linux/tools/perf/util/expr.c
Jiri Olsa f6fb0960f9 perf metric: Add recursion check when processing nested metrics
Keeping the stack of nested metrics via 'struct expr_id' objects
and checking if we are in recursion via already processed metric.

The stack is implemented as static array within the struct egroup
with 100 entries, which should be enough nesting depth for any
metric we have or plan to have at the moment.

Adding test that simulates the recursion and checks we can
detect it.

Committer notes:

Bumped RECURSION_ID_MAX to 1000 as per Jiri's reply to Paul Clark on the
patch series e-mail discussion.

Fixed these:

  tests/parse-metric.c:308:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers]
                  { 0 },
                      ^

  util/metricgroup.c:924:28: error: missing field 'parent' initializer [-Werror,-Wmissing-field-initializers]
          struct expr_ids ids = { 0 };
                                    ^
  util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
          struct expr_ids ids = { 0 };
                                  ^
                                  {}
  util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
          struct expr_ids ids = { 0 };
                                  ^
                                  {}
  util/metricgroup.c:924:28: error: missing field 'cnt' initializer [-Werror,-Wmissing-field-initializers]
          struct expr_ids ids = { 0 };
                                    ^

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200719181320.785305-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-30 07:01:49 -03:00

244 lines
5.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <stdbool.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "metricgroup.h"
#include "debug.h"
#include "expr.h"
#include "expr-bison.h"
#include "expr-flex.h"
#include <linux/kernel.h>
#include <linux/zalloc.h>
#include <ctype.h>
#ifdef PARSER_DEBUG
extern int expr_debug;
#endif
static size_t key_hash(const void *key, void *ctx __maybe_unused)
{
const char *str = (const char *)key;
size_t hash = 0;
while (*str != '\0') {
hash *= 31;
hash += *str;
str++;
}
return hash;
}
static bool key_equal(const void *key1, const void *key2,
void *ctx __maybe_unused)
{
return !strcmp((const char *)key1, (const char *)key2);
}
/* Caller must make sure id is allocated */
int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
{
struct expr_id_data *data_ptr = NULL, *old_data = NULL;
char *old_key = NULL;
int ret;
data_ptr = malloc(sizeof(*data_ptr));
if (!data_ptr)
return -ENOMEM;
data_ptr->parent = ctx->parent;
ret = hashmap__set(&ctx->ids, id, data_ptr,
(const void **)&old_key, (void **)&old_data);
if (ret)
free(data_ptr);
free(old_key);
free(old_data);
return ret;
}
/* Caller must make sure id is allocated */
int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
{
struct expr_id_data *data_ptr = NULL, *old_data = NULL;
char *old_key = NULL;
int ret;
data_ptr = malloc(sizeof(*data_ptr));
if (!data_ptr)
return -ENOMEM;
data_ptr->val = val;
data_ptr->is_ref = false;
ret = hashmap__set(&ctx->ids, id, data_ptr,
(const void **)&old_key, (void **)&old_data);
if (ret)
free(data_ptr);
free(old_key);
free(old_data);
return ret;
}
int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
{
struct expr_id_data *data_ptr = NULL, *old_data = NULL;
char *old_key = NULL;
char *name, *p;
int ret;
data_ptr = zalloc(sizeof(*data_ptr));
if (!data_ptr)
return -ENOMEM;
name = strdup(ref->metric_name);
if (!name) {
free(data_ptr);
return -ENOMEM;
}
/*
* The jevents tool converts all metric expressions
* to lowercase, including metric references, hence
* we need to add lowercase name for metric, so it's
* properly found.
*/
for (p = name; *p; p++)
*p = tolower(*p);
/*
* Intentionally passing just const char pointers,
* originally from 'struct pmu_event' object.
* We don't need to change them, so there's no
* need to create our own copy.
*/
data_ptr->ref.metric_name = ref->metric_name;
data_ptr->ref.metric_expr = ref->metric_expr;
data_ptr->ref.counted = false;
data_ptr->is_ref = true;
ret = hashmap__set(&ctx->ids, name, data_ptr,
(const void **)&old_key, (void **)&old_data);
if (ret)
free(data_ptr);
pr_debug2("adding ref metric %s: %s\n",
ref->metric_name, ref->metric_expr);
free(old_key);
free(old_data);
return ret;
}
int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
struct expr_id_data **data)
{
return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
}
int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
struct expr_id_data **datap)
{
struct expr_id_data *data;
if (expr__get_id(ctx, id, datap) || !*datap) {
pr_debug("%s not found\n", id);
return -1;
}
data = *datap;
pr_debug2("lookup: is_ref %d, counted %d, val %f: %s\n",
data->is_ref, data->ref.counted, data->val, id);
if (data->is_ref && !data->ref.counted) {
data->ref.counted = true;
pr_debug("processing metric: %s ENTRY\n", id);
if (expr__parse(&data->val, ctx, data->ref.metric_expr, 1)) {
pr_debug("%s failed to count\n", id);
return -1;
}
pr_debug("processing metric: %s EXIT: %f\n", id, data->val);
}
return 0;
}
void expr__del_id(struct expr_parse_ctx *ctx, const char *id)
{
struct expr_id_data *old_val = NULL;
char *old_key = NULL;
hashmap__delete(&ctx->ids, id,
(const void **)&old_key, (void **)&old_val);
free(old_key);
free(old_val);
}
void expr__ctx_init(struct expr_parse_ctx *ctx)
{
hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
}
void expr__ctx_clear(struct expr_parse_ctx *ctx)
{
struct hashmap_entry *cur;
size_t bkt;
hashmap__for_each_entry((&ctx->ids), cur, bkt) {
free((char *)cur->key);
free(cur->value);
}
hashmap__clear(&ctx->ids);
}
static int
__expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
int start, int runtime)
{
struct expr_scanner_ctx scanner_ctx = {
.start_token = start,
.runtime = runtime,
};
YY_BUFFER_STATE buffer;
void *scanner;
int ret;
pr_debug2("parsing metric: %s\n", expr);
ret = expr_lex_init_extra(&scanner_ctx, &scanner);
if (ret)
return ret;
buffer = expr__scan_string(expr, scanner);
#ifdef PARSER_DEBUG
expr_debug = 1;
expr_set_debug(1, scanner);
#endif
ret = expr_parse(val, ctx, scanner);
expr__flush_buffer(buffer, scanner);
expr__delete_buffer(buffer, scanner);
expr_lex_destroy(scanner);
return ret;
}
int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
const char *expr, int runtime)
{
return __expr__parse(final_val, ctx, expr, EXPR_PARSE, runtime) ? -1 : 0;
}
int expr__find_other(const char *expr, const char *one,
struct expr_parse_ctx *ctx, int runtime)
{
int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
if (one)
expr__del_id(ctx, one);
return ret;
}