diff options
Diffstat (limited to 'test/syscalls/linux/proc.cc')
| -rw-r--r-- | test/syscalls/linux/proc.cc | 342 |
1 files changed, 257 insertions, 85 deletions
diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc index e4c030bbb..d6b875dbf 100644 --- a/test/syscalls/linux/proc.cc +++ b/test/syscalls/linux/proc.cc @@ -37,6 +37,7 @@ #include <map> #include <memory> #include <ostream> +#include <regex> #include <string> #include <unordered_set> #include <utility> @@ -51,6 +52,7 @@ #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" @@ -98,9 +100,39 @@ namespace { #define SUID_DUMP_ROOT 2 #endif /* SUID_DUMP_ROOT */ -// O_LARGEFILE as defined by Linux. glibc tries to be clever by setting it to 0 -// because "it isn't needed", even though Linux can return it via F_GETFL. -constexpr int kOLargeFile = 00100000; +#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. @@ -183,7 +215,8 @@ PosixError WithSubprocess(SubprocessCallback const& running, siginfo_t info; // Wait until the child process has exited (WEXITED flag) but don't // reap the child (WNOWAIT flag). - waitid(P_PID, child_pid, &info, WNOWAIT | WEXITED); + EXPECT_THAT(waitid(P_PID, child_pid, &info, WNOWAIT | WEXITED), + SyscallSucceeds()); if (zombied) { // Arg of "Z" refers to a Zombied Process. @@ -714,28 +747,6 @@ TEST(ProcCpuinfo, RequiredFieldsArePresent) { ASSERT_FALSE(proc_cpuinfo.empty()); std::vector<std::string> cpuinfo_fields = absl::StrSplit(proc_cpuinfo, '\n'); - // 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", - }; - // Check that the usual fields are there. We don't really care about the // contents. for (const std::string& field : required_fields) { @@ -743,8 +754,53 @@ TEST(ProcCpuinfo, RequiredFieldsArePresent) { } } -TEST(ProcCpuinfo, DeniesWrite) { - EXPECT_THAT(open("/proc/cpuinfo", O_WRONLY), SyscallFailsWithErrno(EACCES)); +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)); + // TODO(gvisor.dev/issue/1193): Properly support setting size attributes in + // kernfs. + if (!IsRunningOnGvisor() || IsRunningWithVFS1()) { + 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 will return EIO. +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) { + EXPECT_THAT(write(fd, "x", 1), SyscallFailsWithErrno(EIO)); + EXPECT_THAT(pwrite(fd, "x", 1, 123), SyscallFailsWithErrno(EIO)); + } + // TODO(gvisor.dev/issue/1193): Properly support setting size attributes in + // kernfs. + if (!IsRunningOnGvisor() || IsRunningWithVFS1()) { + if (fd > 0) { + EXPECT_THAT(ftruncate(fd, 123), SyscallFailsWithErrno(EIO)); + } + EXPECT_THAT(truncate("/proc/cpuinfo", 123), SyscallFailsWithErrno(EIO)); + } } // Sanity checks that uptime is present. @@ -983,7 +1039,7 @@ 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 = 5 << 20; +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) { @@ -1315,8 +1371,6 @@ TEST(ProcPidSymlink, SubprocessRunning) { SyscallSucceedsWithValue(sizeof(buf))); } -// FIXME(gvisor.dev/issue/164): Inconsistent behavior between gVisor and linux -// on proc files. TEST(ProcPidSymlink, SubprocessZombied) { ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); @@ -1326,7 +1380,7 @@ TEST(ProcPidSymlink, SubprocessZombied) { int want = EACCES; if (!IsRunningOnGvisor()) { auto version = ASSERT_NO_ERRNO_AND_VALUE(GetKernelVersion()); - if (version.major == 4 && version.minor > 3) { + if (version.major > 4 || (version.major == 4 && version.minor > 3)) { want = ENOENT; } } @@ -1339,24 +1393,25 @@ TEST(ProcPidSymlink, SubprocessZombied) { SyscallFailsWithErrno(want)); } - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between gVisor and linux - // on proc files. - // 4.17 & gVisor: Syscall succeeds and returns 1 - // EXPECT_THAT(ReadlinkWhileZombied("ns/pid", buf, sizeof(buf)), - // SyscallFailsWithErrno(EACCES)); + // 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; + } - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between gVisor and linux - // on proc files. - // 4.17 & gVisor: Syscall succeeds and returns 1. - // EXPECT_THAT(ReadlinkWhileZombied("ns/user", buf, sizeof(buf)), - // SyscallFailsWithErrno(EACCES)); + 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) { - // FIXME(gvisor.dev/issue/164): These all succeed on gVisor. - SKIP_IF(IsRunningOnGvisor()); - char buf[1]; EXPECT_THAT(ReadlinkWhileExited("exe", buf, sizeof(buf)), @@ -1414,14 +1469,24 @@ TEST(ProcPidFile, SubprocessRunning) { 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]; - // 4.17: Succeeds and returns 1 - // gVisor: Succeeds and returns 0 + // 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)), @@ -1445,9 +1510,18 @@ TEST(ProcPidFile, SubprocessZombie) { 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)); } @@ -1456,9 +1530,12 @@ TEST(ProcPidFile, SubprocessZombie) { TEST(ProcPidFile, SubprocessExited) { char buf[1]; - // FIXME(gvisor.dev/issue/164): Inconsistent behavior between kernels + // 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)); @@ -1500,6 +1577,15 @@ TEST(ProcPidFile, SubprocessExited) { 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, @@ -1630,7 +1716,7 @@ TEST(ProcTask, KilledThreadsDisappear) { EXPECT_NO_ERRNO(DirContainsExactly("/proc/self/task", TaskFiles(initial, {child1.Tid()}))); - // Stat child1's task file. + // 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()); @@ -1658,7 +1744,7 @@ TEST(ProcTask, KilledThreadsDisappear) { EXPECT_NO_ERRNO(EventuallyDirContainsExactly( "/proc/self/task", TaskFiles(initial, {child3.Tid(), child5.Tid()}))); - // Stat child1's task file again. This time it should fail. + // 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)); @@ -1813,7 +1899,7 @@ TEST(ProcSysVmOvercommitMemory, HasNumericValue) { } // Check that link for proc fd entries point the target node, not the -// symlink itself. +// symlink itself. Regression test for b/31155070. TEST(ProcTaskFd, FstatatFollowsSymlink) { const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); const FileDescriptor fd = @@ -1872,6 +1958,20 @@ TEST(ProcMounts, IsSymlink) { 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")); @@ -1884,43 +1984,77 @@ TEST(ProcSelfMounts, RequiredFieldsArePresent) { } void CheckDuplicatesRecursively(std::string path) { - errno = 0; - 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. + 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; - struct dirent* dp = readdir(dir); - if (dp == nullptr) { - ASSERT_EQ(errno, 0) << path; - break; // We're done. + 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; + } - if (strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0) { - continue; + // 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); + } } - - ASSERT_EQ(children.find(std::string(dp->d_name)), children.end()) - << dp->d_name; - children.insert(std::string(dp->d_name)); - - ASSERT_NE(dp->d_type, DT_UNKNOWN); - - if (dp->d_type != DT_DIR) { - continue; + if (success) { + break; } - CheckDuplicatesRecursively(absl::StrCat(path, "/", dp->d_name)); + } + for (auto dname = child_dirs.begin(); dname != child_dirs.end(); dname++) { + CheckDuplicatesRecursively(absl::StrCat(path, "/", *dname)); } } @@ -1983,10 +2117,48 @@ TEST(Proc, GetdentsEnoent) { }, nullptr, nullptr)); char buf[1024]; - ASSERT_THAT(syscall(SYS_getdents, fd.get(), buf, sizeof(buf)), + 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(); +} + } // namespace } // namespace testing } // namespace gvisor @@ -1997,5 +2169,5 @@ int main(int argc, char** argv) { } gvisor::testing::TestInit(&argc, &argv); - return RUN_ALL_TESTS(); + return gvisor::testing::RunAllTests(); } |