mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-27 04:47:05 +00:00
de6d014a09
Currently, perf_event sample period in perf_event_stackmap is set too low
that the test fails randomly. Fix this by using the max sample frequency,
from read_perf_max_sample_freq().
Move read_perf_max_sample_freq() to testing_helpers.c. Replace the CHECK()
with if-printf, as CHECK is not available in testing_helpers.c.
Fixes: 1da4864c2b
("selftests/bpf: Add callchain_stackid")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230412210423.900851-2-song@kernel.org
132 lines
4 KiB
C
132 lines
4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <test_progs.h>
|
|
#include "test_stacktrace_build_id.skel.h"
|
|
|
|
void test_stacktrace_build_id_nmi(void)
|
|
{
|
|
int control_map_fd, stackid_hmap_fd, stackmap_fd;
|
|
struct test_stacktrace_build_id *skel;
|
|
int err, pmu_fd;
|
|
struct perf_event_attr attr = {
|
|
.freq = 1,
|
|
.type = PERF_TYPE_HARDWARE,
|
|
.config = PERF_COUNT_HW_CPU_CYCLES,
|
|
};
|
|
__u32 key, prev_key, val, duration = 0;
|
|
char buf[BPF_BUILD_ID_SIZE];
|
|
struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
|
|
int build_id_matches = 0, build_id_size;
|
|
int i, retry = 1;
|
|
|
|
attr.sample_freq = read_perf_max_sample_freq();
|
|
|
|
retry:
|
|
skel = test_stacktrace_build_id__open();
|
|
if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
|
|
return;
|
|
|
|
/* override program type */
|
|
bpf_program__set_type(skel->progs.oncpu, BPF_PROG_TYPE_PERF_EVENT);
|
|
|
|
err = test_stacktrace_build_id__load(skel);
|
|
if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err))
|
|
goto cleanup;
|
|
|
|
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
|
|
0 /* cpu 0 */, -1 /* group id */,
|
|
0 /* flags */);
|
|
if (pmu_fd < 0 && errno == ENOENT) {
|
|
printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__);
|
|
test__skip();
|
|
goto cleanup;
|
|
}
|
|
if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
|
|
pmu_fd, errno))
|
|
goto cleanup;
|
|
|
|
skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu,
|
|
pmu_fd);
|
|
if (!ASSERT_OK_PTR(skel->links.oncpu, "attach_perf_event")) {
|
|
close(pmu_fd);
|
|
goto cleanup;
|
|
}
|
|
|
|
/* find map fds */
|
|
control_map_fd = bpf_map__fd(skel->maps.control_map);
|
|
stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
|
|
stackmap_fd = bpf_map__fd(skel->maps.stackmap);
|
|
|
|
if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")))
|
|
goto cleanup;
|
|
if (CHECK_FAIL(system("taskset 0x1 ./urandom_read 100000")))
|
|
goto cleanup;
|
|
/* disable stack trace collection */
|
|
key = 0;
|
|
val = 1;
|
|
bpf_map_update_elem(control_map_fd, &key, &val, 0);
|
|
|
|
/* for every element in stackid_hmap, we can find a corresponding one
|
|
* in stackmap, and vise versa.
|
|
*/
|
|
err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
|
|
if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
|
|
"err %d errno %d\n", err, errno))
|
|
goto cleanup;
|
|
|
|
err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
|
|
if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
|
|
"err %d errno %d\n", err, errno))
|
|
goto cleanup;
|
|
|
|
build_id_size = read_build_id("urandom_read", buf, sizeof(buf));
|
|
err = build_id_size < 0 ? build_id_size : 0;
|
|
|
|
if (CHECK(err, "get build_id with readelf",
|
|
"err %d errno %d\n", err, errno))
|
|
goto cleanup;
|
|
|
|
err = bpf_map__get_next_key(skel->maps.stackmap, NULL, &key, sizeof(key));
|
|
if (CHECK(err, "get_next_key from stackmap",
|
|
"err %d, errno %d\n", err, errno))
|
|
goto cleanup;
|
|
|
|
do {
|
|
err = bpf_map__lookup_elem(skel->maps.stackmap, &key, sizeof(key),
|
|
id_offs, sizeof(id_offs), 0);
|
|
if (CHECK(err, "lookup_elem from stackmap",
|
|
"err %d, errno %d\n", err, errno))
|
|
goto cleanup;
|
|
for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
|
|
if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
|
|
id_offs[i].offset != 0) {
|
|
if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0)
|
|
build_id_matches = 1;
|
|
}
|
|
prev_key = key;
|
|
} while (bpf_map__get_next_key(skel->maps.stackmap, &prev_key, &key, sizeof(key)) == 0);
|
|
|
|
/* stack_map_get_build_id_offset() is racy and sometimes can return
|
|
* BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID;
|
|
* try it one more time.
|
|
*/
|
|
if (build_id_matches < 1 && retry--) {
|
|
test_stacktrace_build_id__destroy(skel);
|
|
printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
|
|
__func__);
|
|
goto retry;
|
|
}
|
|
|
|
if (CHECK(build_id_matches < 1, "build id match",
|
|
"Didn't find expected build ID from the map\n"))
|
|
goto cleanup;
|
|
|
|
/*
|
|
* We intentionally skip compare_stack_ips(). This is because we
|
|
* only support one in_nmi() ips-to-build_id translation per cpu
|
|
* at any time, thus stack_amap here will always fallback to
|
|
* BPF_STACK_BUILD_ID_IP;
|
|
*/
|
|
|
|
cleanup:
|
|
test_stacktrace_build_id__destroy(skel);
|
|
}
|