X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-events.c;h=d7efd425e88c9b2ed109ee11d12fbf919f67eba3;hb=7e6f9ef6f2e62dfe359b94562cd98197367ddbac;hp=879097b4a8c7af056c0f0ec57dbef4d9376e7c57;hpb=3b731ab1a88c60e0a3a8eeddd225f751e821b1f3;p=lttng-modules.git diff --git a/lttng-events.c b/lttng-events.c index 879097b4..d7efd425 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -27,10 +27,16 @@ #include #include #include +#include +#include +#include +#include +#include "wrapper/file.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" @@ -60,9 +66,15 @@ void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream); 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) @@ -90,6 +102,8 @@ 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; @@ -137,6 +151,8 @@ void lttng_session_destroy(struct lttng_session *session) } list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list) _lttng_metadata_channel_hangup(metadata_stream); + if (session->pid_tracker) + lttng_pid_tracker_destroy(session->pid_tracker); kref_put(&session->metadata_cache->refcount, metadata_cache_destroy); list_del(&session->list); mutex_unlock(&sessions_mutex); @@ -359,18 +375,31 @@ struct lttng_event *lttng_event_create(struct lttng_channel *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)) - goto exist; + list_for_each_entry(event, &chan->session->events, list) { + if (!strcmp(event->desc->name, event_param->name)) { + /* + * 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) + if (!event) { + ret = -ENOMEM; goto cache_error; + } event->chan = chan; event->filter = filter; event->id = chan->free_event_id++; @@ -381,13 +410,17 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, 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 = lttng_wrapper_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, @@ -395,8 +428,10 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, 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; @@ -407,8 +442,10 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, /* 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++; @@ -425,6 +462,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, 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. */ @@ -434,6 +472,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, 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); @@ -447,22 +486,29 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan, 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; @@ -475,7 +521,7 @@ cache_error: exist: full: mutex_unlock(&sessions_mutex); - return NULL; + return ERR_PTR(ret); } /* @@ -487,7 +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) @@ -546,6 +592,235 @@ void _lttng_event_destroy(struct lttng_event *event) kmem_cache_free(event_cache, event); } +int lttng_session_track_pid(struct lttng_session *session, int pid) +{ + int ret; + + if (pid < -1) + return -EINVAL; + mutex_lock(&sessions_mutex); + if (pid == -1) { + /* track all pids: destroy tracker. */ + if (session->pid_tracker) { + struct lttng_pid_tracker *lpf; + + lpf = session->pid_tracker; + rcu_assign_pointer(session->pid_tracker, NULL); + synchronize_trace(); + lttng_pid_tracker_destroy(lpf); + } + ret = 0; + } else { + if (!session->pid_tracker) { + struct lttng_pid_tracker *lpf; + + lpf = lttng_pid_tracker_create(); + if (!lpf) { + ret = -ENOMEM; + goto unlock; + } + ret = lttng_pid_tracker_add(lpf, pid); + rcu_assign_pointer(session->pid_tracker, lpf); + } else { + ret = lttng_pid_tracker_add(session->pid_tracker, pid); + } + } +unlock: + mutex_unlock(&sessions_mutex); + return ret; +} + +int lttng_session_untrack_pid(struct lttng_session *session, int pid) +{ + int ret; + + if (pid < -1) + return -EINVAL; + mutex_lock(&sessions_mutex); + if (pid == -1) { + /* untrack all pids: replace by empty tracker. */ + struct lttng_pid_tracker *old_lpf = session->pid_tracker; + struct lttng_pid_tracker *lpf; + + lpf = lttng_pid_tracker_create(); + if (!lpf) { + ret = -ENOMEM; + goto unlock; + } + rcu_assign_pointer(session->pid_tracker, lpf); + synchronize_trace(); + if (old_lpf) + lttng_pid_tracker_destroy(old_lpf); + ret = 0; + } else { + if (!session->pid_tracker) { + ret = -ENOENT; + goto unlock; + } + ret = lttng_pid_tracker_del(session->pid_tracker, pid); + } +unlock: + mutex_unlock(&sessions_mutex); + return ret; +} + +static +void *pid_list_start(struct seq_file *m, loff_t *pos) +{ + struct lttng_session *session = m->private; + struct lttng_pid_tracker *lpf; + struct lttng_pid_hash_node *e; + int iter = 0, i; + + mutex_lock(&sessions_mutex); + lpf = session->pid_tracker; + if (lpf) { + for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) { + struct hlist_head *head = &lpf->pid_hash[i]; + + hlist_for_each_entry(e, head, hlist) { + if (iter++ >= *pos) + return e; + } + } + } else { + /* PID tracker disabled. */ + if (iter >= *pos && iter == 0) { + return session; /* empty tracker */ + } + iter++; + } + /* End of list */ + return NULL; +} + +/* Called with sessions_mutex held. */ +static +void *pid_list_next(struct seq_file *m, void *p, loff_t *ppos) +{ + struct lttng_session *session = m->private; + struct lttng_pid_tracker *lpf; + struct lttng_pid_hash_node *e; + int iter = 0, i; + + (*ppos)++; + lpf = session->pid_tracker; + if (lpf) { + for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) { + struct hlist_head *head = &lpf->pid_hash[i]; + + hlist_for_each_entry(e, head, hlist) { + if (iter++ >= *ppos) + return e; + } + } + } else { + /* PID tracker disabled. */ + if (iter >= *ppos && iter == 0) + return session; /* empty tracker */ + iter++; + } + + /* End of list */ + return NULL; +} + +static +void pid_list_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&sessions_mutex); +} + +static +int pid_list_show(struct seq_file *m, void *p) +{ + int pid; + + if (p == m->private) { + /* Tracker disabled. */ + pid = -1; + } else { + const struct lttng_pid_hash_node *e = p; + + pid = lttng_pid_tracker_get_node_pid(e); + } + seq_printf(m, "process { pid = %d; };\n", pid); + return 0; +} + +static +const struct seq_operations lttng_tracker_pids_list_seq_ops = { + .start = pid_list_start, + .next = pid_list_next, + .stop = pid_list_stop, + .show = pid_list_show, +}; + +static +int lttng_tracker_pids_list_open(struct inode *inode, struct file *file) +{ + return seq_open(file, <tng_tracker_pids_list_seq_ops); +} + +static +int lttng_tracker_pids_list_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct lttng_session *session = m->private; + int ret; + + WARN_ON_ONCE(!session); + ret = seq_release(inode, file); + if (!ret && session) + fput(session->file); + return ret; +} + +const struct file_operations lttng_tracker_pids_list_fops = { + .owner = THIS_MODULE, + .open = lttng_tracker_pids_list_open, + .read = seq_read, + .llseek = seq_lseek, + .release = lttng_tracker_pids_list_release, +}; + +int lttng_session_list_tracker_pids(struct lttng_session *session) +{ + struct file *tracker_pids_list_file; + struct seq_file *m; + int file_fd, ret; + + file_fd = lttng_get_unused_fd(); + if (file_fd < 0) { + ret = file_fd; + goto fd_error; + } + + tracker_pids_list_file = anon_inode_getfile("[lttng_tracker_pids_list]", + <tng_tracker_pids_list_fops, + NULL, O_RDWR); + if (IS_ERR(tracker_pids_list_file)) { + ret = PTR_ERR(tracker_pids_list_file); + goto file_error; + } + ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file); + if (ret < 0) + goto open_error; + m = tracker_pids_list_file->private_data; + m->private = session; + fd_install(file_fd, tracker_pids_list_file); + atomic_long_inc(&session->file->f_count); + + return file_fd; + +open_error: + fput(tracker_pids_list_file); +file_error: + put_unused_fd(file_fd); +fd_error: + return ret; +} + /* * Serialize at most one packet worth of metadata into a metadata * channel. @@ -553,6 +828,8 @@ void _lttng_event_destroy(struct lttng_event *event) * 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_metadata_stream *stream, struct channel *chan) @@ -563,16 +840,20 @@ 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); @@ -594,6 +875,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, ret = reserve_len; end: + mutex_unlock(&stream->lock); return ret; } @@ -825,7 +1107,7 @@ int _lttng_event_metadata_statedump(struct lttng_session *session, ret = lttng_metadata_printf(session, "event {\n" - " name = %s;\n" + " name = \"%s\";\n" " id = %u;\n" " stream_id = %u;\n", event->desc->name, @@ -1221,15 +1503,32 @@ static int __init lttng_events_init(void) { int ret; + ret = wrapper_lttng_fixup_sig(THIS_MODULE); + 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; } @@ -1239,10 +1538,12 @@ 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); @@ -1250,3 +1551,7 @@ module_exit(lttng_events_exit); MODULE_LICENSE("GPL and additional rights"); 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) + LTTNG_MODULES_EXTRAVERSION);