diff options
Diffstat (limited to 'kernel/trace/trace_dynevent.c')
| -rw-r--r-- | kernel/trace/trace_dynevent.c | 98 |
1 files changed, 71 insertions, 27 deletions
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 9f2e8520b748..154996684fb5 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -13,11 +13,49 @@ #include <linux/tracefs.h> #include "trace.h" +#include "trace_output.h" /* for trace_event_sem */ #include "trace_dynevent.h" static DEFINE_MUTEX(dyn_event_ops_mutex); static LIST_HEAD(dyn_event_ops_list); +bool trace_event_dyn_try_get_ref(struct trace_event_call *dyn_call) +{ + struct trace_event_call *call; + bool ret = false; + + if (WARN_ON_ONCE(!(dyn_call->flags & TRACE_EVENT_FL_DYNAMIC))) + return false; + + down_read(&trace_event_sem); + list_for_each_entry(call, &ftrace_events, list) { + if (call == dyn_call) { + atomic_inc(&dyn_call->refcnt); + ret = true; + } + } + up_read(&trace_event_sem); + return ret; +} + +void trace_event_dyn_put_ref(struct trace_event_call *call) +{ + if (WARN_ON_ONCE(!(call->flags & TRACE_EVENT_FL_DYNAMIC))) + return; + + if (WARN_ON_ONCE(atomic_read(&call->refcnt) <= 0)) { + atomic_set(&call->refcnt, 0); + return; + } + + atomic_dec(&call->refcnt); +} + +bool trace_event_dyn_busy(struct trace_event_call *call) +{ + return atomic_read(&call->refcnt) != 0; +} + int dyn_event_register(struct dyn_event_operations *ops) { if (!ops || !ops->create || !ops->show || !ops->is_busy || @@ -31,23 +69,31 @@ int dyn_event_register(struct dyn_event_operations *ops) return 0; } -int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type) +int dyn_event_release(const char *raw_command, struct dyn_event_operations *type) { struct dyn_event *pos, *n; char *system = NULL, *event, *p; - int ret = -ENOENT; + int argc, ret = -ENOENT; + char **argv; + + argv = argv_split(GFP_KERNEL, raw_command, &argc); + if (!argv) + return -ENOMEM; if (argv[0][0] == '-') { - if (argv[0][1] != ':') - return -EINVAL; + if (argv[0][1] != ':') { + ret = -EINVAL; + goto out; + } event = &argv[0][2]; } else { event = strchr(argv[0], ':'); - if (!event) - return -EINVAL; + if (!event) { + ret = -EINVAL; + goto out; + } event++; } - argc--; argv++; p = strchr(event, '/'); if (p) { @@ -55,15 +101,17 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type) event = p + 1; *p = '\0'; } - if (event[0] == '\0') - return -EINVAL; + if (!system && event[0] == '\0') { + ret = -EINVAL; + goto out; + } mutex_lock(&event_mutex); for_each_dyn_event_safe(pos, n) { if (type && type != pos->ops) continue; if (!pos->ops->match(system, event, - argc, (const char **)argv, pos)) + argc - 1, (const char **)argv + 1, pos)) continue; ret = pos->ops->free(pos); @@ -71,21 +119,22 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type) break; } mutex_unlock(&event_mutex); - +out: + argv_free(argv); return ret; } -static int create_dyn_event(int argc, char **argv) +static int create_dyn_event(const char *raw_command) { struct dyn_event_operations *ops; int ret = -ENODEV; - if (argv[0][0] == '-' || argv[0][0] == '!') - return dyn_event_release(argc, argv, NULL); + if (raw_command[0] == '-' || raw_command[0] == '!') + return dyn_event_release(raw_command, NULL); mutex_lock(&dyn_event_ops_mutex); list_for_each_entry(ops, &dyn_event_ops_list, list) { - ret = ops->create(argc, (const char **)argv); + ret = ops->create(raw_command); if (!ret || ret != -ECANCELED) break; } @@ -206,19 +255,14 @@ static const struct file_operations dynamic_events_ops = { /* Make a tracefs interface for controlling dynamic events */ static __init int init_dynamic_event(void) { - struct dentry *d_tracer; - struct dentry *entry; + int ret; - d_tracer = tracing_init_dentry(); - if (IS_ERR(d_tracer)) + ret = tracing_init_dentry(); + if (ret) return 0; - entry = tracefs_create_file("dynamic_events", 0644, d_tracer, - NULL, &dynamic_events_ops); - - /* Event list interface */ - if (!entry) - pr_warn("Could not create tracefs 'dynamic_events' entry\n"); + trace_create_file("dynamic_events", TRACE_MODE_WRITE, NULL, + NULL, &dynamic_events_ops); return 0; } @@ -276,7 +320,7 @@ int dynevent_arg_add(struct dynevent_cmd *cmd, * arguments of the form 'type variable_name;' or 'x+y'. * * The lhs argument string will be appended to the current cmd string, - * followed by an operator, if applicable, followd by the rhs string, + * followed by an operator, if applicable, followed by the rhs string, * followed finally by a separator, if applicable. Before the * argument is added, the @check_arg function, if present, will be * used to check the sanity of the current arg strings. @@ -402,7 +446,7 @@ void dynevent_arg_init(struct dynevent_arg *arg, * whitespace, all followed by a separator, if applicable. After the * first arg string is successfully appended to the command string, * the optional @operator is appended, followed by the second arg and - * and optional @separator. If no separator was specified when + * optional @separator. If no separator was specified when * initializing the arg, a space will be appended. */ void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair, |