X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=lttng-events.c;h=7055c3ed05af5f812edf319d8d7323a93b4a3c84;hb=f934e302d314d76563484f31caed56ad680eb17b;hp=135c8c527123acd43266c7191148d9bc314121a8;hpb=f046a95d1c0f66297332962fb5fd1b715367b69d;p=lttng-modules.git diff --git a/lttng-events.c b/lttng-events.c index 135c8c52..7055c3ed 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -21,17 +21,21 @@ */ #include -#include #include #include #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 "wrapper/list.h" #include "lttng-kernel-version.h" #include "lttng-events.h" #include "lttng-tracer.h" @@ -147,6 +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); @@ -586,6 +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]; + + lttng_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]; + + lttng_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.