1 // SPDX-License-Identifier: GPL-2.0
3 * trace_events_synth - synthetic trace events
5 * Copyright (C) 2015, 2020 Tom Zanussi <tom.zanussi@linux.intel.com>
8 #include <linux/module.h>
9 #include <linux/kallsyms.h>
10 #include <linux/security.h>
11 #include <linux/mutex.h>
12 #include <linux/slab.h>
13 #include <linux/stacktrace.h>
14 #include <linux/rculist.h>
15 #include <linux/tracefs.h>
17 /* for gfp flag names */
18 #include <linux/trace_events.h>
19 #include <trace/events/mmflags.h>
20 #include "trace_probe.h"
21 #include "trace_probe_kernel.h"
23 #include "trace_synth.h"
27 C(BAD_NAME, "Illegal name"), \
28 C(INVALID_CMD, "Command must be of the form: <name> field[;field] ..."),\
29 C(INVALID_DYN_CMD, "Command must be of the form: s or -:[synthetic/]<name> field[;field] ..."),\
30 C(EVENT_EXISTS, "Event already exists"), \
31 C(TOO_MANY_FIELDS, "Too many fields"), \
32 C(INCOMPLETE_TYPE, "Incomplete type"), \
33 C(INVALID_TYPE, "Invalid type"), \
34 C(INVALID_FIELD, "Invalid field"), \
35 C(INVALID_ARRAY_SPEC, "Invalid array specification"),
38 #define C(a, b) SYNTH_ERR_##a
45 static const char *err_text[] = { ERRORS };
47 static DEFINE_MUTEX(lastcmd_mutex);
48 static char *last_cmd;
50 static int errpos(const char *str)
54 mutex_lock(&lastcmd_mutex);
55 if (!str || !last_cmd)
58 ret = err_pos(last_cmd, str);
60 mutex_unlock(&lastcmd_mutex);
64 static void last_cmd_set(const char *str)
69 mutex_lock(&lastcmd_mutex);
71 last_cmd = kstrdup(str, GFP_KERNEL);
72 mutex_unlock(&lastcmd_mutex);
75 static void synth_err(u8 err_type, u16 err_pos)
77 mutex_lock(&lastcmd_mutex);
81 tracing_log_err(NULL, "synthetic_events", last_cmd, err_text,
84 mutex_unlock(&lastcmd_mutex);
87 static int create_synth_event(const char *raw_command);
88 static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
89 static int synth_event_release(struct dyn_event *ev);
90 static bool synth_event_is_busy(struct dyn_event *ev);
91 static bool synth_event_match(const char *system, const char *event,
92 int argc, const char **argv, struct dyn_event *ev);
94 static struct dyn_event_operations synth_event_ops = {
95 .create = create_synth_event,
96 .show = synth_event_show,
97 .is_busy = synth_event_is_busy,
98 .free = synth_event_release,
99 .match = synth_event_match,
102 static bool is_synth_event(struct dyn_event *ev)
104 return ev->ops == &synth_event_ops;
107 static struct synth_event *to_synth_event(struct dyn_event *ev)
109 return container_of(ev, struct synth_event, devent);
112 static bool synth_event_is_busy(struct dyn_event *ev)
114 struct synth_event *event = to_synth_event(ev);
116 return event->ref != 0;
119 static bool synth_event_match(const char *system, const char *event,
120 int argc, const char **argv, struct dyn_event *ev)
122 struct synth_event *sev = to_synth_event(ev);
124 return strcmp(sev->name, event) == 0 &&
125 (!system || strcmp(system, SYNTH_SYSTEM) == 0);
128 struct synth_trace_event {
129 struct trace_entry ent;
133 static int synth_event_define_fields(struct trace_event_call *call)
135 struct synth_trace_event trace;
136 int offset = offsetof(typeof(trace), fields);
137 struct synth_event *event = call->data;
138 unsigned int i, size, n_u64;
143 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
144 size = event->fields[i]->size;
145 is_signed = event->fields[i]->is_signed;
146 type = event->fields[i]->type;
147 name = event->fields[i]->name;
148 ret = trace_define_field(call, type, name, offset, size,
149 is_signed, FILTER_OTHER);
153 event->fields[i]->offset = n_u64;
155 if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) {
156 offset += STR_VAR_LEN_MAX;
157 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
159 offset += sizeof(u64);
164 event->n_u64 = n_u64;
169 static bool synth_field_signed(char *type)
171 if (str_has_prefix(type, "u"))
173 if (strcmp(type, "gfp_t") == 0)
179 static int synth_field_is_string(char *type)
181 if (strstr(type, "char[") != NULL)
187 static int synth_field_string_size(char *type)
189 char buf[4], *end, *start;
193 start = strstr(type, "char[");
196 start += sizeof("char[") - 1;
198 end = strchr(type, ']');
199 if (!end || end < start || type + strlen(type) > end + 1)
207 return 0; /* variable-length string */
209 strncpy(buf, start, len);
212 err = kstrtouint(buf, 0, &size);
216 if (size > STR_VAR_LEN_MAX)
222 static int synth_field_size(char *type)
226 if (strcmp(type, "s64") == 0)
228 else if (strcmp(type, "u64") == 0)
230 else if (strcmp(type, "s32") == 0)
232 else if (strcmp(type, "u32") == 0)
234 else if (strcmp(type, "s16") == 0)
236 else if (strcmp(type, "u16") == 0)
238 else if (strcmp(type, "s8") == 0)
240 else if (strcmp(type, "u8") == 0)
242 else if (strcmp(type, "char") == 0)
244 else if (strcmp(type, "unsigned char") == 0)
245 size = sizeof(unsigned char);
246 else if (strcmp(type, "int") == 0)
248 else if (strcmp(type, "unsigned int") == 0)
249 size = sizeof(unsigned int);
250 else if (strcmp(type, "long") == 0)
252 else if (strcmp(type, "unsigned long") == 0)
253 size = sizeof(unsigned long);
254 else if (strcmp(type, "bool") == 0)
256 else if (strcmp(type, "pid_t") == 0)
257 size = sizeof(pid_t);
258 else if (strcmp(type, "gfp_t") == 0)
259 size = sizeof(gfp_t);
260 else if (synth_field_is_string(type))
261 size = synth_field_string_size(type);
266 static const char *synth_field_fmt(char *type)
268 const char *fmt = "%llu";
270 if (strcmp(type, "s64") == 0)
272 else if (strcmp(type, "u64") == 0)
274 else if (strcmp(type, "s32") == 0)
276 else if (strcmp(type, "u32") == 0)
278 else if (strcmp(type, "s16") == 0)
280 else if (strcmp(type, "u16") == 0)
282 else if (strcmp(type, "s8") == 0)
284 else if (strcmp(type, "u8") == 0)
286 else if (strcmp(type, "char") == 0)
288 else if (strcmp(type, "unsigned char") == 0)
290 else if (strcmp(type, "int") == 0)
292 else if (strcmp(type, "unsigned int") == 0)
294 else if (strcmp(type, "long") == 0)
296 else if (strcmp(type, "unsigned long") == 0)
298 else if (strcmp(type, "bool") == 0)
300 else if (strcmp(type, "pid_t") == 0)
302 else if (strcmp(type, "gfp_t") == 0)
304 else if (synth_field_is_string(type))
310 static void print_synth_event_num_val(struct trace_seq *s,
311 char *print_fmt, char *name,
312 int size, u64 val, char *space)
316 trace_seq_printf(s, print_fmt, name, (u8)val, space);
320 trace_seq_printf(s, print_fmt, name, (u16)val, space);
324 trace_seq_printf(s, print_fmt, name, (u32)val, space);
328 trace_seq_printf(s, print_fmt, name, val, space);
333 static enum print_line_t print_synth_event(struct trace_iterator *iter,
335 struct trace_event *event)
337 struct trace_array *tr = iter->tr;
338 struct trace_seq *s = &iter->seq;
339 struct synth_trace_event *entry;
340 struct synth_event *se;
341 unsigned int i, n_u64;
345 entry = (struct synth_trace_event *)iter->ent;
346 se = container_of(event, struct synth_event, call.event);
348 trace_seq_printf(s, "%s: ", se->name);
350 for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
351 if (trace_seq_has_overflowed(s))
354 fmt = synth_field_fmt(se->fields[i]->type);
356 /* parameter types */
357 if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
358 trace_seq_printf(s, "%s ", fmt);
360 snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
362 /* parameter values */
363 if (se->fields[i]->is_string) {
364 if (se->fields[i]->is_dynamic) {
365 u32 offset, data_offset;
368 offset = (u32)entry->fields[n_u64];
369 data_offset = offset & 0xffff;
371 str_field = (char *)entry + data_offset;
373 trace_seq_printf(s, print_fmt, se->fields[i]->name,
376 i == se->n_fields - 1 ? "" : " ");
379 trace_seq_printf(s, print_fmt, se->fields[i]->name,
381 (char *)&entry->fields[n_u64],
382 i == se->n_fields - 1 ? "" : " ");
383 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
386 struct trace_print_flags __flags[] = {
387 __def_gfpflag_names, {-1, NULL} };
388 char *space = (i == se->n_fields - 1 ? "" : " ");
390 print_synth_event_num_val(s, print_fmt,
393 entry->fields[n_u64],
396 if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
397 trace_seq_puts(s, " (");
398 trace_print_flags_seq(s, "|",
399 entry->fields[n_u64],
401 trace_seq_putc(s, ')');
407 trace_seq_putc(s, '\n');
409 return trace_handle_return(s);
412 static struct trace_event_functions synth_event_funcs = {
413 .trace = print_synth_event
416 static unsigned int trace_string(struct synth_trace_event *entry,
417 struct synth_event *event,
420 unsigned int data_size,
423 unsigned int len = 0;
430 data_offset = offsetof(typeof(*entry), fields);
431 data_offset += event->n_u64 * sizeof(u64);
432 data_offset += data_size;
434 len = kern_fetch_store_strlen((unsigned long)str_val);
436 data_offset |= len << 16;
437 *(u32 *)&entry->fields[*n_u64] = data_offset;
439 ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
443 str_field = (char *)&entry->fields[*n_u64];
445 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
446 if ((unsigned long)str_val < TASK_SIZE)
447 ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
450 ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
453 strcpy(str_field, FAULT_STRING);
455 (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
461 static notrace void trace_event_raw_event_synth(void *__data,
463 unsigned int *var_ref_idx)
465 unsigned int i, n_u64, val_idx, len, data_size = 0;
466 struct trace_event_file *trace_file = __data;
467 struct synth_trace_event *entry;
468 struct trace_event_buffer fbuffer;
469 struct trace_buffer *buffer;
470 struct synth_event *event;
473 event = trace_file->event_call->data;
475 if (trace_trigger_soft_disabled(trace_file))
478 fields_size = event->n_u64 * sizeof(u64);
480 for (i = 0; i < event->n_dynamic_fields; i++) {
481 unsigned int field_pos = event->dynamic_fields[i]->field_pos;
484 val_idx = var_ref_idx[field_pos];
485 str_val = (char *)(long)var_ref_vals[val_idx];
487 len = kern_fetch_store_strlen((unsigned long)str_val);
493 * Avoid ring buffer recursion detection, as this event
494 * is being performed within another event.
496 buffer = trace_file->tr->array_buffer.buffer;
497 ring_buffer_nest_start(buffer);
499 entry = trace_event_buffer_reserve(&fbuffer, trace_file,
500 sizeof(*entry) + fields_size);
504 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
505 val_idx = var_ref_idx[i];
506 if (event->fields[i]->is_string) {
507 char *str_val = (char *)(long)var_ref_vals[val_idx];
509 len = trace_string(entry, event, str_val,
510 event->fields[i]->is_dynamic,
512 data_size += len; /* only dynamic string increments */
514 struct synth_field *field = event->fields[i];
515 u64 val = var_ref_vals[val_idx];
517 switch (field->size) {
519 *(u8 *)&entry->fields[n_u64] = (u8)val;
523 *(u16 *)&entry->fields[n_u64] = (u16)val;
527 *(u32 *)&entry->fields[n_u64] = (u32)val;
531 entry->fields[n_u64] = val;
538 trace_event_buffer_commit(&fbuffer);
540 ring_buffer_nest_end(buffer);
543 static void free_synth_event_print_fmt(struct trace_event_call *call)
546 kfree(call->print_fmt);
547 call->print_fmt = NULL;
551 static int __set_synth_event_print_fmt(struct synth_event *event,
558 /* When len=0, we just calculate the needed length */
559 #define LEN_OR_ZERO (len ? len - pos : 0)
561 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
562 for (i = 0; i < event->n_fields; i++) {
563 fmt = synth_field_fmt(event->fields[i]->type);
564 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
565 event->fields[i]->name, fmt,
566 i == event->n_fields - 1 ? "" : ", ");
568 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
570 for (i = 0; i < event->n_fields; i++) {
571 if (event->fields[i]->is_string &&
572 event->fields[i]->is_dynamic)
573 pos += snprintf(buf + pos, LEN_OR_ZERO,
574 ", __get_str(%s)", event->fields[i]->name);
576 pos += snprintf(buf + pos, LEN_OR_ZERO,
577 ", REC->%s", event->fields[i]->name);
582 /* return the length of print_fmt */
586 static int set_synth_event_print_fmt(struct trace_event_call *call)
588 struct synth_event *event = call->data;
592 /* First: called with 0 length to calculate the needed length */
593 len = __set_synth_event_print_fmt(event, NULL, 0);
595 print_fmt = kmalloc(len + 1, GFP_KERNEL);
599 /* Second: actually write the @print_fmt */
600 __set_synth_event_print_fmt(event, print_fmt, len + 1);
601 call->print_fmt = print_fmt;
606 static void free_synth_field(struct synth_field *field)
613 static int check_field_version(const char *prefix, const char *field_type,
614 const char *field_name)
617 * For backward compatibility, the old synthetic event command
618 * format did not require semicolons, and in order to not
619 * break user space, that old format must still work. If a new
620 * feature is added, then the format that uses the new feature
621 * will be required to have semicolons, as nothing that uses
622 * the old format would be using the new, yet to be created,
623 * feature. When a new feature is added, this will detect it,
624 * and return a number greater than 1, and require the format
630 static struct synth_field *parse_synth_field(int argc, char **argv,
631 int *consumed, int *field_version)
633 const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
634 struct synth_field *field;
635 int len, ret = -ENOMEM;
639 if (!strcmp(field_type, "unsigned")) {
641 synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));
642 return ERR_PTR(-EINVAL);
644 prefix = "unsigned ";
645 field_type = argv[1];
646 field_name = argv[2];
649 field_name = argv[1];
654 synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type));
655 return ERR_PTR(-EINVAL);
658 *field_version = check_field_version(prefix, field_type, field_name);
660 field = kzalloc(sizeof(*field), GFP_KERNEL);
662 return ERR_PTR(-ENOMEM);
664 len = strlen(field_name);
665 array = strchr(field_name, '[');
667 len -= strlen(array);
669 field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
673 if (!is_good_name(field->name)) {
674 synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));
679 len = strlen(field_type) + 1;
682 len += strlen(array);
685 len += strlen(prefix);
687 field->type = kzalloc(len, GFP_KERNEL);
691 seq_buf_init(&s, field->type, len);
693 seq_buf_puts(&s, prefix);
694 seq_buf_puts(&s, field_type);
696 seq_buf_puts(&s, array);
697 if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
700 s.buffer[s.len] = '\0';
702 size = synth_field_size(field->type);
705 synth_err(SYNTH_ERR_INVALID_ARRAY_SPEC, errpos(field_name));
707 synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
710 } else if (size == 0) {
711 if (synth_field_is_string(field->type)) {
714 len = sizeof("__data_loc ") + strlen(field->type) + 1;
715 type = kzalloc(len, GFP_KERNEL);
719 seq_buf_init(&s, type, len);
720 seq_buf_puts(&s, "__data_loc ");
721 seq_buf_puts(&s, field->type);
723 if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
725 s.buffer[s.len] = '\0';
730 field->is_dynamic = true;
733 synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
740 if (synth_field_is_string(field->type))
741 field->is_string = true;
743 field->is_signed = synth_field_signed(field->type);
747 free_synth_field(field);
748 field = ERR_PTR(ret);
752 static void free_synth_tracepoint(struct tracepoint *tp)
761 static struct tracepoint *alloc_synth_tracepoint(char *name)
763 struct tracepoint *tp;
765 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
767 return ERR_PTR(-ENOMEM);
769 tp->name = kstrdup(name, GFP_KERNEL);
772 return ERR_PTR(-ENOMEM);
778 struct synth_event *find_synth_event(const char *name)
780 struct dyn_event *pos;
781 struct synth_event *event;
783 for_each_dyn_event(pos) {
784 if (!is_synth_event(pos))
786 event = to_synth_event(pos);
787 if (strcmp(event->name, name) == 0)
794 static struct trace_event_fields synth_event_fields_array[] = {
795 { .type = TRACE_FUNCTION_TYPE,
796 .define_fields = synth_event_define_fields },
800 static int register_synth_event(struct synth_event *event)
802 struct trace_event_call *call = &event->call;
805 event->call.class = &event->class;
806 event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
807 if (!event->class.system) {
812 event->tp = alloc_synth_tracepoint(event->name);
813 if (IS_ERR(event->tp)) {
814 ret = PTR_ERR(event->tp);
819 INIT_LIST_HEAD(&call->class->fields);
820 call->event.funcs = &synth_event_funcs;
821 call->class->fields_array = synth_event_fields_array;
823 ret = register_trace_event(&call->event);
828 call->flags = TRACE_EVENT_FL_TRACEPOINT;
829 call->class->reg = trace_event_reg;
830 call->class->probe = trace_event_raw_event_synth;
832 call->tp = event->tp;
834 ret = trace_add_event_call(call);
836 pr_warn("Failed to register synthetic event: %s\n",
837 trace_event_name(call));
841 ret = set_synth_event_print_fmt(call);
842 /* unregister_trace_event() will be called inside */
844 trace_remove_event_call(call);
848 unregister_trace_event(&call->event);
852 static int unregister_synth_event(struct synth_event *event)
854 struct trace_event_call *call = &event->call;
857 ret = trace_remove_event_call(call);
862 static void free_synth_event(struct synth_event *event)
869 for (i = 0; i < event->n_fields; i++)
870 free_synth_field(event->fields[i]);
872 kfree(event->fields);
873 kfree(event->dynamic_fields);
875 kfree(event->class.system);
876 free_synth_tracepoint(event->tp);
877 free_synth_event_print_fmt(&event->call);
881 static struct synth_event *alloc_synth_event(const char *name, int n_fields,
882 struct synth_field **fields)
884 unsigned int i, j, n_dynamic_fields = 0;
885 struct synth_event *event;
887 event = kzalloc(sizeof(*event), GFP_KERNEL);
889 event = ERR_PTR(-ENOMEM);
893 event->name = kstrdup(name, GFP_KERNEL);
896 event = ERR_PTR(-ENOMEM);
900 event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
901 if (!event->fields) {
902 free_synth_event(event);
903 event = ERR_PTR(-ENOMEM);
907 for (i = 0; i < n_fields; i++)
908 if (fields[i]->is_dynamic)
911 if (n_dynamic_fields) {
912 event->dynamic_fields = kcalloc(n_dynamic_fields,
913 sizeof(*event->dynamic_fields),
915 if (!event->dynamic_fields) {
916 free_synth_event(event);
917 event = ERR_PTR(-ENOMEM);
922 dyn_event_init(&event->devent, &synth_event_ops);
924 for (i = 0, j = 0; i < n_fields; i++) {
925 fields[i]->field_pos = i;
926 event->fields[i] = fields[i];
928 if (fields[i]->is_dynamic)
929 event->dynamic_fields[j++] = fields[i];
931 event->n_dynamic_fields = j;
932 event->n_fields = n_fields;
937 static int synth_event_check_arg_fn(void *data)
939 struct dynevent_arg_pair *arg_pair = data;
942 size = synth_field_size((char *)arg_pair->lhs);
944 if (strstr((char *)arg_pair->lhs, "["))
948 return size ? 0 : -EINVAL;
952 * synth_event_add_field - Add a new field to a synthetic event cmd
953 * @cmd: A pointer to the dynevent_cmd struct representing the new event
954 * @type: The type of the new field to add
955 * @name: The name of the new field to add
957 * Add a new field to a synthetic event cmd object. Field ordering is in
958 * the same order the fields are added.
960 * See synth_field_size() for available types. If field_name contains
961 * [n] the field is considered to be an array.
963 * Return: 0 if successful, error otherwise.
965 int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
968 struct dynevent_arg_pair arg_pair;
971 if (cmd->type != DYNEVENT_TYPE_SYNTH)
977 dynevent_arg_pair_init(&arg_pair, 0, ';');
982 ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
986 if (++cmd->n_fields > SYNTH_FIELDS_MAX)
991 EXPORT_SYMBOL_GPL(synth_event_add_field);
994 * synth_event_add_field_str - Add a new field to a synthetic event cmd
995 * @cmd: A pointer to the dynevent_cmd struct representing the new event
996 * @type_name: The type and name of the new field to add, as a single string
998 * Add a new field to a synthetic event cmd object, as a single
999 * string. The @type_name string is expected to be of the form 'type
1000 * name', which will be appended by ';'. No sanity checking is done -
1001 * what's passed in is assumed to already be well-formed. Field
1002 * ordering is in the same order the fields are added.
1004 * See synth_field_size() for available types. If field_name contains
1005 * [n] the field is considered to be an array.
1007 * Return: 0 if successful, error otherwise.
1009 int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
1011 struct dynevent_arg arg;
1014 if (cmd->type != DYNEVENT_TYPE_SYNTH)
1020 dynevent_arg_init(&arg, ';');
1022 arg.str = type_name;
1024 ret = dynevent_arg_add(cmd, &arg, NULL);
1028 if (++cmd->n_fields > SYNTH_FIELDS_MAX)
1033 EXPORT_SYMBOL_GPL(synth_event_add_field_str);
1036 * synth_event_add_fields - Add multiple fields to a synthetic event cmd
1037 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1038 * @fields: An array of type/name field descriptions
1039 * @n_fields: The number of field descriptions contained in the fields array
1041 * Add a new set of fields to a synthetic event cmd object. The event
1042 * fields that will be defined for the event should be passed in as an
1043 * array of struct synth_field_desc, and the number of elements in the
1044 * array passed in as n_fields. Field ordering will retain the
1045 * ordering given in the fields array.
1047 * See synth_field_size() for available types. If field_name contains
1048 * [n] the field is considered to be an array.
1050 * Return: 0 if successful, error otherwise.
1052 int synth_event_add_fields(struct dynevent_cmd *cmd,
1053 struct synth_field_desc *fields,
1054 unsigned int n_fields)
1059 for (i = 0; i < n_fields; i++) {
1060 if (fields[i].type == NULL || fields[i].name == NULL) {
1065 ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
1072 EXPORT_SYMBOL_GPL(synth_event_add_fields);
1075 * __synth_event_gen_cmd_start - Start a synthetic event command from arg list
1076 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1077 * @name: The name of the synthetic event
1078 * @mod: The module creating the event, NULL if not created from a module
1079 * @args: Variable number of arg (pairs), one pair for each field
1081 * NOTE: Users normally won't want to call this function directly, but
1082 * rather use the synth_event_gen_cmd_start() wrapper, which
1083 * automatically adds a NULL to the end of the arg list. If this
1084 * function is used directly, make sure the last arg in the variable
1087 * Generate a synthetic event command to be executed by
1088 * synth_event_gen_cmd_end(). This function can be used to generate
1089 * the complete command or only the first part of it; in the latter
1090 * case, synth_event_add_field(), synth_event_add_field_str(), or
1091 * synth_event_add_fields() can be used to add more fields following
1094 * There should be an even number variable args, each pair consisting
1095 * of a type followed by a field name.
1097 * See synth_field_size() for available types. If field_name contains
1098 * [n] the field is considered to be an array.
1100 * Return: 0 if successful, error otherwise.
1102 int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
1103 struct module *mod, ...)
1105 struct dynevent_arg arg;
1109 cmd->event_name = name;
1110 cmd->private_data = mod;
1112 if (cmd->type != DYNEVENT_TYPE_SYNTH)
1115 dynevent_arg_init(&arg, 0);
1117 ret = dynevent_arg_add(cmd, &arg, NULL);
1121 va_start(args, mod);
1123 const char *type, *name;
1125 type = va_arg(args, const char *);
1128 name = va_arg(args, const char *);
1132 if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
1137 ret = synth_event_add_field(cmd, type, name);
1145 EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
1148 * synth_event_gen_cmd_array_start - Start synthetic event command from an array
1149 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1150 * @name: The name of the synthetic event
1151 * @fields: An array of type/name field descriptions
1152 * @n_fields: The number of field descriptions contained in the fields array
1154 * Generate a synthetic event command to be executed by
1155 * synth_event_gen_cmd_end(). This function can be used to generate
1156 * the complete command or only the first part of it; in the latter
1157 * case, synth_event_add_field(), synth_event_add_field_str(), or
1158 * synth_event_add_fields() can be used to add more fields following
1161 * The event fields that will be defined for the event should be
1162 * passed in as an array of struct synth_field_desc, and the number of
1163 * elements in the array passed in as n_fields. Field ordering will
1164 * retain the ordering given in the fields array.
1166 * See synth_field_size() for available types. If field_name contains
1167 * [n] the field is considered to be an array.
1169 * Return: 0 if successful, error otherwise.
1171 int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
1173 struct synth_field_desc *fields,
1174 unsigned int n_fields)
1176 struct dynevent_arg arg;
1180 cmd->event_name = name;
1181 cmd->private_data = mod;
1183 if (cmd->type != DYNEVENT_TYPE_SYNTH)
1186 if (n_fields > SYNTH_FIELDS_MAX)
1189 dynevent_arg_init(&arg, 0);
1191 ret = dynevent_arg_add(cmd, &arg, NULL);
1195 for (i = 0; i < n_fields; i++) {
1196 if (fields[i].type == NULL || fields[i].name == NULL)
1199 ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
1206 EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
1208 static int __create_synth_event(const char *name, const char *raw_fields)
1210 char **argv, *field_str, *tmp_fields, *saved_fields = NULL;
1211 struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
1212 int consumed, cmd_version = 1, n_fields_this_loop;
1213 int i, argc, n_fields = 0, ret = 0;
1214 struct synth_event *event = NULL;
1218 * - Add synthetic event: <event_name> field[;field] ...
1219 * - Remove synthetic event: !<event_name> field[;field] ...
1220 * where 'field' = type field_name
1223 if (name[0] == '\0') {
1224 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1228 if (!is_good_name(name)) {
1229 synth_err(SYNTH_ERR_BAD_NAME, errpos(name));
1233 mutex_lock(&event_mutex);
1235 event = find_synth_event(name);
1237 synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name));
1242 tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL);
1248 while ((field_str = strsep(&tmp_fields, ";")) != NULL) {
1249 argv = argv_split(GFP_KERNEL, field_str, &argc);
1260 n_fields_this_loop = 0;
1262 while (argc > consumed) {
1265 field = parse_synth_field(argc - consumed,
1266 argv + consumed, &consumed,
1268 if (IS_ERR(field)) {
1269 ret = PTR_ERR(field);
1274 * Track the highest version of any field we
1275 * found in the command.
1277 if (field_version > cmd_version)
1278 cmd_version = field_version;
1281 * Now sort out what is and isn't valid for
1282 * each supported version.
1284 * If we see more than 1 field per loop, it
1285 * means we have multiple fields between
1286 * semicolons, and that's something we no
1287 * longer support in a version 2 or greater
1290 if (cmd_version > 1 && n_fields_this_loop >= 1) {
1291 synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str));
1296 if (n_fields == SYNTH_FIELDS_MAX) {
1297 synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);
1301 fields[n_fields++] = field;
1303 n_fields_this_loop++;
1307 if (consumed < argc) {
1308 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1315 if (n_fields == 0) {
1316 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1321 event = alloc_synth_event(name, n_fields, fields);
1322 if (IS_ERR(event)) {
1323 ret = PTR_ERR(event);
1327 ret = register_synth_event(event);
1329 dyn_event_add(&event->devent, &event->call);
1331 free_synth_event(event);
1333 mutex_unlock(&event_mutex);
1335 kfree(saved_fields);
1341 for (i = 0; i < n_fields; i++)
1342 free_synth_field(fields[i]);
1348 * synth_event_create - Create a new synthetic event
1349 * @name: The name of the new synthetic event
1350 * @fields: An array of type/name field descriptions
1351 * @n_fields: The number of field descriptions contained in the fields array
1352 * @mod: The module creating the event, NULL if not created from a module
1354 * Create a new synthetic event with the given name under the
1355 * trace/events/synthetic/ directory. The event fields that will be
1356 * defined for the event should be passed in as an array of struct
1357 * synth_field_desc, and the number elements in the array passed in as
1358 * n_fields. Field ordering will retain the ordering given in the
1361 * If the new synthetic event is being created from a module, the mod
1362 * param must be non-NULL. This will ensure that the trace buffer
1363 * won't contain unreadable events.
1365 * The new synth event should be deleted using synth_event_delete()
1366 * function. The new synthetic event can be generated from modules or
1367 * other kernel code using trace_synth_event() and related functions.
1369 * Return: 0 if successful, error otherwise.
1371 int synth_event_create(const char *name, struct synth_field_desc *fields,
1372 unsigned int n_fields, struct module *mod)
1374 struct dynevent_cmd cmd;
1378 buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
1382 synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
1384 ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
1389 ret = synth_event_gen_cmd_end(&cmd);
1395 EXPORT_SYMBOL_GPL(synth_event_create);
1397 static int destroy_synth_event(struct synth_event *se)
1404 if (trace_event_dyn_busy(&se->call))
1407 ret = unregister_synth_event(se);
1409 dyn_event_remove(&se->devent);
1410 free_synth_event(se);
1417 * synth_event_delete - Delete a synthetic event
1418 * @event_name: The name of the new synthetic event
1420 * Delete a synthetic event that was created with synth_event_create().
1422 * Return: 0 if successful, error otherwise.
1424 int synth_event_delete(const char *event_name)
1426 struct synth_event *se = NULL;
1427 struct module *mod = NULL;
1430 mutex_lock(&event_mutex);
1431 se = find_synth_event(event_name);
1434 ret = destroy_synth_event(se);
1436 mutex_unlock(&event_mutex);
1440 * It is safest to reset the ring buffer if the module
1441 * being unloaded registered any events that were
1442 * used. The only worry is if a new module gets
1443 * loaded, and takes on the same id as the events of
1444 * this module. When printing out the buffer, traced
1445 * events left over from this module may be passed to
1446 * the new module events and unexpected results may
1449 tracing_reset_all_online_cpus();
1454 EXPORT_SYMBOL_GPL(synth_event_delete);
1456 static int check_command(const char *raw_command)
1458 char **argv = NULL, *cmd, *saved_cmd, *name_and_field;
1461 cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL);
1465 name_and_field = strsep(&cmd, ";");
1466 if (!name_and_field) {
1471 if (name_and_field[0] == '!')
1474 argv = argv_split(GFP_KERNEL, name_and_field, &argc);
1489 static int create_or_delete_synth_event(const char *raw_command)
1491 char *name = NULL, *fields, *p;
1494 raw_command = skip_spaces(raw_command);
1495 if (raw_command[0] == '\0')
1498 last_cmd_set(raw_command);
1500 ret = check_command(raw_command);
1502 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1506 p = strpbrk(raw_command, " \t");
1507 if (!p && raw_command[0] != '!') {
1508 synth_err(SYNTH_ERR_INVALID_CMD, 0);
1513 name = kmemdup_nul(raw_command, p ? p - raw_command : strlen(raw_command), GFP_KERNEL);
1517 if (name[0] == '!') {
1518 ret = synth_event_delete(name + 1);
1522 fields = skip_spaces(p);
1524 ret = __create_synth_event(name, fields);
1531 static int synth_event_run_command(struct dynevent_cmd *cmd)
1533 struct synth_event *se;
1536 ret = create_or_delete_synth_event(cmd->seq.buffer);
1540 se = find_synth_event(cmd->event_name);
1544 se->mod = cmd->private_data;
1550 * synth_event_cmd_init - Initialize a synthetic event command object
1551 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1552 * @buf: A pointer to the buffer used to build the command
1553 * @maxlen: The length of the buffer passed in @buf
1555 * Initialize a synthetic event command object. Use this before
1556 * calling any of the other dyenvent_cmd functions.
1558 void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
1560 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
1561 synth_event_run_command);
1563 EXPORT_SYMBOL_GPL(synth_event_cmd_init);
1566 __synth_event_trace_init(struct trace_event_file *file,
1567 struct synth_event_trace_state *trace_state)
1571 memset(trace_state, '\0', sizeof(*trace_state));
1574 * Normal event tracing doesn't get called at all unless the
1575 * ENABLED bit is set (which attaches the probe thus allowing
1576 * this code to be called, etc). Because this is called
1577 * directly by the user, we don't have that but we still need
1578 * to honor not logging when disabled. For the iterated
1579 * trace case, we save the enabled state upon start and just
1580 * ignore the following data calls.
1582 if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
1583 trace_trigger_soft_disabled(file)) {
1584 trace_state->disabled = true;
1589 trace_state->event = file->event_call->data;
1595 __synth_event_trace_start(struct trace_event_file *file,
1596 struct synth_event_trace_state *trace_state,
1597 int dynamic_fields_size)
1599 int entry_size, fields_size = 0;
1602 fields_size = trace_state->event->n_u64 * sizeof(u64);
1603 fields_size += dynamic_fields_size;
1606 * Avoid ring buffer recursion detection, as this event
1607 * is being performed within another event.
1609 trace_state->buffer = file->tr->array_buffer.buffer;
1610 ring_buffer_nest_start(trace_state->buffer);
1612 entry_size = sizeof(*trace_state->entry) + fields_size;
1613 trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
1616 if (!trace_state->entry) {
1617 ring_buffer_nest_end(trace_state->buffer);
1625 __synth_event_trace_end(struct synth_event_trace_state *trace_state)
1627 trace_event_buffer_commit(&trace_state->fbuffer);
1629 ring_buffer_nest_end(trace_state->buffer);
1633 * synth_event_trace - Trace a synthetic event
1634 * @file: The trace_event_file representing the synthetic event
1635 * @n_vals: The number of values in vals
1636 * @args: Variable number of args containing the event values
1638 * Trace a synthetic event using the values passed in the variable
1641 * The argument list should be a list 'n_vals' u64 values. The number
1642 * of vals must match the number of field in the synthetic event, and
1643 * must be in the same order as the synthetic event fields.
1645 * All vals should be cast to u64, and string vals are just pointers
1646 * to strings, cast to u64. Strings will be copied into space
1647 * reserved in the event for the string, using these pointers.
1649 * Return: 0 on success, err otherwise.
1651 int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
1653 unsigned int i, n_u64, len, data_size = 0;
1654 struct synth_event_trace_state state;
1658 ret = __synth_event_trace_init(file, &state);
1661 ret = 0; /* just disabled, not really an error */
1665 if (state.event->n_dynamic_fields) {
1666 va_start(args, n_vals);
1668 for (i = 0; i < state.event->n_fields; i++) {
1669 u64 val = va_arg(args, u64);
1671 if (state.event->fields[i]->is_string &&
1672 state.event->fields[i]->is_dynamic) {
1673 char *str_val = (char *)(long)val;
1675 data_size += strlen(str_val) + 1;
1682 ret = __synth_event_trace_start(file, &state, data_size);
1686 if (n_vals != state.event->n_fields) {
1693 va_start(args, n_vals);
1694 for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
1697 val = va_arg(args, u64);
1699 if (state.event->fields[i]->is_string) {
1700 char *str_val = (char *)(long)val;
1702 len = trace_string(state.entry, state.event, str_val,
1703 state.event->fields[i]->is_dynamic,
1705 data_size += len; /* only dynamic string increments */
1707 struct synth_field *field = state.event->fields[i];
1709 switch (field->size) {
1711 *(u8 *)&state.entry->fields[n_u64] = (u8)val;
1715 *(u16 *)&state.entry->fields[n_u64] = (u16)val;
1719 *(u32 *)&state.entry->fields[n_u64] = (u32)val;
1723 state.entry->fields[n_u64] = val;
1731 __synth_event_trace_end(&state);
1735 EXPORT_SYMBOL_GPL(synth_event_trace);
1738 * synth_event_trace_array - Trace a synthetic event from an array
1739 * @file: The trace_event_file representing the synthetic event
1740 * @vals: Array of values
1741 * @n_vals: The number of values in vals
1743 * Trace a synthetic event using the values passed in as 'vals'.
1745 * The 'vals' array is just an array of 'n_vals' u64. The number of
1746 * vals must match the number of field in the synthetic event, and
1747 * must be in the same order as the synthetic event fields.
1749 * All vals should be cast to u64, and string vals are just pointers
1750 * to strings, cast to u64. Strings will be copied into space
1751 * reserved in the event for the string, using these pointers.
1753 * Return: 0 on success, err otherwise.
1755 int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
1756 unsigned int n_vals)
1758 unsigned int i, n_u64, field_pos, len, data_size = 0;
1759 struct synth_event_trace_state state;
1763 ret = __synth_event_trace_init(file, &state);
1766 ret = 0; /* just disabled, not really an error */
1770 if (state.event->n_dynamic_fields) {
1771 for (i = 0; i < state.event->n_dynamic_fields; i++) {
1772 field_pos = state.event->dynamic_fields[i]->field_pos;
1773 str_val = (char *)(long)vals[field_pos];
1774 len = strlen(str_val) + 1;
1779 ret = __synth_event_trace_start(file, &state, data_size);
1783 if (n_vals != state.event->n_fields) {
1790 for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
1791 if (state.event->fields[i]->is_string) {
1792 char *str_val = (char *)(long)vals[i];
1794 len = trace_string(state.entry, state.event, str_val,
1795 state.event->fields[i]->is_dynamic,
1797 data_size += len; /* only dynamic string increments */
1799 struct synth_field *field = state.event->fields[i];
1802 switch (field->size) {
1804 *(u8 *)&state.entry->fields[n_u64] = (u8)val;
1808 *(u16 *)&state.entry->fields[n_u64] = (u16)val;
1812 *(u32 *)&state.entry->fields[n_u64] = (u32)val;
1816 state.entry->fields[n_u64] = val;
1823 __synth_event_trace_end(&state);
1827 EXPORT_SYMBOL_GPL(synth_event_trace_array);
1830 * synth_event_trace_start - Start piecewise synthetic event trace
1831 * @file: The trace_event_file representing the synthetic event
1832 * @trace_state: A pointer to object tracking the piecewise trace state
1834 * Start the trace of a synthetic event field-by-field rather than all
1837 * This function 'opens' an event trace, which means space is reserved
1838 * for the event in the trace buffer, after which the event's
1839 * individual field values can be set through either
1840 * synth_event_add_next_val() or synth_event_add_val().
1842 * A pointer to a trace_state object is passed in, which will keep
1843 * track of the current event trace state until the event trace is
1844 * closed (and the event finally traced) using
1845 * synth_event_trace_end().
1847 * Note that synth_event_trace_end() must be called after all values
1848 * have been added for each event trace, regardless of whether adding
1849 * all field values succeeded or not.
1851 * Note also that for a given event trace, all fields must be added
1852 * using either synth_event_add_next_val() or synth_event_add_val()
1853 * but not both together or interleaved.
1855 * Return: 0 on success, err otherwise.
1857 int synth_event_trace_start(struct trace_event_file *file,
1858 struct synth_event_trace_state *trace_state)
1865 ret = __synth_event_trace_init(file, trace_state);
1868 ret = 0; /* just disabled, not really an error */
1872 if (trace_state->event->n_dynamic_fields)
1875 ret = __synth_event_trace_start(file, trace_state, 0);
1879 EXPORT_SYMBOL_GPL(synth_event_trace_start);
1881 static int __synth_event_add_val(const char *field_name, u64 val,
1882 struct synth_event_trace_state *trace_state)
1884 struct synth_field *field = NULL;
1885 struct synth_trace_event *entry;
1886 struct synth_event *event;
1894 /* can't mix add_next_synth_val() with add_synth_val() */
1896 if (trace_state->add_next) {
1900 trace_state->add_name = true;
1902 if (trace_state->add_name) {
1906 trace_state->add_next = true;
1909 if (trace_state->disabled)
1912 event = trace_state->event;
1913 if (trace_state->add_name) {
1914 for (i = 0; i < event->n_fields; i++) {
1915 field = event->fields[i];
1916 if (strcmp(field->name, field_name) == 0)
1924 if (trace_state->cur_field >= event->n_fields) {
1928 field = event->fields[trace_state->cur_field++];
1931 entry = trace_state->entry;
1932 if (field->is_string) {
1933 char *str_val = (char *)(long)val;
1936 if (field->is_dynamic) { /* add_val can't do dynamic strings */
1946 str_field = (char *)&entry->fields[field->offset];
1947 strscpy(str_field, str_val, STR_VAR_LEN_MAX);
1949 switch (field->size) {
1951 *(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
1955 *(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
1959 *(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
1963 trace_state->entry->fields[field->offset] = val;
1972 * synth_event_add_next_val - Add the next field's value to an open synth trace
1973 * @val: The value to set the next field to
1974 * @trace_state: A pointer to object tracking the piecewise trace state
1976 * Set the value of the next field in an event that's been opened by
1977 * synth_event_trace_start().
1979 * The val param should be the value cast to u64. If the value points
1980 * to a string, the val param should be a char * cast to u64.
1982 * This function assumes all the fields in an event are to be set one
1983 * after another - successive calls to this function are made, one for
1984 * each field, in the order of the fields in the event, until all
1985 * fields have been set. If you'd rather set each field individually
1986 * without regard to ordering, synth_event_add_val() can be used
1989 * Note however that synth_event_add_next_val() and
1990 * synth_event_add_val() can't be intermixed for a given event trace -
1991 * one or the other but not both can be used at the same time.
1993 * Note also that synth_event_trace_end() must be called after all
1994 * values have been added for each event trace, regardless of whether
1995 * adding all field values succeeded or not.
1997 * Return: 0 on success, err otherwise.
1999 int synth_event_add_next_val(u64 val,
2000 struct synth_event_trace_state *trace_state)
2002 return __synth_event_add_val(NULL, val, trace_state);
2004 EXPORT_SYMBOL_GPL(synth_event_add_next_val);
2007 * synth_event_add_val - Add a named field's value to an open synth trace
2008 * @field_name: The name of the synthetic event field value to set
2009 * @val: The value to set the named field to
2010 * @trace_state: A pointer to object tracking the piecewise trace state
2012 * Set the value of the named field in an event that's been opened by
2013 * synth_event_trace_start().
2015 * The val param should be the value cast to u64. If the value points
2016 * to a string, the val param should be a char * cast to u64.
2018 * This function looks up the field name, and if found, sets the field
2019 * to the specified value. This lookup makes this function more
2020 * expensive than synth_event_add_next_val(), so use that or the
2021 * none-piecewise synth_event_trace() instead if efficiency is more
2024 * Note however that synth_event_add_next_val() and
2025 * synth_event_add_val() can't be intermixed for a given event trace -
2026 * one or the other but not both can be used at the same time.
2028 * Note also that synth_event_trace_end() must be called after all
2029 * values have been added for each event trace, regardless of whether
2030 * adding all field values succeeded or not.
2032 * Return: 0 on success, err otherwise.
2034 int synth_event_add_val(const char *field_name, u64 val,
2035 struct synth_event_trace_state *trace_state)
2037 return __synth_event_add_val(field_name, val, trace_state);
2039 EXPORT_SYMBOL_GPL(synth_event_add_val);
2042 * synth_event_trace_end - End piecewise synthetic event trace
2043 * @trace_state: A pointer to object tracking the piecewise trace state
2045 * End the trace of a synthetic event opened by
2046 * synth_event_trace__start().
2048 * This function 'closes' an event trace, which basically means that
2049 * it commits the reserved event and cleans up other loose ends.
2051 * A pointer to a trace_state object is passed in, which will keep
2052 * track of the current event trace state opened with
2053 * synth_event_trace_start().
2055 * Note that this function must be called after all values have been
2056 * added for each event trace, regardless of whether adding all field
2057 * values succeeded or not.
2059 * Return: 0 on success, err otherwise.
2061 int synth_event_trace_end(struct synth_event_trace_state *trace_state)
2066 __synth_event_trace_end(trace_state);
2070 EXPORT_SYMBOL_GPL(synth_event_trace_end);
2072 static int create_synth_event(const char *raw_command)
2078 raw_command = skip_spaces(raw_command);
2079 if (raw_command[0] == '\0')
2082 last_cmd_set(raw_command);
2086 /* Don't try to process if not our system */
2087 if (name[0] != 's' || name[1] != ':')
2091 p = strpbrk(raw_command, " \t");
2093 synth_err(SYNTH_ERR_INVALID_CMD, 0);
2097 fields = skip_spaces(p);
2099 /* This interface accepts group name prefix */
2100 if (strchr(name, '/')) {
2101 len = str_has_prefix(name, SYNTH_SYSTEM "/");
2103 synth_err(SYNTH_ERR_INVALID_DYN_CMD, 0);
2109 len = name - raw_command;
2111 ret = check_command(raw_command + len);
2113 synth_err(SYNTH_ERR_INVALID_CMD, 0);
2117 name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL);
2121 ret = __create_synth_event(name, fields);
2128 static int synth_event_release(struct dyn_event *ev)
2130 struct synth_event *event = to_synth_event(ev);
2136 if (trace_event_dyn_busy(&event->call))
2139 ret = unregister_synth_event(event);
2143 dyn_event_remove(ev);
2144 free_synth_event(event);
2148 static int __synth_event_show(struct seq_file *m, struct synth_event *event)
2150 struct synth_field *field;
2154 seq_printf(m, "%s\t", event->name);
2156 for (i = 0; i < event->n_fields; i++) {
2157 field = event->fields[i];
2160 t = strstr(type, "__data_loc");
2161 if (t) { /* __data_loc belongs in format but not event desc */
2162 t += sizeof("__data_loc");
2166 /* parameter values */
2167 seq_printf(m, "%s %s%s", type, field->name,
2168 i == event->n_fields - 1 ? "" : "; ");
2176 static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
2178 struct synth_event *event = to_synth_event(ev);
2180 seq_printf(m, "s:%s/", event->class.system);
2182 return __synth_event_show(m, event);
2185 static int synth_events_seq_show(struct seq_file *m, void *v)
2187 struct dyn_event *ev = v;
2189 if (!is_synth_event(ev))
2192 return __synth_event_show(m, to_synth_event(ev));
2195 static const struct seq_operations synth_events_seq_op = {
2196 .start = dyn_event_seq_start,
2197 .next = dyn_event_seq_next,
2198 .stop = dyn_event_seq_stop,
2199 .show = synth_events_seq_show,
2202 static int synth_events_open(struct inode *inode, struct file *file)
2206 ret = security_locked_down(LOCKDOWN_TRACEFS);
2210 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
2211 ret = dyn_events_release_all(&synth_event_ops);
2216 return seq_open(file, &synth_events_seq_op);
2219 static ssize_t synth_events_write(struct file *file,
2220 const char __user *buffer,
2221 size_t count, loff_t *ppos)
2223 return trace_parse_run_command(file, buffer, count, ppos,
2224 create_or_delete_synth_event);
2227 static const struct file_operations synth_events_fops = {
2228 .open = synth_events_open,
2229 .write = synth_events_write,
2231 .llseek = seq_lseek,
2232 .release = seq_release,
2236 * Register dynevent at core_initcall. This allows kernel to setup kprobe
2237 * events in postcore_initcall without tracefs.
2239 static __init int trace_events_synth_init_early(void)
2243 err = dyn_event_register(&synth_event_ops);
2245 pr_warn("Could not register synth_event_ops\n");
2249 core_initcall(trace_events_synth_init_early);
2251 static __init int trace_events_synth_init(void)
2253 struct dentry *entry = NULL;
2255 err = tracing_init_dentry();
2259 entry = tracefs_create_file("synthetic_events", TRACE_MODE_WRITE,
2260 NULL, NULL, &synth_events_fops);
2268 pr_warn("Could not create tracefs 'synthetic_events' entry\n");
2273 fs_initcall(trace_events_synth_init);