diff options
Diffstat (limited to '')
| -rw-r--r-- | src/tracefs-hist.c | 2401 |
1 files changed, 2401 insertions, 0 deletions
diff --git a/src/tracefs-hist.c b/src/tracefs-hist.c new file mode 100644 index 0000000..fb6231e --- /dev/null +++ b/src/tracefs-hist.c @@ -0,0 +1,2401 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * Copyright (C) 2021 VMware Inc, Steven Rostedt <rostedt@goodmis.org> + * + * Updates: + * Copyright (C) 2021, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com> + * + */ +#include <stdio.h> +#include <stdlib.h> +#include <dirent.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <sys/time.h> +#include <sys/types.h> + +#include "tracefs.h" +#include "tracefs-local.h" + +#define HIST_FILE "hist" + +#define ASCENDING ".ascending" +#define DESCENDING ".descending" + +#define SYNTHETIC_GROUP "synthetic" + +struct tracefs_hist { + struct tep_handle *tep; + struct tep_event *event; + char *system; + char *event_name; + char *name; + char **keys; + char **values; + char **sort; + char *filter; + int size; + unsigned int filter_parens; + unsigned int filter_state; +}; + +/* + * tracefs_hist_get_name - get the name of the histogram + * @hist: The histogram to get the name for + * + * Returns name string owned by @hist on success, or NULL on error. + */ +const char *tracefs_hist_get_name(struct tracefs_hist *hist) +{ + return hist ? hist->name : NULL; +} + +/* + * tracefs_hist_get_event - get the event name of the histogram + * @hist: The histogram to get the event name for + * + * Returns event name string owned by @hist on success, or NULL on error. + */ +const char *tracefs_hist_get_event(struct tracefs_hist *hist) +{ + return hist ? hist->event_name : NULL; +} + +/* + * tracefs_hist_get_system - get the system name of the histogram + * @hist: The histogram to get the system name for + * + * Returns system name string owned by @hist on success, or NULL on error. + */ +const char *tracefs_hist_get_system(struct tracefs_hist *hist) +{ + return hist ? hist->system : NULL; +} + +static void add_list(struct trace_seq *seq, const char *start, + char **list) +{ + int i; + + trace_seq_puts(seq, start); + for (i = 0; list[i]; i++) { + if (i) + trace_seq_putc(seq, ','); + trace_seq_puts(seq, list[i]); + } +} + +static void add_hist_commands(struct trace_seq *seq, struct tracefs_hist *hist, + enum tracefs_hist_command command) +{ + if (command == TRACEFS_HIST_CMD_DESTROY) + trace_seq_putc(seq, '!'); + + add_list(seq, "hist:keys=", hist->keys); + + if (hist->values) + add_list(seq, ":vals=", hist->values); + + if (hist->sort) + add_list(seq, ":sort=", hist->sort); + + if (hist->size) + trace_seq_printf(seq, ":size=%d", hist->size); + + switch(command) { + case TRACEFS_HIST_CMD_START: break; + case TRACEFS_HIST_CMD_PAUSE: trace_seq_puts(seq, ":pause"); break; + case TRACEFS_HIST_CMD_CONT: trace_seq_puts(seq, ":cont"); break; + case TRACEFS_HIST_CMD_CLEAR: trace_seq_puts(seq, ":clear"); break; + default: break; + } + + if (hist->name) + trace_seq_printf(seq, ":name=%s", hist->name); + + if (hist->filter) + trace_seq_printf(seq, " if %s", hist->filter); + +} + +/* + * trace_hist_echo_cmd - show how to start the histogram + * @seq: A trace_seq to store the commands to create + * @hist: The histogram to write into the trigger file + * @command: If not zero, can pause, continue or clear the histogram + * + * This shows the echo commands to create the histogram for an event + * with the given fields. + * + * Returns 0 on succes -1 on error. + */ +int +tracefs_hist_echo_cmd(struct trace_seq *seq, struct tracefs_instance *instance, + struct tracefs_hist *hist, + enum tracefs_hist_command command) +{ + const char *system = hist->system; + const char *event = hist->event_name; + char *path; + + if (!hist->keys) { + errno = -EINVAL; + return -1; + } + + path = tracefs_event_get_file(instance, system, event, "trigger"); + if (!path) + return -1; + + trace_seq_puts(seq, "echo '"); + + add_hist_commands(seq, hist, command); + + trace_seq_printf(seq, "' > %s\n", path); + + tracefs_put_tracing_file(path); + + return 0; +} + +/* + * tracefs_hist_command - Create, start, pause, destroy a histogram for an event + * @instance: The instance the histogram will be in (NULL for toplevel) + * @hist: The histogram to write into the trigger file + * @command: Command to perform on a histogram. + * + * Creates, pause, continue, clears, or destroys a histogram. + * + * Returns 0 on succes -1 on error. + */ +int tracefs_hist_command(struct tracefs_instance *instance, + struct tracefs_hist *hist, + enum tracefs_hist_command command) +{ + const char *system = hist->system; + const char *event = hist->event_name; + struct trace_seq seq; + int ret; + + if (!tracefs_event_file_exists(instance, system, event, HIST_FILE)) + return -1; + + errno = -EINVAL; + if (!hist->keys) + return -1; + + trace_seq_init(&seq); + + add_hist_commands(&seq, hist, command); + + trace_seq_putc(&seq, '\n'); + trace_seq_terminate(&seq); + + ret = -1; + if (seq.state == TRACE_SEQ__GOOD) + ret = tracefs_event_file_append(instance, system, event, + "trigger", seq.buffer); + + trace_seq_destroy(&seq); + + return ret < 0 ? -1 : 0; +} + +/** + * tracefs_hist_free - free a tracefs_hist element + * @hist: The histogram to free + */ +void tracefs_hist_free(struct tracefs_hist *hist) +{ + if (!hist) + return; + + tep_unref(hist->tep); + free(hist->system); + free(hist->event_name); + free(hist->name); + free(hist->filter); + tracefs_list_free(hist->keys); + tracefs_list_free(hist->values); + tracefs_list_free(hist->sort); + free(hist); +} + +/** + * tracefs_hist_alloc - Initialize one-dimensional histogram + * @tep: The tep handle that has the @system and @event. + * @system: The system the histogram event is in. + * @event_name: The name of the event that the histogram will be attached to. + * @key: The primary key the histogram will use + * @type: The format type of the key. + * + * Will initialize a histogram descriptor that will be attached to + * the @system/@event with the given @key as the primary. This only + * initializes the descriptor, it does not start the histogram + * in the kernel. + * + * Returns an initialized histogram on success. + * NULL on failure. + */ +struct tracefs_hist * +tracefs_hist_alloc(struct tep_handle *tep, + const char *system, const char *event_name, + const char *key, enum tracefs_hist_key_type type) +{ + struct tracefs_hist_axis axis[] = {{key, type}, {NULL, 0}}; + + return tracefs_hist_alloc_nd(tep, system, event_name, axis); +} + +/** + * tracefs_hist_alloc_2d - Initialize two-dimensional histogram + * @tep: The tep handle that has the @system and @event. + * @system: The system the histogram event is in. + * @event: The event that the histogram will be attached to. + * @key1: The first primary key the histogram will use + * @type1: The format type of the first key. + * @key2: The second primary key the histogram will use + * @type2: The format type of the second key. + * + * Will initialize a histogram descriptor that will be attached to + * the @system/@event with the given @key1 and @key2 as the primaries. + * This only initializes the descriptor, it does not start the histogram + * in the kernel. + * + * Returns an initialized histogram on success. + * NULL on failure. + */ +struct tracefs_hist * +tracefs_hist_alloc_2d(struct tep_handle *tep, + const char *system, const char *event_name, + const char *key1, enum tracefs_hist_key_type type1, + const char *key2, enum tracefs_hist_key_type type2) +{ + struct tracefs_hist_axis axis[] = {{key1, type1}, + {key2, type2}, + {NULL, 0}}; + + return tracefs_hist_alloc_nd(tep, system, event_name, axis); +} + +static struct tracefs_hist * +hist_alloc_nd(struct tep_handle *tep, + const char *system, const char *event_name, + struct tracefs_hist_axis *axes, + struct tracefs_hist_axis_cnt *axes_cnt) +{ + struct tep_event *event; + struct tracefs_hist *hist; + + if (!system || !event_name) + return NULL; + + event = tep_find_event_by_name(tep, system, event_name); + if (!event) + return NULL; + + hist = calloc(1, sizeof(*hist)); + if (!hist) + return NULL; + + tep_ref(tep); + hist->tep = tep; + hist->event = event; + hist->system = strdup(system); + hist->event_name = strdup(event_name); + if (!hist->system || !hist->event_name) + goto fail; + + for (; axes && axes->key; axes++) + if (tracefs_hist_add_key(hist, axes->key, axes->type) < 0) + goto fail; + + for (; axes_cnt && axes_cnt->key; axes_cnt++) + if (tracefs_hist_add_key_cnt(hist, axes_cnt->key, axes_cnt->type, axes_cnt->cnt) < 0) + goto fail; + + return hist; + + fail: + tracefs_hist_free(hist); + return NULL; +} +/** + * tracefs_hist_alloc_nd - Initialize N-dimensional histogram + * @tep: The tep handle that has the @system and @event. + * @system: The system the histogram event is in + * @event: The event that the histogram will be attached to + * @axes: An array of histogram axes, terminated by a {NULL, 0} entry + * + * Will initialize a histogram descriptor that will be attached to + * the @system/@event. This only initializes the descriptor with the given + * @axes keys as primaries. This only initializes the descriptor, it does + * not start the histogram in the kernel. + * + * Returns an initialized histogram on success. + * NULL on failure. + */ +struct tracefs_hist * +tracefs_hist_alloc_nd(struct tep_handle *tep, + const char *system, const char *event_name, + struct tracefs_hist_axis *axes) +{ + return hist_alloc_nd(tep, system, event_name, axes, NULL); +} + +/** + * tracefs_hist_alloc_nd_cnt - Initialize N-dimensional histogram + * @tep: The tep handle that has the @system and @event. + * @system: The system the histogram event is in + * @event: The event that the histogram will be attached to + * @axes: An array of histogram axes, terminated by a {NULL, 0} entry + * + * Will initialize a histogram descriptor that will be attached to + * the @system/@event. This only initializes the descriptor with the given + * @axes keys as primaries. This only initializes the descriptor, it does + * not start the histogram in the kernel. + * + * Returns an initialized histogram on success. + * NULL on failure. + */ +struct tracefs_hist * +tracefs_hist_alloc_nd_cnt(struct tep_handle *tep, + const char *system, const char *event_name, + struct tracefs_hist_axis_cnt *axes) +{ + return hist_alloc_nd(tep, system, event_name, NULL, axes); +} + +/** + * tracefs_hist_add_key - add to a key to a histogram + * @hist: The histogram to add the key to. + * @key: The name of the key field. + * @type: The type of the key format. + * @cnt: Some types require a counter, for those, this is used + * + * This adds a secondary or tertiary key to the histogram. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_add_key_cnt(struct tracefs_hist *hist, const char *key, + enum tracefs_hist_key_type type, int cnt) +{ + bool use_key = false; + char *key_type = NULL; + char **new_list; + int ret = -1; + + switch (type) { + case TRACEFS_HIST_KEY_NORMAL: + use_key = true; + ret = 0; + break; + case TRACEFS_HIST_KEY_HEX: + ret = asprintf(&key_type, "%s.hex", key); + break; + case TRACEFS_HIST_KEY_SYM: + ret = asprintf(&key_type, "%s.sym", key); + break; + case TRACEFS_HIST_KEY_SYM_OFFSET: + ret = asprintf(&key_type, "%s.sym-offset", key); + break; + case TRACEFS_HIST_KEY_SYSCALL: + ret = asprintf(&key_type, "%s.syscall", key); + break; + case TRACEFS_HIST_KEY_EXECNAME: + ret = asprintf(&key_type, "%s.execname", key); + break; + case TRACEFS_HIST_KEY_LOG: + ret = asprintf(&key_type, "%s.log2", key); + break; + case TRACEFS_HIST_KEY_USECS: + ret = asprintf(&key_type, "%s.usecs", key); + break; + case TRACEFS_HIST_KEY_BUCKETS: + ret = asprintf(&key_type, "%s.buckets=%d", key, cnt); + break; + case TRACEFS_HIST_KEY_MAX: + /* error */ + break; + } + + if (ret < 0) + return -1; + + new_list = tracefs_list_add(hist->keys, use_key ? key : key_type); + free(key_type); + if (!new_list) + return -1; + + hist->keys = new_list; + + return 0; +} + +/** + * tracefs_hist_add_key - add to a key to a histogram + * @hist: The histogram to add the key to. + * @key: The name of the key field. + * @type: The type of the key format. + * + * This adds a secondary or tertiary key to the histogram. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_add_key(struct tracefs_hist *hist, const char *key, + enum tracefs_hist_key_type type) +{ + return tracefs_hist_add_key_cnt(hist, key, type, 0); +} + +/** + * tracefs_hist_add_value - add to a value to a histogram + * @hist: The histogram to add the value to. + * @key: The name of the value field. + * + * This adds a value field to the histogram. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_add_value(struct tracefs_hist *hist, const char *value) +{ + char **new_list; + + new_list = tracefs_list_add(hist->values, value); + if (!new_list) + return -1; + + hist->values = new_list; + + return 0; +} + +/** + * tracefs_hist_add_name - name a histogram + * @hist: The histogram to name. + * @name: The name of the histogram. + * + * Adds a name to the histogram. Named histograms will share their + * data with other events that have the same name as if it was + * a single histogram. + * + * If the histogram already has a name, this will fail. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_add_name(struct tracefs_hist *hist, const char *name) +{ + if (hist->name) + return -1; + + hist->name = strdup(name); + + return hist->name ? 0 : -1; +} + +static char ** +add_sort_key(struct tracefs_hist *hist, const char *sort_key, char **list) +{ + char **key_list = hist->keys; + char **val_list = hist->values; + int i; + + if (strcmp(sort_key, TRACEFS_HIST_HITCOUNT) == 0) + goto out; + + for (i = 0; key_list[i]; i++) { + if (strcmp(key_list[i], sort_key) == 0) + break; + } + + if (!key_list[i] && val_list) { + for (i = 0; val_list[i]; i++) { + if (strcmp(val_list[i], sort_key) == 0) + break; + if (!val_list[i]) + return NULL; + } + } + + + out: + return tracefs_list_add(list, sort_key); +} + +/** + * tracefs_hist_add_sort_key - add a key for sorting the histogram + * @hist: The histogram to add the sort key to + * @sort_key: The key to sort + * + * Call the function to add to the list of sort keys of the histohram in + * the order of priority that the keys would be sorted on output. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_add_sort_key(struct tracefs_hist *hist, + const char *sort_key) +{ + char **list = hist->sort; + + if (!hist || !sort_key) + return -1; + + list = add_sort_key(hist, sort_key, hist->sort); + if (!list) + return -1; + + hist->sort = list; + + return 0; +} + +/** + * tracefs_hist_set_sort_key - set a key for sorting the histogram + * @hist: The histogram to set the sort key to + * @sort_key: The key to sort (and the strings after it) + * Last one must be NULL. + * + * Set a list of sort keys in the order of priority that the + * keys would be sorted on output. Keys must be added first. + * + * Returns 0 on success, -1 on error. + */ +int tracefs_hist_set_sort_key(struct tracefs_hist *hist, + const char *sort_key, ...) +{ + char **list = NULL; + char **tmp; + va_list ap; + + if (!hist || !sort_key) + return -1; + + tmp = add_sort_key(hist, sort_key, list); + if (!tmp) + goto fail; + list = tmp; + + va_start(ap, sort_key); + for (;;) { + sort_key = va_arg(ap, const char *); + if (!sort_key) + break; + tmp = add_sort_key(hist, sort_key, list); + if (!tmp) + goto fail; + list = tmp; + } + va_end(ap); + + tracefs_list_free(hist->sort); + hist->sort = list; + + return 0; + fail: + tracefs_list_free(list); + return -1; +} + +static int end_match(const char *sort_key, const char *ending) +{ + int key_len = strlen(sort_key); + int end_len = strlen(ending); + + if (key_len <= end_len) + return 0; + + sort_key += key_len - end_len; + + return strcmp(sort_key, ending) == 0 ? key_len - end_len : 0; +} + +/** + * tracefs_hist_sort_key_direction - set direction of a sort key + * @hist: The histogram to modify. + * @sort_str: The sort key to set the direction for + * @dir: The direction to set the sort key to. + * + * Returns 0 on success, and -1 on error; + */ +int tracefs_hist_sort_key_direction(struct tracefs_hist *hist, + const char *sort_str, + enum tracefs_hist_sort_direction dir) +{ + char **sort = hist->sort; + char *sort_key; + char *direct; + int match; + int i; + + if (!sort) + return -1; + + for (i = 0; sort[i]; i++) { + if (strcmp(sort[i], sort_str) == 0) + break; + } + if (!sort[i]) + return -1; + + sort_key = sort[i]; + + switch (dir) { + case TRACEFS_HIST_SORT_ASCENDING: + direct = ASCENDING; + break; + case TRACEFS_HIST_SORT_DESCENDING: + direct = DESCENDING; + break; + default: + return -1; + } + + match = end_match(sort_key, ASCENDING); + if (match) { + /* Already match? */ + if (dir == TRACEFS_HIST_SORT_ASCENDING) + return 0; + } else { + match = end_match(sort_key, DESCENDING); + /* Already match? */ + if (match && dir == TRACEFS_HIST_SORT_DESCENDING) + return 0; + } + + if (match) + /* Clear the original text */ + sort_key[match] = '\0'; + + sort_key = realloc(sort_key, strlen(sort_key) + strlen(direct) + 1); + if (!sort_key) { + /* Failed to alloc, may need to put back the match */ + sort_key = sort[i]; + if (match) + sort_key[match] = '.'; + return -1; + } + + strcat(sort_key, direct); + sort[i] = sort_key; + return 0; +} + +int tracefs_hist_append_filter(struct tracefs_hist *hist, + enum tracefs_filter type, + const char *field, + enum tracefs_compare compare, + const char *val) +{ + return trace_append_filter(&hist->filter, &hist->filter_state, + &hist->filter_parens, + hist->event, + type, field, compare, val); +} + +enum action_type { + ACTION_NONE, + ACTION_TRACE, + ACTION_SNAPSHOT, + ACTION_SAVE, +}; + +struct action { + struct action *next; + enum action_type type; + enum tracefs_synth_handler handler; + char *handle_field; + char *save; +}; + +struct name_hash { + struct name_hash *next; + char *name; + char *hash; +}; + +/* + * @name: name of the synthetic event + * @start_system: system of the starting event + * @start_event: the starting event + * @end_system: system of the ending event + * @end_event: the ending event + * @actions: List of actions to take + * @match_names: If a match set is to be a synthetic field, it has a name + * @start_match: list of keys in the start event that matches end event + * @end_match: list of keys in the end event that matches the start event + * @compare_names: The synthetic field names of the compared fields + * @start_compare: A list of compare fields in the start to compare to end + * @end_compare: A list of compare fields in the end to compare to start + * @compare_ops: The type of operations to perform between the start and end + * @start_names: The fields in the start event to record + * @end_names: The fields in the end event to record + * @start_filters: The fields in the end event to record + * @end_filters: The fields in the end event to record + * @start_parens: Current parenthesis level for start event + * @end_parens: Current parenthesis level for end event + * @new_format: onmatch().trace(synth_event,..) or onmatch().synth_event(...) + */ +struct tracefs_synth { + struct tracefs_instance *instance; + struct tep_handle *tep; + struct tep_event *start_event; + struct tep_event *end_event; + struct action *actions; + struct action **next_action; + struct tracefs_dynevent *dyn_event; + struct name_hash *name_hash[1 << HASH_BITS]; + char *start_hist; + char *end_hist; + char *name; + char **synthetic_fields; + char **synthetic_args; + char **start_selection; + char **start_keys; + char **end_keys; + char **start_vars; + char **end_vars; + char *start_filter; + char *end_filter; + unsigned int start_parens; + unsigned int start_state; + unsigned int end_parens; + unsigned int end_state; + int *start_type; + char arg_name[16]; + int arg_cnt; + bool new_format; +}; + + /* + * tracefs_synth_get_name - get the name of the synthetic event + * @synth: The synthetic event to get the name for + * + * Returns name string owned by @synth on success, or NULL on error. + */ +const char *tracefs_synth_get_name(struct tracefs_synth *synth) +{ + return synth ? synth->name : NULL; +} + +static void action_free(struct action *action) +{ + free(action->handle_field); + free(action->save); + free(action); +} + +static void free_name_hash(struct name_hash **hash) +{ + struct name_hash *item; + int i; + + for (i = 0; i < 1 << HASH_BITS; i++) { + while ((item = hash[i])) { + hash[i] = item->next; + free(item->name); + free(item->hash); + free(item); + } + } +} + +/** + * tracefs_synth_free - free the resources alloced to a synth + * @synth: The tracefs_synth descriptor + * + * Frees the resources allocated for a @synth created with + * tracefs_synth_alloc(). It does not touch the system. That is, + * any synthetic event created, will not be destroyed by this + * function. + */ +void tracefs_synth_free(struct tracefs_synth *synth) +{ + struct action *action; + + if (!synth) + return; + + free(synth->name); + free(synth->start_hist); + free(synth->end_hist); + tracefs_list_free(synth->synthetic_fields); + tracefs_list_free(synth->synthetic_args); + tracefs_list_free(synth->start_selection); + tracefs_list_free(synth->start_keys); + tracefs_list_free(synth->end_keys); + tracefs_list_free(synth->start_vars); + tracefs_list_free(synth->end_vars); + free_name_hash(synth->name_hash); + free(synth->start_filter); + free(synth->end_filter); + free(synth->start_type); + + tep_unref(synth->tep); + + while ((action = synth->actions)) { + synth->actions = action->next; + action_free(action); + } + tracefs_dynevent_free(synth->dyn_event); + + free(synth); +} + +static bool verify_event_fields(struct tep_event *start_event, + struct tep_event *end_event, + const char *start_field_name, + const char *end_field_name, + const struct tep_format_field **ptr_start_field) +{ + const struct tep_format_field *start_field; + const struct tep_format_field *end_field; + int start_flags, end_flags; + + if (!trace_verify_event_field(start_event, start_field_name, + &start_field)) + return false; + + if (end_event) { + if (!trace_verify_event_field(end_event, end_field_name, + &end_field)) + return false; + + /* A pointer can still match a long */ + start_flags = start_field->flags & ~TEP_FIELD_IS_POINTER; + end_flags = end_field->flags & ~TEP_FIELD_IS_POINTER; + + if (start_flags != end_flags || + start_field->size != end_field->size) { + errno = EBADE; + return false; + } + } + + if (ptr_start_field) + *ptr_start_field = start_field; + + return true; +} + +__hidden char *append_string(char *str, const char *space, const char *add) +{ + char *new; + int len; + + /* String must already be allocated */ + if (!str) + return NULL; + + len = strlen(str) + strlen(add) + 2; + if (space) + len += strlen(space); + + new = realloc(str, len); + if (!new) { + free(str); + return NULL; + } + str = new; + + if (space) + strcat(str, space); + strcat(str, add); + + return str; +} + +static char *add_synth_field(const struct tep_format_field *field, + const char *name) +{ + const char *type; + char size[64]; + char *str; + bool sign; + + if (field->flags & TEP_FIELD_IS_ARRAY) { + str = strdup("char"); + str = append_string(str, " ", name); + str = append_string(str, NULL, "["); + + if (!(field->flags & TEP_FIELD_IS_DYNAMIC)) { + snprintf(size, 64, "%d", field->size); + str = append_string(str, NULL, size); + } + return append_string(str, NULL, "];"); + } + + /* Synthetic events understand pid_t, gfp_t and bool */ + if (strcmp(field->type, "pid_t") == 0 || + strcmp(field->type, "gfp_t") == 0 || + strcmp(field->type, "bool") == 0) { + str = strdup(field->type); + str = append_string(str, " ", name); + return append_string(str, NULL, ";"); + } + + sign = field->flags & TEP_FIELD_IS_SIGNED; + + switch (field->size) { + case 1: + if (!sign) + type = "unsigned char"; + else + type = "char"; + break; + case 2: + if (sign) + type = "s16"; + else + type = "u16"; + break; + case 4: + if (sign) + type = "s32"; + else + type = "u32"; + break; + case 8: + if (sign) + type = "s64"; + else + type = "u64"; + break; + default: + errno = EBADF; + return NULL; + } + + str = strdup(type); + str = append_string(str, " ", name); + return append_string(str, NULL, ";"); +} + +static int add_var(char ***list, const char *name, const char *var, bool is_var) +{ + char **new; + char *assign; + int ret; + + if (is_var) + ret = asprintf(&assign, "%s=$%s", name, var); + else + ret = asprintf(&assign, "%s=%s", name, var); + + if (ret < 0) + return -1; + + new = tracefs_list_add(*list, assign); + free(assign); + + if (!new) + return -1; + *list = new; + return 0; +} + +__hidden struct tracefs_synth * +synth_init_from(struct tep_handle *tep, const char *start_system, + const char *start_event_name) +{ + struct tep_event *start_event; + struct tracefs_synth *synth; + + start_event = tep_find_event_by_name(tep, start_system, + start_event_name); + if (!start_event) { + errno = ENODEV; + return NULL; + } + + synth = calloc(1, sizeof(*synth)); + if (!synth) + return NULL; + + synth->start_event = start_event; + synth->next_action = &synth->actions; + + /* Hold onto a reference to this handler */ + tep_ref(tep); + synth->tep = tep; + + return synth; +} + +static int alloc_synthetic_event(struct tracefs_synth *synth) +{ + char *format; + const char *field; + int i; + + format = strdup(""); + if (!format) + return -1; + + for (i = 0; synth->synthetic_fields && synth->synthetic_fields[i]; i++) { + field = synth->synthetic_fields[i]; + format = append_string(format, i ? " " : NULL, field); + } + + synth->dyn_event = dynevent_alloc(TRACEFS_DYNEVENT_SYNTH, SYNTHETIC_GROUP, + synth->name, NULL, format); + free(format); + + return synth->dyn_event ? 0 : -1; +} + +/* + * See if it is onmatch().trace(synth_event,...) or + * onmatch().synth_event(...) + */ +static bool has_new_format() +{ + char *readme; + char *p; + int size; + + readme = tracefs_instance_file_read(NULL, "README", &size); + if (!readme) + return false; + + p = strstr(readme, "trace(<synthetic_event>,param list)"); + free(readme); + + return p != NULL; +} + +/** + * tracefs_synth_alloc - create a new tracefs_synth instance + * @tep: The tep handle that holds the events to work on + * @name: The name of the synthetic event being created + * @start_system: The name of the system of the start event (can be NULL) + * @start_event_name: The name of the start event + * @end_system: The name of the system of the end event (can be NULL) + * @end_event_name: The name of the end event + * @start_match_field: The name of the field in start event to match @end_match_field + * @end_match_field: The name of the field in end event to match @start_match_field + * @match_name: Name to call the fields that match (can be NULL) + * + * Creates a tracefs_synth instance that has the minimum requirements to + * create a synthetic event. + * + * @name is will be the name of the synthetic event that this can create. + * + * The start event is found with @start_system and @start_event_name. If + * @start_system is NULL, then the first event with @start_event_name will + * be used. + * + * The end event is found with @end_system and @end_event_name. If + * @end_system is NULL, then the first event with @end_event_name will + * be used. + * + * The @start_match_field is the field in the start event that will be used + * to match the @end_match_field of the end event. + * + * If @match_name is given, then the field that matched the start and + * end events will be passed an a field to the sythetic event with this + * as the field name. + * + * Returns an allocated tracefs_synth descriptor on success and NULL + * on error, with the following set in errno. + * + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be + * ENODEV - could not find an event or field + * EBADE - The start and end fields are not compatible to match + * + * Note, this does not modify the system. That is, the synthetic + * event on the system is not created. That needs to be done with + * tracefs_synth_create(). + */ +struct tracefs_synth *tracefs_synth_alloc(struct tep_handle *tep, + const char *name, + const char *start_system, + const char *start_event_name, + const char *end_system, + const char *end_event_name, + const char *start_match_field, + const char *end_match_field, + const char *match_name) +{ + struct tep_event *end_event; + struct tracefs_synth *synth; + int ret = 0; + + if (!tep || !name || !start_event_name || !end_event_name || + !start_match_field || !end_match_field) { + errno = EINVAL; + return NULL; + } + + synth = synth_init_from(tep, start_system, start_event_name); + if (!synth) + return NULL; + + end_event = tep_find_event_by_name(tep, end_system, + end_event_name); + if (!end_event) { + tep_unref(tep); + errno = ENODEV; + return NULL; + } + + synth->end_event = end_event; + + synth->name = strdup(name); + + ret = tracefs_synth_add_match_field(synth, start_match_field, + end_match_field, match_name); + + if (!synth->name || !synth->start_keys || !synth->end_keys || ret) { + tracefs_synth_free(synth); + synth = NULL; + } else + synth->new_format = has_new_format(); + + return synth; +} + +static int add_synth_fields(struct tracefs_synth *synth, + const struct tep_format_field *field, + const char *name, const char *var) +{ + char **list; + char *str; + int ret; + + str = add_synth_field(field, name ? : field->name); + if (!str) + return -1; + + if (!name) + name = var; + + list = tracefs_list_add(synth->synthetic_fields, str); + free(str); + if (!list) + return -1; + synth->synthetic_fields = list; + + ret = asprintf(&str, "$%s", var ? : name); + if (ret < 0) { + trace_list_pop(synth->synthetic_fields); + return -1; + } + + list = tracefs_list_add(synth->synthetic_args, str); + free(str); + if (!list) { + trace_list_pop(synth->synthetic_fields); + return -1; + } + + synth->synthetic_args = list; + + return 0; +} + +/** + * tracefs_synth_add_match_field - add another key to match events + * @synth: The tracefs_synth descriptor + * @start_match_field: The field of the start event to match the end event + * @end_match_field: The field of the end event to match the start event + * @name: The name to show in the synthetic event (NULL is allowed) + * + * This will add another set of keys to use for a match between + * the start event and the end event. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be + * ENODEV - could not find a field + * EBADE - The start and end fields are not compatible to match + */ +int tracefs_synth_add_match_field(struct tracefs_synth *synth, + const char *start_match_field, + const char *end_match_field, + const char *name) +{ + const struct tep_format_field *key_field; + char **list; + int ret; + + if (!synth || !start_match_field || !end_match_field) { + errno = EINVAL; + return -1; + } + + if (!verify_event_fields(synth->start_event, synth->end_event, + start_match_field, end_match_field, + &key_field)) + return -1; + + list = tracefs_list_add(synth->start_keys, start_match_field); + if (!list) + return -1; + + synth->start_keys = list; + + list = tracefs_list_add(synth->end_keys, end_match_field); + if (!list) { + trace_list_pop(synth->start_keys); + return -1; + } + synth->end_keys = list; + + if (!name) + return 0; + + ret = add_var(&synth->end_vars, name, end_match_field, false); + + if (ret < 0) + goto pop_lists; + + ret = add_synth_fields(synth, key_field, name, NULL); + if (ret < 0) + goto pop_lists; + + return 0; + + pop_lists: + trace_list_pop(synth->start_keys); + trace_list_pop(synth->end_keys); + return -1; +} + +static unsigned int make_rand(void) +{ + struct timeval tv; + unsigned long seed; + + gettimeofday(&tv, NULL); + seed = (tv.tv_sec + tv.tv_usec) + getpid(); + + /* taken from the rand(3) man page */ + seed = seed * 1103515245 + 12345; + return((unsigned)(seed/65536) % 32768); +} + +static char *new_name(struct tracefs_synth *synth, const char *name) +{ + int cnt = synth->arg_cnt + 1; + char *arg; + int ret; + + /* Create a unique argument name */ + if (!synth->arg_name[0]) { + /* make_rand() returns at most 32768 (total 13 bytes in use) */ + sprintf(synth->arg_name, "%u", make_rand()); + } + ret = asprintf(&arg, "__%s_%s_%d", name, synth->arg_name, cnt); + if (ret < 0) + return NULL; + + synth->arg_cnt = cnt; + return arg; +} + +static struct name_hash *find_name(struct tracefs_synth *synth, const char *name) +{ + unsigned int key = quick_hash(name); + struct name_hash *hash = synth->name_hash[key]; + + for (; hash; hash = hash->next) { + if (!strcmp(hash->name, name)) + return hash; + } + return NULL; +} + +static const char *hash_name(struct tracefs_synth *synth, const char *name) +{ + struct name_hash *hash; + int key; + + hash = find_name(synth, name); + if (hash) + return hash->hash; + + hash = malloc(sizeof(*hash)); + if (!hash) + return name; + + hash->hash = new_name(synth, name); + if (!hash->hash) { + free(hash); + return name; + } + + key = quick_hash(name); + hash->next = synth->name_hash[key]; + synth->name_hash[key] = hash; + + hash->name = strdup(name); + if (!hash->name) { + free(hash->hash); + free(hash); + return name; + } + return hash->hash; +} + +static char *new_arg(struct tracefs_synth *synth) +{ + return new_name(synth, "arg"); +} + +/** + * tracefs_synth_add_compare_field - add a comparison between start and end + * @synth: The tracefs_synth descriptor + * @start_compare_field: The field of the start event to compare to the end + * @end_compare_field: The field of the end event to compare to the start + * @calc - How to go about the comparing the fields. + * @name: The name to show in the synthetic event (must NOT be NULL) + * + * This will add a way to compare two different fields between the + * start end end events. + * + * The comparing between events is decided by @calc: + * TRACEFS_SYNTH_DELTA_END - name = end - start + * TRACEFS_SYNTH_DELTA_START - name = start - end + * TRACEFS_SYNTH_ADD - name = end + start + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be + * ENODEV - could not find a field + * EBADE - The start and end fields are not compatible to compare + */ +int tracefs_synth_add_compare_field(struct tracefs_synth *synth, + const char *start_compare_field, + const char *end_compare_field, + enum tracefs_synth_calc calc, + const char *name) +{ + const struct tep_format_field *start_field; + const char *hname; + char *start_arg; + char *compare; + int ret; + + /* Compare fields require a name */ + if (!name || !start_compare_field || !end_compare_field) { + errno = -EINVAL; + return -1; + } + + if (!verify_event_fields(synth->start_event, synth->end_event, + start_compare_field, end_compare_field, + &start_field)) + return -1; + + /* Calculations are not allowed on string */ + if (start_field->flags & (TEP_FIELD_IS_ARRAY | + TEP_FIELD_IS_DYNAMIC)) { + errno = -EINVAL; + return -1; + } + + start_arg = new_arg(synth); + if (!start_arg) + return -1; + + ret = add_var(&synth->start_vars, start_arg, start_compare_field, false); + if (ret < 0) { + free(start_arg); + return -1; + } + + ret = -1; + switch (calc) { + case TRACEFS_SYNTH_DELTA_END: + ret = asprintf(&compare, "%s-$%s", end_compare_field, + start_arg); + break; + case TRACEFS_SYNTH_DELTA_START: + ret = asprintf(&compare, "$%s-%s", start_arg, + end_compare_field); + break; + case TRACEFS_SYNTH_ADD: + ret = asprintf(&compare, "%s+$%s", end_compare_field, + start_arg); + break; + } + free(start_arg); + if (ret < 0) + return -1; + + hname = hash_name(synth, name); + ret = add_var(&synth->end_vars, hname, compare, false); + if (ret < 0) + goto out_free; + + ret = add_synth_fields(synth, start_field, name, hname); + if (ret < 0) + goto out_free; + + out_free: + free(compare); + + return ret ? -1 : 0; +} + +__hidden int synth_add_start_field(struct tracefs_synth *synth, + const char *start_field, + const char *name, + enum tracefs_hist_key_type type, int count) +{ + const struct tep_format_field *field; + const char *var; + char *start_arg; + char **tmp; + int *types; + int len; + int ret; + + if (!synth || !start_field) { + errno = EINVAL; + return -1; + } + + if (!name) + name = start_field; + + var = hash_name(synth, name); + + if (!trace_verify_event_field(synth->start_event, start_field, &field)) + return -1; + + start_arg = new_arg(synth); + if (!start_arg) + return -1; + + ret = add_var(&synth->start_vars, start_arg, start_field, false); + if (ret) + goto out_free; + + ret = add_var(&synth->end_vars, var, start_arg, true); + if (ret) + goto out_free; + + ret = add_synth_fields(synth, field, name, var); + if (ret) + goto out_free; + + tmp = tracefs_list_add(synth->start_selection, start_field); + if (!tmp) { + ret = -1; + goto out_free; + } + synth->start_selection = tmp; + + len = tracefs_list_size(tmp); + if (len <= 0) { /* ?? */ + ret = -1; + goto out_free; + } + + types = realloc(synth->start_type, sizeof(*types) * len); + if (!types) { + ret = -1; + goto out_free; + } + synth->start_type = types; + synth->start_type[len - 1] = type; + + out_free: + free(start_arg); + return ret; +} + +/** + * tracefs_synth_add_start_field - add a start field to save + * @synth: The tracefs_synth descriptor + * @start_field: The field of the start event to save + * @name: The name to show in the synthetic event (if NULL @start_field is used) + * + * This adds a field named by @start_field of the start event to + * record in the synthetic event. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be + * ENODEV - could not find a field + */ +int tracefs_synth_add_start_field(struct tracefs_synth *synth, + const char *start_field, + const char *name) +{ + return synth_add_start_field(synth, start_field, name, 0, 0); +} + +/** + * tracefs_synth_add_end_field - add a end field to save + * @synth: The tracefs_synth descriptor + * @end_field: The field of the end event to save + * @name: The name to show in the synthetic event (if NULL @end_field is used) + * + * This adds a field named by @end_field of the start event to + * record in the synthetic event. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be + * ENODEV - could not find a field + */ +int tracefs_synth_add_end_field(struct tracefs_synth *synth, + const char *end_field, + const char *name) +{ + const struct tep_format_field *field; + const char *hname = NULL; + char *tmp_var = NULL; + int ret; + + if (!synth || !end_field) { + errno = EINVAL; + return -1; + } + + if (name) { + if (strncmp(name, "__arg", 5) != 0) + hname = hash_name(synth, name); + else + hname = name; + } + + if (!name) + tmp_var = new_arg(synth); + + if (!trace_verify_event_field(synth->end_event, end_field, &field)) + return -1; + + ret = add_var(&synth->end_vars, name ? hname : tmp_var, end_field, false); + if (ret) + goto out; + + ret = add_synth_fields(synth, field, name, hname ? : tmp_var); + free(tmp_var); + out: + return ret; +} + +/** + * tracefs_synth_append_start_filter - create or append a filter + * @synth: The tracefs_synth descriptor + * @type: The type of element to add to the filter + * @field: For @type == TRACEFS_FILTER_COMPARE, the field to compare + * @compare: For @type == TRACEFS_FILTER_COMPARE, how to compare @field to @val + * @val: For @type == TRACEFS_FILTER_COMPARE, what value @field is to be + * + * This will put together a filter string for the starting event + * of @synth. It check to make sure that what is added is correct compared + * to the filter that is already built. + * + * @type can be: + * TRACEFS_FILTER_COMPARE: See below + * TRACEFS_FILTER_AND: Append "&&" to the filter + * TRACEFS_FILTER_OR: Append "||" to the filter + * TRACEFS_FILTER_NOT: Append "!" to the filter + * TRACEFS_FILTER_OPEN_PAREN: Append "(" to the filter + * TRACEFS_FILTER_CLOSE_PAREN: Append ")" to the filter + * + * For all types except TRACEFS_FILTER_COMPARE, the @field, @compare, + * and @val are ignored. + * + * For @type == TRACEFS_FILTER_COMPARE. + * + * @field is the name of the field for the start event to compare. + * If it is not a field for the start event, this return an + * error. + * + * @compare can be one of: + * TRACEFS_COMPARE_EQ: Test @field == @val + * TRACEFS_COMPARE_NE: Test @field != @val + * TRACEFS_COMPARE_GT: Test @field > @val + * TRACEFS_COMPARE_GE: Test @field >= @val + * TRACEFS_COMPARE_LT: Test @field < @val + * TRACEFS_COMPARE_LE: Test @field <= @val + * TRACEFS_COMPARE_RE: Test @field ~ @val + * TRACEFS_COMPARE_AND: Test @field & @val + * + * If the @field is of type string, and @compare is not + * TRACEFS_COMPARE_EQ, TRACEFS_COMPARE_NE or TRACEFS_COMPARE_RE, + * then this will return an error. + * + * Various other checks are made, for instance, if more CLOSE_PARENs + * are added than existing OPEN_PARENs. Or if AND is added after an + * OPEN_PAREN or another AND or an OR or a NOT. + * + * Returns 0 on success and -1 on failure. + */ +int tracefs_synth_append_start_filter(struct tracefs_synth *synth, + enum tracefs_filter type, + const char *field, + enum tracefs_compare compare, + const char *val) +{ + return trace_append_filter(&synth->start_filter, &synth->start_state, + &synth->start_parens, + synth->start_event, + type, field, compare, val); +} + +/** + * tracefs_synth_append_end_filter - create or append a filter + * @synth: The tracefs_synth descriptor + * @type: The type of element to add to the filter + * @field: For @type == TRACEFS_FILTER_COMPARE, the field to compare + * @compare: For @type == TRACEFS_FILTER_COMPARE, how to compare @field to @val + * @val: For @type == TRACEFS_FILTER_COMPARE, what value @field is to be + * + * Performs the same thing as tracefs_synth_append_start_filter() but + * for the @synth end event. + */ +int tracefs_synth_append_end_filter(struct tracefs_synth *synth, + enum tracefs_filter type, + const char *field, + enum tracefs_compare compare, + const char *val) +{ + return trace_append_filter(&synth->end_filter, &synth->end_state, + &synth->end_parens, + synth->end_event, + type, field, compare, val); +} + +static int test_max_var(struct tracefs_synth *synth, const char *var) +{ + char **vars = synth->end_vars; + char *p; + int len; + int i; + + len = strlen(var); + + /* Make sure the var is defined for the end event */ + for (i = 0; vars[i]; i++) { + p = strchr(vars[i], '='); + if (!p) + continue; + if (p - vars[i] != len) + continue; + if (!strncmp(var, vars[i], len)) + return 0; + } + errno = ENODEV; + return -1; +} + +static struct action *create_action(enum tracefs_synth_handler type, + struct tracefs_synth *synth, + const char *var) +{ + struct action *action; + int ret; + + switch (type) { + case TRACEFS_SYNTH_HANDLE_MAX: + case TRACEFS_SYNTH_HANDLE_CHANGE: + ret = test_max_var(synth, var); + if (ret < 0) + return NULL; + break; + default: + break; + } + + action = calloc(1, sizeof(*action)); + if (!action) + return NULL; + + if (var) { + ret = asprintf(&action->handle_field, "$%s", var); + if (!action->handle_field) { + free(action); + return NULL; + } + } + return action; +} + +static void add_action(struct tracefs_synth *synth, struct action *action) +{ + *synth->next_action = action; + synth->next_action = &action->next; +} + +/** + * tracefs_synth_trace - Execute the trace option + * @synth: The tracefs_synth descriptor + * @type: The type of handler to attach the trace action with + * @field: The field for handlers onmax and onchange (ignored otherwise) + * + * Add the action 'trace' for handlers onmatch, onmax and onchange. + * + * Returns 0 on succes, -1 on error. + */ +int tracefs_synth_trace(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *field) +{ + struct action *action; + + if (!synth || (!field && (type != TRACEFS_SYNTH_HANDLE_MATCH))) { + errno = EINVAL; + return -1; + } + + action = create_action(type, synth, field); + if (!action) + return -1; + + action->type = ACTION_TRACE; + action->handler = type; + add_action(synth, action); + return 0; +} + +/** + * tracefs_synth_snapshot - create a snapshot command to the histogram + * @synth: The tracefs_synth descriptor + * @type: The type of handler to attach the snapshot action with + * @field: The field for handlers onmax and onchange + * + * Add the action to do a snapshot for handlers onmax and onchange. + * + * Returns 0 on succes, -1 on error. + */ +int tracefs_synth_snapshot(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *field) +{ + struct action *action; + + if (!synth || !field || (type == TRACEFS_SYNTH_HANDLE_MATCH)) { + errno = EINVAL; + return -1; + } + + action = create_action(type, synth, field); + if (!action) + return -1; + + action->type = ACTION_SNAPSHOT; + action->handler = type; + add_action(synth, action); + return 0; +} + +/** + * tracefs_synth_save - create a save command to the histogram + * @synth: The tracefs_synth descriptor + * @type: The type of handler to attach the save action + * @max_field: The field for handlers onmax and onchange + * @fields: The fields to save for the end variable + * + * Add the action to save fields for handlers onmax and onchange. + * + * Returns 0 on succes, -1 on error. + */ +int tracefs_synth_save(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *max_field, + char **fields) +{ + struct action *action; + char *save; + int i; + + if (!synth || !max_field || (type == TRACEFS_SYNTH_HANDLE_MATCH)) { + errno = EINVAL; + return -1; + } + + action = create_action(type, synth, max_field); + if (!action) + return -1; + + action->type = ACTION_SAVE; + action->handler = type; + *synth->next_action = action; + synth->next_action = &action->next; + + save = strdup(".save("); + if (!save) + goto error; + + for (i = 0; fields[i]; i++) { + char *delim = i ? "," : NULL; + + if (!trace_verify_event_field(synth->end_event, fields[i], NULL)) + goto error; + save = append_string(save, delim, fields[i]); + } + save = append_string(save, NULL, ")"); + if (!save) + goto error; + + action->save = save; + add_action(synth, action); + return 0; + error: + action_free(action); + free(save); + return -1; + return 0; +} + +static int remove_hist(struct tracefs_instance *instance, + struct tep_event *event, const char *hist) +{ + char *str; + int ret; + + ret = asprintf(&str, "!%s", hist); + if (ret < 0) + return -1; + + ret = tracefs_event_file_append(instance, event->system, event->name, + "trigger", str); + free(str); + return ret < 0 ? -1 : 0; +} + +static char *create_hist(char **keys, char **vars) +{ + char *hist = strdup("hist:keys="); + char *name; + int i; + + if (!hist) + return NULL; + + for (i = 0; keys[i]; i++) { + name = keys[i]; + if (i) + hist = append_string(hist, NULL, ","); + hist = append_string(hist, NULL, name); + } + + if (!vars) + return hist; + + hist = append_string(hist, NULL, ":"); + + for (i = 0; vars[i]; i++) { + name = vars[i]; + if (i) + hist = append_string(hist, NULL, ","); + hist = append_string(hist, NULL, name); + } + + return hist; +} + +static char *create_onmatch(char *hist, struct tracefs_synth *synth) +{ + hist = append_string(hist, NULL, ":onmatch("); + hist = append_string(hist, NULL, synth->start_event->system); + hist = append_string(hist, NULL, "."); + hist = append_string(hist, NULL, synth->start_event->name); + return append_string(hist, NULL, ")"); +} + +static char *create_trace(char *hist, struct tracefs_synth *synth) +{ + char *name; + int i; + + if (synth->new_format) { + hist = append_string(hist, NULL, ".trace("); + hist = append_string(hist, NULL, synth->name); + hist = append_string(hist, NULL, ","); + } else { + hist = append_string(hist, NULL, "."); + hist = append_string(hist, NULL, synth->name); + hist = append_string(hist, NULL, "("); + } + + for (i = 0; synth->synthetic_args && synth->synthetic_args[i]; i++) { + name = synth->synthetic_args[i]; + + if (i) + hist = append_string(hist, NULL, ","); + hist = append_string(hist, NULL, name); + } + + return append_string(hist, NULL, ")"); +} + +static char *create_max(char *hist, struct tracefs_synth *synth, char *field) +{ + hist = append_string(hist, NULL, ":onmax("); + hist = append_string(hist, NULL, field); + return append_string(hist, NULL, ")"); +} + +static char *create_change(char *hist, struct tracefs_synth *synth, char *field) +{ + hist = append_string(hist, NULL, ":onchange("); + hist = append_string(hist, NULL, field); + return append_string(hist, NULL, ")"); +} + +static char *create_actions(char *hist, struct tracefs_synth *synth) +{ + struct action *action; + + if (!synth->actions) { + /* Default is "onmatch" and "trace" */ + hist = create_onmatch(hist, synth); + return create_trace(hist, synth); + } + + for (action = synth->actions; action; action = action->next) { + switch (action->handler) { + case TRACEFS_SYNTH_HANDLE_MATCH: + hist = create_onmatch(hist, synth); + break; + case TRACEFS_SYNTH_HANDLE_MAX: + hist = create_max(hist, synth, action->handle_field); + break; + case TRACEFS_SYNTH_HANDLE_CHANGE: + hist = create_change(hist, synth, action->handle_field); + break; + default: + continue; + } + switch (action->type) { + case ACTION_TRACE: + hist = create_trace(hist, synth); + break; + case ACTION_SNAPSHOT: + hist = append_string(hist, NULL, ".snapshot()"); + break; + case ACTION_SAVE: + hist = append_string(hist, NULL, action->save); + break; + default: + continue; + } + } + return hist; +} + +static char *create_end_hist(struct tracefs_synth *synth) +{ + char *end_hist; + + end_hist = create_hist(synth->end_keys, synth->end_vars); + return create_actions(end_hist, synth); +} + +/* + * tracefs_synth_raw_fmt - show the raw format of a synthetic event + * @seq: A trace_seq to store the format string + * @synth: The synthetic event to read format from + * + * This shows the raw format that describes the synthetic event, including + * the format of the dynamic event and the start / end histograms. + * + * Returns 0 on succes -1 on error. + */ +int tracefs_synth_raw_fmt(struct trace_seq *seq, struct tracefs_synth *synth) +{ + if (!synth->dyn_event) + return -1; + + trace_seq_printf(seq, "%s", synth->dyn_event->format); + trace_seq_printf(seq, "\n%s", synth->start_hist); + trace_seq_printf(seq, "\n%s", synth->end_hist); + + return 0; +} + +/* + * tracefs_synth_show_event - show the dynamic event used by a synth event + * @synth: The synthetic event to read format from + * + * This shows the raw format of the dynamic event used by the synthetic event. + * + * Returns format string owned by @synth on success, or NULL on error. + */ +const char *tracefs_synth_show_event(struct tracefs_synth *synth) +{ + return synth->dyn_event ? synth->dyn_event->format : NULL; +} + +/* + * tracefs_synth_show_start_hist - show the start histogram used by a synth event + * @synth: The synthetic event to read format from + * + * This shows the raw format of the start histogram used by the synthetic event. + * + * Returns format string owned by @synth on success, or NULL on error. + */ +const char *tracefs_synth_show_start_hist(struct tracefs_synth *synth) +{ + return synth->start_hist; +} + +/* + * tracefs_synth_show_end_hist - show the end histogram used by a synth event + * @synth: The synthetic event to read format from + * + * This shows the raw format of the end histogram used by the synthetic event. + * + * Returns format string owned by @synth on success, or NULL on error. + */ +const char *tracefs_synth_show_end_hist(struct tracefs_synth *synth) +{ + return synth->end_hist; +} + +static char *append_filter(char *hist, char *filter, unsigned int parens) +{ + int i; + + if (!filter) + return hist; + + hist = append_string(hist, NULL, " if "); + hist = append_string(hist, NULL, filter); + for (i = 0; i < parens; i++) + hist = append_string(hist, NULL, ")"); + return hist; +} + +static int verify_state(struct tracefs_synth *synth) +{ + if (trace_test_state(synth->start_state) < 0 || + trace_test_state(synth->end_state) < 0) + return -1; + return 0; +} + +/** + * tracefs_synth_complete - tell if the tracefs_synth is complete or not + * @synth: The synthetic event to get the start hist from. + * + * Retruns true if the synthetic event @synth has both a start and + * end event (ie. a synthetic event, or just a histogram), and + * false otherwise. + */ +bool tracefs_synth_complete(struct tracefs_synth *synth) +{ + return synth && synth->start_event && synth->end_event; +} + +/** + * tracefs_synth_get_start_hist - Return the histogram of the start event + * @synth: The synthetic event to get the start hist from. + * + * On success, returns a tracefs_hist descriptor that holds the + * histogram information of the start_event of the synthetic event + * structure. Returns NULL on failure. + */ +struct tracefs_hist * +tracefs_synth_get_start_hist(struct tracefs_synth *synth) +{ + struct tracefs_hist *hist = NULL; + struct tep_handle *tep; + const char *system; + const char *event; + const char *key; + char **keys; + int *types; + int ret; + int i; + + if (!synth) { + errno = EINVAL; + return NULL; + } + + system = synth->start_event->system; + event = synth->start_event->name; + types = synth->start_type; + keys = synth->start_keys; + tep = synth->tep; + + if (!keys) + keys = synth->start_selection; + + if (!keys) + return NULL; + + for (i = 0; keys[i]; i++) { + int type = types ? types[i] : 0; + + if (type == HIST_COUNTER_TYPE) + continue; + + key = keys[i]; + + if (i) { + ret = tracefs_hist_add_key(hist, key, type); + if (ret < 0) { + tracefs_hist_free(hist); + return NULL; + } + } else { + hist = tracefs_hist_alloc(tep, system, event, + key, type); + if (!hist) + return NULL; + } + } + + if (!hist) + return NULL; + + for (i = 0; keys[i]; i++) { + int type = types ? types[i] : 0; + + if (type != HIST_COUNTER_TYPE) + continue; + + key = keys[i]; + + ret = tracefs_hist_add_value(hist, key); + if (ret < 0) { + tracefs_hist_free(hist); + return NULL; + } + } + + if (synth->start_filter) { + hist->filter = strdup(synth->start_filter); + if (!hist->filter) { + tracefs_hist_free(hist); + return NULL; + } + } + + return hist; +} + +/** + * tracefs_synth_create - creates the synthetic event on the system + * @synth: The tracefs_synth descriptor + * + * This creates the synthetic events. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be or a problem + * writing into the system. + */ +int tracefs_synth_create(struct tracefs_synth *synth) +{ + int ret; + + if (!synth) { + errno = EINVAL; + return -1; + } + + if (!synth->name || !synth->end_event) { + errno = EUNATCH; + return -1; + } + + if (verify_state(synth) < 0) + return -1; + + if (!synth->dyn_event && alloc_synthetic_event(synth)) + return -1; + if (tracefs_dynevent_create(synth->dyn_event)) + return -1; + + synth->start_hist = create_hist(synth->start_keys, synth->start_vars); + synth->start_hist = append_filter(synth->start_hist, synth->start_filter, + synth->start_parens); + if (!synth->start_hist) + goto remove_synthetic; + + synth->end_hist = create_end_hist(synth); + synth->end_hist = append_filter(synth->end_hist, synth->end_filter, + synth->end_parens); + if (!synth->end_hist) + goto remove_synthetic; + + ret = tracefs_event_file_append(synth->instance, synth->start_event->system, + synth->start_event->name, + "trigger", synth->start_hist); + if (ret < 0) + goto remove_synthetic; + + ret = tracefs_event_file_append(synth->instance, synth->end_event->system, + synth->end_event->name, + "trigger", synth->end_hist); + if (ret < 0) + goto remove_start_hist; + + return 0; + + remove_start_hist: + remove_hist(synth->instance, synth->start_event, synth->start_hist); + remove_synthetic: + tracefs_dynevent_destroy(synth->dyn_event, false); + return -1; +} + +/** + * tracefs_synth_destroy - delete the synthetic event from the system + * @synth: The tracefs_synth descriptor + * + * This will destroy a synthetic event created by tracefs_synth_create() + * with the same @synth. + * + * It will attempt to disable the synthetic event in its instance (top by default), + * but if other instances have it active, it is likely to fail, which will likely + * fail on all other parts of tearing down the synthetic event. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + * ENIVAL - a parameter is passed as NULL that should not be or a problem + * writing into the system. + */ +int tracefs_synth_destroy(struct tracefs_synth *synth) +{ + char *hist; + int ret; + + if (!synth) { + errno = EINVAL; + return -1; + } + + if (!synth->name || !synth->end_event) { + errno = EUNATCH; + return -1; + } + + /* Try to disable the event if possible */ + tracefs_event_disable(synth->instance, "synthetic", synth->name); + + hist = create_end_hist(synth); + hist = append_filter(hist, synth->end_filter, + synth->end_parens); + if (!hist) + return -1; + ret = remove_hist(synth->instance, synth->end_event, hist); + free(hist); + + hist = create_hist(synth->start_keys, synth->start_vars); + hist = append_filter(hist, synth->start_filter, + synth->start_parens); + if (!hist) + return -1; + + ret = remove_hist(synth->instance, synth->start_event, hist); + free(hist); + + ret = tracefs_dynevent_destroy(synth->dyn_event, true); + + return ret ? -1 : 0; +} + +/** + * tracefs_synth_echo_cmd - show the command lines to create the synthetic event + * @seq: The trace_seq to store the command lines in + * @synth: The tracefs_synth descriptor + * + * This will list the "echo" commands that are equivalent to what would + * be executed by the tracefs_synth_create() command. + * + * Returns 0 on succes and -1 on error. + * On error, errno is set to: + * ENOMEM - memory allocation failure. + */ +int tracefs_synth_echo_cmd(struct trace_seq *seq, + struct tracefs_synth *synth) +{ + bool new_event = false; + char *hist = NULL; + char *path; + int ret = -1; + + if (!synth) { + errno = EINVAL; + return -1; + } + + if (!synth->name || !synth->end_event) { + errno = EUNATCH; + return -1; + } + + if (!synth->dyn_event) { + if (alloc_synthetic_event(synth)) + return -1; + new_event = true; + } + + path = trace_find_tracing_dir(false); + if (!path) + goto out_free; + + trace_seq_printf(seq, "echo '%s%s%s %s' >> %s/%s\n", + synth->dyn_event->prefix, + strlen(synth->dyn_event->prefix) ? ":" : "", + synth->dyn_event->event, + synth->dyn_event->format, path, synth->dyn_event->trace_file); + + tracefs_put_tracing_file(path); + path = tracefs_instance_get_dir(synth->instance); + + hist = create_hist(synth->start_keys, synth->start_vars); + hist = append_filter(hist, synth->start_filter, + synth->start_parens); + if (!hist) + goto out_free; + + trace_seq_printf(seq, "echo '%s' >> %s/events/%s/%s/trigger\n", + hist, path, synth->start_event->system, + synth->start_event->name); + free(hist); + hist = create_end_hist(synth); + hist = append_filter(hist, synth->end_filter, + synth->end_parens); + if (!hist) + goto out_free; + + trace_seq_printf(seq, "echo '%s' >> %s/events/%s/%s/trigger\n", + hist, path, synth->end_event->system, + synth->end_event->name); + + ret = 0; + out_free: + free(hist); + tracefs_put_tracing_file(path); + if (new_event) { + tracefs_dynevent_free(synth->dyn_event); + synth->dyn_event = NULL; + } + return ret; +} + +/** + * tracefs_synth_get_event - return tep event representing the given synthetic event + * @tep: a handle to the trace event parser context that holds the events + * @synth: a synthetic event context, describing given synthetic event. + * + * Returns a pointer to a tep event describing the given synthetic event. The pointer + * is managed by the @tep handle and must not be freed. In case of an error, or in case + * the requested synthetic event is missing in the @tep handler - NULL is returned. + */ +struct tep_event * +tracefs_synth_get_event(struct tep_handle *tep, struct tracefs_synth *synth) +{ + if (!tep || !synth || !synth->name) + return NULL; + + return get_tep_event(tep, SYNTHETIC_GROUP, synth->name); +} |