trace_events_hist.c 24.6 KB
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/*
 * 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;
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	unsigned int			offset;
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};

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
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#define HIST_KEY_SIZE_MAX	(MAX_FILTER_STR_VAL + sizeof(u64))
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enum hist_field_flags {
	HIST_FIELD_FL_HITCOUNT	= 1,
	HIST_FIELD_FL_KEY	= 2,
	HIST_FIELD_FL_STRING	= 4,
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	HIST_FIELD_FL_HEX	= 8,
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};

struct hist_trigger_attrs {
	char		*keys_str;
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	char		*vals_str;
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	char		*sort_key_str;
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	bool		pause;
	bool		cont;
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	bool		clear;
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	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;

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	kfree(attrs->sort_key_str);
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	kfree(attrs->keys_str);
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	kfree(attrs->vals_str);
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	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);
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		else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
			 (strncmp(str, "vals=", strlen("vals=")) == 0) ||
			 (strncmp(str, "values=", strlen("values=")) == 0))
			attrs->vals_str = kstrdup(str, GFP_KERNEL);
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		else if (strncmp(str, "sort=", strlen("sort=")) == 0)
			attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
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		else if (strcmp(str, "pause") == 0)
			attrs->pause = true;
		else if ((strcmp(str, "cont") == 0) ||
			 (strcmp(str, "continue") == 0))
			attrs->cont = true;
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		else if (strcmp(str, "clear") == 0)
			attrs->clear = true;
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		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;
}

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static int create_val_field(struct hist_trigger_data *hist_data,
			    unsigned int val_idx,
			    struct trace_event_file *file,
			    char *field_str)
{
	struct ftrace_event_field *field = NULL;
	unsigned long flags = 0;
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	char *field_name;
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	int ret = 0;

	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
		return -EINVAL;
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	field_name = strsep(&field_str, ".");
	if (field_str) {
		if (strcmp(field_str, "hex") == 0)
			flags |= HIST_FIELD_FL_HEX;
		else {
			ret = -EINVAL;
			goto out;
		}
	}

	field = trace_find_event_field(file->event_call, field_name);
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	if (!field) {
		ret = -EINVAL;
		goto out;
	}

	hist_data->fields[val_idx] = create_hist_field(field, flags);
	if (!hist_data->fields[val_idx]) {
		ret = -ENOMEM;
		goto out;
	}

	++hist_data->n_vals;

	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
		ret = -EINVAL;
 out:
	return ret;
}

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static int create_val_fields(struct hist_trigger_data *hist_data,
			     struct trace_event_file *file)
{
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	char *fields_str, *field_str;
	unsigned int i, j;
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	int ret;

	ret = create_hitcount_val(hist_data);
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	if (ret)
		goto out;
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	fields_str = hist_data->attrs->vals_str;
	if (!fields_str)
		goto out;

	strsep(&fields_str, "=");
	if (!fields_str)
		goto out;

	for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
		     j < TRACING_MAP_VALS_MAX; i++) {
		field_str = strsep(&fields_str, ",");
		if (!field_str)
			break;
		if (strcmp(field_str, "hitcount") == 0)
			continue;
		ret = create_val_field(hist_data, j++, file, field_str);
		if (ret)
			goto out;
	}
	if (fields_str && (strcmp(fields_str, "hitcount") != 0))
		ret = -EINVAL;
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	return ret;
}

static int create_key_field(struct hist_trigger_data *hist_data,
			    unsigned int key_idx,
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			    unsigned int key_offset,
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			    struct trace_event_file *file,
			    char *field_str)
{
	struct ftrace_event_field *field = NULL;
	unsigned long flags = 0;
	unsigned int key_size;
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	char *field_name;
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	int ret = 0;

	if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
		return -EINVAL;

	flags |= HIST_FIELD_FL_KEY;

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	field_name = strsep(&field_str, ".");
	if (field_str) {
		if (strcmp(field_str, "hex") == 0)
			flags |= HIST_FIELD_FL_HEX;
		else {
			ret = -EINVAL;
			goto out;
		}
	}

	field = trace_find_event_field(file->event_call, field_name);
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	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;
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	hist_data->fields[key_idx]->offset = key_offset;
	hist_data->key_size += key_size;
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	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)
{
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	unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
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	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;

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	for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
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		field_str = strsep(&fields_str, ",");
		if (!field_str)
			break;
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		ret = create_key_field(hist_data, i, key_offset,
				       file, field_str);
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		if (ret < 0)
			goto out;
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		key_offset += ret;
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	}
	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;
}

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static int is_descending(const char *str)
{
	if (!str)
		return 0;

	if (strcmp(str, "descending") == 0)
		return 1;

	if (strcmp(str, "ascending") == 0)
		return 0;

	return -EINVAL;
}

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static int create_sort_keys(struct hist_trigger_data *hist_data)
{
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	char *fields_str = hist_data->attrs->sort_key_str;
	struct ftrace_event_field *field = NULL;
	struct tracing_map_sort_key *sort_key;
	int descending, ret = 0;
	unsigned int i, j;

	hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */

	if (!fields_str)
		goto out;

	strsep(&fields_str, "=");
	if (!fields_str) {
		ret = -EINVAL;
		goto out;
	}

	for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
		char *field_str, *field_name;

		sort_key = &hist_data->sort_keys[i];

		field_str = strsep(&fields_str, ",");
		if (!field_str) {
			if (i == 0)
				ret = -EINVAL;
			break;
		}

		if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
			ret = -EINVAL;
			break;
		}
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		field_name = strsep(&field_str, ".");
		if (!field_name) {
			ret = -EINVAL;
			break;
		}

		if (strcmp(field_name, "hitcount") == 0) {
			descending = is_descending(field_str);
			if (descending < 0) {
				ret = descending;
				break;
			}
			sort_key->descending = descending;
			continue;
		}
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		for (j = 1; j < hist_data->n_fields; j++) {
			field = hist_data->fields[j]->field;
			if (field && (strcmp(field_name, field->name) == 0)) {
				sort_key->field_idx = j;
				descending = is_descending(field_str);
				if (descending < 0) {
					ret = descending;
					goto out;
				}
				sort_key->descending = descending;
				break;
			}
		}
		if (j == hist_data->n_fields) {
			ret = -EINVAL;
			break;
		}
	}
	hist_data->n_sort_keys = i;
 out:
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	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);
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			idx = tracing_map_add_key_field(map,
							hist_field->offset,
							cmp_fn);

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		} 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;
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	char compound_key[HIST_KEY_SIZE_MAX];
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	struct hist_field *key_field;
	struct tracing_map_elt *elt;
	u64 field_contents;
	void *key = NULL;
	unsigned int i;

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	if (hist_data->n_keys > 1)
		memset(compound_key, 0, hist_data->key_size);

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	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;
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		if (hist_data->n_keys > 1) {
			memcpy(compound_key + key_field->offset, key,
			       key_field->size);
		}
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	}

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	if (hist_data->n_keys > 1)
		key = compound_key;

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	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, ", ");

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		if (key_field->flags & HIST_FIELD_FL_HEX) {
			uval = *(u64 *)(key + key_field->offset);
			seq_printf(m, "%s: %llx",
				   key_field->field->name, uval);
		} else if (key_field->flags & HIST_FIELD_FL_STRING) {
745
			seq_printf(m, "%s: %-50s", key_field->field->name,
746
				   (char *)(key + key_field->offset));
747
		} else {
748 749 750
			uval = *(u64 *)(key + key_field->offset);
			seq_printf(m, "%s: %10llu", key_field->field->name,
				   uval);
751 752 753 754 755 756 757 758
		}
	}

	seq_puts(m, " }");

	seq_printf(m, " hitcount: %10llu",
		   tracing_map_read_sum(elt, HITCOUNT_IDX));

759
	for (i = 1; i < hist_data->n_vals; i++) {
760 761 762 763 764 765 766 767 768
		if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
			seq_printf(m, "  %s: %10llx",
				   hist_data->fields[i]->field->name,
				   tracing_map_read_sum(elt, i));
		} else {
			seq_printf(m, "  %s: %10llu",
				   hist_data->fields[i]->field->name,
				   tracing_map_read_sum(elt, i));
		}
769 770
	}

771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
	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,
};

853 854 855 856 857 858 859 860 861 862
static const char *get_hist_field_flags(struct hist_field *hist_field)
{
	const char *flags_str = NULL;

	if (hist_field->flags & HIST_FIELD_FL_HEX)
		flags_str = "hex";

	return flags_str;
}

863 864 865
static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
	seq_printf(m, "%s", hist_field->field->name);
866 867 868 869 870 871
	if (hist_field->flags) {
		const char *flags_str = get_hist_field_flags(hist_field);

		if (flags_str)
			seq_printf(m, ".%s", flags_str);
	}
872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893
}

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=");
894 895 896 897 898 899 900 901 902

	for_each_hist_val_field(i, hist_data) {
		if (i == HITCOUNT_IDX)
			seq_puts(m, "hitcount");
		else {
			seq_puts(m, ",");
			hist_field_print(m, hist_data->fields[i]);
		}
	}
903 904

	seq_puts(m, ":sort=");
905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927

	for (i = 0; i < hist_data->n_sort_keys; i++) {
		struct tracing_map_sort_key *sort_key;

		sort_key = &hist_data->sort_keys[i];

		if (i > 0)
			seq_puts(m, ",");

		if (sort_key->field_idx == HITCOUNT_IDX)
			seq_puts(m, "hitcount");
		else {
			unsigned int idx = sort_key->field_idx;

			if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
				return -EINVAL;

			hist_field_print(m, hist_data->fields[idx]);
		}

		if (sort_key->descending)
			seq_puts(m, ".descending");
	}
928 929 930 931 932 933

	seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));

	if (data->filter_str)
		seq_printf(m, " if %s", data->filter_str);

934 935 936 937
	if (data->paused)
		seq_puts(m, " [paused]");
	else
		seq_puts(m, " [active]");
938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971

	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;
}

972 973 974 975 976 977 978 979 980 981 982 983 984 985 986
static void hist_clear(struct event_trigger_data *data)
{
	struct hist_trigger_data *hist_data = data->private_data;
	bool paused;

	paused = data->paused;
	data->paused = true;

	synchronize_sched();

	tracing_map_clear(hist_data->map);

	data->paused = paused;
}

987 988 989 990
static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
				 struct event_trigger_data *data,
				 struct trace_event_file *file)
{
991
	struct hist_trigger_data *hist_data = data->private_data;
992 993 994 995 996
	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) {
997 998 999 1000
			if (hist_data->attrs->pause)
				test->paused = true;
			else if (hist_data->attrs->cont)
				test->paused = false;
1001 1002
			else if (hist_data->attrs->clear)
				hist_clear(test);
1003 1004
			else
				ret = -EEXIST;
1005 1006 1007 1008
			goto out;
		}
	}

1009
	if (hist_data->attrs->cont || hist_data->attrs->clear) {
1010 1011 1012 1013 1014 1015 1016
		ret = -ENOENT;
		goto out;
	}

	if (hist_data->attrs->pause)
		data->paused = true;

1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
	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(&param, " \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) {
1108
		if (!(attrs->pause || attrs->cont || attrs->clear))
1109
			ret = -ENOENT;
1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146
		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;
}