diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/Kconfig | 16 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 1 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 17 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 7 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 849 | ||||
| -rw-r--r-- | kernel/trace/trace_events_trigger.c | 1 |
7 files changed, 895 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d39556fd863a..fafeaf803bd0 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -538,6 +538,22 @@ config TRACING_MAP generally used outside of that context, and is normally selected by tracers that use it. +config HIST_TRIGGERS + bool "Histogram triggers" + depends on ARCH_HAVE_NMI_SAFE_CMPXCHG + select TRACING_MAP + default n + help + Hist triggers allow one or more arbitrary trace event fields + to be aggregated into hash tables and dumped to stdout by + reading a debugfs/tracefs file. They're useful for + gathering quick and dirty (though precise) summaries of + event activity as an initial guide for further investigation + using more advanced tools. + + See Documentation/trace/events.txt. + If in doubt, say N. + config MMIOTRACE_TEST tristate "Test module for mmiotrace" depends on MMIOTRACE && m diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 4255c4057aaa..979e7bfbde7a 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o endif obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o +obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o obj-$(CONFIG_TRACEPOINTS) += power-traces.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0d12dbde8399..6cf8fd03b028 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3813,6 +3813,9 @@ static const char readme_msg[] = #ifdef CONFIG_TRACER_SNAPSHOT "\t\t snapshot\n" #endif +#ifdef CONFIG_HIST_TRIGGERS + "\t\t hist (see below)\n" +#endif "\t example: echo traceoff > events/block/block_unplug/trigger\n" "\t echo traceoff:3 > events/block/block_unplug/trigger\n" "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" @@ -3828,6 +3831,20 @@ static const char readme_msg[] = "\t To remove a trigger with a count:\n" "\t echo '!<trigger>:0 > <system>/<event>/trigger\n" "\t Filters can be ignored when removing a trigger.\n" +#ifdef CONFIG_HIST_TRIGGERS + " hist trigger\t- If set, event hits are aggregated into a hash table\n" + "\t Format: hist:keys=<field1>\n" + "\t [:size=#entries]\n" + "\t [if <filter>]\n\n" + "\t When a matching event is hit, an entry is added to a hash\n" + "\t table using the key named, and the value of a sum called\n" + "\t 'hitcount' is incremented. Keys correspond to fields in the\n" + "\t event's format description. Keys can be any field. The\n" + "\t 'size' parameter can be used to specify more or fewer than\n" + "\t the default 2048 entries for the hashtable size.\n\n" + "\t Reading the 'hist' file for the event will dump the hash\n" + "\t table in its entirety to stdout." +#endif ; static ssize_t diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2525042760e6..505f8a45f426 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1162,6 +1162,13 @@ extern struct mutex event_mutex; extern struct list_head ftrace_events; extern const struct file_operations event_trigger_fops; +extern const struct file_operations event_hist_fops; + +#ifdef CONFIG_HIST_TRIGGERS +extern int register_trigger_hist_cmd(void); +#else +static inline int register_trigger_hist_cmd(void) { return 0; } +#endif extern int register_trigger_cmds(void); extern void clear_event_triggers(struct trace_array *tr); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index add81dff7520..e7cb983ee93c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2141,6 +2141,10 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file) trace_create_file("trigger", 0644, file->dir, file, &event_trigger_fops); +#ifdef CONFIG_HIST_TRIGGERS + trace_create_file("hist", 0444, file->dir, file, + &event_hist_fops); +#endif trace_create_file("format", 0444, file->dir, call, &ftrace_event_format_fops); diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c new file mode 100644 index 000000000000..23b45e462117 --- /dev/null +++ b/kernel/trace/trace_events_hist.c @@ -0,0 +1,849 @@ +/* + * trace_events_hist - trace event hist triggers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com> + */ + +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/stacktrace.h> + +#include "tracing_map.h" +#include "trace.h" + +struct hist_field; + +typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event); + +struct hist_field { + struct ftrace_event_field *field; + unsigned long flags; + hist_field_fn_t fn; + unsigned int size; +}; + +static u64 hist_field_counter(struct hist_field *field, void *event) +{ + return 1; +} + +static u64 hist_field_string(struct hist_field *hist_field, void *event) +{ + char *addr = (char *)(event + hist_field->field->offset); + + return (u64)(unsigned long)addr; +} + +#define DEFINE_HIST_FIELD_FN(type) \ +static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ +{ \ + type *addr = (type *)(event + hist_field->field->offset); \ + \ + return (u64)*addr; \ +} + +DEFINE_HIST_FIELD_FN(s64); +DEFINE_HIST_FIELD_FN(u64); +DEFINE_HIST_FIELD_FN(s32); +DEFINE_HIST_FIELD_FN(u32); +DEFINE_HIST_FIELD_FN(s16); +DEFINE_HIST_FIELD_FN(u16); +DEFINE_HIST_FIELD_FN(s8); +DEFINE_HIST_FIELD_FN(u8); + +#define for_each_hist_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_fields; (i)++) + +#define for_each_hist_val_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_vals; (i)++) + +#define for_each_hist_key_field(i, hist_data) \ + for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) + +#define HITCOUNT_IDX 0 +#define HIST_KEY_MAX 1 +#define HIST_KEY_SIZE_MAX MAX_FILTER_STR_VAL + +enum hist_field_flags { + HIST_FIELD_FL_HITCOUNT = 1, + HIST_FIELD_FL_KEY = 2, + HIST_FIELD_FL_STRING = 4, +}; + +struct hist_trigger_attrs { + char *keys_str; + unsigned int map_bits; +}; + +struct hist_trigger_data { + struct hist_field *fields[TRACING_MAP_FIELDS_MAX]; + unsigned int n_vals; + unsigned int n_keys; + unsigned int n_fields; + unsigned int key_size; + struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; + unsigned int n_sort_keys; + struct trace_event_file *event_file; + struct hist_trigger_attrs *attrs; + struct tracing_map *map; +}; + +static hist_field_fn_t select_value_fn(int field_size, int field_is_signed) +{ + hist_field_fn_t fn = NULL; + + switch (field_size) { + case 8: + if (field_is_signed) + fn = hist_field_s64; + else + fn = hist_field_u64; + break; + case 4: + if (field_is_signed) + fn = hist_field_s32; + else + fn = hist_field_u32; + break; + case 2: + if (field_is_signed) + fn = hist_field_s16; + else + fn = hist_field_u16; + break; + case 1: + if (field_is_signed) + fn = hist_field_s8; + else + fn = hist_field_u8; + break; + } + + return fn; +} + +static int parse_map_size(char *str) +{ + unsigned long size, map_bits; + int ret; + + strsep(&str, "="); + if (!str) { + ret = -EINVAL; + goto out; + } + + ret = kstrtoul(str, 0, &size); + if (ret) + goto out; + + map_bits = ilog2(roundup_pow_of_two(size)); + if (map_bits < TRACING_MAP_BITS_MIN || + map_bits > TRACING_MAP_BITS_MAX) + ret = -EINVAL; + else + ret = map_bits; + out: + return ret; +} + +static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) +{ + if (!attrs) + return; + + kfree(attrs->keys_str); + kfree(attrs); +} + +static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) +{ + struct hist_trigger_attrs *attrs; + int ret = 0; + + attrs = kzalloc(sizeof(*attrs), GFP_KERNEL); + if (!attrs) + return ERR_PTR(-ENOMEM); + + while (trigger_str) { + char *str = strsep(&trigger_str, ":"); + + if ((strncmp(str, "key=", strlen("key=")) == 0) || + (strncmp(str, "keys=", strlen("keys=")) == 0)) + attrs->keys_str = kstrdup(str, GFP_KERNEL); + else if (strncmp(str, "size=", strlen("size=")) == 0) { + int map_bits = parse_map_size(str); + + if (map_bits < 0) { + ret = map_bits; + goto free; + } + attrs->map_bits = map_bits; + } else { + ret = -EINVAL; + goto free; + } + } + + if (!attrs->keys_str) { + ret = -EINVAL; + goto free; + } + + return attrs; + free: + destroy_hist_trigger_attrs(attrs); + + return ERR_PTR(ret); +} + +static void destroy_hist_field(struct hist_field *hist_field) +{ + kfree(hist_field); +} + +static struct hist_field *create_hist_field(struct ftrace_event_field *field, + unsigned long flags) +{ + struct hist_field *hist_field; + + if (field && is_function_field(field)) + return NULL; + + hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL); + if (!hist_field) + return NULL; + + if (flags & HIST_FIELD_FL_HITCOUNT) { + hist_field->fn = hist_field_counter; + goto out; + } + + if (is_string_field(field)) { + flags |= HIST_FIELD_FL_STRING; + hist_field->fn = hist_field_string; + } else { + hist_field->fn = select_value_fn(field->size, + field->is_signed); + if (!hist_field->fn) { + destroy_hist_field(hist_field); + return NULL; + } + } + out: + hist_field->field = field; + hist_field->flags = flags; + + return hist_field; +} + +static void destroy_hist_fields(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) { + if (hist_data->fields[i]) { + destroy_hist_field(hist_data->fields[i]); + hist_data->fields[i] = NULL; + } + } +} + +static int create_hitcount_val(struct hist_trigger_data *hist_data) +{ + hist_data->fields[HITCOUNT_IDX] = + create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT); + if (!hist_data->fields[HITCOUNT_IDX]) + return -ENOMEM; + + hist_data->n_vals++; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return 0; +} + +static int create_val_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + int ret; + + ret = create_hitcount_val(hist_data); + + return ret; +} + +static int create_key_field(struct hist_trigger_data *hist_data, + unsigned int key_idx, + struct trace_event_file *file, + char *field_str) +{ + struct ftrace_event_field *field = NULL; + unsigned long flags = 0; + unsigned int key_size; + int ret = 0; + + if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) + return -EINVAL; + + flags |= HIST_FIELD_FL_KEY; + + field = trace_find_event_field(file->event_call, field_str); + if (!field) { + ret = -EINVAL; + goto out; + } + + key_size = field->size; + + hist_data->fields[key_idx] = create_hist_field(field, flags); + if (!hist_data->fields[key_idx]) { + ret = -ENOMEM; + goto out; + } + + key_size = ALIGN(key_size, sizeof(u64)); + hist_data->fields[key_idx]->size = key_size; + hist_data->key_size = key_size; + if (hist_data->key_size > HIST_KEY_SIZE_MAX) { + ret = -EINVAL; + goto out; + } + + hist_data->n_keys++; + + if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX)) + return -EINVAL; + + ret = key_size; + out: + return ret; +} + +static int create_key_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, n_vals = hist_data->n_vals; + char *fields_str, *field_str; + int ret = -EINVAL; + + fields_str = hist_data->attrs->keys_str; + if (!fields_str) + goto out; + + strsep(&fields_str, "="); + if (!fields_str) + goto out; + + for (i = n_vals; i < n_vals + HIST_KEY_MAX; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + ret = create_key_field(hist_data, i, file, field_str); + if (ret < 0) + goto out; + } + if (fields_str) { + ret = -EINVAL; + goto out; + } + ret = 0; + out: + return ret; +} + +static int create_hist_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + int ret; + + ret = create_val_fields(hist_data, file); + if (ret) + goto out; + + ret = create_key_fields(hist_data, file); + if (ret) + goto out; + + hist_data->n_fields = hist_data->n_vals + hist_data->n_keys; + out: + return ret; +} + +static int create_sort_keys(struct hist_trigger_data *hist_data) +{ + int ret = 0; + + hist_data->n_sort_keys = 1; /* sort_keys[0] is always hitcount */ + + return ret; +} + +static void destroy_hist_data(struct hist_trigger_data *hist_data) +{ + destroy_hist_trigger_attrs(hist_data->attrs); + destroy_hist_fields(hist_data); + tracing_map_destroy(hist_data->map); + kfree(hist_data); +} + +static int create_tracing_map_fields(struct hist_trigger_data *hist_data) +{ + struct tracing_map *map = hist_data->map; + struct ftrace_event_field *field; + struct hist_field *hist_field; + unsigned int i, idx; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_KEY) { + tracing_map_cmp_fn_t cmp_fn; + + field = hist_field->field; + + if (is_string_field(field)) + cmp_fn = tracing_map_cmp_string; + else + cmp_fn = tracing_map_cmp_num(field->size, + field->is_signed); + idx = tracing_map_add_key_field(map, 0, cmp_fn); + } else + idx = tracing_map_add_sum_field(map); + + if (idx < 0) + return idx; + } + + return 0; +} + +static struct hist_trigger_data * +create_hist_data(unsigned int map_bits, + struct hist_trigger_attrs *attrs, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + int ret = 0; + + hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL); + if (!hist_data) + return ERR_PTR(-ENOMEM); + + hist_data->attrs = attrs; + + ret = create_hist_fields(hist_data, file); + if (ret) + goto free; + + ret = create_sort_keys(hist_data); + if (ret) + goto free; + + hist_data->map = tracing_map_create(map_bits, hist_data->key_size, + NULL, hist_data); + if (IS_ERR(hist_data->map)) { + ret = PTR_ERR(hist_data->map); + hist_data->map = NULL; + goto free; + } + + ret = create_tracing_map_fields(hist_data); + if (ret) + goto free; + + ret = tracing_map_init(hist_data->map); + if (ret) + goto free; + + hist_data->event_file = file; + out: + return hist_data; + free: + hist_data->attrs = NULL; + + destroy_hist_data(hist_data); + + hist_data = ERR_PTR(ret); + + goto out; +} + +static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + void *rec) +{ + struct hist_field *hist_field; + unsigned int i; + u64 hist_val; + + for_each_hist_val_field(i, hist_data) { + hist_field = hist_data->fields[i]; + hist_val = hist_field->fn(hist_field, rec); + tracing_map_update_sum(elt, i, hist_val); + } +} + +static void event_hist_trigger(struct event_trigger_data *data, void *rec) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct hist_field *key_field; + struct tracing_map_elt *elt; + u64 field_contents; + void *key = NULL; + unsigned int i; + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + field_contents = key_field->fn(key_field, rec); + if (key_field->flags & HIST_FIELD_FL_STRING) + key = (void *)(unsigned long)field_contents; + else + key = (void *)&field_contents; + } + + elt = tracing_map_insert(hist_data->map, key); + if (elt) + hist_trigger_elt_update(hist_data, elt, rec); +} + +static void +hist_trigger_entry_print(struct seq_file *m, + struct hist_trigger_data *hist_data, void *key, + struct tracing_map_elt *elt) +{ + struct hist_field *key_field; + unsigned int i; + u64 uval; + + seq_puts(m, "{ "); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ", "); + + if (key_field->flags & HIST_FIELD_FL_STRING) { + seq_printf(m, "%s: %-50s", key_field->field->name, + (char *)key); + } else { + uval = *(u64 *)key; + seq_printf(m, "%s: %10llu", + key_field->field->name, uval); + } + } + + seq_puts(m, " }"); + + seq_printf(m, " hitcount: %10llu", + tracing_map_read_sum(elt, HITCOUNT_IDX)); + + seq_puts(m, "\n"); +} + +static int print_entries(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + struct tracing_map_sort_entry **sort_entries = NULL; + struct tracing_map *map = hist_data->map; + unsigned int i, n_entries; + + n_entries = tracing_map_sort_entries(map, hist_data->sort_keys, + hist_data->n_sort_keys, + &sort_entries); + if (n_entries < 0) + return n_entries; + + for (i = 0; i < n_entries; i++) + hist_trigger_entry_print(m, hist_data, + sort_entries[i]->key, + sort_entries[i]->elt); + + tracing_map_destroy_sort_entries(sort_entries, n_entries); + + return n_entries; +} + +static int hist_show(struct seq_file *m, void *v) +{ + struct event_trigger_data *test, *data = NULL; + struct trace_event_file *event_file; + struct hist_trigger_data *hist_data; + int n_entries, ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(m->private); + if (unlikely(!event_file)) { + ret = -ENODEV; + goto out_unlock; + } + + list_for_each_entry_rcu(test, &event_file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + data = test; + break; + } + } + if (!data) + goto out_unlock; + + seq_puts(m, "# event histogram\n#\n# trigger info: "); + data->ops->print(m, data->ops, data); + seq_puts(m, "\n"); + + hist_data = data->private_data; + n_entries = print_entries(m, hist_data); + if (n_entries < 0) { + ret = n_entries; + n_entries = 0; + } + + seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n", + (u64)atomic64_read(&hist_data->map->hits), + n_entries, (u64)atomic64_read(&hist_data->map->drops)); + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +static int event_hist_open(struct inode *inode, struct file *file) +{ + return single_open(file, hist_show, file); +} + +const struct file_operations event_hist_fops = { + .open = event_hist_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) +{ + seq_printf(m, "%s", hist_field->field->name); +} + +static int event_hist_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct hist_field *key_field; + unsigned int i; + + seq_puts(m, "hist:keys="); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ","); + + hist_field_print(m, key_field); + } + + seq_puts(m, ":vals="); + seq_puts(m, "hitcount"); + + seq_puts(m, ":sort="); + seq_puts(m, "hitcount"); + + seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits)); + + if (data->filter_str) + seq_printf(m, " if %s", data->filter_str); + + seq_puts(m, " [active]"); + + seq_putc(m, '\n'); + + return 0; +} + +static void event_hist_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + data->ref--; + if (!data->ref) { + trigger_data_free(data); + destroy_hist_data(hist_data); + } +} + +static struct event_trigger_ops event_hist_trigger_ops = { + .func = event_hist_trigger, + .print = event_hist_trigger_print, + .init = event_trigger_init, + .free = event_hist_trigger_free, +}; + +static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, + char *param) +{ + return &event_hist_trigger_ops; +} + +static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct event_trigger_data *test; + int ret = 0; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + ret = -EEXIST; + goto out; + } + } + + if (data->ops->init) { + ret = data->ops->init(data->ops, data); + if (ret < 0) + goto out; + } + + list_add_rcu(&data->list, &file->triggers); + ret++; + + update_cond_flag(file); + if (trace_event_trigger_enable_disable(file, 1) < 0) { + list_del_rcu(&data->list); + update_cond_flag(file); + ret--; + } + out: + return ret; +} + +static int event_hist_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) +{ + unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT; + struct event_trigger_data *trigger_data; + struct hist_trigger_attrs *attrs; + struct event_trigger_ops *trigger_ops; + struct hist_trigger_data *hist_data; + char *trigger; + int ret = 0; + + if (!param) + return -EINVAL; + + /* separate the trigger from the filter (k:v [if filter]) */ + trigger = strsep(¶m, " \t"); + if (!trigger) + return -EINVAL; + + attrs = parse_hist_trigger_attrs(trigger); + if (IS_ERR(attrs)) + return PTR_ERR(attrs); + + if (attrs->map_bits) + hist_trigger_bits = attrs->map_bits; + + hist_data = create_hist_data(hist_trigger_bits, attrs, file); + if (IS_ERR(hist_data)) { + destroy_hist_trigger_attrs(attrs); + return PTR_ERR(hist_data); + } + + trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); + + ret = -ENOMEM; + trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); + if (!trigger_data) + goto out_free; + + trigger_data->count = -1; + trigger_data->ops = trigger_ops; + trigger_data->cmd_ops = cmd_ops; + + INIT_LIST_HEAD(&trigger_data->list); + RCU_INIT_POINTER(trigger_data->filter, NULL); + + trigger_data->private_data = hist_data; + + if (glob[0] == '!') { + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + ret = 0; + goto out_free; + } + + if (!param) /* if param is non-empty, it's supposed to be a filter */ + goto out_reg; + + if (!cmd_ops->set_filter) + goto out_reg; + + ret = cmd_ops->set_filter(param, trigger_data, file); + if (ret < 0) + goto out_free; + out_reg: + ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + /* + * The above returns on success the # of triggers registered, + * but if it didn't register any it returns zero. Consider no + * triggers registered a failure too. + */ + if (!ret) { + ret = -ENOENT; + goto out_free; + } else if (ret < 0) + goto out_free; + /* Just return zero, not the number of registered triggers */ + ret = 0; + out: + return ret; + out_free: + if (cmd_ops->set_filter) + cmd_ops->set_filter(NULL, trigger_data, NULL); + + kfree(trigger_data); + + destroy_hist_data(hist_data); + goto out; +} + +static struct event_command trigger_hist_cmd = { + .name = "hist", + .trigger_type = ETT_EVENT_HIST, + .flags = EVENT_CMD_FL_NEEDS_REC, + .func = event_hist_trigger_func, + .reg = hist_register_trigger, + .unreg = unregister_trigger, + .get_trigger_ops = event_hist_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +__init int register_trigger_hist_cmd(void) +{ + int ret; + + ret = register_event_command(&trigger_hist_cmd); + WARN_ON(ret < 0); + + return ret; +} diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index d67992f3bb0e..d29092afe005 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1447,6 +1447,7 @@ __init int register_trigger_cmds(void) register_trigger_snapshot_cmd(); register_trigger_stacktrace_cmd(); register_trigger_enable_disable_cmds(); + register_trigger_hist_cmd(); return 0; } |