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Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c107
1 files changed, 90 insertions, 17 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f29e815ca5b2..7c364b87352e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1893,9 +1893,9 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
}
static ssize_t
-show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+show_header_page_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
{
- int (*func)(struct trace_seq *s) = filp->private_data;
+ struct trace_array *tr = filp->private_data;
struct trace_seq *s;
int r;
@@ -1908,7 +1908,31 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
trace_seq_init(s);
- func(s);
+ ring_buffer_print_page_header(tr->array_buffer.buffer, s);
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ s->buffer, trace_seq_used(s));
+
+ kfree(s);
+
+ return r;
+}
+
+static ssize_t
+show_header_event_file(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct trace_seq *s;
+ int r;
+
+ if (*ppos)
+ return 0;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ ring_buffer_print_entry_header(s);
r = simple_read_from_buffer(ubuf, cnt, ppos,
s->buffer, trace_seq_used(s));
@@ -2165,10 +2189,18 @@ static const struct file_operations ftrace_tr_enable_fops = {
.release = subsystem_release,
};
-static const struct file_operations ftrace_show_header_fops = {
- .open = tracing_open_generic,
- .read = show_header,
+static const struct file_operations ftrace_show_header_page_fops = {
+ .open = tracing_open_generic_tr,
+ .read = show_header_page_file,
+ .llseek = default_llseek,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations ftrace_show_header_event_fops = {
+ .open = tracing_open_generic_tr,
+ .read = show_header_event_file,
.llseek = default_llseek,
+ .release = tracing_release_generic_tr,
};
static int
@@ -2896,6 +2928,27 @@ void trace_event_eval_update(struct trace_eval_map **map, int len)
up_write(&trace_event_sem);
}
+static bool event_in_systems(struct trace_event_call *call,
+ const char *systems)
+{
+ const char *system;
+ const char *p;
+
+ if (!systems)
+ return true;
+
+ system = call->class->system;
+ p = strstr(systems, system);
+ if (!p)
+ return false;
+
+ if (p != systems && !isspace(*(p - 1)) && *(p - 1) != ',')
+ return false;
+
+ p += strlen(system);
+ return !*p || isspace(*p) || *p == ',';
+}
+
static struct trace_event_file *
trace_create_new_event(struct trace_event_call *call,
struct trace_array *tr)
@@ -2905,9 +2958,12 @@ trace_create_new_event(struct trace_event_call *call,
struct trace_event_file *file;
unsigned int first;
+ if (!event_in_systems(call, tr->system_names))
+ return NULL;
+
file = kmem_cache_alloc(file_cachep, GFP_TRACE);
if (!file)
- return NULL;
+ return ERR_PTR(-ENOMEM);
pid_list = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
@@ -2972,8 +3028,17 @@ __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
struct trace_event_file *file;
file = trace_create_new_event(call, tr);
+ /*
+ * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
+ * allocation, or NULL if the event is not part of the tr->system_names.
+ * When the event is not part of the tr->system_names, return zero, not
+ * an error.
+ */
if (!file)
- return -ENOMEM;
+ return 0;
+
+ if (IS_ERR(file))
+ return PTR_ERR(file);
if (eventdir_initialized)
return event_create_dir(tr->event_dir, file);
@@ -3012,8 +3077,17 @@ __trace_early_add_new_event(struct trace_event_call *call,
int ret;
file = trace_create_new_event(call, tr);
+ /*
+ * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed
+ * allocation, or NULL if the event is not part of the tr->system_names.
+ * When the event is not part of the tr->system_names, return zero, not
+ * an error.
+ */
if (!file)
- return -ENOMEM;
+ return 0;
+
+ if (IS_ERR(file))
+ return PTR_ERR(file);
ret = event_define_fields(call);
if (ret)
@@ -3752,17 +3826,16 @@ static int events_callback(const char *name, umode_t *mode, void **data,
return 1;
}
- if (strcmp(name, "header_page") == 0)
- *data = ring_buffer_print_page_header;
-
- else if (strcmp(name, "header_event") == 0)
- *data = ring_buffer_print_entry_header;
+ if (strcmp(name, "header_page") == 0) {
+ *mode = TRACE_MODE_READ;
+ *fops = &ftrace_show_header_page_fops;
- else
+ } else if (strcmp(name, "header_event") == 0) {
+ *mode = TRACE_MODE_READ;
+ *fops = &ftrace_show_header_event_fops;
+ } else
return 0;
- *mode = TRACE_MODE_READ;
- *fops = &ftrace_show_header_fops;
return 1;
}