; @@ -2769,6 +2785,7 @@ skip_session: } session->metadata_dumped = 1; end: + lttng_metadata_end(session); return ret; } @@ -2779,9 +2796,9 @@ end: * Registers a transport which can be used as output to extract the data out of * LTTng. The module calling this registration function must ensure that no * trap-inducing code will be executed by the transport functions. E.g. - * vmalloc_sync_all() must be called between a vmalloc and the moment the memory + * vmalloc_sync_mappings() must be called between a vmalloc and the moment the memory * is made visible to the transport function. This registration acts as a - * vmalloc_sync_all. Therefore, only if the module allocates virtual memory + * vmalloc_sync_mappings. Therefore, only if the module allocates virtual memory * after its registration must it synchronize the TLBs. */ void lttng_transport_register(struct lttng_transport *transport) @@ -2789,9 +2806,9 @@ void lttng_transport_register(struct lttng_transport *transport) /* * Make sure no page fault can be triggered by the module about to be * registered. We deal with this here so we don't have to call - * vmalloc_sync_all() in each module's init. + * vmalloc_sync_mappings() in each module's init. */ - wrapper_vmalloc_sync_all(); + wrapper_vmalloc_sync_mappings(); mutex_lock(&sessions_mutex); list_add_tail(&transport->node, <tng_transport_list);