diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_events.c | 137 | ||||
| -rw-r--r-- | kernel/trace/trace_events.h | 7 |
2 files changed, 137 insertions, 7 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 05bc80ec8d2c..3bcb9df93342 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -12,6 +12,11 @@ #include "trace_events.h" +#define events_for_each(event) \ + for (event = __start_ftrace_events; \ + (unsigned long)event < (unsigned long)__stop_ftrace_events; \ + event++) + void event_trace_printk(unsigned long ip, const char *fmt, ...) { va_list ap; @@ -39,15 +44,16 @@ static void ftrace_clear_events(void) static int ftrace_set_clr_event(char *buf, int set) { - struct ftrace_event_call *call = (void *)__start_ftrace_events; + struct ftrace_event_call *call = __start_ftrace_events; - while ((unsigned long)call < (unsigned long)__stop_ftrace_events) { + events_for_each(call) { - if (strcmp(buf, call->name) != 0) { - call++; + if (!call->name) + continue; + + if (strcmp(buf, call->name) != 0) continue; - } if (set) { /* Already set? */ @@ -223,6 +229,67 @@ ftrace_event_seq_open(struct inode *inode, struct file *file) return ret; } +static ssize_t +event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct ftrace_event_call *call = filp->private_data; + char *buf; + + if (call->enabled) + buf = "1\n"; + else + buf = "0\n"; + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); +} + +static ssize_t +event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + struct ftrace_event_call *call = filp->private_data; + char buf[64]; + unsigned long val; + int 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; + + switch (val) { + case 0: + if (!call->enabled) + break; + + call->enabled = 0; + call->unregfunc(); + break; + case 1: + if (call->enabled) + break; + + call->enabled = 1; + call->regfunc(); + break; + + default: + return -EINVAL; + } + + *ppos += cnt; + + return cnt; +} + static const struct seq_operations show_event_seq_ops = { .start = t_start, .next = t_next, @@ -252,10 +319,59 @@ static const struct file_operations ftrace_set_event_fops = { .release = seq_release, }; +static const struct file_operations ftrace_enable_fops = { + .open = tracing_open_generic, + .read = event_enable_read, + .write = event_enable_write, +}; + +static struct dentry *event_trace_events_dir(void) +{ + static struct dentry *d_tracer; + static struct dentry *d_events; + + if (d_events) + return d_events; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return NULL; + + d_events = debugfs_create_dir("events", d_tracer); + if (!d_events) + pr_warning("Could not create debugfs " + "'events' directory\n"); + + return d_events; +} + +static int +event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) +{ + struct dentry *entry; + + call->dir = debugfs_create_dir(call->name, d_events); + if (!call->dir) { + pr_warning("Could not create debugfs " + "'%s' directory\n", call->name); + return -1; + } + + entry = debugfs_create_file("enable", 0644, call->dir, call, + &ftrace_enable_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'%s/enable' entry\n", call->name); + + return 0; +} + static __init int event_trace_init(void) { + struct ftrace_event_call *call = __start_ftrace_events; struct dentry *d_tracer; struct dentry *entry; + struct dentry *d_events; d_tracer = tracing_init_dentry(); if (!d_tracer) @@ -275,6 +391,17 @@ static __init int event_trace_init(void) pr_warning("Could not create debugfs " "'set_event' entry\n"); + d_events = event_trace_events_dir(); + if (!d_events) + return 0; + + events_for_each(call) { + /* The linker may leave blanks */ + if (!call->name) + continue; + event_create_dir(call, d_events); + } + return 0; } fs_initcall(event_trace_init); diff --git a/kernel/trace/trace_events.h b/kernel/trace/trace_events.h index 39342f86db27..cb8455b3ac9a 100644 --- a/kernel/trace/trace_events.h +++ b/kernel/trace/trace_events.h @@ -1,11 +1,13 @@ #ifndef _LINUX_KERNEL_TRACE_EVENTS_H #define _LINUX_KERNEL_TRACE_EVENTS_H +#include <linux/debugfs.h> #include <linux/ftrace.h> #include "trace.h" struct ftrace_event_call { char *name; + struct dentry *dir; int enabled; int (*regfunc)(void); void (*unregfunc)(void); @@ -39,6 +41,7 @@ static void ftrace_unreg_event_##call(void) \ } \ \ static struct ftrace_event_call __used \ +__attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_events"))) event_##call = { \ .name = #call, \ .regfunc = ftrace_reg_event_##call, \ @@ -46,7 +49,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ } void event_trace_printk(unsigned long ip, const char *fmt, ...); -extern unsigned long __start_ftrace_events[]; -extern unsigned long __stop_ftrace_events[]; +extern struct ftrace_event_call __start_ftrace_events[]; +extern struct ftrace_event_call __stop_ftrace_events[]; #endif /* _LINUX_KERNEL_TRACE_EVENTS_H */ |