blob: 321234b66822467a6373c0591259da100c6a2be1 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/linux_util.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <iomanip>
#include <memory>
#include "base/files/dir_reader_posix.h"
#include "base/files/file_util.h"
#include "base/files/scoped_file.h"
#include "base/no_destructor.h"
#include "base/strings/safe_sprintf.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_tokenizer.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
namespace base {
namespace {
#if !defined(OS_CHROMEOS)
std::string GetKeyValueFromOSReleaseFile(const std::string& input,
const char* key) {
StringPairs key_value_pairs;
SplitStringIntoKeyValuePairs(input, '=', '\n', &key_value_pairs);
for (const auto& pair : key_value_pairs) {
const std::string& key_str = pair.first;
const std::string& value_str = pair.second;
if (key_str == key) {
// It can contain quoted characters.
std::stringstream ss;
std::string pretty_name;
ss << value_str;
// Quoted with a single tick?
if (value_str[0] == '\'')
ss >> std::quoted(pretty_name, '\'');
ss >> std::quoted(pretty_name);
return pretty_name;
return "";
bool ReadDistroFromOSReleaseFile(const char* file) {
static const char kPrettyName[] = "PRETTY_NAME";
std::string os_release_content;
if (!ReadFileToString(FilePath(file), &os_release_content))
return false;
std::string pretty_name =
GetKeyValueFromOSReleaseFile(os_release_content, kPrettyName);
if (pretty_name.empty())
return false;
return true;
class DistroNameGetter {
DistroNameGetter() {
static const char* const kFilesToCheck[] = {"/etc/os-release",
for (const char* file : kFilesToCheck) {
if (ReadDistroFromOSReleaseFile(file))
#endif // !defined(OS_CHROMEOS)
// Account for the terminating null character.
constexpr int kDistroSize = 128 + 1;
} // namespace
// We use this static string to hold the Linux distro info. If we
// crash, the crash handler code will send this in the crash dump.
char g_linux_distro[kDistroSize] =
#if defined(OS_CHROMEOS)
#elif defined(OS_ANDROID)
// This function is only supposed to be used in tests. The declaration in the
// header file is guarded by "#if defined(UNIT_TEST)" so that they can be used
// by tests but not non-test code. However, this .cc file is compiled as part
// of "base" where "UNIT_TEST" is not defined. So we need to specify
// "BASE_EXPORT" here again so that they are visible to tests.
BASE_EXPORT std::string GetKeyValueFromOSReleaseFileForTesting(
const std::string& input,
const char* key) {
#if !defined(OS_CHROMEOS)
return GetKeyValueFromOSReleaseFile(input, key);
return "";
#endif // !defined(OS_CHROMEOS)
std::string GetLinuxDistro() {
#if !defined(OS_CHROMEOS)
// We do this check only once per process. If it fails, there's
// little reason to believe it will work if we attempt to run it again.
static NoDestructor<DistroNameGetter> distro_name_getter;
return g_linux_distro;
void SetLinuxDistro(const std::string& distro) {
std::string trimmed_distro;
TrimWhitespaceASCII(distro, TRIM_ALL, &trimmed_distro);
strlcpy(g_linux_distro, trimmed_distro.c_str(), kDistroSize);
bool GetThreadsForProcess(pid_t pid, std::vector<pid_t>* tids) {
// 25 > strlen("/proc//task") + strlen(std::to_string(INT_MAX)) + 1 = 22
char buf[25];
strings::SafeSPrintf(buf, "/proc/%d/task", pid);
DirReaderPosix dir_reader(buf);
if (!dir_reader.IsValid()) {
DLOG(WARNING) << "Cannot open " << buf;
return false;
while (dir_reader.Next()) {
char* endptr;
const unsigned long int tid_ul = strtoul(, &endptr, 10);
if (tid_ul == ULONG_MAX || *endptr)
return true;
pid_t FindThreadIDWithSyscall(pid_t pid, const std::string& expected_data,
bool* syscall_supported) {
if (syscall_supported)
*syscall_supported = false;
std::vector<pid_t> tids;
if (!GetThreadsForProcess(pid, &tids))
return -1;
std::vector<char> syscall_data(expected_data.size());
for (pid_t tid : tids) {
char buf[256];
snprintf(buf, sizeof(buf), "/proc/%d/task/%d/syscall", pid, tid);
ScopedFD fd(open(buf, O_RDONLY));
if (!fd.is_valid())
*syscall_supported = true;
if (!ReadFromFD(fd.get(),, syscall_data.size()))
if (0 == strncmp(expected_data.c_str(),,
expected_data.size())) {
return tid;
return -1;
pid_t FindThreadID(pid_t pid, pid_t ns_tid, bool* ns_pid_supported) {
*ns_pid_supported = false;
std::vector<pid_t> tids;
if (!GetThreadsForProcess(pid, &tids))
return -1;
for (pid_t tid : tids) {
char buf[256];
snprintf(buf, sizeof(buf), "/proc/%d/task/%d/status", pid, tid);
std::string status;
if (!ReadFileToString(FilePath(buf), &status))
return -1;
StringTokenizer tokenizer(status, "\n");
while (tokenizer.GetNext()) {
StringPiece value_str(tokenizer.token_piece());
if (!value_str.starts_with("NSpid"))
*ns_pid_supported = true;
std::vector<StringPiece> split_value_str = SplitStringPiece(
DCHECK_GE(split_value_str.size(), 2u);
int value;
// The last value in the list is the PID in the namespace.
if (StringToInt(split_value_str.back(), &value) && value == ns_tid) {
// The second value in the list is the real PID.
if (StringToInt(split_value_str[1], &value))
return value;
return -1;
} // namespace base