761 lines
24 KiB
C++
761 lines
24 KiB
C++
// 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/process/launch.h"
|
|
|
|
#include <dirent.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <signal.h>
|
|
#include <stdlib.h>
|
|
#include <sys/resource.h>
|
|
#include <sys/time.h>
|
|
#include <sys/types.h>
|
|
#include <sys/wait.h>
|
|
#include <unistd.h>
|
|
|
|
#include <iterator>
|
|
#include <limits>
|
|
#include <set>
|
|
|
|
#include "base/allocator/type_profiler_control.h"
|
|
#include "base/command_line.h"
|
|
#include "base/compiler_specific.h"
|
|
#include "base/debug/debugger.h"
|
|
#include "base/debug/stack_trace.h"
|
|
#include "base/file_util.h"
|
|
#include "base/files/dir_reader_posix.h"
|
|
#include "base/logging.h"
|
|
#include "base/memory/scoped_ptr.h"
|
|
#include "base/posix/eintr_wrapper.h"
|
|
#include "base/process/kill.h"
|
|
#include "base/process/process_metrics.h"
|
|
#include "base/strings/stringprintf.h"
|
|
#include "base/synchronization/waitable_event.h"
|
|
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
|
|
#include "base/threading/platform_thread.h"
|
|
#include "base/threading/thread_restrictions.h"
|
|
|
|
#if defined(OS_CHROMEOS)
|
|
#include <sys/ioctl.h>
|
|
#endif
|
|
|
|
#if defined(OS_FREEBSD)
|
|
#include <sys/event.h>
|
|
#include <sys/ucontext.h>
|
|
#endif
|
|
|
|
#if defined(OS_MACOSX)
|
|
#include <crt_externs.h>
|
|
#include <sys/event.h>
|
|
#else
|
|
extern char** environ;
|
|
#endif
|
|
|
|
namespace base {
|
|
|
|
namespace {
|
|
|
|
// Get the process's "environment" (i.e. the thing that setenv/getenv
|
|
// work with).
|
|
char** GetEnvironment() {
|
|
#if defined(OS_MACOSX)
|
|
return *_NSGetEnviron();
|
|
#else
|
|
return environ;
|
|
#endif
|
|
}
|
|
|
|
// Set the process's "environment" (i.e. the thing that setenv/getenv
|
|
// work with).
|
|
void SetEnvironment(char** env) {
|
|
#if defined(OS_MACOSX)
|
|
*_NSGetEnviron() = env;
|
|
#else
|
|
environ = env;
|
|
#endif
|
|
}
|
|
|
|
// Set the calling thread's signal mask to new_sigmask and return
|
|
// the previous signal mask.
|
|
sigset_t SetSignalMask(const sigset_t& new_sigmask) {
|
|
sigset_t old_sigmask;
|
|
#if defined(OS_ANDROID)
|
|
// POSIX says pthread_sigmask() must be used in multi-threaded processes,
|
|
// but Android's pthread_sigmask() was broken until 4.1:
|
|
// https://code.google.com/p/android/issues/detail?id=15337
|
|
// http://stackoverflow.com/questions/13777109/pthread-sigmask-on-android-not-working
|
|
RAW_CHECK(sigprocmask(SIG_SETMASK, &new_sigmask, &old_sigmask) == 0);
|
|
#else
|
|
RAW_CHECK(pthread_sigmask(SIG_SETMASK, &new_sigmask, &old_sigmask) == 0);
|
|
#endif
|
|
return old_sigmask;
|
|
}
|
|
|
|
#if !defined(OS_LINUX) || \
|
|
(!defined(__i386__) && !defined(__x86_64__) && !defined(__arm__))
|
|
void ResetChildSignalHandlersToDefaults() {
|
|
// The previous signal handlers are likely to be meaningless in the child's
|
|
// context so we reset them to the defaults for now. http://crbug.com/44953
|
|
// These signal handlers are set up at least in browser_main_posix.cc:
|
|
// BrowserMainPartsPosix::PreEarlyInitialization and stack_trace_posix.cc:
|
|
// EnableInProcessStackDumping.
|
|
signal(SIGHUP, SIG_DFL);
|
|
signal(SIGINT, SIG_DFL);
|
|
signal(SIGILL, SIG_DFL);
|
|
signal(SIGABRT, SIG_DFL);
|
|
signal(SIGFPE, SIG_DFL);
|
|
signal(SIGBUS, SIG_DFL);
|
|
signal(SIGSEGV, SIG_DFL);
|
|
signal(SIGSYS, SIG_DFL);
|
|
signal(SIGTERM, SIG_DFL);
|
|
}
|
|
|
|
#else
|
|
|
|
// TODO(jln): remove the Linux special case once kernels are fixed.
|
|
|
|
// Internally the kernel makes sigset_t an array of long large enough to have
|
|
// one bit per signal.
|
|
typedef uint64_t kernel_sigset_t;
|
|
|
|
// This is what struct sigaction looks like to the kernel at least on X86 and
|
|
// ARM. MIPS, for instance, is very different.
|
|
struct kernel_sigaction {
|
|
void* k_sa_handler; // For this usage it only needs to be a generic pointer.
|
|
unsigned long k_sa_flags;
|
|
void* k_sa_restorer; // For this usage it only needs to be a generic pointer.
|
|
kernel_sigset_t k_sa_mask;
|
|
};
|
|
|
|
// glibc's sigaction() will prevent access to sa_restorer, so we need to roll
|
|
// our own.
|
|
int sys_rt_sigaction(int sig, const struct kernel_sigaction* act,
|
|
struct kernel_sigaction* oact) {
|
|
return syscall(SYS_rt_sigaction, sig, act, oact, sizeof(kernel_sigset_t));
|
|
}
|
|
|
|
// This function is intended to be used in between fork() and execve() and will
|
|
// reset all signal handlers to the default.
|
|
// The motivation for going through all of them is that sa_restorer can leak
|
|
// from parents and help defeat ASLR on buggy kernels. We reset it to NULL.
|
|
// See crbug.com/177956.
|
|
void ResetChildSignalHandlersToDefaults(void) {
|
|
for (int signum = 1; ; ++signum) {
|
|
struct kernel_sigaction act = {0};
|
|
int sigaction_get_ret = sys_rt_sigaction(signum, NULL, &act);
|
|
if (sigaction_get_ret && errno == EINVAL) {
|
|
#if !defined(NDEBUG)
|
|
// Linux supports 32 real-time signals from 33 to 64.
|
|
// If the number of signals in the Linux kernel changes, someone should
|
|
// look at this code.
|
|
const int kNumberOfSignals = 64;
|
|
RAW_CHECK(signum == kNumberOfSignals + 1);
|
|
#endif // !defined(NDEBUG)
|
|
break;
|
|
}
|
|
// All other failures are fatal.
|
|
if (sigaction_get_ret) {
|
|
RAW_LOG(FATAL, "sigaction (get) failed.");
|
|
}
|
|
|
|
// The kernel won't allow to re-set SIGKILL or SIGSTOP.
|
|
if (signum != SIGSTOP && signum != SIGKILL) {
|
|
act.k_sa_handler = reinterpret_cast<void*>(SIG_DFL);
|
|
act.k_sa_restorer = NULL;
|
|
if (sys_rt_sigaction(signum, &act, NULL)) {
|
|
RAW_LOG(FATAL, "sigaction (set) failed.");
|
|
}
|
|
}
|
|
#if !defined(NDEBUG)
|
|
// Now ask the kernel again and check that no restorer will leak.
|
|
if (sys_rt_sigaction(signum, NULL, &act) || act.k_sa_restorer) {
|
|
RAW_LOG(FATAL, "Cound not fix sa_restorer.");
|
|
}
|
|
#endif // !defined(NDEBUG)
|
|
}
|
|
}
|
|
#endif // !defined(OS_LINUX) ||
|
|
// (!defined(__i386__) && !defined(__x86_64__) && !defined(__arm__))
|
|
|
|
} // anonymous namespace
|
|
|
|
// A class to handle auto-closing of DIR*'s.
|
|
class ScopedDIRClose {
|
|
public:
|
|
inline void operator()(DIR* x) const {
|
|
if (x) {
|
|
closedir(x);
|
|
}
|
|
}
|
|
};
|
|
typedef scoped_ptr_malloc<DIR, ScopedDIRClose> ScopedDIR;
|
|
|
|
#if defined(OS_LINUX)
|
|
static const char kFDDir[] = "/proc/self/fd";
|
|
#elif defined(OS_MACOSX)
|
|
static const char kFDDir[] = "/dev/fd";
|
|
#elif defined(OS_SOLARIS)
|
|
static const char kFDDir[] = "/dev/fd";
|
|
#elif defined(OS_FREEBSD)
|
|
static const char kFDDir[] = "/dev/fd";
|
|
#elif defined(OS_OPENBSD)
|
|
static const char kFDDir[] = "/dev/fd";
|
|
#elif defined(OS_ANDROID)
|
|
static const char kFDDir[] = "/proc/self/fd";
|
|
#endif
|
|
|
|
void CloseSuperfluousFds(const base::InjectiveMultimap& saved_mapping) {
|
|
// DANGER: no calls to malloc are allowed from now on:
|
|
// http://crbug.com/36678
|
|
|
|
// Get the maximum number of FDs possible.
|
|
size_t max_fds = GetMaxFds();
|
|
|
|
DirReaderPosix fd_dir(kFDDir);
|
|
if (!fd_dir.IsValid()) {
|
|
// Fallback case: Try every possible fd.
|
|
for (size_t i = 0; i < max_fds; ++i) {
|
|
const int fd = static_cast<int>(i);
|
|
if (fd == STDIN_FILENO || fd == STDOUT_FILENO || fd == STDERR_FILENO)
|
|
continue;
|
|
InjectiveMultimap::const_iterator j;
|
|
for (j = saved_mapping.begin(); j != saved_mapping.end(); j++) {
|
|
if (fd == j->dest)
|
|
break;
|
|
}
|
|
if (j != saved_mapping.end())
|
|
continue;
|
|
|
|
// Since we're just trying to close anything we can find,
|
|
// ignore any error return values of close().
|
|
ignore_result(HANDLE_EINTR(close(fd)));
|
|
}
|
|
return;
|
|
}
|
|
|
|
const int dir_fd = fd_dir.fd();
|
|
|
|
for ( ; fd_dir.Next(); ) {
|
|
// Skip . and .. entries.
|
|
if (fd_dir.name()[0] == '.')
|
|
continue;
|
|
|
|
char *endptr;
|
|
errno = 0;
|
|
const long int fd = strtol(fd_dir.name(), &endptr, 10);
|
|
if (fd_dir.name()[0] == 0 || *endptr || fd < 0 || errno)
|
|
continue;
|
|
if (fd == STDIN_FILENO || fd == STDOUT_FILENO || fd == STDERR_FILENO)
|
|
continue;
|
|
InjectiveMultimap::const_iterator i;
|
|
for (i = saved_mapping.begin(); i != saved_mapping.end(); i++) {
|
|
if (fd == i->dest)
|
|
break;
|
|
}
|
|
if (i != saved_mapping.end())
|
|
continue;
|
|
if (fd == dir_fd)
|
|
continue;
|
|
|
|
// When running under Valgrind, Valgrind opens several FDs for its
|
|
// own use and will complain if we try to close them. All of
|
|
// these FDs are >= |max_fds|, so we can check against that here
|
|
// before closing. See https://bugs.kde.org/show_bug.cgi?id=191758
|
|
if (fd < static_cast<int>(max_fds)) {
|
|
int ret = HANDLE_EINTR(close(fd));
|
|
DPCHECK(ret == 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
char** AlterEnvironment(const EnvironmentVector& changes,
|
|
const char* const* const env) {
|
|
unsigned count = 0;
|
|
unsigned size = 0;
|
|
|
|
// First assume that all of the current environment will be included.
|
|
for (unsigned i = 0; env[i]; i++) {
|
|
const char *const pair = env[i];
|
|
count++;
|
|
size += strlen(pair) + 1 /* terminating NUL */;
|
|
}
|
|
|
|
for (EnvironmentVector::const_iterator j = changes.begin();
|
|
j != changes.end();
|
|
++j) {
|
|
bool found = false;
|
|
const char *pair;
|
|
|
|
for (unsigned i = 0; env[i]; i++) {
|
|
pair = env[i];
|
|
const char *const equals = strchr(pair, '=');
|
|
if (!equals)
|
|
continue;
|
|
const unsigned keylen = equals - pair;
|
|
if (keylen == j->first.size() &&
|
|
memcmp(pair, j->first.data(), keylen) == 0) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// if found, we'll either be deleting or replacing this element.
|
|
if (found) {
|
|
count--;
|
|
size -= strlen(pair) + 1;
|
|
if (j->second.size())
|
|
found = false;
|
|
}
|
|
|
|
// if !found, then we have a new element to add.
|
|
if (!found && !j->second.empty()) {
|
|
count++;
|
|
size += j->first.size() + 1 /* '=' */ + j->second.size() + 1 /* NUL */;
|
|
}
|
|
}
|
|
|
|
count++; // for the final NULL
|
|
uint8_t *buffer = new uint8_t[sizeof(char*) * count + size];
|
|
char **const ret = reinterpret_cast<char**>(buffer);
|
|
unsigned k = 0;
|
|
char *scratch = reinterpret_cast<char*>(buffer + sizeof(char*) * count);
|
|
|
|
for (unsigned i = 0; env[i]; i++) {
|
|
const char *const pair = env[i];
|
|
const char *const equals = strchr(pair, '=');
|
|
if (!equals) {
|
|
const unsigned len = strlen(pair);
|
|
ret[k++] = scratch;
|
|
memcpy(scratch, pair, len + 1);
|
|
scratch += len + 1;
|
|
continue;
|
|
}
|
|
const unsigned keylen = equals - pair;
|
|
bool handled = false;
|
|
for (EnvironmentVector::const_iterator
|
|
j = changes.begin(); j != changes.end(); j++) {
|
|
if (j->first.size() == keylen &&
|
|
memcmp(j->first.data(), pair, keylen) == 0) {
|
|
if (!j->second.empty()) {
|
|
ret[k++] = scratch;
|
|
memcpy(scratch, pair, keylen + 1);
|
|
scratch += keylen + 1;
|
|
memcpy(scratch, j->second.c_str(), j->second.size() + 1);
|
|
scratch += j->second.size() + 1;
|
|
}
|
|
handled = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!handled) {
|
|
const unsigned len = strlen(pair);
|
|
ret[k++] = scratch;
|
|
memcpy(scratch, pair, len + 1);
|
|
scratch += len + 1;
|
|
}
|
|
}
|
|
|
|
// Now handle new elements
|
|
for (EnvironmentVector::const_iterator
|
|
j = changes.begin(); j != changes.end(); j++) {
|
|
if (j->second.empty())
|
|
continue;
|
|
|
|
bool found = false;
|
|
for (unsigned i = 0; env[i]; i++) {
|
|
const char *const pair = env[i];
|
|
const char *const equals = strchr(pair, '=');
|
|
if (!equals)
|
|
continue;
|
|
const unsigned keylen = equals - pair;
|
|
if (keylen == j->first.size() &&
|
|
memcmp(pair, j->first.data(), keylen) == 0) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
ret[k++] = scratch;
|
|
memcpy(scratch, j->first.data(), j->first.size());
|
|
scratch += j->first.size();
|
|
*scratch++ = '=';
|
|
memcpy(scratch, j->second.c_str(), j->second.size() + 1);
|
|
scratch += j->second.size() + 1;
|
|
}
|
|
}
|
|
|
|
ret[k] = NULL;
|
|
return ret;
|
|
}
|
|
|
|
bool LaunchProcess(const std::vector<std::string>& argv,
|
|
const LaunchOptions& options,
|
|
ProcessHandle* process_handle) {
|
|
size_t fd_shuffle_size = 0;
|
|
if (options.fds_to_remap) {
|
|
fd_shuffle_size = options.fds_to_remap->size();
|
|
}
|
|
|
|
InjectiveMultimap fd_shuffle1;
|
|
InjectiveMultimap fd_shuffle2;
|
|
fd_shuffle1.reserve(fd_shuffle_size);
|
|
fd_shuffle2.reserve(fd_shuffle_size);
|
|
|
|
scoped_ptr<char*[]> argv_cstr(new char*[argv.size() + 1]);
|
|
scoped_ptr<char*[]> new_environ;
|
|
if (options.environ)
|
|
new_environ.reset(AlterEnvironment(*options.environ, GetEnvironment()));
|
|
|
|
sigset_t full_sigset;
|
|
sigfillset(&full_sigset);
|
|
const sigset_t orig_sigmask = SetSignalMask(full_sigset);
|
|
|
|
pid_t pid;
|
|
#if defined(OS_LINUX)
|
|
if (options.clone_flags) {
|
|
// Signal handling in this function assumes the creation of a new
|
|
// process, so we check that a thread is not being created by mistake
|
|
// and that signal handling follows the process-creation rules.
|
|
RAW_CHECK(
|
|
!(options.clone_flags & (CLONE_SIGHAND | CLONE_THREAD | CLONE_VM)));
|
|
pid = syscall(__NR_clone, options.clone_flags, 0, 0, 0);
|
|
} else
|
|
#endif
|
|
{
|
|
pid = fork();
|
|
}
|
|
|
|
// Always restore the original signal mask in the parent.
|
|
if (pid != 0) {
|
|
SetSignalMask(orig_sigmask);
|
|
}
|
|
|
|
if (pid < 0) {
|
|
DPLOG(ERROR) << "fork";
|
|
return false;
|
|
} else if (pid == 0) {
|
|
// Child process
|
|
|
|
// DANGER: fork() rule: in the child, if you don't end up doing exec*(),
|
|
// you call _exit() instead of exit(). This is because _exit() does not
|
|
// call any previously-registered (in the parent) exit handlers, which
|
|
// might do things like block waiting for threads that don't even exist
|
|
// in the child.
|
|
|
|
// If a child process uses the readline library, the process block forever.
|
|
// In BSD like OSes including OS X it is safe to assign /dev/null as stdin.
|
|
// See http://crbug.com/56596.
|
|
int null_fd = HANDLE_EINTR(open("/dev/null", O_RDONLY));
|
|
if (null_fd < 0) {
|
|
RAW_LOG(ERROR, "Failed to open /dev/null");
|
|
_exit(127);
|
|
}
|
|
|
|
file_util::ScopedFD null_fd_closer(&null_fd);
|
|
int new_fd = HANDLE_EINTR(dup2(null_fd, STDIN_FILENO));
|
|
if (new_fd != STDIN_FILENO) {
|
|
RAW_LOG(ERROR, "Failed to dup /dev/null for stdin");
|
|
_exit(127);
|
|
}
|
|
|
|
if (options.new_process_group) {
|
|
// Instead of inheriting the process group ID of the parent, the child
|
|
// starts off a new process group with pgid equal to its process ID.
|
|
if (setpgid(0, 0) < 0) {
|
|
RAW_LOG(ERROR, "setpgid failed");
|
|
_exit(127);
|
|
}
|
|
}
|
|
|
|
// Stop type-profiler.
|
|
// The profiler should be stopped between fork and exec since it inserts
|
|
// locks at new/delete expressions. See http://crbug.com/36678.
|
|
base::type_profiler::Controller::Stop();
|
|
|
|
if (options.maximize_rlimits) {
|
|
// Some resource limits need to be maximal in this child.
|
|
std::set<int>::const_iterator resource;
|
|
for (resource = options.maximize_rlimits->begin();
|
|
resource != options.maximize_rlimits->end();
|
|
++resource) {
|
|
struct rlimit limit;
|
|
if (getrlimit(*resource, &limit) < 0) {
|
|
RAW_LOG(WARNING, "getrlimit failed");
|
|
} else if (limit.rlim_cur < limit.rlim_max) {
|
|
limit.rlim_cur = limit.rlim_max;
|
|
if (setrlimit(*resource, &limit) < 0) {
|
|
RAW_LOG(WARNING, "setrlimit failed");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if defined(OS_MACOSX)
|
|
RestoreDefaultExceptionHandler();
|
|
#endif // defined(OS_MACOSX)
|
|
|
|
ResetChildSignalHandlersToDefaults();
|
|
SetSignalMask(orig_sigmask);
|
|
|
|
#if 0
|
|
// When debugging it can be helpful to check that we really aren't making
|
|
// any hidden calls to malloc.
|
|
void *malloc_thunk =
|
|
reinterpret_cast<void*>(reinterpret_cast<intptr_t>(malloc) & ~4095);
|
|
mprotect(malloc_thunk, 4096, PROT_READ | PROT_WRITE | PROT_EXEC);
|
|
memset(reinterpret_cast<void*>(malloc), 0xff, 8);
|
|
#endif // 0
|
|
|
|
// DANGER: no calls to malloc are allowed from now on:
|
|
// http://crbug.com/36678
|
|
|
|
#if defined(OS_CHROMEOS)
|
|
if (options.ctrl_terminal_fd >= 0) {
|
|
// Set process' controlling terminal.
|
|
if (HANDLE_EINTR(setsid()) != -1) {
|
|
if (HANDLE_EINTR(
|
|
ioctl(options.ctrl_terminal_fd, TIOCSCTTY, NULL)) == -1) {
|
|
RAW_LOG(WARNING, "ioctl(TIOCSCTTY), ctrl terminal not set");
|
|
}
|
|
} else {
|
|
RAW_LOG(WARNING, "setsid failed, ctrl terminal not set");
|
|
}
|
|
}
|
|
#endif // defined(OS_CHROMEOS)
|
|
|
|
if (options.fds_to_remap) {
|
|
for (FileHandleMappingVector::const_iterator
|
|
it = options.fds_to_remap->begin();
|
|
it != options.fds_to_remap->end(); ++it) {
|
|
fd_shuffle1.push_back(InjectionArc(it->first, it->second, false));
|
|
fd_shuffle2.push_back(InjectionArc(it->first, it->second, false));
|
|
}
|
|
}
|
|
|
|
if (options.environ)
|
|
SetEnvironment(new_environ.get());
|
|
|
|
// fd_shuffle1 is mutated by this call because it cannot malloc.
|
|
if (!ShuffleFileDescriptors(&fd_shuffle1))
|
|
_exit(127);
|
|
|
|
CloseSuperfluousFds(fd_shuffle2);
|
|
|
|
for (size_t i = 0; i < argv.size(); i++)
|
|
argv_cstr[i] = const_cast<char*>(argv[i].c_str());
|
|
argv_cstr[argv.size()] = NULL;
|
|
execvp(argv_cstr[0], argv_cstr.get());
|
|
|
|
RAW_LOG(ERROR, "LaunchProcess: failed to execvp:");
|
|
RAW_LOG(ERROR, argv_cstr[0]);
|
|
_exit(127);
|
|
} else {
|
|
// Parent process
|
|
if (options.wait) {
|
|
// While this isn't strictly disk IO, waiting for another process to
|
|
// finish is the sort of thing ThreadRestrictions is trying to prevent.
|
|
base::ThreadRestrictions::AssertIOAllowed();
|
|
pid_t ret = HANDLE_EINTR(waitpid(pid, 0, 0));
|
|
DPCHECK(ret > 0);
|
|
}
|
|
|
|
if (process_handle)
|
|
*process_handle = pid;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
bool LaunchProcess(const CommandLine& cmdline,
|
|
const LaunchOptions& options,
|
|
ProcessHandle* process_handle) {
|
|
return LaunchProcess(cmdline.argv(), options, process_handle);
|
|
}
|
|
|
|
void RaiseProcessToHighPriority() {
|
|
// On POSIX, we don't actually do anything here. We could try to nice() or
|
|
// setpriority() or sched_getscheduler, but these all require extra rights.
|
|
}
|
|
|
|
// Return value used by GetAppOutputInternal to encapsulate the various exit
|
|
// scenarios from the function.
|
|
enum GetAppOutputInternalResult {
|
|
EXECUTE_FAILURE,
|
|
EXECUTE_SUCCESS,
|
|
GOT_MAX_OUTPUT,
|
|
};
|
|
|
|
// Executes the application specified by |argv| and wait for it to exit. Stores
|
|
// the output (stdout) in |output|. If |do_search_path| is set, it searches the
|
|
// path for the application; in that case, |envp| must be null, and it will use
|
|
// the current environment. If |do_search_path| is false, |argv[0]| should fully
|
|
// specify the path of the application, and |envp| will be used as the
|
|
// environment. Redirects stderr to /dev/null.
|
|
// If we successfully start the application and get all requested output, we
|
|
// return GOT_MAX_OUTPUT, or if there is a problem starting or exiting
|
|
// the application we return RUN_FAILURE. Otherwise we return EXECUTE_SUCCESS.
|
|
// The GOT_MAX_OUTPUT return value exists so a caller that asks for limited
|
|
// output can treat this as a success, despite having an exit code of SIG_PIPE
|
|
// due to us closing the output pipe.
|
|
// In the case of EXECUTE_SUCCESS, the application exit code will be returned
|
|
// in |*exit_code|, which should be checked to determine if the application
|
|
// ran successfully.
|
|
static GetAppOutputInternalResult GetAppOutputInternal(
|
|
const std::vector<std::string>& argv,
|
|
char* const envp[],
|
|
std::string* output,
|
|
size_t max_output,
|
|
bool do_search_path,
|
|
int* exit_code) {
|
|
// Doing a blocking wait for another command to finish counts as IO.
|
|
base::ThreadRestrictions::AssertIOAllowed();
|
|
// exit_code must be supplied so calling function can determine success.
|
|
DCHECK(exit_code);
|
|
*exit_code = EXIT_FAILURE;
|
|
|
|
int pipe_fd[2];
|
|
pid_t pid;
|
|
InjectiveMultimap fd_shuffle1, fd_shuffle2;
|
|
scoped_ptr<char*[]> argv_cstr(new char*[argv.size() + 1]);
|
|
|
|
fd_shuffle1.reserve(3);
|
|
fd_shuffle2.reserve(3);
|
|
|
|
// Either |do_search_path| should be false or |envp| should be null, but not
|
|
// both.
|
|
DCHECK(!do_search_path ^ !envp);
|
|
|
|
if (pipe(pipe_fd) < 0)
|
|
return EXECUTE_FAILURE;
|
|
|
|
switch (pid = fork()) {
|
|
case -1: // error
|
|
close(pipe_fd[0]);
|
|
close(pipe_fd[1]);
|
|
return EXECUTE_FAILURE;
|
|
case 0: // child
|
|
{
|
|
#if defined(OS_MACOSX)
|
|
RestoreDefaultExceptionHandler();
|
|
#endif
|
|
// DANGER: no calls to malloc are allowed from now on:
|
|
// http://crbug.com/36678
|
|
|
|
// Obscure fork() rule: in the child, if you don't end up doing exec*(),
|
|
// you call _exit() instead of exit(). This is because _exit() does not
|
|
// call any previously-registered (in the parent) exit handlers, which
|
|
// might do things like block waiting for threads that don't even exist
|
|
// in the child.
|
|
int dev_null = open("/dev/null", O_WRONLY);
|
|
if (dev_null < 0)
|
|
_exit(127);
|
|
|
|
// Stop type-profiler.
|
|
// The profiler should be stopped between fork and exec since it inserts
|
|
// locks at new/delete expressions. See http://crbug.com/36678.
|
|
base::type_profiler::Controller::Stop();
|
|
|
|
fd_shuffle1.push_back(InjectionArc(pipe_fd[1], STDOUT_FILENO, true));
|
|
fd_shuffle1.push_back(InjectionArc(dev_null, STDERR_FILENO, true));
|
|
fd_shuffle1.push_back(InjectionArc(dev_null, STDIN_FILENO, true));
|
|
// Adding another element here? Remeber to increase the argument to
|
|
// reserve(), above.
|
|
|
|
std::copy(fd_shuffle1.begin(), fd_shuffle1.end(),
|
|
std::back_inserter(fd_shuffle2));
|
|
|
|
if (!ShuffleFileDescriptors(&fd_shuffle1))
|
|
_exit(127);
|
|
|
|
CloseSuperfluousFds(fd_shuffle2);
|
|
|
|
for (size_t i = 0; i < argv.size(); i++)
|
|
argv_cstr[i] = const_cast<char*>(argv[i].c_str());
|
|
argv_cstr[argv.size()] = NULL;
|
|
if (do_search_path)
|
|
execvp(argv_cstr[0], argv_cstr.get());
|
|
else
|
|
execve(argv_cstr[0], argv_cstr.get(), envp);
|
|
_exit(127);
|
|
}
|
|
default: // parent
|
|
{
|
|
// Close our writing end of pipe now. Otherwise later read would not
|
|
// be able to detect end of child's output (in theory we could still
|
|
// write to the pipe).
|
|
close(pipe_fd[1]);
|
|
|
|
output->clear();
|
|
char buffer[256];
|
|
size_t output_buf_left = max_output;
|
|
ssize_t bytes_read = 1; // A lie to properly handle |max_output == 0|
|
|
// case in the logic below.
|
|
|
|
while (output_buf_left > 0) {
|
|
bytes_read = HANDLE_EINTR(read(pipe_fd[0], buffer,
|
|
std::min(output_buf_left, sizeof(buffer))));
|
|
if (bytes_read <= 0)
|
|
break;
|
|
output->append(buffer, bytes_read);
|
|
output_buf_left -= static_cast<size_t>(bytes_read);
|
|
}
|
|
close(pipe_fd[0]);
|
|
|
|
// Always wait for exit code (even if we know we'll declare
|
|
// GOT_MAX_OUTPUT).
|
|
bool success = WaitForExitCode(pid, exit_code);
|
|
|
|
// If we stopped because we read as much as we wanted, we return
|
|
// GOT_MAX_OUTPUT (because the child may exit due to |SIGPIPE|).
|
|
if (!output_buf_left && bytes_read > 0)
|
|
return GOT_MAX_OUTPUT;
|
|
else if (success)
|
|
return EXECUTE_SUCCESS;
|
|
return EXECUTE_FAILURE;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool GetAppOutput(const CommandLine& cl, std::string* output) {
|
|
return GetAppOutput(cl.argv(), output);
|
|
}
|
|
|
|
bool GetAppOutput(const std::vector<std::string>& argv, std::string* output) {
|
|
// Run |execve()| with the current environment and store "unlimited" data.
|
|
int exit_code;
|
|
GetAppOutputInternalResult result = GetAppOutputInternal(
|
|
argv, NULL, output, std::numeric_limits<std::size_t>::max(), true,
|
|
&exit_code);
|
|
return result == EXECUTE_SUCCESS && exit_code == EXIT_SUCCESS;
|
|
}
|
|
|
|
// TODO(viettrungluu): Conceivably, we should have a timeout as well, so we
|
|
// don't hang if what we're calling hangs.
|
|
bool GetAppOutputRestricted(const CommandLine& cl,
|
|
std::string* output, size_t max_output) {
|
|
// Run |execve()| with the empty environment.
|
|
char* const empty_environ = NULL;
|
|
int exit_code;
|
|
GetAppOutputInternalResult result = GetAppOutputInternal(
|
|
cl.argv(), &empty_environ, output, max_output, false, &exit_code);
|
|
return result == GOT_MAX_OUTPUT || (result == EXECUTE_SUCCESS &&
|
|
exit_code == EXIT_SUCCESS);
|
|
}
|
|
|
|
bool GetAppOutputWithExitCode(const CommandLine& cl,
|
|
std::string* output,
|
|
int* exit_code) {
|
|
// Run |execve()| with the current environment and store "unlimited" data.
|
|
GetAppOutputInternalResult result = GetAppOutputInternal(
|
|
cl.argv(), NULL, output, std::numeric_limits<std::size_t>::max(), true,
|
|
exit_code);
|
|
return result == EXECUTE_SUCCESS;
|
|
}
|
|
|
|
} // namespace base
|