// SPDX-License-Identifier: GPL-2.0
|
/*
|
* trace_events_synth - synthetic trace events
|
*
|
* Copyright (C) 2015, 2020 Tom Zanussi <tom.zanussi@linux.intel.com>
|
*/
|
|
#include <linux/module.h>
|
#include <linux/kallsyms.h>
|
#include <linux/security.h>
|
#include <linux/mutex.h>
|
#include <linux/slab.h>
|
#include <linux/stacktrace.h>
|
#include <linux/rculist.h>
|
#include <linux/tracefs.h>
|
|
/* for gfp flag names */
|
#include <linux/trace_events.h>
|
#include <trace/events/mmflags.h>
|
|
#include "trace_synth.h"
|
|
#undef ERRORS
|
#define ERRORS \
|
C(BAD_NAME, "Illegal name"), \
|
C(CMD_INCOMPLETE, "Incomplete command"), \
|
C(EVENT_EXISTS, "Event already exists"), \
|
C(TOO_MANY_FIELDS, "Too many fields"), \
|
C(INCOMPLETE_TYPE, "Incomplete type"), \
|
C(INVALID_TYPE, "Invalid type"), \
|
C(INVALID_FIELD, "Invalid field"), \
|
C(CMD_TOO_LONG, "Command too long"),
|
|
#undef C
|
#define C(a, b) SYNTH_ERR_##a
|
|
enum { ERRORS };
|
|
#undef C
|
#define C(a, b) b
|
|
static const char *err_text[] = { ERRORS };
|
|
static char last_cmd[MAX_FILTER_STR_VAL];
|
|
static int errpos(const char *str)
|
{
|
return err_pos(last_cmd, str);
|
}
|
|
static void last_cmd_set(char *str)
|
{
|
if (!str)
|
return;
|
|
strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
|
}
|
|
static void synth_err(u8 err_type, u8 err_pos)
|
{
|
tracing_log_err(NULL, "synthetic_events", last_cmd, err_text,
|
err_type, err_pos);
|
}
|
|
static int create_synth_event(int argc, const char **argv);
|
static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
|
static int synth_event_release(struct dyn_event *ev);
|
static bool synth_event_is_busy(struct dyn_event *ev);
|
static bool synth_event_match(const char *system, const char *event,
|
int argc, const char **argv, struct dyn_event *ev);
|
|
static struct dyn_event_operations synth_event_ops = {
|
.create = create_synth_event,
|
.show = synth_event_show,
|
.is_busy = synth_event_is_busy,
|
.free = synth_event_release,
|
.match = synth_event_match,
|
};
|
|
static bool is_synth_event(struct dyn_event *ev)
|
{
|
return ev->ops == &synth_event_ops;
|
}
|
|
static struct synth_event *to_synth_event(struct dyn_event *ev)
|
{
|
return container_of(ev, struct synth_event, devent);
|
}
|
|
static bool synth_event_is_busy(struct dyn_event *ev)
|
{
|
struct synth_event *event = to_synth_event(ev);
|
|
return event->ref != 0;
|
}
|
|
static bool synth_event_match(const char *system, const char *event,
|
int argc, const char **argv, struct dyn_event *ev)
|
{
|
struct synth_event *sev = to_synth_event(ev);
|
|
return strcmp(sev->name, event) == 0 &&
|
(!system || strcmp(system, SYNTH_SYSTEM) == 0);
|
}
|
|
struct synth_trace_event {
|
struct trace_entry ent;
|
u64 fields[];
|
};
|
|
static int synth_event_define_fields(struct trace_event_call *call)
|
{
|
struct synth_trace_event trace;
|
int offset = offsetof(typeof(trace), fields);
|
struct synth_event *event = call->data;
|
unsigned int i, size, n_u64;
|
char *name, *type;
|
bool is_signed;
|
int ret = 0;
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
size = event->fields[i]->size;
|
is_signed = event->fields[i]->is_signed;
|
type = event->fields[i]->type;
|
name = event->fields[i]->name;
|
ret = trace_define_field(call, type, name, offset, size,
|
is_signed, FILTER_OTHER);
|
if (ret)
|
break;
|
|
event->fields[i]->offset = n_u64;
|
|
if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) {
|
offset += STR_VAR_LEN_MAX;
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
} else {
|
offset += sizeof(u64);
|
n_u64++;
|
}
|
}
|
|
event->n_u64 = n_u64;
|
|
return ret;
|
}
|
|
static bool synth_field_signed(char *type)
|
{
|
if (str_has_prefix(type, "u"))
|
return false;
|
if (strcmp(type, "gfp_t") == 0)
|
return false;
|
|
return true;
|
}
|
|
static int synth_field_is_string(char *type)
|
{
|
if (strstr(type, "char[") != NULL)
|
return true;
|
|
return false;
|
}
|
|
static int synth_field_string_size(char *type)
|
{
|
char buf[4], *end, *start;
|
unsigned int len;
|
int size, err;
|
|
start = strstr(type, "char[");
|
if (start == NULL)
|
return -EINVAL;
|
start += sizeof("char[") - 1;
|
|
end = strchr(type, ']');
|
if (!end || end < start || type + strlen(type) > end + 1)
|
return -EINVAL;
|
|
len = end - start;
|
if (len > 3)
|
return -EINVAL;
|
|
if (len == 0)
|
return 0; /* variable-length string */
|
|
strncpy(buf, start, len);
|
buf[len] = '\0';
|
|
err = kstrtouint(buf, 0, &size);
|
if (err)
|
return err;
|
|
if (size > STR_VAR_LEN_MAX)
|
return -EINVAL;
|
|
return size;
|
}
|
|
static int synth_field_size(char *type)
|
{
|
int size = 0;
|
|
if (strcmp(type, "s64") == 0)
|
size = sizeof(s64);
|
else if (strcmp(type, "u64") == 0)
|
size = sizeof(u64);
|
else if (strcmp(type, "s32") == 0)
|
size = sizeof(s32);
|
else if (strcmp(type, "u32") == 0)
|
size = sizeof(u32);
|
else if (strcmp(type, "s16") == 0)
|
size = sizeof(s16);
|
else if (strcmp(type, "u16") == 0)
|
size = sizeof(u16);
|
else if (strcmp(type, "s8") == 0)
|
size = sizeof(s8);
|
else if (strcmp(type, "u8") == 0)
|
size = sizeof(u8);
|
else if (strcmp(type, "char") == 0)
|
size = sizeof(char);
|
else if (strcmp(type, "unsigned char") == 0)
|
size = sizeof(unsigned char);
|
else if (strcmp(type, "int") == 0)
|
size = sizeof(int);
|
else if (strcmp(type, "unsigned int") == 0)
|
size = sizeof(unsigned int);
|
else if (strcmp(type, "long") == 0)
|
size = sizeof(long);
|
else if (strcmp(type, "unsigned long") == 0)
|
size = sizeof(unsigned long);
|
else if (strcmp(type, "bool") == 0)
|
size = sizeof(bool);
|
else if (strcmp(type, "pid_t") == 0)
|
size = sizeof(pid_t);
|
else if (strcmp(type, "gfp_t") == 0)
|
size = sizeof(gfp_t);
|
else if (synth_field_is_string(type))
|
size = synth_field_string_size(type);
|
|
return size;
|
}
|
|
static const char *synth_field_fmt(char *type)
|
{
|
const char *fmt = "%llu";
|
|
if (strcmp(type, "s64") == 0)
|
fmt = "%lld";
|
else if (strcmp(type, "u64") == 0)
|
fmt = "%llu";
|
else if (strcmp(type, "s32") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "u32") == 0)
|
fmt = "%u";
|
else if (strcmp(type, "s16") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "u16") == 0)
|
fmt = "%u";
|
else if (strcmp(type, "s8") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "u8") == 0)
|
fmt = "%u";
|
else if (strcmp(type, "char") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "unsigned char") == 0)
|
fmt = "%u";
|
else if (strcmp(type, "int") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "unsigned int") == 0)
|
fmt = "%u";
|
else if (strcmp(type, "long") == 0)
|
fmt = "%ld";
|
else if (strcmp(type, "unsigned long") == 0)
|
fmt = "%lu";
|
else if (strcmp(type, "bool") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "pid_t") == 0)
|
fmt = "%d";
|
else if (strcmp(type, "gfp_t") == 0)
|
fmt = "%x";
|
else if (synth_field_is_string(type))
|
fmt = "%.*s";
|
|
return fmt;
|
}
|
|
static void print_synth_event_num_val(struct trace_seq *s,
|
char *print_fmt, char *name,
|
int size, u64 val, char *space)
|
{
|
switch (size) {
|
case 1:
|
trace_seq_printf(s, print_fmt, name, (u8)val, space);
|
break;
|
|
case 2:
|
trace_seq_printf(s, print_fmt, name, (u16)val, space);
|
break;
|
|
case 4:
|
trace_seq_printf(s, print_fmt, name, (u32)val, space);
|
break;
|
|
default:
|
trace_seq_printf(s, print_fmt, name, val, space);
|
break;
|
}
|
}
|
|
static enum print_line_t print_synth_event(struct trace_iterator *iter,
|
int flags,
|
struct trace_event *event)
|
{
|
struct trace_array *tr = iter->tr;
|
struct trace_seq *s = &iter->seq;
|
struct synth_trace_event *entry;
|
struct synth_event *se;
|
unsigned int i, n_u64;
|
char print_fmt[32];
|
const char *fmt;
|
|
entry = (struct synth_trace_event *)iter->ent;
|
se = container_of(event, struct synth_event, call.event);
|
|
trace_seq_printf(s, "%s: ", se->name);
|
|
for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
|
if (trace_seq_has_overflowed(s))
|
goto end;
|
|
fmt = synth_field_fmt(se->fields[i]->type);
|
|
/* parameter types */
|
if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
|
trace_seq_printf(s, "%s ", fmt);
|
|
snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
|
|
/* parameter values */
|
if (se->fields[i]->is_string) {
|
if (se->fields[i]->is_dynamic) {
|
u32 offset, data_offset;
|
char *str_field;
|
|
offset = (u32)entry->fields[n_u64];
|
data_offset = offset & 0xffff;
|
|
str_field = (char *)entry + data_offset;
|
|
trace_seq_printf(s, print_fmt, se->fields[i]->name,
|
STR_VAR_LEN_MAX,
|
str_field,
|
i == se->n_fields - 1 ? "" : " ");
|
n_u64++;
|
} else {
|
trace_seq_printf(s, print_fmt, se->fields[i]->name,
|
STR_VAR_LEN_MAX,
|
(char *)&entry->fields[n_u64],
|
i == se->n_fields - 1 ? "" : " ");
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
}
|
} else {
|
struct trace_print_flags __flags[] = {
|
__def_gfpflag_names, {-1, NULL} };
|
char *space = (i == se->n_fields - 1 ? "" : " ");
|
|
print_synth_event_num_val(s, print_fmt,
|
se->fields[i]->name,
|
se->fields[i]->size,
|
entry->fields[n_u64],
|
space);
|
|
if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
|
trace_seq_puts(s, " (");
|
trace_print_flags_seq(s, "|",
|
entry->fields[n_u64],
|
__flags);
|
trace_seq_putc(s, ')');
|
}
|
n_u64++;
|
}
|
}
|
end:
|
trace_seq_putc(s, '\n');
|
|
return trace_handle_return(s);
|
}
|
|
static struct trace_event_functions synth_event_funcs = {
|
.trace = print_synth_event
|
};
|
|
static unsigned int trace_string(struct synth_trace_event *entry,
|
struct synth_event *event,
|
char *str_val,
|
bool is_dynamic,
|
unsigned int data_size,
|
unsigned int *n_u64)
|
{
|
unsigned int len = 0;
|
char *str_field;
|
|
if (is_dynamic) {
|
u32 data_offset;
|
|
data_offset = offsetof(typeof(*entry), fields);
|
data_offset += event->n_u64 * sizeof(u64);
|
data_offset += data_size;
|
|
str_field = (char *)entry + data_offset;
|
|
len = strlen(str_val) + 1;
|
strscpy(str_field, str_val, len);
|
|
data_offset |= len << 16;
|
*(u32 *)&entry->fields[*n_u64] = data_offset;
|
|
(*n_u64)++;
|
} else {
|
str_field = (char *)&entry->fields[*n_u64];
|
|
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
|
(*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
|
}
|
|
return len;
|
}
|
|
static notrace void trace_event_raw_event_synth(void *__data,
|
u64 *var_ref_vals,
|
unsigned int *var_ref_idx)
|
{
|
unsigned int i, n_u64, val_idx, len, data_size = 0;
|
struct trace_event_file *trace_file = __data;
|
struct synth_trace_event *entry;
|
struct trace_event_buffer fbuffer;
|
struct trace_buffer *buffer;
|
struct synth_event *event;
|
int fields_size = 0;
|
|
event = trace_file->event_call->data;
|
|
if (trace_trigger_soft_disabled(trace_file))
|
return;
|
|
fields_size = event->n_u64 * sizeof(u64);
|
|
for (i = 0; i < event->n_dynamic_fields; i++) {
|
unsigned int field_pos = event->dynamic_fields[i]->field_pos;
|
char *str_val;
|
|
val_idx = var_ref_idx[field_pos];
|
str_val = (char *)(long)var_ref_vals[val_idx];
|
|
len = strlen(str_val) + 1;
|
|
fields_size += len;
|
}
|
|
/*
|
* Avoid ring buffer recursion detection, as this event
|
* is being performed within another event.
|
*/
|
buffer = trace_file->tr->array_buffer.buffer;
|
ring_buffer_nest_start(buffer);
|
|
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
|
sizeof(*entry) + fields_size);
|
if (!entry)
|
goto out;
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
val_idx = var_ref_idx[i];
|
if (event->fields[i]->is_string) {
|
char *str_val = (char *)(long)var_ref_vals[val_idx];
|
|
len = trace_string(entry, event, str_val,
|
event->fields[i]->is_dynamic,
|
data_size, &n_u64);
|
data_size += len; /* only dynamic string increments */
|
} else {
|
struct synth_field *field = event->fields[i];
|
u64 val = var_ref_vals[val_idx];
|
|
switch (field->size) {
|
case 1:
|
*(u8 *)&entry->fields[n_u64] = (u8)val;
|
break;
|
|
case 2:
|
*(u16 *)&entry->fields[n_u64] = (u16)val;
|
break;
|
|
case 4:
|
*(u32 *)&entry->fields[n_u64] = (u32)val;
|
break;
|
|
default:
|
entry->fields[n_u64] = val;
|
break;
|
}
|
n_u64++;
|
}
|
}
|
|
trace_event_buffer_commit(&fbuffer);
|
out:
|
ring_buffer_nest_end(buffer);
|
}
|
|
static void free_synth_event_print_fmt(struct trace_event_call *call)
|
{
|
if (call) {
|
kfree(call->print_fmt);
|
call->print_fmt = NULL;
|
}
|
}
|
|
static int __set_synth_event_print_fmt(struct synth_event *event,
|
char *buf, int len)
|
{
|
const char *fmt;
|
int pos = 0;
|
int i;
|
|
/* When len=0, we just calculate the needed length */
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
for (i = 0; i < event->n_fields; i++) {
|
fmt = synth_field_fmt(event->fields[i]->type);
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
|
event->fields[i]->name, fmt,
|
i == event->n_fields - 1 ? "" : ", ");
|
}
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
|
for (i = 0; i < event->n_fields; i++) {
|
if (event->fields[i]->is_string &&
|
event->fields[i]->is_dynamic)
|
pos += snprintf(buf + pos, LEN_OR_ZERO,
|
", __get_str(%s)", event->fields[i]->name);
|
else
|
pos += snprintf(buf + pos, LEN_OR_ZERO,
|
", REC->%s", event->fields[i]->name);
|
}
|
|
#undef LEN_OR_ZERO
|
|
/* return the length of print_fmt */
|
return pos;
|
}
|
|
static int set_synth_event_print_fmt(struct trace_event_call *call)
|
{
|
struct synth_event *event = call->data;
|
char *print_fmt;
|
int len;
|
|
/* First: called with 0 length to calculate the needed length */
|
len = __set_synth_event_print_fmt(event, NULL, 0);
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
if (!print_fmt)
|
return -ENOMEM;
|
|
/* Second: actually write the @print_fmt */
|
__set_synth_event_print_fmt(event, print_fmt, len + 1);
|
call->print_fmt = print_fmt;
|
|
return 0;
|
}
|
|
static void free_synth_field(struct synth_field *field)
|
{
|
kfree(field->type);
|
kfree(field->name);
|
kfree(field);
|
}
|
|
static struct synth_field *parse_synth_field(int argc, const char **argv,
|
int *consumed)
|
{
|
struct synth_field *field;
|
const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
|
int len, ret = -ENOMEM;
|
struct seq_buf s;
|
ssize_t size;
|
|
if (field_type[0] == ';')
|
field_type++;
|
|
if (!strcmp(field_type, "unsigned")) {
|
if (argc < 3) {
|
synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));
|
return ERR_PTR(-EINVAL);
|
}
|
prefix = "unsigned ";
|
field_type = argv[1];
|
field_name = argv[2];
|
*consumed = 3;
|
} else {
|
field_name = argv[1];
|
*consumed = 2;
|
}
|
|
field = kzalloc(sizeof(*field), GFP_KERNEL);
|
if (!field)
|
return ERR_PTR(-ENOMEM);
|
|
len = strlen(field_name);
|
array = strchr(field_name, '[');
|
if (array)
|
len -= strlen(array);
|
else if (field_name[len - 1] == ';')
|
len--;
|
|
field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
|
if (!field->name)
|
goto free;
|
|
if (!is_good_name(field->name)) {
|
synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));
|
ret = -EINVAL;
|
goto free;
|
}
|
|
if (field_type[0] == ';')
|
field_type++;
|
len = strlen(field_type) + 1;
|
|
if (array)
|
len += strlen(array);
|
|
if (prefix)
|
len += strlen(prefix);
|
|
field->type = kzalloc(len, GFP_KERNEL);
|
if (!field->type)
|
goto free;
|
|
seq_buf_init(&s, field->type, len);
|
if (prefix)
|
seq_buf_puts(&s, prefix);
|
seq_buf_puts(&s, field_type);
|
if (array) {
|
seq_buf_puts(&s, array);
|
if (s.buffer[s.len - 1] == ';')
|
s.len--;
|
}
|
if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
|
goto free;
|
|
s.buffer[s.len] = '\0';
|
|
size = synth_field_size(field->type);
|
if (size < 0) {
|
synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
|
ret = -EINVAL;
|
goto free;
|
} else if (size == 0) {
|
if (synth_field_is_string(field->type)) {
|
char *type;
|
|
len = sizeof("__data_loc ") + strlen(field->type) + 1;
|
type = kzalloc(len, GFP_KERNEL);
|
if (!type)
|
goto free;
|
|
seq_buf_init(&s, type, len);
|
seq_buf_puts(&s, "__data_loc ");
|
seq_buf_puts(&s, field->type);
|
|
if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
|
goto free;
|
s.buffer[s.len] = '\0';
|
|
kfree(field->type);
|
field->type = type;
|
|
field->is_dynamic = true;
|
size = sizeof(u64);
|
} else {
|
synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
|
ret = -EINVAL;
|
goto free;
|
}
|
}
|
field->size = size;
|
|
if (synth_field_is_string(field->type))
|
field->is_string = true;
|
|
field->is_signed = synth_field_signed(field->type);
|
out:
|
return field;
|
free:
|
free_synth_field(field);
|
field = ERR_PTR(ret);
|
goto out;
|
}
|
|
static void free_synth_tracepoint(struct tracepoint *tp)
|
{
|
if (!tp)
|
return;
|
|
kfree(tp->name);
|
kfree(tp);
|
}
|
|
static struct tracepoint *alloc_synth_tracepoint(char *name)
|
{
|
struct tracepoint *tp;
|
|
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
|
if (!tp)
|
return ERR_PTR(-ENOMEM);
|
|
tp->name = kstrdup(name, GFP_KERNEL);
|
if (!tp->name) {
|
kfree(tp);
|
return ERR_PTR(-ENOMEM);
|
}
|
|
return tp;
|
}
|
|
struct synth_event *find_synth_event(const char *name)
|
{
|
struct dyn_event *pos;
|
struct synth_event *event;
|
|
for_each_dyn_event(pos) {
|
if (!is_synth_event(pos))
|
continue;
|
event = to_synth_event(pos);
|
if (strcmp(event->name, name) == 0)
|
return event;
|
}
|
|
return NULL;
|
}
|
|
static struct trace_event_fields synth_event_fields_array[] = {
|
{ .type = TRACE_FUNCTION_TYPE,
|
.define_fields = synth_event_define_fields },
|
{}
|
};
|
|
static int register_synth_event(struct synth_event *event)
|
{
|
struct trace_event_call *call = &event->call;
|
int ret = 0;
|
|
event->call.class = &event->class;
|
event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
|
if (!event->class.system) {
|
ret = -ENOMEM;
|
goto out;
|
}
|
|
event->tp = alloc_synth_tracepoint(event->name);
|
if (IS_ERR(event->tp)) {
|
ret = PTR_ERR(event->tp);
|
event->tp = NULL;
|
goto out;
|
}
|
|
INIT_LIST_HEAD(&call->class->fields);
|
call->event.funcs = &synth_event_funcs;
|
call->class->fields_array = synth_event_fields_array;
|
|
ret = register_trace_event(&call->event);
|
if (!ret) {
|
ret = -ENODEV;
|
goto out;
|
}
|
call->flags = TRACE_EVENT_FL_TRACEPOINT;
|
call->class->reg = trace_event_reg;
|
call->class->probe = trace_event_raw_event_synth;
|
call->data = event;
|
call->tp = event->tp;
|
|
ret = trace_add_event_call(call);
|
if (ret) {
|
pr_warn("Failed to register synthetic event: %s\n",
|
trace_event_name(call));
|
goto err;
|
}
|
|
ret = set_synth_event_print_fmt(call);
|
/* unregister_trace_event() will be called inside */
|
if (ret < 0)
|
trace_remove_event_call(call);
|
out:
|
return ret;
|
err:
|
unregister_trace_event(&call->event);
|
goto out;
|
}
|
|
static int unregister_synth_event(struct synth_event *event)
|
{
|
struct trace_event_call *call = &event->call;
|
int ret;
|
|
ret = trace_remove_event_call(call);
|
|
return ret;
|
}
|
|
static void free_synth_event(struct synth_event *event)
|
{
|
unsigned int i;
|
|
if (!event)
|
return;
|
|
for (i = 0; i < event->n_fields; i++)
|
free_synth_field(event->fields[i]);
|
|
kfree(event->fields);
|
kfree(event->dynamic_fields);
|
kfree(event->name);
|
kfree(event->class.system);
|
free_synth_tracepoint(event->tp);
|
free_synth_event_print_fmt(&event->call);
|
kfree(event);
|
}
|
|
static struct synth_event *alloc_synth_event(const char *name, int n_fields,
|
struct synth_field **fields)
|
{
|
unsigned int i, j, n_dynamic_fields = 0;
|
struct synth_event *event;
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
if (!event) {
|
event = ERR_PTR(-ENOMEM);
|
goto out;
|
}
|
|
event->name = kstrdup(name, GFP_KERNEL);
|
if (!event->name) {
|
kfree(event);
|
event = ERR_PTR(-ENOMEM);
|
goto out;
|
}
|
|
event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
|
if (!event->fields) {
|
free_synth_event(event);
|
event = ERR_PTR(-ENOMEM);
|
goto out;
|
}
|
|
for (i = 0; i < n_fields; i++)
|
if (fields[i]->is_dynamic)
|
n_dynamic_fields++;
|
|
if (n_dynamic_fields) {
|
event->dynamic_fields = kcalloc(n_dynamic_fields,
|
sizeof(*event->dynamic_fields),
|
GFP_KERNEL);
|
if (!event->dynamic_fields) {
|
free_synth_event(event);
|
event = ERR_PTR(-ENOMEM);
|
goto out;
|
}
|
}
|
|
dyn_event_init(&event->devent, &synth_event_ops);
|
|
for (i = 0, j = 0; i < n_fields; i++) {
|
event->fields[i] = fields[i];
|
|
if (fields[i]->is_dynamic) {
|
event->dynamic_fields[j] = fields[i];
|
event->dynamic_fields[j]->field_pos = i;
|
event->dynamic_fields[j++] = fields[i];
|
event->n_dynamic_fields++;
|
}
|
}
|
event->n_fields = n_fields;
|
out:
|
return event;
|
}
|
|
static int synth_event_check_arg_fn(void *data)
|
{
|
struct dynevent_arg_pair *arg_pair = data;
|
int size;
|
|
size = synth_field_size((char *)arg_pair->lhs);
|
if (size == 0) {
|
if (strstr((char *)arg_pair->lhs, "["))
|
return 0;
|
}
|
|
return size ? 0 : -EINVAL;
|
}
|
|
/**
|
* synth_event_add_field - Add a new field to a synthetic event cmd
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @type: The type of the new field to add
|
* @name: The name of the new field to add
|
*
|
* Add a new field to a synthetic event cmd object. Field ordering is in
|
* the same order the fields are added.
|
*
|
* See synth_field_size() for available types. If field_name contains
|
* [n] the field is considered to be an array.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
|
const char *name)
|
{
|
struct dynevent_arg_pair arg_pair;
|
int ret;
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH)
|
return -EINVAL;
|
|
if (!type || !name)
|
return -EINVAL;
|
|
dynevent_arg_pair_init(&arg_pair, 0, ';');
|
|
arg_pair.lhs = type;
|
arg_pair.rhs = name;
|
|
ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
|
if (ret)
|
return ret;
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX)
|
ret = -EINVAL;
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_add_field);
|
|
/**
|
* synth_event_add_field_str - Add a new field to a synthetic event cmd
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @type_name: The type and name of the new field to add, as a single string
|
*
|
* Add a new field to a synthetic event cmd object, as a single
|
* string. The @type_name string is expected to be of the form 'type
|
* name', which will be appended by ';'. No sanity checking is done -
|
* what's passed in is assumed to already be well-formed. Field
|
* ordering is in the same order the fields are added.
|
*
|
* See synth_field_size() for available types. If field_name contains
|
* [n] the field is considered to be an array.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
|
{
|
struct dynevent_arg arg;
|
int ret;
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH)
|
return -EINVAL;
|
|
if (!type_name)
|
return -EINVAL;
|
|
dynevent_arg_init(&arg, ';');
|
|
arg.str = type_name;
|
|
ret = dynevent_arg_add(cmd, &arg, NULL);
|
if (ret)
|
return ret;
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX)
|
ret = -EINVAL;
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_add_field_str);
|
|
/**
|
* synth_event_add_fields - Add multiple fields to a synthetic event cmd
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @fields: An array of type/name field descriptions
|
* @n_fields: The number of field descriptions contained in the fields array
|
*
|
* Add a new set of fields to a synthetic event cmd object. The event
|
* fields that will be defined for the event should be passed in as an
|
* array of struct synth_field_desc, and the number of elements in the
|
* array passed in as n_fields. Field ordering will retain the
|
* ordering given in the fields array.
|
*
|
* See synth_field_size() for available types. If field_name contains
|
* [n] the field is considered to be an array.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_add_fields(struct dynevent_cmd *cmd,
|
struct synth_field_desc *fields,
|
unsigned int n_fields)
|
{
|
unsigned int i;
|
int ret = 0;
|
|
for (i = 0; i < n_fields; i++) {
|
if (fields[i].type == NULL || fields[i].name == NULL) {
|
ret = -EINVAL;
|
break;
|
}
|
|
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
|
if (ret)
|
break;
|
}
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_add_fields);
|
|
/**
|
* __synth_event_gen_cmd_start - Start a synthetic event command from arg list
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @name: The name of the synthetic event
|
* @mod: The module creating the event, NULL if not created from a module
|
* @args: Variable number of arg (pairs), one pair for each field
|
*
|
* NOTE: Users normally won't want to call this function directly, but
|
* rather use the synth_event_gen_cmd_start() wrapper, which
|
* automatically adds a NULL to the end of the arg list. If this
|
* function is used directly, make sure the last arg in the variable
|
* arg list is NULL.
|
*
|
* Generate a synthetic event command to be executed by
|
* synth_event_gen_cmd_end(). This function can be used to generate
|
* the complete command or only the first part of it; in the latter
|
* case, synth_event_add_field(), synth_event_add_field_str(), or
|
* synth_event_add_fields() can be used to add more fields following
|
* this.
|
*
|
* There should be an even number variable args, each pair consisting
|
* of a type followed by a field name.
|
*
|
* See synth_field_size() for available types. If field_name contains
|
* [n] the field is considered to be an array.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
|
struct module *mod, ...)
|
{
|
struct dynevent_arg arg;
|
va_list args;
|
int ret;
|
|
cmd->event_name = name;
|
cmd->private_data = mod;
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH)
|
return -EINVAL;
|
|
dynevent_arg_init(&arg, 0);
|
arg.str = name;
|
ret = dynevent_arg_add(cmd, &arg, NULL);
|
if (ret)
|
return ret;
|
|
va_start(args, mod);
|
for (;;) {
|
const char *type, *name;
|
|
type = va_arg(args, const char *);
|
if (!type)
|
break;
|
name = va_arg(args, const char *);
|
if (!name)
|
break;
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
|
ret = -EINVAL;
|
break;
|
}
|
|
ret = synth_event_add_field(cmd, type, name);
|
if (ret)
|
break;
|
}
|
va_end(args);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
|
|
/**
|
* synth_event_gen_cmd_array_start - Start synthetic event command from an array
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @name: The name of the synthetic event
|
* @fields: An array of type/name field descriptions
|
* @n_fields: The number of field descriptions contained in the fields array
|
*
|
* Generate a synthetic event command to be executed by
|
* synth_event_gen_cmd_end(). This function can be used to generate
|
* the complete command or only the first part of it; in the latter
|
* case, synth_event_add_field(), synth_event_add_field_str(), or
|
* synth_event_add_fields() can be used to add more fields following
|
* this.
|
*
|
* The event fields that will be defined for the event should be
|
* passed in as an array of struct synth_field_desc, and the number of
|
* elements in the array passed in as n_fields. Field ordering will
|
* retain the ordering given in the fields array.
|
*
|
* See synth_field_size() for available types. If field_name contains
|
* [n] the field is considered to be an array.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
|
struct module *mod,
|
struct synth_field_desc *fields,
|
unsigned int n_fields)
|
{
|
struct dynevent_arg arg;
|
unsigned int i;
|
int ret = 0;
|
|
cmd->event_name = name;
|
cmd->private_data = mod;
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH)
|
return -EINVAL;
|
|
if (n_fields > SYNTH_FIELDS_MAX)
|
return -EINVAL;
|
|
dynevent_arg_init(&arg, 0);
|
arg.str = name;
|
ret = dynevent_arg_add(cmd, &arg, NULL);
|
if (ret)
|
return ret;
|
|
for (i = 0; i < n_fields; i++) {
|
if (fields[i].type == NULL || fields[i].name == NULL)
|
return -EINVAL;
|
|
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
|
if (ret)
|
break;
|
}
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
|
|
static int save_cmdstr(int argc, const char *name, const char **argv)
|
{
|
struct seq_buf s;
|
char *buf;
|
int i;
|
|
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
|
if (!buf)
|
return -ENOMEM;
|
|
seq_buf_init(&s, buf, MAX_DYNEVENT_CMD_LEN);
|
|
seq_buf_puts(&s, name);
|
|
for (i = 0; i < argc; i++) {
|
seq_buf_putc(&s, ' ');
|
seq_buf_puts(&s, argv[i]);
|
}
|
|
if (!seq_buf_buffer_left(&s)) {
|
synth_err(SYNTH_ERR_CMD_TOO_LONG, 0);
|
kfree(buf);
|
return -EINVAL;
|
}
|
buf[s.len] = 0;
|
last_cmd_set(buf);
|
|
kfree(buf);
|
return 0;
|
}
|
|
static int __create_synth_event(int argc, const char *name, const char **argv)
|
{
|
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
|
struct synth_event *event = NULL;
|
int i, consumed = 0, n_fields = 0, ret = 0;
|
|
ret = save_cmdstr(argc, name, argv);
|
if (ret)
|
return ret;
|
|
/*
|
* Argument syntax:
|
* - Add synthetic event: <event_name> field[;field] ...
|
* - Remove synthetic event: !<event_name> field[;field] ...
|
* where 'field' = type field_name
|
*/
|
|
if (name[0] == '\0' || argc < 1) {
|
synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
|
return -EINVAL;
|
}
|
|
mutex_lock(&event_mutex);
|
|
if (!is_good_name(name)) {
|
synth_err(SYNTH_ERR_BAD_NAME, errpos(name));
|
ret = -EINVAL;
|
goto out;
|
}
|
|
event = find_synth_event(name);
|
if (event) {
|
synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name));
|
ret = -EEXIST;
|
goto out;
|
}
|
|
for (i = 0; i < argc - 1; i++) {
|
if (strcmp(argv[i], ";") == 0)
|
continue;
|
if (n_fields == SYNTH_FIELDS_MAX) {
|
synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);
|
ret = -EINVAL;
|
goto err;
|
}
|
|
field = parse_synth_field(argc - i, &argv[i], &consumed);
|
if (IS_ERR(field)) {
|
ret = PTR_ERR(field);
|
goto err;
|
}
|
fields[n_fields++] = field;
|
i += consumed - 1;
|
}
|
|
if (i < argc && strcmp(argv[i], ";") != 0) {
|
synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i]));
|
ret = -EINVAL;
|
goto err;
|
}
|
|
event = alloc_synth_event(name, n_fields, fields);
|
if (IS_ERR(event)) {
|
ret = PTR_ERR(event);
|
event = NULL;
|
goto err;
|
}
|
ret = register_synth_event(event);
|
if (!ret)
|
dyn_event_add(&event->devent);
|
else
|
free_synth_event(event);
|
out:
|
mutex_unlock(&event_mutex);
|
|
return ret;
|
err:
|
for (i = 0; i < n_fields; i++)
|
free_synth_field(fields[i]);
|
|
goto out;
|
}
|
|
/**
|
* synth_event_create - Create a new synthetic event
|
* @name: The name of the new sythetic event
|
* @fields: An array of type/name field descriptions
|
* @n_fields: The number of field descriptions contained in the fields array
|
* @mod: The module creating the event, NULL if not created from a module
|
*
|
* Create a new synthetic event with the given name under the
|
* trace/events/synthetic/ directory. The event fields that will be
|
* defined for the event should be passed in as an array of struct
|
* synth_field_desc, and the number elements in the array passed in as
|
* n_fields. Field ordering will retain the ordering given in the
|
* fields array.
|
*
|
* If the new synthetic event is being created from a module, the mod
|
* param must be non-NULL. This will ensure that the trace buffer
|
* won't contain unreadable events.
|
*
|
* The new synth event should be deleted using synth_event_delete()
|
* function. The new synthetic event can be generated from modules or
|
* other kernel code using trace_synth_event() and related functions.
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_create(const char *name, struct synth_field_desc *fields,
|
unsigned int n_fields, struct module *mod)
|
{
|
struct dynevent_cmd cmd;
|
char *buf;
|
int ret;
|
|
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
|
if (!buf)
|
return -ENOMEM;
|
|
synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
|
|
ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
|
fields, n_fields);
|
if (ret)
|
goto out;
|
|
ret = synth_event_gen_cmd_end(&cmd);
|
out:
|
kfree(buf);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_create);
|
|
static int destroy_synth_event(struct synth_event *se)
|
{
|
int ret;
|
|
if (se->ref)
|
ret = -EBUSY;
|
else {
|
ret = unregister_synth_event(se);
|
if (!ret) {
|
dyn_event_remove(&se->devent);
|
free_synth_event(se);
|
}
|
}
|
|
return ret;
|
}
|
|
/**
|
* synth_event_delete - Delete a synthetic event
|
* @event_name: The name of the new sythetic event
|
*
|
* Delete a synthetic event that was created with synth_event_create().
|
*
|
* Return: 0 if successful, error otherwise.
|
*/
|
int synth_event_delete(const char *event_name)
|
{
|
struct synth_event *se = NULL;
|
struct module *mod = NULL;
|
int ret = -ENOENT;
|
|
mutex_lock(&event_mutex);
|
se = find_synth_event(event_name);
|
if (se) {
|
mod = se->mod;
|
ret = destroy_synth_event(se);
|
}
|
mutex_unlock(&event_mutex);
|
|
if (mod) {
|
mutex_lock(&trace_types_lock);
|
/*
|
* It is safest to reset the ring buffer if the module
|
* being unloaded registered any events that were
|
* used. The only worry is if a new module gets
|
* loaded, and takes on the same id as the events of
|
* this module. When printing out the buffer, traced
|
* events left over from this module may be passed to
|
* the new module events and unexpected results may
|
* occur.
|
*/
|
tracing_reset_all_online_cpus();
|
mutex_unlock(&trace_types_lock);
|
}
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_delete);
|
|
static int create_or_delete_synth_event(int argc, char **argv)
|
{
|
const char *name = argv[0];
|
int ret;
|
|
/* trace_run_command() ensures argc != 0 */
|
if (name[0] == '!') {
|
ret = synth_event_delete(name + 1);
|
return ret;
|
}
|
|
ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
|
return ret == -ECANCELED ? -EINVAL : ret;
|
}
|
|
static int synth_event_run_command(struct dynevent_cmd *cmd)
|
{
|
struct synth_event *se;
|
int ret;
|
|
ret = trace_run_command(cmd->seq.buffer, create_or_delete_synth_event);
|
if (ret)
|
return ret;
|
|
se = find_synth_event(cmd->event_name);
|
if (WARN_ON(!se))
|
return -ENOENT;
|
|
se->mod = cmd->private_data;
|
|
return ret;
|
}
|
|
/**
|
* synth_event_cmd_init - Initialize a synthetic event command object
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event
|
* @buf: A pointer to the buffer used to build the command
|
* @maxlen: The length of the buffer passed in @buf
|
*
|
* Initialize a synthetic event command object. Use this before
|
* calling any of the other dyenvent_cmd functions.
|
*/
|
void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
|
{
|
dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
|
synth_event_run_command);
|
}
|
EXPORT_SYMBOL_GPL(synth_event_cmd_init);
|
|
static inline int
|
__synth_event_trace_init(struct trace_event_file *file,
|
struct synth_event_trace_state *trace_state)
|
{
|
int ret = 0;
|
|
memset(trace_state, '\0', sizeof(*trace_state));
|
|
/*
|
* 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 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;
|
out:
|
return ret;
|
}
|
|
static inline int
|
__synth_event_trace_start(struct trace_event_file *file,
|
struct synth_event_trace_state *trace_state,
|
int dynamic_fields_size)
|
{
|
int entry_size, fields_size = 0;
|
int ret = 0;
|
|
fields_size = trace_state->event->n_u64 * sizeof(u64);
|
fields_size += dynamic_fields_size;
|
|
/*
|
* 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;
|
}
|
|
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
|
* @file: The trace_event_file representing the synthetic event
|
* @n_vals: The number of values in vals
|
* @args: Variable number of args containing the event values
|
*
|
* Trace a synthetic event using the values passed in the variable
|
* argument list.
|
*
|
* The argument list should be a list 'n_vals' u64 values. The number
|
* of vals must match the number of field in the synthetic event, and
|
* must be in the same order as the synthetic event fields.
|
*
|
* All vals should be cast to u64, and string vals are just pointers
|
* to strings, cast to u64. Strings will be copied into space
|
* reserved in the event for the string, using these pointers.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
|
{
|
unsigned int i, n_u64, len, data_size = 0;
|
struct synth_event_trace_state state;
|
va_list args;
|
int ret;
|
|
ret = __synth_event_trace_init(file, &state);
|
if (ret) {
|
if (ret == -ENOENT)
|
ret = 0; /* just disabled, not really an error */
|
return ret;
|
}
|
|
if (state.event->n_dynamic_fields) {
|
va_start(args, n_vals);
|
|
for (i = 0; i < state.event->n_fields; i++) {
|
u64 val = va_arg(args, u64);
|
|
if (state.event->fields[i]->is_string &&
|
state.event->fields[i]->is_dynamic) {
|
char *str_val = (char *)(long)val;
|
|
data_size += strlen(str_val) + 1;
|
}
|
}
|
|
va_end(args);
|
}
|
|
ret = __synth_event_trace_start(file, &state, data_size);
|
if (ret)
|
return ret;
|
|
if (n_vals != state.event->n_fields) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
data_size = 0;
|
|
va_start(args, n_vals);
|
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
|
u64 val;
|
|
val = va_arg(args, u64);
|
|
if (state.event->fields[i]->is_string) {
|
char *str_val = (char *)(long)val;
|
|
len = trace_string(state.entry, state.event, str_val,
|
state.event->fields[i]->is_dynamic,
|
data_size, &n_u64);
|
data_size += len; /* only dynamic string increments */
|
} else {
|
struct synth_field *field = state.event->fields[i];
|
|
switch (field->size) {
|
case 1:
|
*(u8 *)&state.entry->fields[n_u64] = (u8)val;
|
break;
|
|
case 2:
|
*(u16 *)&state.entry->fields[n_u64] = (u16)val;
|
break;
|
|
case 4:
|
*(u32 *)&state.entry->fields[n_u64] = (u32)val;
|
break;
|
|
default:
|
state.entry->fields[n_u64] = val;
|
break;
|
}
|
n_u64++;
|
}
|
}
|
va_end(args);
|
out:
|
__synth_event_trace_end(&state);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_trace);
|
|
/**
|
* synth_event_trace_array - Trace a synthetic event from an array
|
* @file: The trace_event_file representing the synthetic event
|
* @vals: Array of values
|
* @n_vals: The number of values in vals
|
*
|
* Trace a synthetic event using the values passed in as 'vals'.
|
*
|
* The 'vals' array is just an array of 'n_vals' u64. The number of
|
* vals must match the number of field in the synthetic event, and
|
* must be in the same order as the synthetic event fields.
|
*
|
* All vals should be cast to u64, and string vals are just pointers
|
* to strings, cast to u64. Strings will be copied into space
|
* reserved in the event for the string, using these pointers.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
|
unsigned int n_vals)
|
{
|
unsigned int i, n_u64, field_pos, len, data_size = 0;
|
struct synth_event_trace_state state;
|
char *str_val;
|
int ret;
|
|
ret = __synth_event_trace_init(file, &state);
|
if (ret) {
|
if (ret == -ENOENT)
|
ret = 0; /* just disabled, not really an error */
|
return ret;
|
}
|
|
if (state.event->n_dynamic_fields) {
|
for (i = 0; i < state.event->n_dynamic_fields; i++) {
|
field_pos = state.event->dynamic_fields[i]->field_pos;
|
str_val = (char *)(long)vals[field_pos];
|
len = strlen(str_val) + 1;
|
data_size += len;
|
}
|
}
|
|
ret = __synth_event_trace_start(file, &state, data_size);
|
if (ret)
|
return ret;
|
|
if (n_vals != state.event->n_fields) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
data_size = 0;
|
|
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
|
if (state.event->fields[i]->is_string) {
|
char *str_val = (char *)(long)vals[i];
|
|
len = trace_string(state.entry, state.event, str_val,
|
state.event->fields[i]->is_dynamic,
|
data_size, &n_u64);
|
data_size += len; /* only dynamic string increments */
|
} else {
|
struct synth_field *field = state.event->fields[i];
|
u64 val = vals[i];
|
|
switch (field->size) {
|
case 1:
|
*(u8 *)&state.entry->fields[n_u64] = (u8)val;
|
break;
|
|
case 2:
|
*(u16 *)&state.entry->fields[n_u64] = (u16)val;
|
break;
|
|
case 4:
|
*(u32 *)&state.entry->fields[n_u64] = (u32)val;
|
break;
|
|
default:
|
state.entry->fields[n_u64] = val;
|
break;
|
}
|
n_u64++;
|
}
|
}
|
out:
|
__synth_event_trace_end(&state);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_trace_array);
|
|
/**
|
* synth_event_trace_start - Start piecewise synthetic event trace
|
* @file: The trace_event_file representing the synthetic event
|
* @trace_state: A pointer to object tracking the piecewise trace state
|
*
|
* Start the trace of a synthetic event field-by-field rather than all
|
* at once.
|
*
|
* This function 'opens' an event trace, which means space is reserved
|
* for the event in the trace buffer, after which the event's
|
* individual field values can be set through either
|
* synth_event_add_next_val() or synth_event_add_val().
|
*
|
* A pointer to a trace_state object is passed in, which will keep
|
* track of the current event trace state until the event trace is
|
* closed (and the event finally traced) using
|
* synth_event_trace_end().
|
*
|
* Note that synth_event_trace_end() must be called after all values
|
* have been added for each event trace, regardless of whether adding
|
* all field values succeeded or not.
|
*
|
* Note also that for a given event trace, all fields must be added
|
* using either synth_event_add_next_val() or synth_event_add_val()
|
* but not both together or interleaved.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_trace_start(struct trace_event_file *file,
|
struct synth_event_trace_state *trace_state)
|
{
|
int ret;
|
|
if (!trace_state)
|
return -EINVAL;
|
|
ret = __synth_event_trace_init(file, trace_state);
|
if (ret) {
|
if (ret == -ENOENT)
|
ret = 0; /* just disabled, not really an error */
|
return ret;
|
}
|
|
if (trace_state->event->n_dynamic_fields)
|
return -ENOTSUPP;
|
|
ret = __synth_event_trace_start(file, trace_state, 0);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_trace_start);
|
|
static int __synth_event_add_val(const char *field_name, u64 val,
|
struct synth_event_trace_state *trace_state)
|
{
|
struct synth_field *field = NULL;
|
struct synth_trace_event *entry;
|
struct synth_event *event;
|
int i, ret = 0;
|
|
if (!trace_state) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
/* can't mix add_next_synth_val() with add_synth_val() */
|
if (field_name) {
|
if (trace_state->add_next) {
|
ret = -EINVAL;
|
goto out;
|
}
|
trace_state->add_name = true;
|
} else {
|
if (trace_state->add_name) {
|
ret = -EINVAL;
|
goto out;
|
}
|
trace_state->add_next = true;
|
}
|
|
if (trace_state->disabled)
|
goto out;
|
|
event = trace_state->event;
|
if (trace_state->add_name) {
|
for (i = 0; i < event->n_fields; i++) {
|
field = event->fields[i];
|
if (strcmp(field->name, field_name) == 0)
|
break;
|
}
|
if (!field) {
|
ret = -EINVAL;
|
goto out;
|
}
|
} else {
|
if (trace_state->cur_field >= event->n_fields) {
|
ret = -EINVAL;
|
goto out;
|
}
|
field = event->fields[trace_state->cur_field++];
|
}
|
|
entry = trace_state->entry;
|
if (field->is_string) {
|
char *str_val = (char *)(long)val;
|
char *str_field;
|
|
if (field->is_dynamic) { /* add_val can't do dynamic strings */
|
ret = -EINVAL;
|
goto out;
|
}
|
|
if (!str_val) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
str_field = (char *)&entry->fields[field->offset];
|
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
|
} else {
|
switch (field->size) {
|
case 1:
|
*(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
|
break;
|
|
case 2:
|
*(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
|
break;
|
|
case 4:
|
*(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
|
break;
|
|
default:
|
trace_state->entry->fields[field->offset] = val;
|
break;
|
}
|
}
|
out:
|
return ret;
|
}
|
|
/**
|
* synth_event_add_next_val - Add the next field's value to an open synth trace
|
* @val: The value to set the next field to
|
* @trace_state: A pointer to object tracking the piecewise trace state
|
*
|
* Set the value of the next field in an event that's been opened by
|
* synth_event_trace_start().
|
*
|
* The val param should be the value cast to u64. If the value points
|
* to a string, the val param should be a char * cast to u64.
|
*
|
* This function assumes all the fields in an event are to be set one
|
* after another - successive calls to this function are made, one for
|
* each field, in the order of the fields in the event, until all
|
* fields have been set. If you'd rather set each field individually
|
* without regard to ordering, synth_event_add_val() can be used
|
* instead.
|
*
|
* Note however that synth_event_add_next_val() and
|
* synth_event_add_val() can't be intermixed for a given event trace -
|
* one or the other but not both can be used at the same time.
|
*
|
* Note also that synth_event_trace_end() must be called after all
|
* values have been added for each event trace, regardless of whether
|
* adding all field values succeeded or not.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_add_next_val(u64 val,
|
struct synth_event_trace_state *trace_state)
|
{
|
return __synth_event_add_val(NULL, val, trace_state);
|
}
|
EXPORT_SYMBOL_GPL(synth_event_add_next_val);
|
|
/**
|
* synth_event_add_val - Add a named field's value to an open synth trace
|
* @field_name: The name of the synthetic event field value to set
|
* @val: The value to set the next field to
|
* @trace_state: A pointer to object tracking the piecewise trace state
|
*
|
* Set the value of the named field in an event that's been opened by
|
* synth_event_trace_start().
|
*
|
* The val param should be the value cast to u64. If the value points
|
* to a string, the val param should be a char * cast to u64.
|
*
|
* This function looks up the field name, and if found, sets the field
|
* to the specified value. This lookup makes this function more
|
* expensive than synth_event_add_next_val(), so use that or the
|
* none-piecewise synth_event_trace() instead if efficiency is more
|
* important.
|
*
|
* Note however that synth_event_add_next_val() and
|
* synth_event_add_val() can't be intermixed for a given event trace -
|
* one or the other but not both can be used at the same time.
|
*
|
* Note also that synth_event_trace_end() must be called after all
|
* values have been added for each event trace, regardless of whether
|
* adding all field values succeeded or not.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_add_val(const char *field_name, u64 val,
|
struct synth_event_trace_state *trace_state)
|
{
|
return __synth_event_add_val(field_name, val, trace_state);
|
}
|
EXPORT_SYMBOL_GPL(synth_event_add_val);
|
|
/**
|
* synth_event_trace_end - End piecewise synthetic event trace
|
* @trace_state: A pointer to object tracking the piecewise trace state
|
*
|
* End the trace of a synthetic event opened by
|
* synth_event_trace__start().
|
*
|
* This function 'closes' an event trace, which basically means that
|
* it commits the reserved event and cleans up other loose ends.
|
*
|
* A pointer to a trace_state object is passed in, which will keep
|
* track of the current event trace state opened with
|
* synth_event_trace_start().
|
*
|
* Note that this function must be called after all values have been
|
* added for each event trace, regardless of whether adding all field
|
* values succeeded or not.
|
*
|
* Return: 0 on success, err otherwise.
|
*/
|
int synth_event_trace_end(struct synth_event_trace_state *trace_state)
|
{
|
if (!trace_state)
|
return -EINVAL;
|
|
__synth_event_trace_end(trace_state);
|
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(synth_event_trace_end);
|
|
static int create_synth_event(int argc, const char **argv)
|
{
|
const char *name = argv[0];
|
int len;
|
|
if (name[0] != 's' || name[1] != ':')
|
return -ECANCELED;
|
name += 2;
|
|
/* This interface accepts group name prefix */
|
if (strchr(name, '/')) {
|
len = str_has_prefix(name, SYNTH_SYSTEM "/");
|
if (len == 0)
|
return -EINVAL;
|
name += len;
|
}
|
return __create_synth_event(argc - 1, name, argv + 1);
|
}
|
|
static int synth_event_release(struct dyn_event *ev)
|
{
|
struct synth_event *event = to_synth_event(ev);
|
int ret;
|
|
if (event->ref)
|
return -EBUSY;
|
|
ret = unregister_synth_event(event);
|
if (ret)
|
return ret;
|
|
dyn_event_remove(ev);
|
free_synth_event(event);
|
return 0;
|
}
|
|
static int __synth_event_show(struct seq_file *m, struct synth_event *event)
|
{
|
struct synth_field *field;
|
unsigned int i;
|
char *type, *t;
|
|
seq_printf(m, "%s\t", event->name);
|
|
for (i = 0; i < event->n_fields; i++) {
|
field = event->fields[i];
|
|
type = field->type;
|
t = strstr(type, "__data_loc");
|
if (t) { /* __data_loc belongs in format but not event desc */
|
t += sizeof("__data_loc");
|
type = t;
|
}
|
|
/* parameter values */
|
seq_printf(m, "%s %s%s", type, field->name,
|
i == event->n_fields - 1 ? "" : "; ");
|
}
|
|
seq_putc(m, '\n');
|
|
return 0;
|
}
|
|
static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
|
{
|
struct synth_event *event = to_synth_event(ev);
|
|
seq_printf(m, "s:%s/", event->class.system);
|
|
return __synth_event_show(m, event);
|
}
|
|
static int synth_events_seq_show(struct seq_file *m, void *v)
|
{
|
struct dyn_event *ev = v;
|
|
if (!is_synth_event(ev))
|
return 0;
|
|
return __synth_event_show(m, to_synth_event(ev));
|
}
|
|
static const struct seq_operations synth_events_seq_op = {
|
.start = dyn_event_seq_start,
|
.next = dyn_event_seq_next,
|
.stop = dyn_event_seq_stop,
|
.show = synth_events_seq_show,
|
};
|
|
static int synth_events_open(struct inode *inode, struct file *file)
|
{
|
int ret;
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS);
|
if (ret)
|
return ret;
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
ret = dyn_events_release_all(&synth_event_ops);
|
if (ret < 0)
|
return ret;
|
}
|
|
return seq_open(file, &synth_events_seq_op);
|
}
|
|
static ssize_t synth_events_write(struct file *file,
|
const char __user *buffer,
|
size_t count, loff_t *ppos)
|
{
|
return trace_parse_run_command(file, buffer, count, ppos,
|
create_or_delete_synth_event);
|
}
|
|
static const struct file_operations synth_events_fops = {
|
.open = synth_events_open,
|
.write = synth_events_write,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
/*
|
* Register dynevent at core_initcall. This allows kernel to setup kprobe
|
* events in postcore_initcall without tracefs.
|
*/
|
static __init int trace_events_synth_init_early(void)
|
{
|
int err = 0;
|
|
err = dyn_event_register(&synth_event_ops);
|
if (err)
|
pr_warn("Could not register synth_event_ops\n");
|
|
return err;
|
}
|
core_initcall(trace_events_synth_init_early);
|
|
static __init int trace_events_synth_init(void)
|
{
|
struct dentry *entry = NULL;
|
int err = 0;
|
err = tracing_init_dentry();
|
if (err)
|
goto err;
|
|
entry = tracefs_create_file("synthetic_events", 0644, NULL,
|
NULL, &synth_events_fops);
|
if (!entry) {
|
err = -ENODEV;
|
goto err;
|
}
|
|
return err;
|
err:
|
pr_warn("Could not create tracefs 'synthetic_events' entry\n");
|
|
return err;
|
}
|
|
fs_initcall(trace_events_synth_init);
|
