X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=ltt-events.c;h=03dbb2036af923e3c60841783bca3f46ac528c00;hb=80996790fa42072d6525f2adb9a910312077bef6;hp=28d17fc772af2a89566468a992a73e1b494d5765;hpb=30bdb6e41d33f7ce7b4eb51f363423c1dc9fd88e;p=lttng-modules.git diff --git a/ltt-events.c b/ltt-events.c index 28d17fc7..03dbb203 100644 --- a/ltt-events.c +++ b/ltt-events.c @@ -4,6 +4,8 @@ * Copyright 2010 (c) - Mathieu Desnoyers * * Holds LTTng per-session event registry. + * + * Dual LGPL v2.1/GPL v2 license. */ #include @@ -12,7 +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" @@ -32,8 +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(); @@ -66,6 +66,10 @@ void ltt_session_destroy(struct ltt_session *session) mutex_lock(&sessions_mutex); ACCESS_ONCE(session->active) = 0; + list_for_each_entry(chan, &session->chan, list) { + ret = lttng_syscalls_unregister(chan); + WARN_ON(ret); + } list_for_each_entry(event, &session->events, list) { ret = _ltt_event_unregister(event); WARN_ON(ret); @@ -80,7 +84,7 @@ 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; @@ -105,18 +109,16 @@ int ltt_session_start(struct ltt_session *session) } ACCESS_ONCE(session->active) = 1; - synchronize_trace(); /* Wait for in-flight events to complete */ + ACCESS_ONCE(session->been_active) = 1; 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; @@ -126,12 +128,59 @@ 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; @@ -151,31 +200,39 @@ 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->active) { - printk(KERN_WARNING "LTTng refusing to add channel to active session\n"); + if (session->been_active) goto active; /* Refuse to add channel to active session */ - } transport = ltt_transport_find(transport_name); if (!transport) { printk(KERN_WARNING "LTTng transport %s not found\n", 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; chan->session = session; - init_waitqueue_head(&chan->notify_wait); + chan->id = session->free_chan_id++; + /* + * Note: the channel creation op already writes into the packet + * headers. Therefore the "chan" information used as input + * should be already accessible. + */ chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, subbuf_size, num_subbuf, switch_timer_interval, read_timer_interval); if (!chan->chan) goto create_error; - chan->id = session->free_chan_id++; + chan->enabled = 1; chan->ops = &transport->ops; + chan->transport = transport; list_add(&chan->list, &session->chan); mutex_unlock(&sessions_mutex); return chan; @@ -183,6 +240,8 @@ 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); @@ -196,7 +255,9 @@ 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); } @@ -205,7 +266,8 @@ void _ltt_channel_destroy(struct ltt_channel *chan) */ struct ltt_event *ltt_event_create(struct ltt_channel *chan, struct lttng_kernel_event *event_param, - void *filter) + void *filter, + const struct lttng_event_desc *internal_desc) { struct ltt_event *event; int ret; @@ -226,11 +288,12 @@ 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(); switch (event_param->instrumentation) { - case LTTNG_KERNEL_TRACEPOINTS: + case LTTNG_KERNEL_TRACEPOINT: event->desc = ltt_event_get(event_param->name); if (!event->desc) goto register_error; @@ -240,7 +303,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, if (ret) goto register_error; break; - case LTTNG_KERNEL_KPROBES: + case LTTNG_KERNEL_KPROBE: ret = lttng_kprobes_register(event_param->name, event_param->u.kprobe.symbol_name, event_param->u.kprobe.offset, @@ -248,13 +311,65 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, event); if (ret) goto register_error; + ret = try_module_get(event->desc->owner); + WARN_ON_ONCE(!ret); break; - case LTTNG_KERNEL_FUNCTION_TRACER: + 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, event); 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) + goto register_error; break; default: WARN_ON_ONCE(1); @@ -267,10 +382,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, return event; statedump_error: - WARN_ON_ONCE(tracepoint_probe_unregister(event_param->name, - event->desc->probe_callback, - event)); - ltt_event_put(event->desc); + /* If a statedump error occurs, events will not be readable. */ register_error: kmem_cache_free(event_cache, event); cache_error: @@ -288,22 +400,28 @@ int _ltt_event_unregister(struct ltt_event *event) int ret = -EINVAL; switch (event->instrumentation) { - case LTTNG_KERNEL_TRACEPOINTS: + case LTTNG_KERNEL_TRACEPOINT: ret = tracepoint_probe_unregister(event->desc->name, event->desc->probe_callback, event); if (ret) return ret; - ltt_event_put(event->desc); break; - case LTTNG_KERNEL_KPROBES: + case LTTNG_KERNEL_KPROBE: lttng_kprobes_unregister(event); ret = 0; break; - case LTTNG_KERNEL_FUNCTION_TRACER: + case LTTNG_KERNEL_KRETPROBE: + lttng_kretprobes_unregister(event); + ret = 0; + break; + case LTTNG_KERNEL_FUNCTION: lttng_ftrace_unregister(event); ret = 0; break; + case LTTNG_KERNEL_NOOP: + ret = 0; + break; default: WARN_ON_ONCE(1); } @@ -316,8 +434,29 @@ int _ltt_event_unregister(struct ltt_event *event) static void _ltt_event_destroy(struct ltt_event *event) { - ltt_event_put(event->desc); + switch (event->instrumentation) { + case LTTNG_KERNEL_TRACEPOINT: + ltt_event_put(event->desc); + break; + case LTTNG_KERNEL_KPROBE: + 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); + break; + case LTTNG_KERNEL_NOOP: + break; + default: + WARN_ON_ONCE(1); + } list_del(&event->list); + lttng_destroy_context(event->ctx); kmem_cache_free(event_cache, event); } @@ -360,9 +499,9 @@ 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), + waitret = wait_event_interruptible_timeout(*chan->ops->get_writer_buf_wait_queue(chan->chan, -1), ({ - ret = chan->ops->event_reserve(&ctx); + ret = chan->ops->event_reserve(&ctx, 0); ret != -ENOBUFS || !ret; }), msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); @@ -374,7 +513,7 @@ int lttng_metadata_printf(struct ltt_session *session, ret = waitret; goto end; } - chan->ops->event_write(&ctx, &str[pos], len); + chan->ops->event_write(&ctx, &str[pos], reserve_len); chan->ops->event_commit(&ctx); } end: @@ -383,124 +522,157 @@ end: } static -int _ltt_fields_metadata_statedump(struct ltt_session *session, - struct ltt_event *event) +int _ltt_field_statedump(struct ltt_session *session, + const struct lttng_event_field *field) { - const struct lttng_event_desc *desc = event->desc; int ret = 0; - int i; - for (i = 0; i < desc->nr_fields; i++) { - const struct lttng_event_field *field = &desc->fields[i]; - - switch (field->type.atype) { - case atype_integer: - ret = lttng_metadata_printf(session, - " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", - field->type.u.basic.integer.size, - field->type.u.basic.integer.alignment, - field->type.u.basic.integer.signedness, - (field->type.u.basic.integer.encoding == lttng_encode_none) - ? "none" - : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) - ? "UTF8" - : "ASCII", - field->type.u.basic.integer.base, + switch (field->type.atype) { + case atype_integer: + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", + field->type.u.basic.integer.size, + field->type.u.basic.integer.alignment, + field->type.u.basic.integer.signedness, + (field->type.u.basic.integer.encoding == lttng_encode_none) + ? "none" + : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) + ? "UTF8" + : "ASCII", + field->type.u.basic.integer.base, #ifdef __BIG_ENDIAN - field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", + field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else - field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", + field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", #endif - field->name); - break; - case atype_enum: - ret = lttng_metadata_printf(session, - " %s %s;\n", - field->type.u.basic.enumeration.name, - field->name); - break; - case atype_array: - { - const struct lttng_basic_type *elem_type; - - elem_type = &field->type.u.array.elem_type; - ret = lttng_metadata_printf(session, - " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", - elem_type->u.basic.integer.size, - elem_type->u.basic.integer.alignment, - elem_type->u.basic.integer.signedness, - (elem_type->u.basic.integer.encoding == lttng_encode_none) - ? "none" - : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) - ? "UTF8" - : "ASCII", - elem_type->u.basic.integer.base, + field->name); + break; + case atype_enum: + ret = lttng_metadata_printf(session, + " %s _%s;\n", + field->type.u.basic.enumeration.name, + field->name); + break; + case atype_array: + { + const struct lttng_basic_type *elem_type; + + elem_type = &field->type.u.array.elem_type; + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", + elem_type->u.basic.integer.size, + elem_type->u.basic.integer.alignment, + elem_type->u.basic.integer.signedness, + (elem_type->u.basic.integer.encoding == lttng_encode_none) + ? "none" + : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) + ? "UTF8" + : "ASCII", + elem_type->u.basic.integer.base, #ifdef __BIG_ENDIAN - elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else - elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", #endif - field->name, field->type.u.array.length); - break; - } - case atype_sequence: - { - const struct lttng_basic_type *elem_type; - const struct lttng_basic_type *length_type; - - elem_type = &field->type.u.sequence.elem_type; - length_type = &field->type.u.sequence.length_type; - ret = lttng_metadata_printf(session, - " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", - " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", - length_type->u.basic.integer.size, - length_type->u.basic.integer.alignment, - length_type->u.basic.integer.signedness, - (length_type->u.basic.integer.encoding == lttng_encode_none) - ? "none" - : (length_type->u.basic.integer.encoding == lttng_encode_UTF8) - ? "UTF8" - : "ASCII", - length_type->u.basic.integer.base, + field->name, field->type.u.array.length); + break; + } + case atype_sequence: + { + const struct lttng_basic_type *elem_type; + const struct lttng_basic_type *length_type; + + elem_type = &field->type.u.sequence.elem_type; + length_type = &field->type.u.sequence.length_type; + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", + length_type->u.basic.integer.size, + (unsigned int) length_type->u.basic.integer.alignment, + length_type->u.basic.integer.signedness, + (length_type->u.basic.integer.encoding == lttng_encode_none) + ? "none" + : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) + ? "UTF8" + : "ASCII"), + length_type->u.basic.integer.base, #ifdef __BIG_ENDIAN - length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", + length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else - length_type->u.basic.integer.reverse_byte_order -? " byte_order = be;" : "", + length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", #endif - field->name, - elem_type->u.basic.integer.size, - elem_type->u.basic.integer.alignment, - elem_type->u.basic.integer.signedness, - (elem_type->u.basic.integer.encoding == lttng_encode_none) - ? "none" - : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) - ? "UTF8" - : "ASCII", - elem_type->u.basic.integer.base, + field->name); + if (ret) + return ret; + + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", + elem_type->u.basic.integer.size, + (unsigned int) elem_type->u.basic.integer.alignment, + elem_type->u.basic.integer.signedness, + (elem_type->u.basic.integer.encoding == lttng_encode_none) + ? "none" + : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) + ? "UTF8" + : "ASCII"), + elem_type->u.basic.integer.base, #ifdef __BIG_ENDIAN - elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", #else - elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", #endif - field->name, - field->name - ); - break; - } + field->name, + field->name); + break; + } - case atype_string: - /* Default encoding is UTF8 */ - ret = lttng_metadata_printf(session, - " string%s %s;\n", - field->type.u.basic.string.encoding == lttng_encode_ASCII ? - " { encoding = ASCII; }" : "", - field->name); - break; - default: - WARN_ON_ONCE(1); - return -EINVAL; - } + case atype_string: + /* Default encoding is UTF8 */ + ret = lttng_metadata_printf(session, + " string%s _%s;\n", + field->type.u.basic.string.encoding == lttng_encode_ASCII ? + " { encoding = ASCII; }" : "", + field->name); + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + return ret; +} + +static +int _ltt_context_metadata_statedump(struct ltt_session *session, + struct lttng_ctx *ctx) +{ + int ret = 0; + int i; + + if (!ctx) + return 0; + for (i = 0; i < ctx->nr_fields; i++) { + const struct lttng_ctx_field *field = &ctx->fields[i]; + + ret = _ltt_field_statedump(session, &field->event_field); + if (ret) + return ret; + } + return ret; +} + +static +int _ltt_fields_metadata_statedump(struct ltt_session *session, + struct ltt_event *event) +{ + const struct lttng_event_desc *desc = event->desc; + int ret = 0; + int i; + + for (i = 0; i < desc->nr_fields; i++) { + const struct lttng_event_field *field = &desc->fields[i]; + + ret = _ltt_field_statedump(session, field); + if (ret) + return ret; } return ret; } @@ -521,14 +693,35 @@ int _ltt_event_metadata_statedump(struct ltt_session *session, "event {\n" " name = %s;\n" " id = %u;\n" - " stream_id = %u;\n" - " event.fields := struct {\n", + " stream_id = %u;\n", event->desc->name, event->id, event->chan->id); if (ret) goto end; + if (event->ctx) { + ret = lttng_metadata_printf(session, + " context := struct {\n"); + if (ret) + goto end; + } + ret = _ltt_context_metadata_statedump(session, event->ctx); + if (ret) + goto end; + if (event->ctx) { + ret = lttng_metadata_printf(session, + " };\n"); + if (ret) + goto end; + } + + ret = lttng_metadata_printf(session, + " fields := struct {\n" + ); + if (ret) + goto end; + ret = _ltt_fields_metadata_statedump(session, event); if (ret) goto end; @@ -565,14 +758,32 @@ int _ltt_channel_metadata_statedump(struct ltt_session *session, "stream {\n" " id = %u;\n" " event.header := %s;\n" - " packet.context := struct packet_context;\n" - "};\n\n", + " packet.context := struct packet_context;\n", chan->id, chan->header_type == 1 ? "struct event_header_compact" : "struct event_header_large"); if (ret) goto end; + if (chan->ctx) { + ret = lttng_metadata_printf(session, + " event.context := struct {\n"); + if (ret) + goto end; + } + ret = _ltt_context_metadata_statedump(session, chan->ctx); + if (ret) + goto end; + if (chan->ctx) { + ret = lttng_metadata_printf(session, + " };\n"); + if (ret) + goto end; + } + + ret = lttng_metadata_printf(session, + "};\n\n"); + chan->metadata_dumped = 1; end: return ret; @@ -715,7 +926,7 @@ skip_session: } list_for_each_entry(event, &session->events, list) { - ret = _ltt_event_metadata_statedump(session, chan, event); + ret = _ltt_event_metadata_statedump(session, event->chan, event); if (ret) goto end; } @@ -770,7 +981,7 @@ static int __init ltt_events_init(void) event_cache = KMEM_CACHE(ltt_event, 0); if (!event_cache) return -ENOMEM; - ret = ltt_debugfs_abi_init(); + ret = lttng_abi_init(); if (ret) goto error_abi; return 0; @@ -785,7 +996,7 @@ static void __exit ltt_events_exit(void) { struct ltt_session *session, *tmpsession; - ltt_debugfs_abi_exit(); + lttng_abi_exit(); list_for_each_entry_safe(session, tmpsession, &sessions, list) ltt_session_destroy(session); kmem_cache_destroy(event_cache);