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Message-ID: <20200715052601.2404533-3-songliubraving@fb.com>
Date: Tue, 14 Jul 2020 22:26:01 -0700
From: Song Liu <songliubraving@...com>
To: <linux-kernel@...r.kernel.org>, <bpf@...r.kernel.org>,
<netdev@...r.kernel.org>
CC: <ast@...nel.org>, <daniel@...earbox.net>, <kernel-team@...com>,
<john.fastabend@...il.com>, <kpsingh@...omium.org>,
<brouer@...hat.com>, <peterz@...radead.org>,
Song Liu <songliubraving@...com>
Subject: [PATCH v2 bpf-next 2/2] 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: Song Liu <songliubraving@...com>
---
.../bpf/prog_tests/perf_event_stackmap.c | 120 ++++++++++++++++++
.../selftests/bpf/progs/perf_event_stackmap.c | 64 ++++++++++
2 files changed, 184 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c
create mode 100644 tools/testing/selftests/bpf/progs/perf_event_stackmap.c
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c
new file mode 100644
index 0000000000000..6dcc67572afc7
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c
@@ -0,0 +1,120 @@
+// 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;
+
+ /* override program type */
+ bpf_program__set_perf_event(skel->progs.oncpu);
+
+ 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");
+ close(pmu_fd);
+
+cleanup:
+ perf_event_stackmap__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c
new file mode 100644
index 0000000000000..1b0457efeedec
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c
@@ -0,0 +1,64 @@
+// 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
+
+#ifndef BPF_F_USER_STACK
+#define BPF_F_USER_STACK (1ULL << 8)
+#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)
+{
+ int max_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
+ 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, max_len, 0);
+ if (val > 0)
+ stack_kernel = 2;
+
+ val = bpf_get_stack(ctx, trace, max_len, BPF_F_USER_STACK);
+ if (val > 0)
+ stack_user = 2;
+
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";
--
2.24.1
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