1//===-- Unittests for VDSO ------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "hdr/signal_macros.h"
10#include "hdr/time_macros.h"
11#include "hdr/types/clockid_t.h"
12#include "hdr/types/struct_sigaction.h"
13#include "hdr/types/struct_timespec.h"
14#include "hdr/types/struct_timeval.h"
15#include "hdr/types/time_t.h"
16#include "src/__support/OSUtil/linux/vdso.h"
17#include "src/__support/OSUtil/syscall.h"
18#include "src/__support/macros/properties/architectures.h"
19#include "src/signal/raise.h"
20#include "src/signal/sigaction.h"
21#include "test/UnitTest/ErrnoSetterMatcher.h"
22#include "test/UnitTest/Test.h"
23#include <linux/time_types.h>
24#include <sys/syscall.h>
25
26struct riscv_hwprobe {
27 int64_t key;
28 uint64_t value;
29};
30
31namespace LIBC_NAMESPACE_DECL {
32// For x86_64, we explicitly test some traditional vdso symbols are indeed
33// available.
34
35TEST(LlvmLibcOSUtilVDSOTest, GetTimeOfDay) {
36 vdso::TypedSymbol<vdso::VDSOSym::GetTimeOfDay> symbol;
37 if (!symbol)
38 return;
39 timeval tv;
40 EXPECT_EQ(symbol(&tv, nullptr), 0);
41 // hopefully people are not building time machines using our libc.
42 EXPECT_GT(tv.tv_sec, static_cast<decltype(tv.tv_sec)>(0));
43}
44
45TEST(LlvmLibcOSUtilVDSOTest, Time) {
46 vdso::TypedSymbol<vdso::VDSOSym::Time> symbol;
47 if (!symbol)
48 return;
49 time_t a, b;
50 EXPECT_GT(symbol(&a), static_cast<time_t>(0));
51 EXPECT_GT(symbol(&b), static_cast<time_t>(0));
52 EXPECT_GE(b, a);
53}
54
55TEST(LlvmLibcOSUtilVDSOTest, ClockGetTime) {
56 vdso::TypedSymbol<vdso::VDSOSym::ClockGetTime> symbol;
57 if (!symbol)
58 return;
59 timespec a, b;
60 EXPECT_EQ(symbol(CLOCK_MONOTONIC, &a), 0);
61 EXPECT_EQ(symbol(CLOCK_MONOTONIC, &b), 0);
62 if (a.tv_sec == b.tv_sec) {
63 EXPECT_LT(a.tv_nsec, b.tv_nsec);
64 } else {
65 EXPECT_LT(a.tv_sec, b.tv_sec);
66 }
67}
68
69TEST(LlvmLibcOSUtilVDSOTest, ClockGetTime64) {
70 vdso::TypedSymbol<vdso::VDSOSym::ClockGetTime64> symbol;
71 if (!symbol)
72 return;
73 // See kernel API at
74 // https://elixir.bootlin.com/linux/latest/source/tools/testing/selftests/vDSO/vdso_test_correctness.c#L155
75 __kernel_timespec a, b;
76 EXPECT_EQ(symbol(CLOCK_MONOTONIC, &a), 0);
77 EXPECT_EQ(symbol(CLOCK_MONOTONIC, &b), 0);
78 if (a.tv_sec == b.tv_sec) {
79 EXPECT_LT(a.tv_nsec, b.tv_nsec);
80 } else {
81 EXPECT_LT(a.tv_sec, b.tv_sec);
82 }
83}
84
85TEST(LlvmLibcOSUtilVDSOTest, ClockGetRes) {
86 vdso::TypedSymbol<vdso::VDSOSym::ClockGetRes> symbol;
87 if (!symbol)
88 return;
89 timespec res{};
90 EXPECT_EQ(symbol(CLOCK_MONOTONIC, &res), 0);
91 EXPECT_TRUE(res.tv_sec > 0 || res.tv_nsec > 0);
92}
93
94TEST(LlvmLibcOSUtilVDSOTest, GetCpu) {
95 // The kernel system call has a third argument, which should be passed as
96 // nullptr.
97 vdso::TypedSymbol<vdso::VDSOSym::GetCpu> symbol;
98 if (!symbol)
99 return;
100 unsigned cpu = static_cast<unsigned>(-1), node = static_cast<unsigned>(-1);
101 EXPECT_EQ(symbol(&cpu, &node, nullptr), 0);
102 EXPECT_GE(cpu, 0u);
103 EXPECT_GE(node, 0u);
104}
105
106static bool flag = false;
107static void sigprof_handler [[gnu::used]] (int) { flag = true; }
108
109TEST(LlvmLibcOSUtilVDSOTest, RtSigReturn) {
110 using namespace testing::ErrnoSetterMatcher;
111 // must use struct since there is a function of the same name in the same
112 // scope.
113 struct sigaction sa {};
114 struct sigaction old_sa {};
115 sa.sa_handler = sigprof_handler;
116 sa.sa_flags = SA_RESTORER;
117 vdso::TypedSymbol<vdso::VDSOSym::RTSigReturn> symbol;
118 if (!symbol)
119 return;
120 sa.sa_restorer = symbol;
121 ASSERT_THAT(LIBC_NAMESPACE::sigaction(SIGPROF, &sa, &old_sa), Succeeds());
122 raise(SIGPROF);
123 ASSERT_TRUE(flag);
124 flag = false;
125 ASSERT_THAT(LIBC_NAMESPACE::sigaction(SIGPROF, &old_sa, nullptr), Succeeds());
126}
127
128TEST(LlvmLibcOSUtilVDSOTest, FlushICache) {
129 vdso::TypedSymbol<vdso::VDSOSym::FlushICache> symbol;
130 if (!symbol)
131 return;
132 char buf[512];
133 // we just check that the flush will not panic the program.
134 // the flags part only take 0/1 as up to kernel 6.10, which is used to
135 // indicate whether the flush is local to the core or global.
136 symbol(buf, buf + sizeof(buf), 0);
137 symbol(buf, buf + sizeof(buf), 1);
138}
139
140// https://docs.kernel.org/6.5/riscv/hwprobe.html
141TEST(LlvmLibcOSUtilVDSOTest, RiscvHwProbe) {
142 using namespace testing::ErrnoSetterMatcher;
143 vdso::TypedSymbol<vdso::VDSOSym::RiscvHwProbe> symbol;
144 if (!symbol)
145 return;
146 // If a key is unknown to the kernel, its key field will be cleared to -1, and
147 // its value set to 0. We expect probes.value are all 0.
148 // Usermode can supply NULL for cpus and 0 for cpu_count as a shortcut for all
149 // online CPUs
150 riscv_hwprobe probes[2] = {{-1, 1}, {-1, 1}};
151 ASSERT_THAT(symbol(/*pairs=*/probes, /*count=*/2, /*cpusetsize=*/0,
152 /*cpuset=*/nullptr,
153 /*flags=*/0),
154 Succeeds());
155 for (auto &probe : probes) {
156 EXPECT_EQ(probe.key, static_cast<decltype(probe.key)>(-1));
157 EXPECT_EQ(probe.value, static_cast<decltype(probe.value)>(0));
158 }
159}
160
161} // namespace LIBC_NAMESPACE_DECL
162

source code of libc/test/src/__support/OSUtil/linux/vdso_test.cpp