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Diffstat (limited to 'test/syscalls/linux/proc.cc')
| -rw-r--r-- | test/syscalls/linux/proc.cc | 2642 |
1 files changed, 0 insertions, 2642 deletions
diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc deleted file mode 100644 index 7a0f33dff..000000000 --- a/test/syscalls/linux/proc.cc +++ /dev/null @@ -1,2642 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#include <elf.h> -#include <errno.h> -#include <fcntl.h> -#include <limits.h> -#include <linux/magic.h> -#include <sched.h> -#include <signal.h> -#include <stddef.h> -#include <stdint.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/mman.h> -#include <sys/prctl.h> -#include <sys/ptrace.h> -#include <sys/stat.h> -#include <sys/statfs.h> -#include <sys/utsname.h> -#include <syscall.h> -#include <unistd.h> - -#include <algorithm> -#include <atomic> -#include <functional> -#include <iostream> -#include <map> -#include <memory> -#include <ostream> -#include <regex> -#include <string> -#include <unordered_set> -#include <utility> -#include <vector> - -#include "gmock/gmock.h" -#include "gtest/gtest.h" -#include "absl/container/node_hash_set.h" -#include "absl/strings/ascii.h" -#include "absl/strings/match.h" -#include "absl/strings/numbers.h" -#include "absl/strings/str_cat.h" -#include "absl/strings/str_split.h" -#include "absl/strings/string_view.h" -#include "absl/synchronization/mutex.h" -#include "absl/synchronization/notification.h" -#include "absl/time/clock.h" -#include "absl/time/time.h" -#include "test/util/capability_util.h" -#include "test/util/cleanup.h" -#include "test/util/file_descriptor.h" -#include "test/util/fs_util.h" -#include "test/util/memory_util.h" -#include "test/util/posix_error.h" -#include "test/util/proc_util.h" -#include "test/util/temp_path.h" -#include "test/util/test_util.h" -#include "test/util/thread_util.h" -#include "test/util/time_util.h" -#include "test/util/timer_util.h" - -// NOTE(magi): No, this isn't really a syscall but this is a really simple -// way to get it tested on both gVisor, PTrace and Linux. - -using ::testing::AllOf; -using ::testing::AnyOf; -using ::testing::ContainerEq; -using ::testing::Contains; -using ::testing::ContainsRegex; -using ::testing::Eq; -using ::testing::Gt; -using ::testing::HasSubstr; -using ::testing::IsSupersetOf; -using ::testing::Pair; -using ::testing::UnorderedElementsAre; -using ::testing::UnorderedElementsAreArray; - -// Exported by glibc. -extern char** environ; - -namespace gvisor { -namespace testing { -namespace { - -#ifndef SUID_DUMP_DISABLE -#define SUID_DUMP_DISABLE 0 -#endif /* SUID_DUMP_DISABLE */ -#ifndef SUID_DUMP_USER -#define SUID_DUMP_USER 1 -#endif /* SUID_DUMP_USER */ -#ifndef SUID_DUMP_ROOT -#define SUID_DUMP_ROOT 2 -#endif /* SUID_DUMP_ROOT */ - -#if defined(__x86_64__) || defined(__i386__) -// This list of "required" fields is taken from reading the file -// arch/x86/kernel/cpu/proc.c and seeing which fields will be unconditionally -// printed by the kernel. -static const char* required_fields[] = { - "processor", - "vendor_id", - "cpu family", - "model\t\t:", - "model name", - "stepping", - "cpu MHz", - "fpu\t\t:", - "fpu_exception", - "cpuid level", - "wp", - "bogomips", - "clflush size", - "cache_alignment", - "address sizes", - "power management", -}; -#elif __aarch64__ -// This list of "required" fields is taken from reading the file -// arch/arm64/kernel/cpuinfo.c and seeing which fields will be unconditionally -// printed by the kernel. -static const char* required_fields[] = { - "processor", "BogoMIPS", "Features", "CPU implementer", - "CPU architecture", "CPU variant", "CPU part", "CPU revision", -}; -#else -#error "Unknown architecture" -#endif - -// Takes the subprocess command line and pid. -// If it returns !OK, WithSubprocess returns immediately. -using SubprocessCallback = std::function<PosixError(int)>; - -std::vector<std::string> saved_argv; // NOLINT - -// Helper function to dump /proc/{pid}/status and check the -// state data. State should = "Z" for zombied or "RSD" for -// running, interruptible sleeping (S), or uninterruptible sleep -// (D). -void CompareProcessState(absl::string_view state, int pid) { - auto status_file = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/", pid, "/status"))); - // N.B. POSIX extended regexes don't support shorthand character classes (\w) - // inside of brackets. - EXPECT_THAT(status_file, - ContainsRegex(absl::StrCat("State:.[", state, - R"EOL(]\s+\([a-zA-Z ]+\))EOL"))); -} - -// Run callbacks while a subprocess is running, zombied, and/or exited. -PosixError WithSubprocess(SubprocessCallback const& running, - SubprocessCallback const& zombied, - SubprocessCallback const& exited) { - int pipe_fds[2] = {}; - if (pipe(pipe_fds) < 0) { - return PosixError(errno, "pipe"); - } - - int child_pid = fork(); - if (child_pid < 0) { - return PosixError(errno, "fork"); - } - - if (child_pid == 0) { - close(pipe_fds[0]); // Close the read end. - const DisableSave ds; // Timing issues. - - // Write to the pipe to tell it we're ready. - char buf = 'a'; - int res = 0; - res = WriteFd(pipe_fds[1], &buf, sizeof(buf)); - TEST_CHECK_MSG(res == sizeof(buf), "Write failure in subprocess"); - - while (true) { - SleepSafe(absl::Milliseconds(100)); - } - } - - close(pipe_fds[1]); // Close the write end. - - int status = 0; - auto wait_cleanup = Cleanup([child_pid, &status] { - EXPECT_THAT(waitpid(child_pid, &status, 0), SyscallSucceeds()); - }); - auto kill_cleanup = Cleanup([child_pid] { - EXPECT_THAT(kill(child_pid, SIGKILL), SyscallSucceeds()); - }); - - // Wait for the child. - char buf = 0; - int res = ReadFd(pipe_fds[0], &buf, sizeof(buf)); - if (res < 0) { - return PosixError(errno, "Read from pipe"); - } else if (res == 0) { - return PosixError(EPIPE, "Unable to read from pipe: EOF"); - } - - if (running) { - // The first arg, RSD, refers to a "running process", or a process with a - // state of Running (R), Interruptable Sleep (S) or Uninterruptable - // Sleep (D). - CompareProcessState("RSD", child_pid); - RETURN_IF_ERRNO(running(child_pid)); - } - - // Kill the process. - kill_cleanup.Release()(); - siginfo_t info; - // Wait until the child process has exited (WEXITED flag) but don't - // reap the child (WNOWAIT flag). - EXPECT_THAT(waitid(P_PID, child_pid, &info, WNOWAIT | WEXITED), - SyscallSucceeds()); - - if (zombied) { - // Arg of "Z" refers to a Zombied Process. - CompareProcessState("Z", child_pid); - RETURN_IF_ERRNO(zombied(child_pid)); - } - - // Wait on the process. - wait_cleanup.Release()(); - // If the process is reaped, then then this should return - // with ECHILD. - EXPECT_THAT(waitpid(child_pid, &status, WNOHANG), - SyscallFailsWithErrno(ECHILD)); - - if (exited) { - RETURN_IF_ERRNO(exited(child_pid)); - } - - return NoError(); -} - -// Access the file returned by name when a subprocess is running. -PosixError AccessWhileRunning(std::function<std::string(int pid)> name, - int flags, std::function<void(int fd)> access) { - FileDescriptor fd; - return WithSubprocess( - [&](int pid) -> PosixError { - // Running. - ASSIGN_OR_RETURN_ERRNO(fd, Open(name(pid), flags)); - - access(fd.get()); - return NoError(); - }, - nullptr, nullptr); -} - -// Access the file returned by name when the a subprocess is zombied. -PosixError AccessWhileZombied(std::function<std::string(int pid)> name, - int flags, std::function<void(int fd)> access) { - FileDescriptor fd; - return WithSubprocess( - [&](int pid) -> PosixError { - // Running. - ASSIGN_OR_RETURN_ERRNO(fd, Open(name(pid), flags)); - return NoError(); - }, - [&](int pid) -> PosixError { - // Zombied. - access(fd.get()); - return NoError(); - }, - nullptr); -} - -// Access the file returned by name when the a subprocess is exited. -PosixError AccessWhileExited(std::function<std::string(int pid)> name, - int flags, std::function<void(int fd)> access) { - FileDescriptor fd; - return WithSubprocess( - [&](int pid) -> PosixError { - // Running. - ASSIGN_OR_RETURN_ERRNO(fd, Open(name(pid), flags)); - return NoError(); - }, - nullptr, - [&](int pid) -> PosixError { - // Exited. - access(fd.get()); - return NoError(); - }); -} - -// ReadFd(fd=/proc/PID/basename) while PID is running. -int ReadWhileRunning(std::string const& basename, void* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileRunning( - [&](int pid) -> std::string { - return absl::StrCat("/proc/", pid, "/", basename); - }, - O_RDONLY, - [&](int fd) { - ret = ReadFd(fd, buf, count); - err = errno; - })); - errno = err; - return ret; -} - -// ReadFd(fd=/proc/PID/basename) while PID is zombied. -int ReadWhileZombied(std::string const& basename, void* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileZombied( - [&](int pid) -> std::string { - return absl::StrCat("/proc/", pid, "/", basename); - }, - O_RDONLY, - [&](int fd) { - ret = ReadFd(fd, buf, count); - err = errno; - })); - errno = err; - return ret; -} - -// ReadFd(fd=/proc/PID/basename) while PID is exited. -int ReadWhileExited(std::string const& basename, void* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileExited( - [&](int pid) -> std::string { - return absl::StrCat("/proc/", pid, "/", basename); - }, - O_RDONLY, - [&](int fd) { - ret = ReadFd(fd, buf, count); - err = errno; - })); - errno = err; - return ret; -} - -// readlinkat(fd=/proc/PID/, basename) while PID is running. -int ReadlinkWhileRunning(std::string const& basename, char* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileRunning( - [&](int pid) -> std::string { return absl::StrCat("/proc/", pid, "/"); }, - O_DIRECTORY, - [&](int fd) { - ret = readlinkat(fd, basename.c_str(), buf, count); - err = errno; - })); - errno = err; - return ret; -} - -// readlinkat(fd=/proc/PID/, basename) while PID is zombied. -int ReadlinkWhileZombied(std::string const& basename, char* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileZombied( - [&](int pid) -> std::string { return absl::StrCat("/proc/", pid, "/"); }, - O_DIRECTORY, - [&](int fd) { - ret = readlinkat(fd, basename.c_str(), buf, count); - err = errno; - })); - errno = err; - return ret; -} - -// readlinkat(fd=/proc/PID/, basename) while PID is exited. -int ReadlinkWhileExited(std::string const& basename, char* buf, size_t count) { - int ret = 0; - int err = 0; - EXPECT_NO_ERRNO(AccessWhileExited( - [&](int pid) -> std::string { return absl::StrCat("/proc/", pid, "/"); }, - O_DIRECTORY, - [&](int fd) { - ret = readlinkat(fd, basename.c_str(), buf, count); - err = errno; - })); - errno = err; - return ret; -} - -TEST(ProcTest, NotFoundInRoot) { - struct stat s; - EXPECT_THAT(stat("/proc/foobar", &s), SyscallFailsWithErrno(ENOENT)); -} - -TEST(ProcSelfTest, IsThreadGroupLeader) { - ScopedThread([] { - const pid_t tgid = getpid(); - const pid_t tid = syscall(SYS_gettid); - EXPECT_NE(tgid, tid); - auto link = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self")); - EXPECT_EQ(link, absl::StrCat(tgid)); - }); -} - -TEST(ProcThreadSelfTest, Basic) { - const pid_t tgid = getpid(); - const pid_t tid = syscall(SYS_gettid); - EXPECT_EQ(tgid, tid); - auto link_threadself = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/thread-self")); - EXPECT_EQ(link_threadself, absl::StrCat(tgid, "/task/", tid)); - // Just read one file inside thread-self to ensure that the link is valid. - auto link_threadself_exe = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/thread-self/exe")); - auto link_procself_exe = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/exe")); - EXPECT_EQ(link_threadself_exe, link_procself_exe); -} - -TEST(ProcThreadSelfTest, Thread) { - ScopedThread([] { - const pid_t tgid = getpid(); - const pid_t tid = syscall(SYS_gettid); - EXPECT_NE(tgid, tid); - auto link_threadself = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/thread-self")); - - EXPECT_EQ(link_threadself, absl::StrCat(tgid, "/task/", tid)); - // Just read one file inside thread-self to ensure that the link is valid. - auto link_threadself_exe = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/thread-self/exe")); - auto link_procself_exe = - ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/exe")); - EXPECT_EQ(link_threadself_exe, link_procself_exe); - // A thread should not have "/proc/<tid>/task". - struct stat s; - EXPECT_THAT(stat("/proc/thread-self/task", &s), - SyscallFailsWithErrno(ENOENT)); - }); -} - -// Returns the /proc/PID/maps entry for the MAP_PRIVATE | MAP_ANONYMOUS mapping -// m with start address addr and length len. -std::string AnonymousMapsEntry(uintptr_t addr, size_t len, int prot) { - return absl::StrCat(absl::Hex(addr, absl::PadSpec::kZeroPad8), "-", - absl::Hex(addr + len, absl::PadSpec::kZeroPad8), " ", - prot & PROT_READ ? "r" : "-", - prot & PROT_WRITE ? "w" : "-", - prot & PROT_EXEC ? "x" : "-", "p 00000000 00:00 0 "); -} - -std::string AnonymousMapsEntryForMapping(const Mapping& m, int prot) { - return AnonymousMapsEntry(m.addr(), m.len(), prot); -} - -PosixErrorOr<std::map<uint64_t, uint64_t>> ReadProcSelfAuxv() { - std::string auxv_file; - RETURN_IF_ERRNO(GetContents("/proc/self/auxv", &auxv_file)); - const Elf64_auxv_t* auxv_data = - reinterpret_cast<const Elf64_auxv_t*>(auxv_file.data()); - std::map<uint64_t, uint64_t> auxv_entries; - for (int i = 0; auxv_data[i].a_type != AT_NULL; i++) { - auto a_type = auxv_data[i].a_type; - EXPECT_EQ(0, auxv_entries.count(a_type)) << "a_type: " << a_type; - auxv_entries.emplace(a_type, auxv_data[i].a_un.a_val); - } - return auxv_entries; -} - -TEST(ProcSelfAuxv, EntryPresence) { - auto auxv_entries = ASSERT_NO_ERRNO_AND_VALUE(ReadProcSelfAuxv()); - - EXPECT_EQ(auxv_entries.count(AT_ENTRY), 1); - EXPECT_EQ(auxv_entries.count(AT_PHDR), 1); - EXPECT_EQ(auxv_entries.count(AT_PHENT), 1); - EXPECT_EQ(auxv_entries.count(AT_PHNUM), 1); - EXPECT_EQ(auxv_entries.count(AT_BASE), 1); - EXPECT_EQ(auxv_entries.count(AT_UID), 1); - EXPECT_EQ(auxv_entries.count(AT_EUID), 1); - EXPECT_EQ(auxv_entries.count(AT_GID), 1); - EXPECT_EQ(auxv_entries.count(AT_EGID), 1); - EXPECT_EQ(auxv_entries.count(AT_SECURE), 1); - EXPECT_EQ(auxv_entries.count(AT_CLKTCK), 1); - EXPECT_EQ(auxv_entries.count(AT_RANDOM), 1); - EXPECT_EQ(auxv_entries.count(AT_EXECFN), 1); - EXPECT_EQ(auxv_entries.count(AT_PAGESZ), 1); - EXPECT_EQ(auxv_entries.count(AT_SYSINFO_EHDR), 1); -} - -TEST(ProcSelfAuxv, EntryValues) { - auto proc_auxv = ASSERT_NO_ERRNO_AND_VALUE(ReadProcSelfAuxv()); - - // We need to find the ELF auxiliary vector. The section of memory pointed to - // by envp contains some pointers to non-null pointers, followed by a single - // pointer to a null pointer, followed by the auxiliary vector. - char** envpi = environ; - while (*envpi) { - ++envpi; - } - - const Elf64_auxv_t* envp_auxv = - reinterpret_cast<const Elf64_auxv_t*>(envpi + 1); - int i; - for (i = 0; envp_auxv[i].a_type != AT_NULL; i++) { - auto a_type = envp_auxv[i].a_type; - EXPECT_EQ(proc_auxv.count(a_type), 1); - EXPECT_EQ(proc_auxv[a_type], envp_auxv[i].a_un.a_val) - << "a_type: " << a_type; - } - EXPECT_EQ(i, proc_auxv.size()); -} - -// Just open and read a part of /proc/self/mem, check that we can read an item. -TEST(ProcPidMem, Read) { - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/mem", O_RDONLY)); - char input[] = "hello-world"; - char output[sizeof(input)]; - ASSERT_THAT(pread(memfd.get(), output, sizeof(output), - reinterpret_cast<off_t>(input)), - SyscallSucceedsWithValue(sizeof(input))); - ASSERT_STREQ(input, output); -} - -// Perform read on an unmapped region. -TEST(ProcPidMem, Unmapped) { - // Strategy: map then unmap, so we have a guaranteed unmapped region - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/mem", O_RDONLY)); - Mapping mapping = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE)); - // Fill it with things - memset(mapping.ptr(), 'x', mapping.len()); - char expected = 'x', output; - ASSERT_THAT(pread(memfd.get(), &output, sizeof(output), - reinterpret_cast<off_t>(mapping.ptr())), - SyscallSucceedsWithValue(sizeof(output))); - ASSERT_EQ(expected, output); - - // Unmap region again - ASSERT_THAT(munmap(mapping.ptr(), mapping.len()), SyscallSucceeds()); - - // Now we want EIO error - ASSERT_THAT(pread(memfd.get(), &output, sizeof(output), - reinterpret_cast<off_t>(mapping.ptr())), - SyscallFailsWithErrno(EIO)); -} - -// Perform read repeatedly to verify offset change. -TEST(ProcPidMem, RepeatedRead) { - auto const num_reads = 3; - char expected[] = "01234567890abcdefghijkl"; - char output[sizeof(expected) / num_reads]; - - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/mem", O_RDONLY)); - ASSERT_THAT(lseek(memfd.get(), reinterpret_cast<off_t>(&expected), SEEK_SET), - SyscallSucceedsWithValue(reinterpret_cast<off_t>(&expected))); - for (auto i = 0; i < num_reads; i++) { - ASSERT_THAT(read(memfd.get(), &output, sizeof(output)), - SyscallSucceedsWithValue(sizeof(output))); - ASSERT_EQ(strncmp(&expected[i * sizeof(output)], output, sizeof(output)), - 0); - } -} - -// Perform seek operations repeatedly. -TEST(ProcPidMem, RepeatedSeek) { - auto const num_reads = 3; - char expected[] = "01234567890abcdefghijkl"; - char output[sizeof(expected) / num_reads]; - - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/mem", O_RDONLY)); - ASSERT_THAT(lseek(memfd.get(), reinterpret_cast<off_t>(&expected), SEEK_SET), - SyscallSucceedsWithValue(reinterpret_cast<off_t>(&expected))); - // Read from start - ASSERT_THAT(read(memfd.get(), &output, sizeof(output)), - SyscallSucceedsWithValue(sizeof(output))); - ASSERT_EQ(strncmp(&expected[0 * sizeof(output)], output, sizeof(output)), 0); - // Skip ahead one read - ASSERT_THAT(lseek(memfd.get(), sizeof(output), SEEK_CUR), - SyscallSucceedsWithValue(reinterpret_cast<off_t>(&expected) + - sizeof(output) * 2)); - // Do read again - ASSERT_THAT(read(memfd.get(), &output, sizeof(output)), - SyscallSucceedsWithValue(sizeof(output))); - ASSERT_EQ(strncmp(&expected[2 * sizeof(output)], output, sizeof(output)), 0); - // Skip back three reads - ASSERT_THAT(lseek(memfd.get(), -3 * sizeof(output), SEEK_CUR), - SyscallSucceedsWithValue(reinterpret_cast<off_t>(&expected))); - // Do read again - ASSERT_THAT(read(memfd.get(), &output, sizeof(output)), - SyscallSucceedsWithValue(sizeof(output))); - ASSERT_EQ(strncmp(&expected[0 * sizeof(output)], output, sizeof(output)), 0); - // Check that SEEK_END does not work - ASSERT_THAT(lseek(memfd.get(), 0, SEEK_END), SyscallFailsWithErrno(EINVAL)); -} - -// Perform read past an allocated memory region. -TEST(ProcPidMem, PartialRead) { - // Strategy: map large region, then do unmap and remap smaller region - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/mem", O_RDONLY)); - - Mapping mapping = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(2 * kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE)); - ASSERT_THAT(munmap(mapping.ptr(), mapping.len()), SyscallSucceeds()); - Mapping smaller_mapping = ASSERT_NO_ERRNO_AND_VALUE( - Mmap(mapping.ptr(), kPageSize, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0)); - - // Fill it with things - memset(smaller_mapping.ptr(), 'x', smaller_mapping.len()); - - // Now we want no error - char expected[] = {'x'}; - std::unique_ptr<char[]> output(new char[kPageSize]); - off_t read_offset = - reinterpret_cast<off_t>(smaller_mapping.ptr()) + kPageSize - 1; - ASSERT_THAT( - pread(memfd.get(), output.get(), sizeof(output.get()), read_offset), - SyscallSucceedsWithValue(sizeof(expected))); - // Since output is larger, than expected we have to do manual compare - ASSERT_EQ(expected[0], (output).get()[0]); -} - -// Perform read on /proc/[pid]/mem after exit. -TEST(ProcPidMem, AfterExit) { - int pfd1[2] = {}; - int pfd2[2] = {}; - - char expected[] = "hello-world"; - - ASSERT_THAT(pipe(pfd1), SyscallSucceeds()); - ASSERT_THAT(pipe(pfd2), SyscallSucceeds()); - - // Create child process - pid_t const child_pid = fork(); - if (child_pid == 0) { - // Close reading end of first pipe - close(pfd1[0]); - - // Tell parent about location of input - char ok = 1; - TEST_CHECK(WriteFd(pfd1[1], &ok, sizeof(ok)) == sizeof(ok)); - TEST_PCHECK(close(pfd1[1]) == 0); - - // Close writing end of second pipe - TEST_PCHECK(close(pfd2[1]) == 0); - - // Await parent OK to die - ok = 0; - TEST_CHECK(ReadFd(pfd2[0], &ok, sizeof(ok)) == sizeof(ok)); - - // Close rest pipes - TEST_PCHECK(close(pfd2[0]) == 0); - _exit(0); - } - - // In parent process. - ASSERT_THAT(child_pid, SyscallSucceeds()); - - // Close writing end of first pipe - EXPECT_THAT(close(pfd1[1]), SyscallSucceeds()); - - // Wait for child to be alive and well - char ok = 0; - EXPECT_THAT(ReadFd(pfd1[0], &ok, sizeof(ok)), - SyscallSucceedsWithValue(sizeof(ok))); - // Close reading end of first pipe - EXPECT_THAT(close(pfd1[0]), SyscallSucceeds()); - - // Open /proc/pid/mem fd - std::string mempath = absl::StrCat("/proc/", child_pid, "/mem"); - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open(mempath, O_RDONLY)); - - // Expect that we can read - char output[sizeof(expected)]; - EXPECT_THAT(pread(memfd.get(), &output, sizeof(output), - reinterpret_cast<off_t>(&expected)), - SyscallSucceedsWithValue(sizeof(output))); - EXPECT_STREQ(expected, output); - - // Tell proc its ok to go - EXPECT_THAT(close(pfd2[0]), SyscallSucceeds()); - ok = 1; - EXPECT_THAT(WriteFd(pfd2[1], &ok, sizeof(ok)), - SyscallSucceedsWithValue(sizeof(ok))); - EXPECT_THAT(close(pfd2[1]), SyscallSucceeds()); - - // Expect termination - int status; - ASSERT_THAT(waitpid(child_pid, &status, 0), SyscallSucceeds()); - - // Expect that we can't read anymore - EXPECT_THAT(pread(memfd.get(), &output, sizeof(output), - reinterpret_cast<off_t>(&expected)), - SyscallSucceedsWithValue(0)); -} - -// Read from /proc/[pid]/mem with different UID/GID and attached state. -TEST(ProcPidMem, DifferentUserAttached) { - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SETUID))); - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_DAC_OVERRIDE))); - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_PTRACE))); - - int pfd1[2] = {}; - int pfd2[2] = {}; - - ASSERT_THAT(pipe(pfd1), SyscallSucceeds()); - ASSERT_THAT(pipe(pfd2), SyscallSucceeds()); - - // Create child process - pid_t const child_pid = fork(); - if (child_pid == 0) { - // Close reading end of first pipe - close(pfd1[0]); - - // Tell parent about location of input - char input[] = "hello-world"; - off_t input_location = reinterpret_cast<off_t>(input); - TEST_CHECK(WriteFd(pfd1[1], &input_location, sizeof(input_location)) == - sizeof(input_location)); - TEST_PCHECK(close(pfd1[1]) == 0); - - // Close writing end of second pipe - TEST_PCHECK(close(pfd2[1]) == 0); - - // Await parent OK to die - char ok = 0; - TEST_CHECK(ReadFd(pfd2[0], &ok, sizeof(ok)) == sizeof(ok)); - - // Close rest pipes - TEST_PCHECK(close(pfd2[0]) == 0); - _exit(0); - } - - // In parent process. - ASSERT_THAT(child_pid, SyscallSucceeds()); - - // Close writing end of first pipe - EXPECT_THAT(close(pfd1[1]), SyscallSucceeds()); - - // Read target location from child - off_t target_location; - EXPECT_THAT(ReadFd(pfd1[0], &target_location, sizeof(target_location)), - SyscallSucceedsWithValue(sizeof(target_location))); - // Close reading end of first pipe - EXPECT_THAT(close(pfd1[0]), SyscallSucceeds()); - - ScopedThread([&] { - // Attach to child subprocess without stopping it - EXPECT_THAT(ptrace(PTRACE_SEIZE, child_pid, NULL, NULL), SyscallSucceeds()); - - // Keep capabilities after setuid - EXPECT_THAT(prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0), SyscallSucceeds()); - constexpr int kNobody = 65534; - EXPECT_THAT(syscall(SYS_setuid, kNobody), SyscallSucceeds()); - - // Only restore CAP_SYS_PTRACE and CAP_DAC_OVERRIDE - EXPECT_NO_ERRNO(SetCapability(CAP_SYS_PTRACE, true)); - EXPECT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, true)); - - // Open /proc/pid/mem fd - std::string mempath = absl::StrCat("/proc/", child_pid, "/mem"); - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open(mempath, O_RDONLY)); - char expected[] = "hello-world"; - char output[sizeof(expected)]; - EXPECT_THAT(pread(memfd.get(), output, sizeof(output), - reinterpret_cast<off_t>(target_location)), - SyscallSucceedsWithValue(sizeof(output))); - EXPECT_STREQ(expected, output); - - // Tell proc its ok to go - EXPECT_THAT(close(pfd2[0]), SyscallSucceeds()); - char ok = 1; - EXPECT_THAT(WriteFd(pfd2[1], &ok, sizeof(ok)), - SyscallSucceedsWithValue(sizeof(ok))); - EXPECT_THAT(close(pfd2[1]), SyscallSucceeds()); - - // Expect termination - int status; - ASSERT_THAT(waitpid(child_pid, &status, 0), SyscallSucceeds()); - EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0) - << " status " << status; - }); -} - -// Attempt to read from /proc/[pid]/mem with different UID/GID. -TEST(ProcPidMem, DifferentUser) { - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SETUID))); - - int pfd1[2] = {}; - int pfd2[2] = {}; - - ASSERT_THAT(pipe(pfd1), SyscallSucceeds()); - ASSERT_THAT(pipe(pfd2), SyscallSucceeds()); - - // Create child process - pid_t const child_pid = fork(); - if (child_pid == 0) { - // Close reading end of first pipe - close(pfd1[0]); - - // Tell parent about location of input - char input[] = "hello-world"; - off_t input_location = reinterpret_cast<off_t>(input); - TEST_CHECK(WriteFd(pfd1[1], &input_location, sizeof(input_location)) == - sizeof(input_location)); - TEST_PCHECK(close(pfd1[1]) == 0); - - // Close writing end of second pipe - TEST_PCHECK(close(pfd2[1]) == 0); - - // Await parent OK to die - char ok = 0; - TEST_CHECK(ReadFd(pfd2[0], &ok, sizeof(ok)) == sizeof(ok)); - - // Close rest pipes - TEST_PCHECK(close(pfd2[0]) == 0); - _exit(0); - } - - // In parent process. - ASSERT_THAT(child_pid, SyscallSucceeds()); - - // Close writing end of first pipe - EXPECT_THAT(close(pfd1[1]), SyscallSucceeds()); - - // Read target location from child - off_t target_location; - EXPECT_THAT(ReadFd(pfd1[0], &target_location, sizeof(target_location)), - SyscallSucceedsWithValue(sizeof(target_location))); - // Close reading end of first pipe - EXPECT_THAT(close(pfd1[0]), SyscallSucceeds()); - - ScopedThread([&] { - constexpr int kNobody = 65534; - EXPECT_THAT(syscall(SYS_setuid, kNobody), SyscallSucceeds()); - - // Attempt to open /proc/[child_pid]/mem - std::string mempath = absl::StrCat("/proc/", child_pid, "/mem"); - EXPECT_THAT(open(mempath.c_str(), O_RDONLY), SyscallFailsWithErrno(EACCES)); - - // Tell proc its ok to go - EXPECT_THAT(close(pfd2[0]), SyscallSucceeds()); - char ok = 1; - EXPECT_THAT(WriteFd(pfd2[1], &ok, sizeof(ok)), - SyscallSucceedsWithValue(sizeof(ok))); - EXPECT_THAT(close(pfd2[1]), SyscallSucceeds()); - - // Expect termination - int status; - ASSERT_THAT(waitpid(child_pid, &status, 0), SyscallSucceeds()); - }); -} - -// Perform read on /proc/[pid]/mem with same UID/GID. -TEST(ProcPidMem, SameUser) { - int pfd1[2] = {}; - int pfd2[2] = {}; - - ASSERT_THAT(pipe(pfd1), SyscallSucceeds()); - ASSERT_THAT(pipe(pfd2), SyscallSucceeds()); - - // Create child process - pid_t const child_pid = fork(); - if (child_pid == 0) { - // Close reading end of first pipe - close(pfd1[0]); - - // Tell parent about location of input - char input[] = "hello-world"; - off_t input_location = reinterpret_cast<off_t>(input); - TEST_CHECK(WriteFd(pfd1[1], &input_location, sizeof(input_location)) == - sizeof(input_location)); - TEST_PCHECK(close(pfd1[1]) == 0); - - // Close writing end of second pipe - TEST_PCHECK(close(pfd2[1]) == 0); - - // Await parent OK to die - char ok = 0; - TEST_CHECK(ReadFd(pfd2[0], &ok, sizeof(ok)) == sizeof(ok)); - - // Close rest pipes - TEST_PCHECK(close(pfd2[0]) == 0); - _exit(0); - } - // In parent process. - ASSERT_THAT(child_pid, SyscallSucceeds()); - - // Close writing end of first pipe - EXPECT_THAT(close(pfd1[1]), SyscallSucceeds()); - - // Read target location from child - off_t target_location; - EXPECT_THAT(ReadFd(pfd1[0], &target_location, sizeof(target_location)), - SyscallSucceedsWithValue(sizeof(target_location))); - // Close reading end of first pipe - EXPECT_THAT(close(pfd1[0]), SyscallSucceeds()); - - // Open /proc/pid/mem fd - std::string mempath = absl::StrCat("/proc/", child_pid, "/mem"); - auto memfd = ASSERT_NO_ERRNO_AND_VALUE(Open(mempath, O_RDONLY)); - char expected[] = "hello-world"; - char output[sizeof(expected)]; - EXPECT_THAT(pread(memfd.get(), output, sizeof(output), - reinterpret_cast<off_t>(target_location)), - SyscallSucceedsWithValue(sizeof(output))); - EXPECT_STREQ(expected, output); - - // Tell proc its ok to go - EXPECT_THAT(close(pfd2[0]), SyscallSucceeds()); - char ok = 1; - EXPECT_THAT(WriteFd(pfd2[1], &ok, sizeof(ok)), - SyscallSucceedsWithValue(sizeof(ok))); - EXPECT_THAT(close(pfd2[1]), SyscallSucceeds()); - - // Expect termination - int status; - ASSERT_THAT(waitpid(child_pid, &status, 0), SyscallSucceeds()); -} - -// Just open and read /proc/self/maps, check that we can find [stack] -TEST(ProcSelfMaps, Basic) { - auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - - std::vector<std::string> strings = absl::StrSplit(proc_self_maps, '\n'); - std::vector<std::string> stacks; - // Make sure there's a stack in there. - for (const auto& str : strings) { - if (str.find("[stack]") != std::string::npos) { - stacks.push_back(str); - } - } - ASSERT_EQ(1, stacks.size()) << "[stack] not found in: " << proc_self_maps; - // Linux pads to 73 characters then we add 7. - EXPECT_EQ(80, stacks[0].length()); -} - -TEST(ProcSelfMaps, Map1) { - Mapping mapping = - ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_READ, MAP_PRIVATE)); - auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - std::vector<std::string> strings = absl::StrSplit(proc_self_maps, '\n'); - std::vector<std::string> addrs; - // Make sure if is listed. - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(mapping, PROT_READ)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()); -} - -TEST(ProcSelfMaps, Map2) { - // NOTE(magi): The permissions must be different or the pages will get merged. - Mapping map1 = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(kPageSize, PROT_READ | PROT_EXEC, MAP_PRIVATE)); - Mapping map2 = - ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_WRITE, MAP_PRIVATE)); - - auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - std::vector<std::string> strings = absl::StrSplit(proc_self_maps, '\n'); - std::vector<std::string> addrs; - // Make sure if is listed. - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map1, PROT_READ | PROT_EXEC)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()); - addrs.clear(); - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map2, PROT_WRITE)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()); -} - -TEST(ProcSelfMaps, MapUnmap) { - Mapping map1 = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(kPageSize, PROT_READ | PROT_EXEC, MAP_PRIVATE)); - Mapping map2 = - ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_WRITE, MAP_PRIVATE)); - - auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - std::vector<std::string> strings = absl::StrSplit(proc_self_maps, '\n'); - std::vector<std::string> addrs; - // Make sure if is listed. - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map1, PROT_READ | PROT_EXEC)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()) << proc_self_maps; - addrs.clear(); - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map2, PROT_WRITE)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()); - - map2.reset(); - - // Read it again. - proc_self_maps = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - strings = absl::StrSplit(proc_self_maps, '\n'); - // First entry should be there. - addrs.clear(); - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map1, PROT_READ | PROT_EXEC)) { - addrs.push_back(str); - } - } - ASSERT_EQ(1, addrs.size()); - addrs.clear(); - // But not the second. - for (const auto& str : strings) { - if (str == AnonymousMapsEntryForMapping(map2, PROT_WRITE)) { - addrs.push_back(str); - } - } - ASSERT_EQ(0, addrs.size()); -} - -TEST(ProcSelfMaps, Mprotect) { - // FIXME(jamieliu): Linux's mprotect() sometimes fails to merge VMAs in this - // case. - SKIP_IF(!IsRunningOnGvisor()); - - // Reserve 5 pages of address space. - Mapping m = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(5 * kPageSize, PROT_NONE, MAP_PRIVATE)); - - // Change the permissions on the middle 3 pages. (The first and last pages may - // be merged with other vmas on either side, so they aren't tested directly; - // they just ensure that the middle 3 pages are bracketed by VMAs with - // incompatible permissions.) - ASSERT_THAT(mprotect(reinterpret_cast<void*>(m.addr() + kPageSize), - 3 * kPageSize, PROT_READ), - SyscallSucceeds()); - - // Check that the middle 3 pages make up a single VMA. - auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - std::vector<std::string> strings = absl::StrSplit(proc_self_maps, '\n'); - EXPECT_THAT(strings, Contains(AnonymousMapsEntry(m.addr() + kPageSize, - 3 * kPageSize, PROT_READ))); - - // Change the permissions on the middle page only. - ASSERT_THAT(mprotect(reinterpret_cast<void*>(m.addr() + 2 * kPageSize), - kPageSize, PROT_READ | PROT_WRITE), - SyscallSucceeds()); - - // Check that the single VMA has been split into 3 VMAs. - proc_self_maps = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - strings = absl::StrSplit(proc_self_maps, '\n'); - EXPECT_THAT( - strings, - IsSupersetOf( - {AnonymousMapsEntry(m.addr() + kPageSize, kPageSize, PROT_READ), - AnonymousMapsEntry(m.addr() + 2 * kPageSize, kPageSize, - PROT_READ | PROT_WRITE), - AnonymousMapsEntry(m.addr() + 3 * kPageSize, kPageSize, - PROT_READ)})); - - // Change the permissions on the middle page back. - ASSERT_THAT(mprotect(reinterpret_cast<void*>(m.addr() + 2 * kPageSize), - kPageSize, PROT_READ), - SyscallSucceeds()); - - // Check that the 3 VMAs have been merged back into a single VMA. - proc_self_maps = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - strings = absl::StrSplit(proc_self_maps, '\n'); - EXPECT_THAT(strings, Contains(AnonymousMapsEntry(m.addr() + kPageSize, - 3 * kPageSize, PROT_READ))); -} - -TEST(ProcSelfMaps, SharedAnon) { - const Mapping m = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(kPageSize, PROT_READ, MAP_SHARED | MAP_ANONYMOUS)); - - const auto proc_self_maps = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); - for (const auto& line : absl::StrSplit(proc_self_maps, '\n')) { - const auto entry = ASSERT_NO_ERRNO_AND_VALUE(ParseProcMapsLine(line)); - if (entry.start <= m.addr() && m.addr() < entry.end) { - // cf. proc(5), "/proc/[pid]/map_files/" - EXPECT_EQ(entry.filename, "/dev/zero (deleted)"); - return; - } - } - FAIL() << "no maps entry containing mapping at " << m.ptr(); -} - -TEST(ProcSelfFd, OpenFd) { - int pipe_fds[2]; - ASSERT_THAT(pipe2(pipe_fds, O_CLOEXEC), SyscallSucceeds()); - - // Reopen the write end. - const std::string path = absl::StrCat("/proc/self/fd/", pipe_fds[1]); - const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(path, O_WRONLY)); - - // Ensure that a read/write works. - const std::string data = "hello"; - std::unique_ptr<char[]> buffer(new char[data.size()]); - EXPECT_THAT(write(fd.get(), data.c_str(), data.size()), - SyscallSucceedsWithValue(5)); - EXPECT_THAT(read(pipe_fds[0], buffer.get(), data.size()), - SyscallSucceedsWithValue(5)); - EXPECT_EQ(strncmp(buffer.get(), data.c_str(), data.size()), 0); - - // Cleanup. - ASSERT_THAT(close(pipe_fds[0]), SyscallSucceeds()); - ASSERT_THAT(close(pipe_fds[1]), SyscallSucceeds()); -} - -static void CheckFdDirGetdentsDuplicates(const std::string& path) { - const FileDescriptor fd = - ASSERT_NO_ERRNO_AND_VALUE(Open(path.c_str(), O_RDONLY | O_DIRECTORY)); - // Open a FD whose value is supposed to be much larger than - // the number of FDs opened by current process. - auto newfd = fcntl(fd.get(), F_DUPFD, 1024); - EXPECT_GE(newfd, 1024); - auto fd_closer = Cleanup([newfd]() { close(newfd); }); - auto fd_files = ASSERT_NO_ERRNO_AND_VALUE(ListDir(path.c_str(), false)); - absl::node_hash_set<std::string> fd_files_dedup(fd_files.begin(), - fd_files.end()); - EXPECT_EQ(fd_files.size(), fd_files_dedup.size()); -} - -// This is a regression test for gvisor.dev/issues/3894 -TEST(ProcSelfFd, GetdentsDuplicates) { - CheckFdDirGetdentsDuplicates("/proc/self/fd"); -} - -// This is a regression test for gvisor.dev/issues/3894 -TEST(ProcSelfFdInfo, GetdentsDuplicates) { - CheckFdDirGetdentsDuplicates("/proc/self/fdinfo"); -} - -TEST(ProcSelfFdInfo, CorrectFds) { - // Make sure there is at least one open file. - auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY)); - - // Get files in /proc/self/fd. - auto fd_files = ASSERT_NO_ERRNO_AND_VALUE(ListDir("/proc/self/fd", false)); - - // Get files in /proc/self/fdinfo. - auto fdinfo_files = - ASSERT_NO_ERRNO_AND_VALUE(ListDir("/proc/self/fdinfo", false)); - - // They should contain the same fds. - EXPECT_THAT(fd_files, UnorderedElementsAreArray(fdinfo_files)); - - // Both should contain fd. - auto fd_s = absl::StrCat(fd.get()); - EXPECT_THAT(fd_files, Contains(fd_s)); -} - -TEST(ProcSelfFdInfo, Flags) { - std::string path = NewTempAbsPath(); - - // Create file here with O_CREAT to test that O_CREAT does not appear in - // fdinfo flags. - int flags = O_CREAT | O_RDWR | O_APPEND | O_CLOEXEC; - const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(path, flags, 0644)); - - // Automatically delete path. - TempPath temp_path(path); - - // O_CREAT does not appear in fdinfo flags. - flags &= ~O_CREAT; - - // O_LARGEFILE always appears (on x86_64). - flags |= kOLargeFile; - - auto fd_info = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/self/fdinfo/", fd.get()))); - EXPECT_THAT(fd_info, HasSubstr(absl::StrFormat("flags:\t%#o", flags))); -} - -TEST(ProcSelfExe, Absolute) { - auto exe = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/exe")); - EXPECT_EQ(exe[0], '/'); -} - -TEST(ProcSelfCwd, Absolute) { - auto exe = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/cwd")); - EXPECT_EQ(exe[0], '/'); -} - -// Sanity check for /proc/cpuinfo fields that must be present. -TEST(ProcCpuinfo, RequiredFieldsArePresent) { - std::string proc_cpuinfo = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/cpuinfo")); - ASSERT_FALSE(proc_cpuinfo.empty()); - std::vector<std::string> cpuinfo_fields = absl::StrSplit(proc_cpuinfo, '\n'); - - // Check that the usual fields are there. We don't really care about the - // contents. - for (const std::string& field : required_fields) { - EXPECT_THAT(proc_cpuinfo, HasSubstr(field)); - } -} - -TEST(ProcCpuinfo, DeniesWriteNonRoot) { - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_FOWNER))); - - // Do setuid in a separate thread so that after finishing this test, the - // process can still open files the test harness created before starting this - // test. Otherwise, the files are created by root (UID before the test), but - // cannot be opened by the `uid` set below after the test. After calling - // setuid(non-zero-UID), there is no way to get root privileges back. - ScopedThread([&] { - // Use syscall instead of glibc setuid wrapper because we want this setuid - // call to only apply to this task. POSIX threads, however, require that all - // threads have the same UIDs, so using the setuid wrapper sets all threads' - // real UID. - // Also drops capabilities. - constexpr int kNobody = 65534; - EXPECT_THAT(syscall(SYS_setuid, kNobody), SyscallSucceeds()); - EXPECT_THAT(open("/proc/cpuinfo", O_WRONLY), SyscallFailsWithErrno(EACCES)); - EXPECT_THAT(truncate("/proc/cpuinfo", 123), SyscallFailsWithErrno(EACCES)); - }); -} - -// With root privileges, it is possible to open /proc/cpuinfo with write mode, -// but all write operations should fail. -TEST(ProcCpuinfo, DeniesWriteRoot) { - // VFS1 does not behave differently for root/non-root. - SKIP_IF(IsRunningWithVFS1()); - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_FOWNER))); - - int fd; - EXPECT_THAT(fd = open("/proc/cpuinfo", O_WRONLY), SyscallSucceeds()); - if (fd > 0) { - // Truncate is not tested--it may succeed on some kernels without doing - // anything. - EXPECT_THAT(write(fd, "x", 1), SyscallFails()); - EXPECT_THAT(pwrite(fd, "x", 1, 123), SyscallFails()); - } -} - -// Sanity checks that uptime is present. -TEST(ProcUptime, IsPresent) { - std::string proc_uptime = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/uptime")); - ASSERT_FALSE(proc_uptime.empty()); - std::vector<std::string> uptime_parts = absl::StrSplit(proc_uptime, ' '); - - // Parse once. - double uptime0, uptime1, idletime0, idletime1; - ASSERT_TRUE(absl::SimpleAtod(uptime_parts[0], &uptime0)); - ASSERT_TRUE(absl::SimpleAtod(uptime_parts[1], &idletime0)); - - // Sleep for one second. - absl::SleepFor(absl::Seconds(1)); - - // Parse again. - proc_uptime = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/uptime")); - ASSERT_FALSE(proc_uptime.empty()); - uptime_parts = absl::StrSplit(proc_uptime, ' '); - ASSERT_TRUE(absl::SimpleAtod(uptime_parts[0], &uptime1)); - ASSERT_TRUE(absl::SimpleAtod(uptime_parts[1], &idletime1)); - - // Sanity check. - // - // We assert that between 0.99 and 59.99 seconds have passed. If more than a - // minute has passed, then we must be executing really, really slowly. - EXPECT_GE(uptime0, 0.0); - EXPECT_GE(idletime0, 0.0); - EXPECT_GT(uptime1, uptime0); - EXPECT_GE(uptime1, uptime0 + 0.99); - EXPECT_LE(uptime1, uptime0 + 59.99); - EXPECT_GE(idletime1, idletime0); -} - -TEST(ProcMeminfo, ContainsBasicFields) { - std::string proc_meminfo = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/meminfo")); - EXPECT_THAT(proc_meminfo, AllOf(ContainsRegex(R"(MemTotal:\s+[0-9]+ kB)"), - ContainsRegex(R"(MemFree:\s+[0-9]+ kB)"))); -} - -TEST(ProcStat, ContainsBasicFields) { - std::string proc_stat = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/stat")); - - std::vector<std::string> names; - for (auto const& line : absl::StrSplit(proc_stat, '\n')) { - std::vector<std::string> fields = - absl::StrSplit(line, ' ', absl::SkipWhitespace()); - if (fields.empty()) { - continue; - } - names.push_back(fields[0]); - } - - EXPECT_THAT(names, - IsSupersetOf({"cpu", "intr", "ctxt", "btime", "processes", - "procs_running", "procs_blocked", "softirq"})); -} - -TEST(ProcStat, EndsWithNewline) { - std::string proc_stat = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/stat")); - EXPECT_EQ(proc_stat.back(), '\n'); -} - -TEST(ProcStat, Fields) { - std::string proc_stat = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/stat")); - - std::vector<std::string> names; - for (auto const& line : absl::StrSplit(proc_stat, '\n')) { - std::vector<std::string> fields = - absl::StrSplit(line, ' ', absl::SkipWhitespace()); - if (fields.empty()) { - continue; - } - - if (absl::StartsWith(fields[0], "cpu")) { - // As of Linux 3.11, each CPU entry has 10 fields, plus the name. - EXPECT_GE(fields.size(), 11) << proc_stat; - } else if (fields[0] == "ctxt") { - // Single field. - EXPECT_EQ(fields.size(), 2) << proc_stat; - } else if (fields[0] == "btime") { - // Single field. - EXPECT_EQ(fields.size(), 2) << proc_stat; - } else if (fields[0] == "itime") { - // Single field. - ASSERT_EQ(fields.size(), 2) << proc_stat; - // This is the only floating point field. - double val; - EXPECT_TRUE(absl::SimpleAtod(fields[1], &val)) << proc_stat; - continue; - } else if (fields[0] == "processes") { - // Single field. - EXPECT_EQ(fields.size(), 2) << proc_stat; - } else if (fields[0] == "procs_running") { - // Single field. - EXPECT_EQ(fields.size(), 2) << proc_stat; - } else if (fields[0] == "procs_blocked") { - // Single field. - EXPECT_EQ(fields.size(), 2) << proc_stat; - } else if (fields[0] == "softirq") { - // As of Linux 3.11, there are 10 softirqs. 12 fields for name + total. - EXPECT_GE(fields.size(), 12) << proc_stat; - } - - // All fields besides itime are valid base 10 numbers. - for (size_t i = 1; i < fields.size(); i++) { - uint64_t val; - EXPECT_TRUE(absl::SimpleAtoi(fields[i], &val)) << proc_stat; - } - } -} - -TEST(ProcLoadavg, EndsWithNewline) { - std::string proc_loadvg = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/loadavg")); - EXPECT_EQ(proc_loadvg.back(), '\n'); -} - -TEST(ProcLoadavg, Fields) { - std::string proc_loadvg = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/loadavg")); - std::vector<std::string> lines = absl::StrSplit(proc_loadvg, '\n'); - - // Single line. - EXPECT_EQ(lines.size(), 2) << proc_loadvg; - - std::vector<std::string> fields = - absl::StrSplit(lines[0], absl::ByAnyChar(" /"), absl::SkipWhitespace()); - - // Six fields. - EXPECT_EQ(fields.size(), 6) << proc_loadvg; - - double val; - uint64_t val2; - // First three fields are floating point numbers. - EXPECT_TRUE(absl::SimpleAtod(fields[0], &val)) << proc_loadvg; - EXPECT_TRUE(absl::SimpleAtod(fields[1], &val)) << proc_loadvg; - EXPECT_TRUE(absl::SimpleAtod(fields[2], &val)) << proc_loadvg; - // Rest of the fields are valid base 10 numbers. - EXPECT_TRUE(absl::SimpleAtoi(fields[3], &val2)) << proc_loadvg; - EXPECT_TRUE(absl::SimpleAtoi(fields[4], &val2)) << proc_loadvg; - EXPECT_TRUE(absl::SimpleAtoi(fields[5], &val2)) << proc_loadvg; -} - -// NOTE: Tests in priority.cc also check certain priority related fields in -// /proc/self/stat. - -class ProcPidStatTest : public ::testing::TestWithParam<std::string> {}; - -TEST_P(ProcPidStatTest, HasBasicFields) { - std::string proc_pid_stat = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/", GetParam(), "/stat"))); - - ASSERT_FALSE(proc_pid_stat.empty()); - std::vector<std::string> fields = absl::StrSplit(proc_pid_stat, ' '); - ASSERT_GE(fields.size(), 24); - EXPECT_EQ(absl::StrCat(getpid()), fields[0]); - // fields[1] is the thread name. - EXPECT_EQ("R", fields[2]); // task state - EXPECT_EQ(absl::StrCat(getppid()), fields[3]); - - // If the test starts up quickly, then the process start time and the kernel - // boot time will be very close, and the proc starttime field (which is the - // delta of the two times) will be 0. For that unfortunate reason, we can - // only check that starttime >= 0, and not that it is strictly > 0. - uint64_t starttime; - ASSERT_TRUE(absl::SimpleAtoi(fields[21], &starttime)); - EXPECT_GE(starttime, 0); - - uint64_t vss; - ASSERT_TRUE(absl::SimpleAtoi(fields[22], &vss)); - EXPECT_GT(vss, 0); - - uint64_t rss; - ASSERT_TRUE(absl::SimpleAtoi(fields[23], &rss)); - EXPECT_GT(rss, 0); - - uint64_t rsslim; - ASSERT_TRUE(absl::SimpleAtoi(fields[24], &rsslim)); - EXPECT_GT(rsslim, 0); -} - -INSTANTIATE_TEST_SUITE_P(SelfAndNumericPid, ProcPidStatTest, - ::testing::Values("self", absl::StrCat(getpid()))); - -using ProcPidStatmTest = ::testing::TestWithParam<std::string>; - -TEST_P(ProcPidStatmTest, HasBasicFields) { - std::string proc_pid_statm = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/", GetParam(), "/statm"))); - ASSERT_FALSE(proc_pid_statm.empty()); - std::vector<std::string> fields = absl::StrSplit(proc_pid_statm, ' '); - ASSERT_GE(fields.size(), 7); - - uint64_t vss; - ASSERT_TRUE(absl::SimpleAtoi(fields[0], &vss)); - EXPECT_GT(vss, 0); - - uint64_t rss; - ASSERT_TRUE(absl::SimpleAtoi(fields[1], &rss)); - EXPECT_GT(rss, 0); -} - -INSTANTIATE_TEST_SUITE_P(SelfAndNumericPid, ProcPidStatmTest, - ::testing::Values("self", absl::StrCat(getpid()))); - -PosixErrorOr<uint64_t> CurrentRSS() { - ASSIGN_OR_RETURN_ERRNO(auto proc_self_stat, GetContents("/proc/self/stat")); - if (proc_self_stat.empty()) { - return PosixError(EINVAL, "empty /proc/self/stat"); - } - - std::vector<std::string> fields = absl::StrSplit(proc_self_stat, ' '); - if (fields.size() < 24) { - return PosixError( - EINVAL, - absl::StrCat("/proc/self/stat has too few fields: ", proc_self_stat)); - } - - uint64_t rss; - if (!absl::SimpleAtoi(fields[23], &rss)) { - return PosixError( - EINVAL, absl::StrCat("/proc/self/stat RSS field is not a number: ", - fields[23])); - } - - // RSS is given in number of pages. - return rss * kPageSize; -} - -// The size of mapping created by MapPopulateRSS. -constexpr uint64_t kMappingSize = 100 << 20; - -// Tolerance on RSS comparisons to account for background thread mappings, -// reclaimed pages, newly faulted pages, etc. -constexpr uint64_t kRSSTolerance = 10 << 20; - -// Capture RSS before and after an anonymous mapping with passed prot. -void MapPopulateRSS(int prot, uint64_t* before, uint64_t* after) { - *before = ASSERT_NO_ERRNO_AND_VALUE(CurrentRSS()); - - // N.B. The kernel asynchronously accumulates per-task RSS counters into the - // mm RSS, which is exposed by /proc/PID/stat. Task exit is a synchronization - // point (kernel/exit.c:do_exit -> sync_mm_rss), so perform the mapping on - // another thread to ensure it is reflected in RSS after the thread exits. - Mapping mapping; - ScopedThread t([&mapping, prot] { - mapping = ASSERT_NO_ERRNO_AND_VALUE( - MmapAnon(kMappingSize, prot, MAP_PRIVATE | MAP_POPULATE)); - }); - t.Join(); - - *after = ASSERT_NO_ERRNO_AND_VALUE(CurrentRSS()); -} - -// TODO(b/73896574): Test for PROT_READ + MAP_POPULATE anonymous mappings. Their -// semantics are more subtle: -// -// Small pages -> Zero page mapped, not counted in RSS -// (mm/memory.c:do_anonymous_page). -// -// Huge pages (THP enabled, use_zero_page=0) -> Pages committed -// (mm/memory.c:__handle_mm_fault -> create_huge_pmd). -// -// Huge pages (THP enabled, use_zero_page=1) -> Zero page mapped, not counted in -// RSS (mm/huge_memory.c:do_huge_pmd_anonymous_page). - -// PROT_WRITE + MAP_POPULATE anonymous mappings are always committed. -TEST(ProcSelfStat, PopulateWriteRSS) { - uint64_t before, after; - MapPopulateRSS(PROT_READ | PROT_WRITE, &before, &after); - - // Mapping is committed. - EXPECT_NEAR(before + kMappingSize, after, kRSSTolerance); -} - -// PROT_NONE + MAP_POPULATE anonymous mappings are never committed. -TEST(ProcSelfStat, PopulateNoneRSS) { - uint64_t before, after; - MapPopulateRSS(PROT_NONE, &before, &after); - - // Mapping not committed. - EXPECT_NEAR(before, after, kRSSTolerance); -} - -// Returns the calling thread's name. -PosixErrorOr<std::string> ThreadName() { - // "The buffer should allow space for up to 16 bytes; the returned std::string - // will be null-terminated if it is shorter than that." - prctl(2). But we - // always want the thread name to be null-terminated. - char thread_name[17]; - int rc = prctl(PR_GET_NAME, thread_name, 0, 0, 0); - MaybeSave(); - if (rc < 0) { - return PosixError(errno, "prctl(PR_GET_NAME)"); - } - thread_name[16] = '\0'; - return std::string(thread_name); -} - -// Parses the contents of a /proc/[pid]/status file into a collection of -// key-value pairs. -PosixErrorOr<std::map<std::string, std::string>> ParseProcStatus( - absl::string_view status_str) { - std::map<std::string, std::string> fields; - for (absl::string_view const line : - absl::StrSplit(status_str, '\n', absl::SkipWhitespace())) { - const std::pair<absl::string_view, absl::string_view> kv = - absl::StrSplit(line, absl::MaxSplits(":\t", 1)); - if (kv.first.empty()) { - return PosixError( - EINVAL, absl::StrCat("failed to parse key in line \"", line, "\"")); - } - std::string key(kv.first); - if (fields.count(key)) { - return PosixError(EINVAL, - absl::StrCat("duplicate key \"", kv.first, "\"")); - } - std::string value(kv.second); - absl::StripLeadingAsciiWhitespace(&value); - fields.emplace(std::move(key), std::move(value)); - } - return fields; -} - -TEST(ParseProcStatusTest, ParsesSimpleStatusFileWithMixedWhitespaceCorrectly) { - EXPECT_THAT( - ParseProcStatus( - "Name:\tinit\nState:\tS (sleeping)\nCapEff:\t 0000001fffffffff\n"), - IsPosixErrorOkAndHolds(UnorderedElementsAre( - Pair("Name", "init"), Pair("State", "S (sleeping)"), - Pair("CapEff", "0000001fffffffff")))); -} - -TEST(ParseProcStatusTest, DetectsDuplicateKeys) { - auto proc_status_or = ParseProcStatus("Name:\tfoo\nName:\tfoo\n"); - EXPECT_THAT(proc_status_or, - PosixErrorIs(EINVAL, ::testing::StrEq("duplicate key \"Name\""))); -} - -TEST(ParseProcStatusTest, DetectsMissingTabs) { - EXPECT_THAT(ParseProcStatus("Name:foo\nPid: 1\n"), - IsPosixErrorOkAndHolds(UnorderedElementsAre(Pair("Name:foo", ""), - Pair("Pid: 1", "")))); -} - -TEST(ProcPidStatusTest, HasBasicFields) { - // Do this on a separate thread since we want tgid != tid. - ScopedThread([] { - const pid_t tgid = getpid(); - const pid_t tid = syscall(SYS_gettid); - EXPECT_NE(tgid, tid); - const auto thread_name = ASSERT_NO_ERRNO_AND_VALUE(ThreadName()); - - std::string status_str = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/", tid, "/status"))); - - ASSERT_FALSE(status_str.empty()); - const auto status = ASSERT_NO_ERRNO_AND_VALUE(ParseProcStatus(status_str)); - EXPECT_THAT(status, IsSupersetOf({Pair("Name", thread_name), - Pair("Tgid", absl::StrCat(tgid)), - Pair("Pid", absl::StrCat(tid)), - Pair("PPid", absl::StrCat(getppid()))})); - }); -} - -TEST(ProcPidStatusTest, StateRunning) { - // Task must be running when reading the file. - const pid_t tid = syscall(SYS_gettid); - std::string status_str = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(absl::StrCat("/proc/", tid, "/status"))); - - EXPECT_THAT(ParseProcStatus(status_str), - IsPosixErrorOkAndHolds(Contains(Pair("State", "R (running)")))); -} - -TEST(ProcPidStatusTest, StateSleeping_NoRandomSave) { - // Starts a child process that blocks and checks that State is sleeping. - auto res = WithSubprocess( - [&](int pid) -> PosixError { - // Because this test is timing based we will disable cooperative saving - // and the test itself also has random saving disabled. - const DisableSave ds; - // Try multiple times in case the child isn't sleeping when status file - // is read. - MonotonicTimer timer; - timer.Start(); - for (;;) { - ASSIGN_OR_RETURN_ERRNO( - std::string status_str, - GetContents(absl::StrCat("/proc/", pid, "/status"))); - ASSIGN_OR_RETURN_ERRNO(auto map, ParseProcStatus(status_str)); - if (map["State"] == std::string("S (sleeping)")) { - // Test passed! - return NoError(); - } - if (timer.Duration() > absl::Seconds(10)) { - return PosixError(ETIMEDOUT, "Timeout waiting for child to sleep"); - } - absl::SleepFor(absl::Milliseconds(10)); - } - }, - nullptr, nullptr); - ASSERT_NO_ERRNO(res); -} - -TEST(ProcPidStatusTest, ValuesAreTabDelimited) { - std::string status_str = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/status")); - ASSERT_FALSE(status_str.empty()); - for (absl::string_view const line : - absl::StrSplit(status_str, '\n', absl::SkipWhitespace())) { - EXPECT_NE(std::string::npos, line.find(":\t")); - } -} - -// Threads properly counts running threads. -// -// TODO(mpratt): Test zombied threads while the thread group leader is still -// running with generalized fork and clone children from the wait test. -TEST(ProcPidStatusTest, Threads) { - char buf[4096] = {}; - EXPECT_THAT(ReadWhileRunning("status", buf, sizeof(buf) - 1), - SyscallSucceedsWithValue(Gt(0))); - - auto status = ASSERT_NO_ERRNO_AND_VALUE(ParseProcStatus(buf)); - auto it = status.find("Threads"); - ASSERT_NE(it, status.end()); - int threads = -1; - EXPECT_TRUE(absl::SimpleAtoi(it->second, &threads)) - << "Threads value " << it->second << " is not a number"; - // Don't make assumptions about the exact number of threads, as it may not be - // constant. - EXPECT_GE(threads, 1); - - memset(buf, 0, sizeof(buf)); - EXPECT_THAT(ReadWhileZombied("status", buf, sizeof(buf) - 1), - SyscallSucceedsWithValue(Gt(0))); - - status = ASSERT_NO_ERRNO_AND_VALUE(ParseProcStatus(buf)); - it = status.find("Threads"); - ASSERT_NE(it, status.end()); - threads = -1; - EXPECT_TRUE(absl::SimpleAtoi(it->second, &threads)) - << "Threads value " << it->second << " is not a number"; - // There must be only the thread group leader remaining, zombied. - EXPECT_EQ(threads, 1); -} - -// Returns true if all characters in s are digits. -bool IsDigits(absl::string_view s) { - return std::all_of(s.begin(), s.end(), absl::ascii_isdigit); -} - -TEST(ProcPidStatTest, VmStats) { - std::string status_str = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/status")); - ASSERT_FALSE(status_str.empty()); - auto status = ASSERT_NO_ERRNO_AND_VALUE(ParseProcStatus(status_str)); - - const auto vss_it = status.find("VmSize"); - ASSERT_NE(vss_it, status.end()); - - absl::string_view vss_str(vss_it->second); - - // Room for the " kB" suffix plus at least one digit. - ASSERT_GT(vss_str.length(), 3); - EXPECT_TRUE(absl::EndsWith(vss_str, " kB")); - // Everything else is part of a number. - EXPECT_TRUE(IsDigits(vss_str.substr(0, vss_str.length() - 3))) << vss_str; - // ... which is not 0. - EXPECT_NE('0', vss_str[0]); - - const auto rss_it = status.find("VmRSS"); - ASSERT_NE(rss_it, status.end()); - - absl::string_view rss_str(rss_it->second); - - // Room for the " kB" suffix plus at least one digit. - ASSERT_GT(rss_str.length(), 3); - EXPECT_TRUE(absl::EndsWith(rss_str, " kB")); - // Everything else is part of a number. - EXPECT_TRUE(IsDigits(rss_str.substr(0, rss_str.length() - 3))) << rss_str; - // ... which is not 0. - EXPECT_NE('0', rss_str[0]); - - const auto data_it = status.find("VmData"); - ASSERT_NE(data_it, status.end()); - - absl::string_view data_str(data_it->second); - - // Room for the " kB" suffix plus at least one digit. - ASSERT_GT(data_str.length(), 3); - EXPECT_TRUE(absl::EndsWith(data_str, " kB")); - // Everything else is part of a number. - EXPECT_TRUE(IsDigits(data_str.substr(0, data_str.length() - 3))) << data_str; - // ... which is not 0. - EXPECT_NE('0', data_str[0]); -} - -// Parse an array of NUL-terminated char* arrays, returning a vector of -// strings. -std::vector<std::string> ParseNulTerminatedStrings(std::string contents) { - EXPECT_EQ('\0', contents.back()); - // The split will leave an empty string if the NUL-byte remains, so pop - // it. - contents.pop_back(); - - return absl::StrSplit(contents, '\0'); -} - -TEST(ProcPidCmdline, MatchesArgv) { - std::vector<std::string> proc_cmdline = ParseNulTerminatedStrings( - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/cmdline"))); - EXPECT_THAT(saved_argv, ContainerEq(proc_cmdline)); -} - -TEST(ProcPidEnviron, MatchesEnviron) { - std::vector<std::string> proc_environ = ParseNulTerminatedStrings( - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/environ"))); - // Get the environment from the environ variable, which we will compare with - // /proc/self/environ. - std::vector<std::string> env; - for (char** v = environ; *v; v++) { - env.push_back(*v); - } - EXPECT_THAT(env, ContainerEq(proc_environ)); -} - -TEST(ProcPidCmdline, SubprocessForkSameCmdline) { - std::vector<std::string> proc_cmdline_parent; - std::vector<std::string> proc_cmdline; - proc_cmdline_parent = ParseNulTerminatedStrings( - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/cmdline"))); - auto res = WithSubprocess( - [&](int pid) -> PosixError { - ASSIGN_OR_RETURN_ERRNO( - auto raw_cmdline, - GetContents(absl::StrCat("/proc/", pid, "/cmdline"))); - proc_cmdline = ParseNulTerminatedStrings(raw_cmdline); - return NoError(); - }, - nullptr, nullptr); - ASSERT_NO_ERRNO(res); - - for (size_t i = 0; i < proc_cmdline_parent.size(); i++) { - EXPECT_EQ(proc_cmdline_parent[i], proc_cmdline[i]); - } -} - -// Test whether /proc/PID/ symlinks can be read for a running process. -TEST(ProcPidSymlink, SubprocessRunning) { - char buf[1]; - - EXPECT_THAT(ReadlinkWhileRunning("exe", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadlinkWhileRunning("ns/net", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadlinkWhileRunning("ns/pid", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadlinkWhileRunning("ns/user", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); -} - -TEST(ProcPidSymlink, SubprocessZombied) { - ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); - ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); - - char buf[1]; - - int want = EACCES; - if (!IsRunningOnGvisor()) { - auto version = ASSERT_NO_ERRNO_AND_VALUE(GetKernelVersion()); - if (version.major > 4 || (version.major == 4 && version.minor > 3)) { - want = ENOENT; - } - } - - EXPECT_THAT(ReadlinkWhileZombied("exe", buf, sizeof(buf)), - SyscallFailsWithErrno(want)); - - if (!IsRunningOnGvisor()) { - EXPECT_THAT(ReadlinkWhileZombied("ns/net", buf, sizeof(buf)), - SyscallFailsWithErrno(want)); - } - - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between linux on proc - // files. - // - // ~4.3: Syscall fails with EACCES. - // 4.17: Syscall succeeds and returns 1. - // - if (!IsRunningOnGvisor()) { - return; - } - - EXPECT_THAT(ReadlinkWhileZombied("ns/pid", buf, sizeof(buf)), - SyscallFailsWithErrno(want)); - - EXPECT_THAT(ReadlinkWhileZombied("ns/user", buf, sizeof(buf)), - SyscallFailsWithErrno(want)); -} - -// Test whether /proc/PID/ symlinks can be read for an exited process. -TEST(ProcPidSymlink, SubprocessExited) { - char buf[1]; - - EXPECT_THAT(ReadlinkWhileExited("exe", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - - EXPECT_THAT(ReadlinkWhileExited("ns/net", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - - EXPECT_THAT(ReadlinkWhileExited("ns/pid", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - - EXPECT_THAT(ReadlinkWhileExited("ns/user", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); -} - -// /proc/PID/exe points to the correct binary. -TEST(ProcPidExe, Subprocess) { - auto link = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/exe")); - auto expected_absolute_path = - ASSERT_NO_ERRNO_AND_VALUE(MakeAbsolute(link, "")); - - char actual[PATH_MAX + 1] = {}; - ASSERT_THAT(ReadlinkWhileRunning("exe", actual, sizeof(actual)), - SyscallSucceedsWithValue(Gt(0))); - EXPECT_EQ(actual, expected_absolute_path); -} - -// /proc/PID/cwd points to the correct directory. -TEST(ProcPidCwd, Subprocess) { - auto want = ASSERT_NO_ERRNO_AND_VALUE(GetCWD()); - - char got[PATH_MAX + 1] = {}; - ASSERT_THAT(ReadlinkWhileRunning("cwd", got, sizeof(got)), - SyscallSucceedsWithValue(Gt(0))); - EXPECT_EQ(got, want); -} - -// Test whether /proc/PID/ files can be read for a running process. -TEST(ProcPidFile, SubprocessRunning) { - char buf[1]; - - EXPECT_THAT(ReadWhileRunning("auxv", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("cmdline", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("comm", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("gid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("io", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("maps", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("stat", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("status", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("uid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("oom_score", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileRunning("oom_score_adj", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); -} - -// Test whether /proc/PID/ files can be read for a zombie process. -TEST(ProcPidFile, SubprocessZombie) { - char buf[1]; - - // FIXME(gvisor.dev/issue/164): Loosen requirement due to inconsistent - // behavior on different kernels. - // - // ~4.3: Succeds and returns 0. - // 4.17: Succeeds and returns 1. - // gVisor: Succeeds and returns 0. - EXPECT_THAT(ReadWhileZombied("auxv", buf, sizeof(buf)), SyscallSucceeds()); - - EXPECT_THAT(ReadWhileZombied("cmdline", buf, sizeof(buf)), - SyscallSucceedsWithValue(0)); - - EXPECT_THAT(ReadWhileZombied("comm", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("gid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("maps", buf, sizeof(buf)), - SyscallSucceedsWithValue(0)); - - EXPECT_THAT(ReadWhileZombied("stat", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("status", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("uid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("oom_score", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - EXPECT_THAT(ReadWhileZombied("oom_score_adj", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between gVisor and linux - // on proc files. - // - // ~4.3: Fails and returns EACCES. - // gVisor & 4.17: Succeeds and returns 1. - // - // EXPECT_THAT(ReadWhileZombied("io", buf, sizeof(buf)), - // SyscallFailsWithErrno(EACCES)); -} - -// Test whether /proc/PID/ files can be read for an exited process. -TEST(ProcPidFile, SubprocessExited) { - char buf[1]; - - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between kernels. - // - // ~4.3: Fails and returns ESRCH. - // gVisor: Fails with ESRCH. - // 4.17: Succeeds and returns 1. - // - // EXPECT_THAT(ReadWhileExited("auxv", buf, sizeof(buf)), - // SyscallFailsWithErrno(ESRCH)); - - EXPECT_THAT(ReadWhileExited("cmdline", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Succeeds on gVisor. - EXPECT_THAT(ReadWhileExited("comm", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - EXPECT_THAT(ReadWhileExited("gid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Succeeds on gVisor. - EXPECT_THAT(ReadWhileExited("io", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Returns EOF on gVisor. - EXPECT_THAT(ReadWhileExited("maps", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Succeeds on gVisor. - EXPECT_THAT(ReadWhileExited("stat", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Succeeds on gVisor. - EXPECT_THAT(ReadWhileExited("status", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - EXPECT_THAT(ReadWhileExited("uid_map", buf, sizeof(buf)), - SyscallSucceedsWithValue(sizeof(buf))); - - if (!IsRunningOnGvisor()) { - // FIXME(gvisor.dev/issue/164): Succeeds on gVisor. - EXPECT_THAT(ReadWhileExited("oom_score", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); - } - - EXPECT_THAT(ReadWhileExited("oom_score_adj", buf, sizeof(buf)), - SyscallFailsWithErrno(ESRCH)); -} - -PosixError DirContainsImpl(absl::string_view path, - const std::vector<std::string>& targets, - bool strict) { - ASSIGN_OR_RETURN_ERRNO(auto listing, ListDir(path, false)); - bool success = true; - - for (auto& expected_entry : targets) { - auto cursor = std::find(listing.begin(), listing.end(), expected_entry); - if (cursor == listing.end()) { - success = false; - } - } - - if (!success) { - return PosixError( - ENOENT, - absl::StrCat("Failed to find one or more paths in '", path, "'")); - } - - if (strict) { - if (targets.size() != listing.size()) { - return PosixError( - EINVAL, - absl::StrCat("Expected to find ", targets.size(), " elements in '", - path, "', but found ", listing.size())); - } - } - - return NoError(); -} - -PosixError DirContains(absl::string_view path, - const std::vector<std::string>& targets) { - return DirContainsImpl(path, targets, false); -} - -PosixError DirContainsExactly(absl::string_view path, - const std::vector<std::string>& targets) { - return DirContainsImpl(path, targets, true); -} - -PosixError EventuallyDirContainsExactly( - absl::string_view path, const std::vector<std::string>& targets) { - constexpr int kRetryCount = 100; - const absl::Duration kRetryDelay = absl::Milliseconds(100); - - for (int i = 0; i < kRetryCount; ++i) { - auto res = DirContainsExactly(path, targets); - if (res.ok()) { - return res; - } else if (i < kRetryCount - 1) { - // Sleep if this isn't the final iteration. - absl::SleepFor(kRetryDelay); - } - } - return PosixError(ETIMEDOUT, - "Timed out while waiting for directory to contain files "); -} - -TEST(ProcTask, Basic) { - EXPECT_NO_ERRNO( - DirContains("/proc/self/task", {".", "..", absl::StrCat(getpid())})); -} - -std::vector<std::string> TaskFiles( - const std::vector<std::string>& initial_contents, - const std::vector<pid_t>& pids) { - return VecCat<std::string>( - initial_contents, - ApplyVec<std::string>([](const pid_t p) { return absl::StrCat(p); }, - pids)); -} - -std::vector<std::string> TaskFiles(const std::vector<pid_t>& pids) { - return TaskFiles({".", "..", absl::StrCat(getpid())}, pids); -} - -// Helper class for creating a new task in the current thread group. -class BlockingChild { - public: - BlockingChild() : thread_([=] { Start(); }) {} - ~BlockingChild() { Join(); } - - pid_t Tid() const { - absl::MutexLock ml(&mu_); - mu_.Await(absl::Condition(&tid_ready_)); - return tid_; - } - - void Join() { Stop(); } - - private: - void Start() { - absl::MutexLock ml(&mu_); - tid_ = syscall(__NR_gettid); - tid_ready_ = true; - mu_.Await(absl::Condition(&stop_)); - } - - void Stop() { - absl::MutexLock ml(&mu_); - stop_ = true; - } - - mutable absl::Mutex mu_; - bool stop_ ABSL_GUARDED_BY(mu_) = false; - pid_t tid_; - bool tid_ready_ ABSL_GUARDED_BY(mu_) = false; - - // Must be last to ensure that the destructor for the thread is run before - // any other member of the object is destroyed. - ScopedThread thread_; -}; - -TEST(ProcTask, NewThreadAppears) { - auto initial = ASSERT_NO_ERRNO_AND_VALUE(ListDir("/proc/self/task", false)); - BlockingChild child1; - EXPECT_NO_ERRNO(DirContainsExactly("/proc/self/task", - TaskFiles(initial, {child1.Tid()}))); -} - -TEST(ProcTask, KilledThreadsDisappear) { - auto initial = ASSERT_NO_ERRNO_AND_VALUE(ListDir("/proc/self/task/", false)); - - BlockingChild child1; - EXPECT_NO_ERRNO(DirContainsExactly("/proc/self/task", - TaskFiles(initial, {child1.Tid()}))); - - // Stat child1's task file. Regression test for b/32097707. - struct stat statbuf; - const std::string child1_task_file = - absl::StrCat("/proc/self/task/", child1.Tid()); - EXPECT_THAT(stat(child1_task_file.c_str(), &statbuf), SyscallSucceeds()); - - BlockingChild child2; - EXPECT_NO_ERRNO(DirContainsExactly( - "/proc/self/task", TaskFiles(initial, {child1.Tid(), child2.Tid()}))); - - BlockingChild child3; - BlockingChild child4; - BlockingChild child5; - EXPECT_NO_ERRNO(DirContainsExactly( - "/proc/self/task", - TaskFiles(initial, {child1.Tid(), child2.Tid(), child3.Tid(), - child4.Tid(), child5.Tid()}))); - - child2.Join(); - EXPECT_NO_ERRNO(EventuallyDirContainsExactly( - "/proc/self/task", TaskFiles(initial, {child1.Tid(), child3.Tid(), - child4.Tid(), child5.Tid()}))); - - child1.Join(); - child4.Join(); - EXPECT_NO_ERRNO(EventuallyDirContainsExactly( - "/proc/self/task", TaskFiles(initial, {child3.Tid(), child5.Tid()}))); - - // Stat child1's task file again. This time it should fail. See b/32097707. - EXPECT_THAT(stat(child1_task_file.c_str(), &statbuf), - SyscallFailsWithErrno(ENOENT)); - - child3.Join(); - child5.Join(); - EXPECT_NO_ERRNO(EventuallyDirContainsExactly("/proc/self/task", initial)); -} - -TEST(ProcTask, ChildTaskDir) { - BlockingChild child1; - EXPECT_NO_ERRNO(DirContains("/proc/self/task", TaskFiles({child1.Tid()}))); - EXPECT_NO_ERRNO(DirContains(absl::StrCat("/proc/", child1.Tid(), "/task"), - TaskFiles({child1.Tid()}))); -} - -PosixError VerifyPidDir(std::string path) { - return DirContains(path, {"exe", "fd", "io", "maps", "ns", "stat", "status"}); -} - -TEST(ProcTask, VerifyTaskDir) { - EXPECT_NO_ERRNO(VerifyPidDir("/proc/self")); - - EXPECT_NO_ERRNO(VerifyPidDir(absl::StrCat("/proc/self/task/", getpid()))); - BlockingChild child1; - EXPECT_NO_ERRNO(VerifyPidDir(absl::StrCat("/proc/self/task/", child1.Tid()))); - - // Only the first level of task directories should contain the 'task' - // directory. That is: - // - // /proc/1234/task <- should exist - // /proc/1234/task/1234/task <- should not exist - // /proc/1234/task/1235/task <- should not exist (where 1235 is in the same - // thread group as 1234). - EXPECT_FALSE( - DirContains(absl::StrCat("/proc/self/task/", getpid()), {"task"}).ok()) - << "Found 'task' directory in an inner directory."; -} - -TEST(ProcTask, TaskDirCannotBeDeleted) { - // Drop capabilities that allow us to override file and directory permissions. - ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); - - EXPECT_THAT(rmdir("/proc/self/task"), SyscallFails()); - EXPECT_THAT(rmdir(absl::StrCat("/proc/self/task/", getpid()).c_str()), - SyscallFailsWithErrno(EACCES)); -} - -TEST(ProcTask, TaskDirHasCorrectMetadata) { - struct stat st; - EXPECT_THAT(stat("/proc/self/task", &st), SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - - // Verify file is readable and executable by everyone. - mode_t expected_permissions = - S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; - mode_t permissions = st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO); - EXPECT_EQ(expected_permissions, permissions); -} - -TEST(ProcTask, TaskDirCanSeekToEnd) { - const FileDescriptor dirfd = - ASSERT_NO_ERRNO_AND_VALUE(Open("/proc/self/task", O_RDONLY)); - EXPECT_THAT(lseek(dirfd.get(), 0, SEEK_END), SyscallSucceeds()); -} - -TEST(ProcTask, VerifyTaskDirNlinks) { - // A task directory will have 3 links if the taskgroup has a single - // thread. For example, the following shows where the links to - // '/proc/12345/task comes' from for a single threaded process with pid 12345: - // - // /proc/12345/task <-- 1 link for the directory itself - // . <-- link from "." - // .. - // 12345 - // . - // .. <-- link from ".." to parent. - // <other contents of a task dir> - // - // We can't assert an absolute number of links since we don't control how many - // threads the test framework spawns. Instead, we'll ensure creating a new - // thread increases the number of links as expected. - - // Once we reach the test body, we can count on the thread count being stable - // unless we spawn a new one. - uint64_t initial_links = ASSERT_NO_ERRNO_AND_VALUE(Links("/proc/self/task")); - ASSERT_GE(initial_links, 3); - - // For each new subtask, we should gain a new link. - BlockingChild child1; - EXPECT_THAT(Links("/proc/self/task"), - IsPosixErrorOkAndHolds(initial_links + 1)); - BlockingChild child2; - EXPECT_THAT(Links("/proc/self/task"), - IsPosixErrorOkAndHolds(initial_links + 2)); -} - -TEST(ProcTask, CommContainsThreadNameAndTrailingNewline) { - constexpr char kThreadName[] = "TestThread12345"; - ASSERT_THAT(prctl(PR_SET_NAME, kThreadName), SyscallSucceeds()); - - auto thread_name = ASSERT_NO_ERRNO_AND_VALUE( - GetContents(JoinPath("/proc", absl::StrCat(getpid()), "task", - absl::StrCat(syscall(SYS_gettid)), "comm"))); - EXPECT_EQ(absl::StrCat(kThreadName, "\n"), thread_name); -} - -TEST(ProcTaskNs, NsDirExistsAndHasCorrectMetadata) { - EXPECT_NO_ERRNO(DirContains("/proc/self/ns", {"net", "pid", "user"})); - - // Let's just test the 'pid' entry, all of them are very similar. - struct stat st; - EXPECT_THAT(lstat("/proc/self/ns/pid", &st), SyscallSucceeds()); - EXPECT_TRUE(S_ISLNK(st.st_mode)); - - auto link = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/self/ns/pid")); - EXPECT_THAT(link, ::testing::StartsWith("pid:[")); -} - -TEST(ProcTaskNs, AccessOnNsNodeSucceeds) { - EXPECT_THAT(access("/proc/self/ns/pid", F_OK), SyscallSucceeds()); -} - -TEST(ProcSysKernelHostname, Exists) { - EXPECT_THAT(open("/proc/sys/kernel/hostname", O_RDONLY), SyscallSucceeds()); -} - -TEST(ProcSysKernelHostname, MatchesUname) { - struct utsname buf; - EXPECT_THAT(uname(&buf), SyscallSucceeds()); - const std::string hostname = absl::StrCat(buf.nodename, "\n"); - auto procfs_hostname = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/kernel/hostname")); - EXPECT_EQ(procfs_hostname, hostname); -} - -TEST(ProcSysVmMmapMinAddr, HasNumericValue) { - const std::string mmap_min_addr_str = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/vm/mmap_min_addr")); - uintptr_t mmap_min_addr; - EXPECT_TRUE(absl::SimpleAtoi(mmap_min_addr_str, &mmap_min_addr)) - << "/proc/sys/vm/mmap_min_addr does not contain a numeric value: " - << mmap_min_addr_str; -} - -TEST(ProcSysVmOvercommitMemory, HasNumericValue) { - const std::string overcommit_memory_str = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/vm/overcommit_memory")); - uintptr_t overcommit_memory; - EXPECT_TRUE(absl::SimpleAtoi(overcommit_memory_str, &overcommit_memory)) - << "/proc/sys/vm/overcommit_memory does not contain a numeric value: " - << overcommit_memory; -} - -// Check that link for proc fd entries point the target node, not the -// symlink itself. Regression test for b/31155070. -TEST(ProcTaskFd, FstatatFollowsSymlink) { - const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor fd = - ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); - - struct stat sproc = {}; - EXPECT_THAT( - fstatat(-1, absl::StrCat("/proc/self/fd/", fd.get()).c_str(), &sproc, 0), - SyscallSucceeds()); - - struct stat sfile = {}; - EXPECT_THAT(fstatat(-1, file.path().c_str(), &sfile, 0), SyscallSucceeds()); - - // If fstatat follows the fd symlink, the device and inode numbers should - // match at a minimum. - EXPECT_EQ(sproc.st_dev, sfile.st_dev); - EXPECT_EQ(sproc.st_ino, sfile.st_ino); - EXPECT_EQ(0, memcmp(&sfile, &sproc, sizeof(sfile))); -} - -TEST(ProcFilesystems, Bug65172365) { - std::string proc_filesystems = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/filesystems")); - ASSERT_FALSE(proc_filesystems.empty()); -} - -TEST(ProcFilesystems, PresenceOfShmMaxMniAll) { - uint64_t shmmax = 0; - uint64_t shmall = 0; - uint64_t shmmni = 0; - std::string proc_file; - proc_file = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/kernel/shmmax")); - ASSERT_FALSE(proc_file.empty()); - ASSERT_TRUE(absl::SimpleAtoi(proc_file, &shmmax)); - proc_file = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/kernel/shmall")); - ASSERT_FALSE(proc_file.empty()); - ASSERT_TRUE(absl::SimpleAtoi(proc_file, &shmall)); - proc_file = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/kernel/shmmni")); - ASSERT_FALSE(proc_file.empty()); - ASSERT_TRUE(absl::SimpleAtoi(proc_file, &shmmni)); - - ASSERT_GT(shmmax, 0); - ASSERT_GT(shmall, 0); - ASSERT_GT(shmmni, 0); - ASSERT_LE(shmall, shmmax); - - // These values should never be higher than this by default, for more - // information see uapi/linux/shm.h - ASSERT_LE(shmmax, ULONG_MAX - (1UL << 24)); - ASSERT_LE(shmall, ULONG_MAX - (1UL << 24)); -} - -// Check that /proc/mounts is a symlink to self/mounts. -TEST(ProcMounts, IsSymlink) { - auto link = ASSERT_NO_ERRNO_AND_VALUE(ReadLink("/proc/mounts")); - EXPECT_EQ(link, "self/mounts"); -} - -TEST(ProcSelfMountinfo, RequiredFieldsArePresent) { - auto mountinfo = - ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/mountinfo")); - EXPECT_THAT( - mountinfo, - AllOf( - // Root mount. - ContainsRegex( - R"([0-9]+ [0-9]+ [0-9]+:[0-9]+ /\S* / (rw|ro).*- \S+ \S+ (rw|ro)\S*)"), - // Proc mount - always rw. - ContainsRegex( - R"([0-9]+ [0-9]+ [0-9]+:[0-9]+ / /proc rw.*- \S+ \S+ rw\S*)"))); -} - -// Check that /proc/self/mounts looks something like a real mounts file. -TEST(ProcSelfMounts, RequiredFieldsArePresent) { - auto mounts = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/mounts")); - EXPECT_THAT(mounts, - AllOf( - // Root mount. - ContainsRegex(R"(\S+ / \S+ (rw|ro)\S* [0-9]+ [0-9]+\s)"), - // Root mount. - ContainsRegex(R"(\S+ /proc \S+ rw\S* [0-9]+ [0-9]+\s)"))); -} - -void CheckDuplicatesRecursively(std::string path) { - std::vector<std::string> child_dirs; - - // There is the known issue of the linux procfs, that two consequent calls of - // readdir can return the same entry twice if between these calls one or more - // entries have been removed from this directory. - int max_attempts = 5; - for (int i = 0; i < max_attempts; i++) { - child_dirs.clear(); - errno = 0; - bool success = true; - DIR* dir = opendir(path.c_str()); - if (dir == nullptr) { - // Ignore any directories we can't read or missing directories as the - // directory could have been deleted/mutated from the time the parent - // directory contents were read. - return; - } - auto dir_closer = Cleanup([&dir]() { closedir(dir); }); - std::unordered_set<std::string> children; - while (true) { - // Readdir(3): If the end of the directory stream is reached, NULL is - // returned and errno is not changed. If an error occurs, NULL is - // returned and errno is set appropriately. To distinguish end of stream - // and from an error, set errno to zero before calling readdir() and then - // check the value of errno if NULL is returned. - errno = 0; - struct dirent* dp = readdir(dir); - if (dp == nullptr) { - // Linux will return EINVAL when calling getdents on a /proc/tid/net - // file corresponding to a zombie task. - // See fs/proc/proc_net.c:proc_tgid_net_readdir(). - // - // We just ignore the directory in this case. - if (errno == EINVAL && absl::StartsWith(path, "/proc/") && - absl::EndsWith(path, "/net")) { - break; - } - - // Otherwise, no errors are allowed. - ASSERT_EQ(errno, 0) << path; - break; // We're done. - } - - const std::string name = dp->d_name; - - if (name == "." || name == "..") { - continue; - } - - // Ignore a duplicate entry if it isn't the last attempt. - if (i == max_attempts - 1) { - ASSERT_EQ(children.find(name), children.end()) - << absl::StrCat(path, "/", name); - } else if (children.find(name) != children.end()) { - std::cerr << "Duplicate entry: " << i << ":" - << absl::StrCat(path, "/", name) << std::endl; - success = false; - break; - } - children.insert(name); - - if (dp->d_type == DT_DIR) { - child_dirs.push_back(name); - } - } - if (success) { - break; - } - } - for (auto dname = child_dirs.begin(); dname != child_dirs.end(); dname++) { - CheckDuplicatesRecursively(absl::StrCat(path, "/", *dname)); - } -} - -TEST(Proc, NoDuplicates) { CheckDuplicatesRecursively("/proc"); } - -// Most /proc/PID files are owned by the task user with SUID_DUMP_USER. -TEST(ProcPid, UserDumpableOwner) { - int before; - ASSERT_THAT(before = prctl(PR_GET_DUMPABLE), SyscallSucceeds()); - auto cleanup = Cleanup([before] { - ASSERT_THAT(prctl(PR_SET_DUMPABLE, before), SyscallSucceeds()); - }); - - EXPECT_THAT(prctl(PR_SET_DUMPABLE, SUID_DUMP_USER), SyscallSucceeds()); - - // This applies to the task directory itself and files inside. - struct stat st; - ASSERT_THAT(stat("/proc/self/", &st), SyscallSucceeds()); - EXPECT_EQ(st.st_uid, geteuid()); - EXPECT_EQ(st.st_gid, getegid()); - - ASSERT_THAT(stat("/proc/self/stat", &st), SyscallSucceeds()); - EXPECT_EQ(st.st_uid, geteuid()); - EXPECT_EQ(st.st_gid, getegid()); -} - -// /proc/PID files are owned by root with SUID_DUMP_DISABLE. -TEST(ProcPid, RootDumpableOwner) { - int before; - ASSERT_THAT(before = prctl(PR_GET_DUMPABLE), SyscallSucceeds()); - auto cleanup = Cleanup([before] { - ASSERT_THAT(prctl(PR_SET_DUMPABLE, before), SyscallSucceeds()); - }); - - EXPECT_THAT(prctl(PR_SET_DUMPABLE, SUID_DUMP_DISABLE), SyscallSucceeds()); - - // This *does not* applies to the task directory itself (or other 0555 - // directories), but does to files inside. - struct stat st; - ASSERT_THAT(stat("/proc/self/", &st), SyscallSucceeds()); - EXPECT_EQ(st.st_uid, geteuid()); - EXPECT_EQ(st.st_gid, getegid()); - - // This file is owned by root. Also allow nobody in case this test is running - // in a userns without root mapped. - ASSERT_THAT(stat("/proc/self/stat", &st), SyscallSucceeds()); - EXPECT_THAT(st.st_uid, AnyOf(Eq(0), Eq(65534))); - EXPECT_THAT(st.st_gid, AnyOf(Eq(0), Eq(65534))); -} - -TEST(Proc, GetdentsEnoent) { - FileDescriptor fd; - ASSERT_NO_ERRNO(WithSubprocess( - [&](int pid) -> PosixError { - // Running. - ASSIGN_OR_RETURN_ERRNO(fd, Open(absl::StrCat("/proc/", pid, "/task"), - O_RDONLY | O_DIRECTORY)); - - return NoError(); - }, - nullptr, nullptr)); - char buf[1024]; - ASSERT_THAT(syscall(SYS_getdents64, fd.get(), buf, sizeof(buf)), - SyscallFailsWithErrno(ENOENT)); -} - -void CheckSyscwFromIOFile(const std::string& path, const std::string& regex) { - std::string output; - ASSERT_NO_ERRNO(GetContents(path, &output)); - ASSERT_THAT(output, ContainsRegex(absl::StrCat("syscw:\\s+", regex, "\n"))); -} - -// Checks that there is variable accounting of IO between threads/tasks. -TEST(Proc, PidTidIOAccounting) { - absl::Notification notification; - - // Run a thread with a bunch of writes. Check that io account records exactly - // the number of write calls. File open/close is there to prevent buffering. - ScopedThread writer([¬ification] { - const int num_writes = 100; - for (int i = 0; i < num_writes; i++) { - auto path = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - ASSERT_NO_ERRNO(SetContents(path.path(), "a")); - } - notification.Notify(); - const std::string& writer_dir = - absl::StrCat("/proc/", getpid(), "/task/", gettid(), "/io"); - - CheckSyscwFromIOFile(writer_dir, std::to_string(num_writes)); - }); - - // Run a thread and do no writes. Check that no writes are recorded. - ScopedThread noop([¬ification] { - notification.WaitForNotification(); - const std::string& noop_dir = - absl::StrCat("/proc/", getpid(), "/task/", gettid(), "/io"); - - CheckSyscwFromIOFile(noop_dir, "0"); - }); - - writer.Join(); - noop.Join(); -} - -TEST(Proc, Statfs) { - struct statfs st; - EXPECT_THAT(statfs("/proc", &st), SyscallSucceeds()); - if (IsRunningWithVFS1()) { - EXPECT_EQ(st.f_type, ANON_INODE_FS_MAGIC); - } else { - EXPECT_EQ(st.f_type, PROC_SUPER_MAGIC); - } - EXPECT_EQ(st.f_bsize, getpagesize()); - EXPECT_EQ(st.f_namelen, NAME_MAX); -} - -} // namespace -} // namespace testing -} // namespace gvisor - -int main(int argc, char** argv) { - for (int i = 0; i < argc; ++i) { - gvisor::testing::saved_argv.emplace_back(std::string(argv[i])); - } - - gvisor::testing::TestInit(&argc, &argv); - return gvisor::testing::RunAllTests(); -} |