Commit 1da4864c authored by Song Liu's avatar Song Liu Committed by Alexei Starovoitov

selftests/bpf: Add callchain_stackid

This tests new helper function bpf_get_stackid_pe and bpf_get_stack_pe.
These two helpers have different implementation for perf_event with PEB
entries.
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-5-songliubraving@fb.com
parent d4b4dd6c
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook
#define _GNU_SOURCE
#include <pthread.h>
#include <sched.h>
#include <test_progs.h>
#include "perf_event_stackmap.skel.h"
#ifndef noinline
#define noinline __attribute__((noinline))
#endif
noinline int func_1(void)
{
static int val = 1;
val += 1;
usleep(100);
return val;
}
noinline int func_2(void)
{
return func_1();
}
noinline int func_3(void)
{
return func_2();
}
noinline int func_4(void)
{
return func_3();
}
noinline int func_5(void)
{
return func_4();
}
noinline int func_6(void)
{
int i, val = 1;
for (i = 0; i < 100; i++)
val += func_5();
return val;
}
void test_perf_event_stackmap(void)
{
struct perf_event_attr attr = {
/* .type = PERF_TYPE_SOFTWARE, */
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.precise_ip = 2,
.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_BRANCH_STACK |
PERF_SAMPLE_CALLCHAIN,
.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 perf_event_stackmap *skel;
__u32 duration = 0;
cpu_set_t cpu_set;
int pmu_fd, err;
skel = perf_event_stackmap__open();
if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
return;
err = perf_event_stackmap__load(skel);
if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err))
goto cleanup;
CPU_ZERO(&cpu_set);
CPU_SET(0, &cpu_set);
err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
if (CHECK(err, "set_affinity", "err %d, errno %d\n", err, errno))
goto cleanup;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
if (pmu_fd < 0) {
printf("%s:SKIP:cpu doesn't support the event\n", __func__);
test__skip();
goto cleanup;
}
skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu,
pmu_fd);
if (CHECK(IS_ERR(skel->links.oncpu), "attach_perf_event",
"err %ld\n", PTR_ERR(skel->links.oncpu))) {
close(pmu_fd);
goto cleanup;
}
/* create kernel and user stack traces for testing */
func_6();
CHECK(skel->data->stackid_kernel != 2, "get_stackid_kernel", "failed\n");
CHECK(skel->data->stackid_user != 2, "get_stackid_user", "failed\n");
CHECK(skel->data->stack_kernel != 2, "get_stack_kernel", "failed\n");
CHECK(skel->data->stack_user != 2, "get_stack_user", "failed\n");
cleanup:
perf_event_stackmap__destroy(skel);
}
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#ifndef PERF_MAX_STACK_DEPTH
#define PERF_MAX_STACK_DEPTH 127
#endif
typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
struct {
__uint(type, BPF_MAP_TYPE_STACK_TRACE);
__uint(max_entries, 16384);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(stack_trace_t));
} stackmap SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, stack_trace_t);
} stackdata_map SEC(".maps");
long stackid_kernel = 1;
long stackid_user = 1;
long stack_kernel = 1;
long stack_user = 1;
SEC("perf_event")
int oncpu(void *ctx)
{
stack_trace_t *trace;
__u32 key = 0;
long val;
val = bpf_get_stackid(ctx, &stackmap, 0);
if (val > 0)
stackid_kernel = 2;
val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK);
if (val > 0)
stackid_user = 2;
trace = bpf_map_lookup_elem(&stackdata_map, &key);
if (!trace)
return 0;
val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), 0);
if (val > 0)
stack_kernel = 2;
val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), BPF_F_USER_STACK);
if (val > 0)
stack_user = 2;
return 0;
}
char LICENSE[] SEC("license") = "GPL";
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