Files
linux-stable-mirror/tools/perf/tests/symbols.c
T
Ian Rogers 979e87ab1f perf symbol: Add setters for bitfields sharing a byte to avoid concurrent update issues
A problem with putting bitfields into struct symbol is that other bits in
the symbol could be updated concurrently and only one update to the
underlying storage unit happen, leading to lost updates.

To avoid this, use atomics to atomically read or set part of 16-bits
of flags in the symbol. Add accessors to simplify this.

The idle value has 3 values in preparation for a later change that
will lazily update it.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Honglei Wang <jameshongleiwang@126.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-03 16:53:45 -03:00

227 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/string.h>
#include <sys/mman.h>
#include <limits.h>
#include "debug.h"
#include "dso.h"
#include "env.h"
#include "machine.h"
#include "thread.h"
#include "symbol.h"
#include "map.h"
#include "util.h"
#include "tests.h"
struct test_info {
struct perf_env host_env;
struct machine *machine;
struct thread *thread;
};
static int init_test_info(struct test_info *ti)
{
perf_env__init(&ti->host_env);
ti->machine = machine__new_host(&ti->host_env);
if (!ti->machine) {
pr_debug("machine__new_host() failed!\n");
perf_env__exit(&ti->host_env);
return TEST_FAIL;
}
/* Create a dummy thread */
ti->thread = machine__findnew_thread(ti->machine, 100, 100);
if (!ti->thread) {
pr_debug("machine__findnew_thread() failed!\n");
perf_env__exit(&ti->host_env);
return TEST_FAIL;
}
return TEST_OK;
}
static void exit_test_info(struct test_info *ti)
{
thread__put(ti->thread);
machine__delete(ti->machine);
perf_env__exit(&ti->host_env);
}
struct dso_map {
struct dso *dso;
struct map *map;
};
static int find_map_cb(struct map *map, void *d)
{
struct dso_map *data = d;
if (map__dso(map) != data->dso)
return 0;
data->map = map;
return 1;
}
static struct map *find_module_map(struct machine *machine, struct dso *dso)
{
struct dso_map data = { .dso = dso };
machine__for_each_kernel_map(machine, find_map_cb, &data);
return data.map;
}
static void get_test_dso_filename(char *filename, size_t max_sz)
{
if (dso_to_test)
strlcpy(filename, dso_to_test, max_sz);
else
perf_exe(filename, max_sz);
}
static int create_map(struct test_info *ti, char *filename, struct map **map_p)
{
struct dso *dso = machine__findnew_dso(ti->machine, filename);
/*
* If 'filename' matches a current kernel module, must use a kernel
* map. Find the one that already exists.
*/
if (dso && dso__kernel(dso) != DSO_SPACE__USER) {
*map_p = find_module_map(ti->machine, dso);
dso__put(dso);
if (!*map_p) {
pr_debug("Failed to find map for current kernel module %s",
filename);
return TEST_FAIL;
}
map__get(*map_p);
return TEST_OK;
}
dso__put(dso);
/* Create a dummy map at 0x100000 */
*map_p = map__new(ti->machine, 0x100000, 0xffffffff, 0, &dso_id_empty,
PROT_EXEC, /*flags=*/0, filename, ti->thread);
if (!*map_p) {
pr_debug("Failed to create map!");
return TEST_FAIL;
}
return TEST_OK;
}
static int test_dso(struct dso *dso)
{
struct symbol *last_sym = NULL;
struct rb_node *nd;
int ret = TEST_OK;
/* dso__fprintf() prints all the symbols */
if (verbose > 1)
dso__fprintf(dso, stderr);
for (nd = rb_first_cached(dso__symbols(dso)); nd; nd = rb_next(nd)) {
struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
if (symbol__type(sym) != STT_FUNC && symbol__type(sym) != STT_GNU_IFUNC)
continue;
/* Check for overlapping function symbols */
if (last_sym && sym->start < last_sym->end) {
pr_debug("Overlapping symbols:\n");
symbol__fprintf(last_sym, stderr);
symbol__fprintf(sym, stderr);
ret = TEST_FAIL;
}
/* Check for zero-length function symbol */
if (sym->start == sym->end) {
pr_debug("Zero-length symbol:\n");
symbol__fprintf(sym, stderr);
ret = TEST_FAIL;
}
last_sym = sym;
}
return ret;
}
static int subdivided_dso_cb(struct dso *dso, struct machine *machine __maybe_unused, void *d)
{
struct dso *text_dso = d;
if (dso != text_dso && strstarts(dso__short_name(dso), dso__short_name(text_dso)))
if (test_dso(dso) != TEST_OK)
return -1;
return 0;
}
static int process_subdivided_dso(struct machine *machine, struct dso *dso)
{
int ret;
ret = machine__for_each_dso(machine, subdivided_dso_cb, dso);
return ret < 0 ? TEST_FAIL : TEST_OK;
}
static int test_file(struct test_info *ti, char *filename)
{
struct map *map = NULL;
int ret, nr;
struct dso *dso;
pr_debug("Testing %s\n", filename);
ret = create_map(ti, filename, &map);
if (ret != TEST_OK)
return ret;
dso = map__dso(map);
nr = dso__load(dso, map);
if (nr < 0) {
pr_debug("dso__load() failed!\n");
ret = TEST_FAIL;
goto out_put;
}
if (nr == 0) {
pr_debug("DSO has no symbols!\n");
ret = TEST_SKIP;
goto out_put;
}
ret = test_dso(dso);
/* Module dso is split into many dsos by section */
if (ret == TEST_OK && dso__kernel(dso) != DSO_SPACE__USER)
ret = process_subdivided_dso(ti->machine, dso);
out_put:
map__put(map);
return ret;
}
static int test__symbols(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
char filename[PATH_MAX];
struct test_info ti;
int ret;
ret = init_test_info(&ti);
if (ret != TEST_OK)
return ret;
get_test_dso_filename(filename, sizeof(filename));
ret = test_file(&ti, filename);
exit_test_info(&ti);
return ret;
}
DEFINE_SUITE("Symbols", symbols);