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tracing: Consolidate trace() functions

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Move the checking, buffer reserve and buffer commit code in
synth_event_trace_start/end() into inline functions
__synth_event_trace_start/end() so they can also be used by
synth_event_trace() and synth_event_trace_array(), and then have all
those functions use them.

Also, change synth_event_trace_state.enabled to disabled so it only
needs to be set if the event is disabled, which is not normally the
case.

Link: http://lkml.kernel.org/r/b1f3108d0f450e58192955a300e31d0405ab4149.1581374549.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Tom Zanussi 2020-02-10 17:06:50 -06:00 committed by Steven Rostedt (VMware)
parent 0c62f6cd9e
commit 7276531d40
2 changed files with 87 additions and 135 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/trace_events.h
View File

@ -424,7 +424,7 @@ struct synth_event_trace_state {
struct synth_event *event; struct synth_event *event;
unsigned int cur_field; unsigned int cur_field;
unsigned int n_u64; unsigned int n_u64;
bool enabled; bool disabled;
bool add_next; bool add_next;
bool add_name; bool add_name;
}; };

220
kernel/trace/trace_events_hist.c
View File

@ -1791,6 +1791,60 @@ void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
} }
EXPORT_SYMBOL_GPL(synth_event_cmd_init); EXPORT_SYMBOL_GPL(synth_event_cmd_init);
static inline int
__synth_event_trace_start(struct trace_event_file *file,
struct synth_event_trace_state *trace_state)
{
int entry_size, fields_size = 0;
int ret = 0;
/*
* Normal event tracing doesn't get called at all unless the
* ENABLED bit is set (which attaches the probe thus allowing
* this code to be called, etc). Because this is called
* directly by the user, we don't have that but we still need
* to honor not logging when disabled. For the the iterated
* trace case, we save the enabed state upon start and just
* ignore the following data calls.
*/
if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
trace_trigger_soft_disabled(file)) {
trace_state->disabled = true;
ret = -ENOENT;
goto out;
}
trace_state->event = file->event_call->data;
fields_size = trace_state->event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
trace_state->buffer = file->tr->array_buffer.buffer;
ring_buffer_nest_start(trace_state->buffer);
entry_size = sizeof(*trace_state->entry) + fields_size;
trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
file,
entry_size);
if (!trace_state->entry) {
ring_buffer_nest_end(trace_state->buffer);
ret = -EINVAL;
}
out:
return ret;
}
static inline void
__synth_event_trace_end(struct synth_event_trace_state *trace_state)
{
trace_event_buffer_commit(&trace_state->fbuffer);
ring_buffer_nest_end(trace_state->buffer);
}
/** /**
* synth_event_trace - Trace a synthetic event * synth_event_trace - Trace a synthetic event
* @file: The trace_event_file representing the synthetic event * @file: The trace_event_file representing the synthetic event
@ -1812,69 +1866,38 @@ EXPORT_SYMBOL_GPL(synth_event_cmd_init);
*/ */
int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...) int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
{ {
struct trace_event_buffer fbuffer; struct synth_event_trace_state state;
struct synth_trace_event *entry;
struct trace_buffer *buffer;
struct synth_event *event;
unsigned int i, n_u64; unsigned int i, n_u64;
int fields_size = 0;
va_list args; va_list args;
int ret = 0; int ret;
/* ret = __synth_event_trace_start(file, &state);
* Normal event generation doesn't get called at all unless if (ret) {
* the ENABLED bit is set (which attaches the probe thus if (ret == -ENOENT)
* allowing this code to be called, etc). Because this is ret = 0; /* just disabled, not really an error */
* called directly by the user, we don't have that but we return ret;
* still need to honor not logging when disabled.
*/
if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
trace_trigger_soft_disabled(file))
return 0;
event = file->event_call->data;
if (n_vals != event->n_fields)
return -EINVAL;
fields_size = event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
buffer = file->tr->array_buffer.buffer;
ring_buffer_nest_start(buffer);
entry = trace_event_buffer_reserve(&fbuffer, file,
sizeof(*entry) + fields_size);
if (!entry) {
ret = -EINVAL;
goto out;
} }
va_start(args, n_vals); va_start(args, n_vals);
for (i = 0, n_u64 = 0; i < event->n_fields; i++) { for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
u64 val; u64 val;
val = va_arg(args, u64); val = va_arg(args, u64);
if (event->fields[i]->is_string) { if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)val; char *str_val = (char *)(long)val;
char *str_field = (char *)&entry->fields[n_u64]; char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX); strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64); n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else { } else {
entry->fields[n_u64] = val; state.entry->fields[n_u64] = val;
n_u64++; n_u64++;
} }
} }
va_end(args); va_end(args);
trace_event_buffer_commit(&fbuffer); __synth_event_trace_end(&state);
out:
ring_buffer_nest_end(buffer);
return ret; return ret;
} }
@ -1901,62 +1924,31 @@ EXPORT_SYMBOL_GPL(synth_event_trace);
int synth_event_trace_array(struct trace_event_file *file, u64 *vals, int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
unsigned int n_vals) unsigned int n_vals)
{ {
struct trace_event_buffer fbuffer; struct synth_event_trace_state state;
struct synth_trace_event *entry;
struct trace_buffer *buffer;
struct synth_event *event;
unsigned int i, n_u64; unsigned int i, n_u64;
int fields_size = 0; int ret;
int ret = 0;
/* ret = __synth_event_trace_start(file, &state);
* Normal event generation doesn't get called at all unless if (ret) {
* the ENABLED bit is set (which attaches the probe thus if (ret == -ENOENT)
* allowing this code to be called, etc). Because this is ret = 0; /* just disabled, not really an error */
* called directly by the user, we don't have that but we return ret;
* still need to honor not logging when disabled.
*/
if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
trace_trigger_soft_disabled(file))
return 0;
event = file->event_call->data;
if (n_vals != event->n_fields)
return -EINVAL;
fields_size = event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
buffer = file->tr->array_buffer.buffer;
ring_buffer_nest_start(buffer);
entry = trace_event_buffer_reserve(&fbuffer, file,
sizeof(*entry) + fields_size);
if (!entry) {
ret = -EINVAL;
goto out;
} }
for (i = 0, n_u64 = 0; i < event->n_fields; i++) { for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
if (event->fields[i]->is_string) { if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)vals[i]; char *str_val = (char *)(long)vals[i];
char *str_field = (char *)&entry->fields[n_u64]; char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX); strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64); n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else { } else {
entry->fields[n_u64] = vals[i]; state.entry->fields[n_u64] = vals[i];
n_u64++; n_u64++;
} }
} }
trace_event_buffer_commit(&fbuffer); __synth_event_trace_end(&state);
out:
ring_buffer_nest_end(buffer);
return ret; return ret;
} }
@ -1993,55 +1985,17 @@ EXPORT_SYMBOL_GPL(synth_event_trace_array);
int synth_event_trace_start(struct trace_event_file *file, int synth_event_trace_start(struct trace_event_file *file,
struct synth_event_trace_state *trace_state) struct synth_event_trace_state *trace_state)
{ {
struct synth_trace_event *entry; int ret;
int fields_size = 0;
int ret = 0;
if (!trace_state) { if (!trace_state)
ret = -EINVAL; return -EINVAL;
goto out;
}
memset(trace_state, '\0', sizeof(*trace_state)); memset(trace_state, '\0', sizeof(*trace_state));
/* ret = __synth_event_trace_start(file, trace_state);
* Normal event tracing doesn't get called at all unless the if (ret == -ENOENT)
* ENABLED bit is set (which attaches the probe thus allowing ret = 0; /* just disabled, not really an error */
* this code to be called, etc). Because this is called
* directly by the user, we don't have that but we still need
* to honor not logging when disabled. For the the iterated
* trace case, we save the enabed state upon start and just
* ignore the following data calls.
*/
if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
trace_trigger_soft_disabled(file)) {
trace_state->enabled = false;
goto out;
}
trace_state->enabled = true;
trace_state->event = file->event_call->data;
fields_size = trace_state->event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
trace_state->buffer = file->tr->array_buffer.buffer;
ring_buffer_nest_start(trace_state->buffer);
entry = trace_event_buffer_reserve(&trace_state->fbuffer, file,
sizeof(*entry) + fields_size);
if (!entry) {
ring_buffer_nest_end(trace_state->buffer);
ret = -EINVAL;
goto out;
}
trace_state->entry = entry;
out:
return ret; return ret;
} }
EXPORT_SYMBOL_GPL(synth_event_trace_start); EXPORT_SYMBOL_GPL(synth_event_trace_start);
@ -2074,7 +2028,7 @@ static int __synth_event_add_val(const char *field_name, u64 val,
trace_state->add_next = true; trace_state->add_next = true;
} }
if (!trace_state->enabled) if (trace_state->disabled)
goto out; goto out;
event = trace_state->event; event = trace_state->event;
@ -2209,9 +2163,7 @@ int synth_event_trace_end(struct synth_event_trace_state *trace_state)
if (!trace_state) if (!trace_state)
return -EINVAL; return -EINVAL;
trace_event_buffer_commit(&trace_state->fbuffer); __synth_event_trace_end(trace_state);
ring_buffer_nest_end(trace_state->buffer);
return 0; return 0;
} }