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Code

selftests/bpf: Add get_stackid_cannot_attach

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This test confirms that BPF program that calls bpf_get_stackid() cannot
attach to perf_event with precise_ip > 0 but not PERF_SAMPLE_CALLCHAIN;
and cannot attach if the perf_event has exclude_callchain_kernel.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-6-songliubraving@fb.com
This commit is contained in:
Song Liu 2020-07-23 11:06:48 -07:00 committed by Alexei Starovoitov
parent 1da4864c2b
commit 346938e938
1 changed files with 91 additions and 0 deletions
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91
tools/testing/selftests/bpf/prog_tests/get_stackid_cannot_attach.c Normal file
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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook
#include <test_progs.h>
#include "test_stacktrace_build_id.skel.h"
void test_get_stackid_cannot_attach(void)
{
struct perf_event_attr attr = {
/* .type = PERF_TYPE_SOFTWARE, */
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.precise_ip = 1,
.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_BRANCH_STACK,
.branch_sample_type = PERF_SAMPLE_BRANCH_USER |
PERF_SAMPLE_BRANCH_NO_FLAGS |
PERF_SAMPLE_BRANCH_NO_CYCLES |
PERF_SAMPLE_BRANCH_CALL_STACK,
.sample_period = 5000,
.size = sizeof(struct perf_event_attr),
};
struct test_stacktrace_build_id *skel;
__u32 duration = 0;
int pmu_fd, err;
skel = test_stacktrace_build_id__open();
if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
return;
/* override program type */
bpf_program__set_perf_event(skel->progs.oncpu);
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 || errno == EOPNOTSUPP)) {
printf("%s:SKIP:cannot open PERF_COUNT_HW_CPU_CYCLES with precise_ip > 0\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);
CHECK(!IS_ERR(skel->links.oncpu), "attach_perf_event_no_callchain",
"should have failed\n");
close(pmu_fd);
/* add PERF_SAMPLE_CALLCHAIN, attach should succeed */
attr.sample_type |= PERF_SAMPLE_CALLCHAIN;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
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);
CHECK(IS_ERR(skel->links.oncpu), "attach_perf_event_callchain",
"err: %ld\n", PTR_ERR(skel->links.oncpu));
close(pmu_fd);
/* add exclude_callchain_kernel, attach should fail */
attr.exclude_callchain_kernel = 1;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
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);
CHECK(!IS_ERR(skel->links.oncpu), "attach_perf_event_exclude_callchain_kernel",
"should have failed\n");
close(pmu_fd);
cleanup:
test_stacktrace_build_id__destroy(skel);
}