OpenCloudOS-Kernel/tools/perf/tests/symbols.c

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perf test: Add Symbols test Add a test to check function symbols do not overlap and are not zero length. The main motivation for the test is to make it easier to review changes to PLT symbol synthesis i.e. changes to dso__synthesize_plt_symbols(). By default the test uses the perf executable as a test DSO, but a specific DSO can be specified via a new perf test option "--dso". The test is useful in the following ways: - Any DSO can be tested, even ones that do not run on the current architecture. For example, using cross-compiled DSOs to see how well perf handles different architectures. - With verbose > 1 (e.g. -vv), all the symbols are printed, which makes it easier to see issues. - perf removes duplicate symbols and expands zero-length symbols to reach the next symbol, however that is done before adding synthesized symbols, so the test is checking those also. Example: $ perf test -v Symbols 74: Symbols : --- start --- test child forked, pid 154918 Testing /home/user/bin/perf Overlapping symbols: 7d000-7f3a0 g _init 7d030-7d040 g __printf_chk@plt test child finished with -1 ---- end ---- Symbols: FAILED! Note the test fails because perf expands the _init symbol over the PLT because there are no PLT symbols at that point, but then dso__synthesize_plt_symbols() creates them. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-01-20 20:34:47 +08:00
// 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 "machine.h"
#include "thread.h"
#include "symbol.h"
#include "map.h"
#include "util.h"
#include "tests.h"
struct test_info {
struct machine *machine;
struct thread *thread;
};
static int init_test_info(struct test_info *ti)
{
ti->machine = machine__new_host();
if (!ti->machine) {
pr_debug("machine__new_host() failed!\n");
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");
return TEST_FAIL;
}
return TEST_OK;
}
static void exit_test_info(struct test_info *ti)
{
thread__put(ti->thread);
machine__delete(ti->machine);
}
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)
{
/* Create a dummy map at 0x100000 */
*map_p = map__new(ti->machine, 0x100000, 0xffffffff, 0, NULL,
PROT_EXEC, 0, NULL, 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); nd; nd = rb_next(nd)) {
struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
if (sym->type != STT_FUNC && sym->type != 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 test_file(struct test_info *ti, char *filename)
{
struct map *map = NULL;
int ret, nr;
pr_debug("Testing %s\n", filename);
ret = create_map(ti, filename, &map);
if (ret != TEST_OK)
return ret;
nr = dso__load(map->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(map->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);