diff options
| -rw-r--r-- | kernel/trace/trace_events.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 6d2c842a0248..87feb0117ce2 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -400,6 +400,133 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, return cnt; } +static ssize_t +system_enable_read(struct file *filp, char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + const char *system = filp->private_data; + struct ftrace_event_call *call; + char buf[2]; + int set = -1; + int all = 0; + int ret; + + if (system[0] == '*') + all = 1; + + mutex_lock(&event_mutex); + list_for_each_entry(call, &ftrace_events, list) { + if (!call->name || !call->regfunc) + continue; + + if (!all && strcmp(call->system, system) != 0) + continue; + + /* + * We need to find out if all the events are set + * or if all events or cleared, or if we have + * a mixture. + */ + if (call->enabled) { + switch (set) { + case -1: + set = 1; + break; + case 0: + set = 2; + break; + } + } else { + switch (set) { + case -1: + set = 0; + break; + case 1: + set = 2; + break; + } + } + /* + * If we have a mixture, no need to look further. + */ + if (set == 2) + break; + } + mutex_unlock(&event_mutex); + + buf[1] = '\n'; + switch (set) { + case 0: + buf[0] = '0'; + break; + case 1: + buf[0] = '1'; + break; + case 2: + buf[0] = 'X'; + break; + default: + buf[0] = '?'; + } + + ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); + + return ret; +} + +static ssize_t +system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + const char *system = filp->private_data; + unsigned long val; + char *command; + char buf[64]; + ssize_t ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + ret = tracing_update_buffers(); + if (ret < 0) + return ret; + + switch (val) { + case 0: + case 1: + break; + + default: + return -EINVAL; + } + + command = kstrdup(system, GFP_KERNEL); + if (!command) + return -ENOMEM; + + ret = ftrace_set_clr_event(command, val); + if (ret) + goto out_free; + + ret = cnt; + + out_free: + kfree(command); + + *ppos += cnt; + + return ret; +} + extern char *__bad_type_size(void); #undef FIELD @@ -686,6 +813,12 @@ static const struct file_operations ftrace_subsystem_filter_fops = { .write = subsystem_filter_write, }; +static const struct file_operations ftrace_system_enable_fops = { + .open = tracing_open_generic, + .read = system_enable_read, + .write = system_enable_write, +}; + static const struct file_operations ftrace_show_header_fops = { .open = tracing_open_generic, .read = show_header, @@ -768,6 +901,10 @@ event_subsystem_dir(const char *name, struct dentry *d_events) "'%s/filter' entry\n", name); } + entry = trace_create_file("enable", 0644, system->entry, + (void *)system->name, + &ftrace_system_enable_fops); + return system->entry; } @@ -1041,6 +1178,9 @@ static __init int event_trace_init(void) ring_buffer_print_entry_header, &ftrace_show_header_fops); + trace_create_file("enable", 0644, d_events, + "*:*", &ftrace_system_enable_fops); + for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { /* The linker may leave blanks */ if (!call->name) |