1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <android-base/file.h>
18 #include <android-base/macros.h>
19 #include <gtest/gtest.h>
20 #include <libbpf.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <iostream>
24 #include "bpf/BpfMap.h"
25 #include "bpf/BpfUtils.h"
26 #include "include/libbpf_android.h"
27
28 namespace android {
29 namespace bpf {
30
31 class BpfLoadTest : public ::testing::Test {
32 protected:
BpfLoadTest()33 BpfLoadTest() {}
34 int mProgFd;
35 std::string mTpProgPath;
36 std::string mTpNeverLoadProgPath;
37 std::string mTpMapPath;
38
SetUp()39 void SetUp() {
40 /*
41 * b/326156952
42 *
43 * Kernels prior to 5.11 used rlimit memlock accounting for bpf memory
44 * allocations, and therefore require increasing the rlimit of this
45 * process for the maps to be created successfully.
46 *
47 * 5.11 introduces cgroup-based accounting as discussed here:
48 * https://lore.kernel.org/bpf/[email protected]/
49 */
50 if (!isAtLeastKernelVersion(5, 11, 0)) EXPECT_EQ(setrlimitForTest(), 0);
51
52 mTpProgPath = "/sys/fs/bpf/prog_bpfLoadTpProg_tracepoint_sched_sched_switch";
53 unlink(mTpProgPath.c_str());
54
55 mTpNeverLoadProgPath = "/sys/fs/bpf/prog_bpfLoadTpProg_tracepoint_sched_sched_wakeup";
56 unlink(mTpNeverLoadProgPath.c_str());
57
58 mTpMapPath = "/sys/fs/bpf/map_bpfLoadTpProg_cpu_pid_map";
59 unlink(mTpMapPath.c_str());
60
61 auto progPath = android::base::GetExecutableDirectory() + "/bpfLoadTpProg.o";
62 bool critical = true;
63
64 bpf_prog_type kAllowed[] = {
65 BPF_PROG_TYPE_UNSPEC,
66 };
67
68 Location loc = {
69 .dir = "",
70 .prefix = "",
71 .allowedProgTypes = kAllowed,
72 .allowedProgTypesLength = arraysize(kAllowed),
73 };
74 EXPECT_EQ(android::bpf::loadProg(progPath.c_str(), &critical, loc), -1);
75
76 ASSERT_EQ(android::bpf::loadProg(progPath.c_str(), &critical), 0);
77 EXPECT_EQ(false, critical);
78
79 mProgFd = retrieveProgram(mTpProgPath.c_str());
80 ASSERT_GT(mProgFd, 0);
81
82 int ret = bpf_attach_tracepoint(mProgFd, "sched", "sched_switch");
83 EXPECT_NE(ret, 0);
84 }
85
TearDown()86 void TearDown() {
87 close(mProgFd);
88 unlink(mTpProgPath.c_str());
89 unlink(mTpMapPath.c_str());
90 }
91
checkMapNonZero()92 void checkMapNonZero() {
93 // The test program installs a tracepoint on sched:sched_switch
94 // and expects the kernel to populate a PID corresponding to CPU
95 android::bpf::BpfMap<uint32_t, uint32_t> m(mTpMapPath.c_str());
96
97 // Wait for program to run a little
98 sleep(1);
99
100 int non_zero = 0;
101 const auto iterFunc = [&non_zero](const uint32_t& key, const uint32_t& val,
102 BpfMap<uint32_t, uint32_t>& map) {
103 if (val && !non_zero) {
104 non_zero = 1;
105 }
106
107 UNUSED(key);
108 UNUSED(map);
109 return base::Result<void>();
110 };
111
112 EXPECT_RESULT_OK(m.iterateWithValue(iterFunc));
113 EXPECT_EQ(non_zero, 1);
114 }
115
checkKernelVersionEnforced()116 void checkKernelVersionEnforced() {
117 ASSERT_EQ(retrieveProgram(mTpNeverLoadProgPath.c_str()), -1);
118 ASSERT_EQ(errno, ENOENT);
119 }
120 };
121
TEST_F(BpfLoadTest,bpfCheckMap)122 TEST_F(BpfLoadTest, bpfCheckMap) {
123 checkMapNonZero();
124 }
125
TEST_F(BpfLoadTest,bpfCheckMinKernelVersionEnforced)126 TEST_F(BpfLoadTest, bpfCheckMinKernelVersionEnforced) {
127 checkKernelVersionEnforced();
128 }
129
130 } // namespace bpf
131 } // namespace android
132