Index: base/process_util_posix.cc |
diff --git a/base/process_util_posix.cc b/base/process_util_posix.cc |
index ecb49371e3de32a942706f198c74760ecf8b05ad..d81776f189499cd4ddabe58779be5b87f0838dce 100644 |
--- a/base/process_util_posix.cc |
+++ b/base/process_util_posix.cc |
@@ -224,25 +224,40 @@ bool LaunchApp(const std::vector<std::string>& argv, |
const environment_vector& environ, |
const file_handle_mapping_vector& fds_to_remap, |
bool wait, ProcessHandle* process_handle) { |
- pid_t pid = fork(); |
+ // We call vfork() for additional performance (avoids touching the page |
+ // tables). This makes things a bit more dangerous since the child and |
+ // parent share the same address space and stack. Try to do most of our |
+ // operations before the fork, and hope that everything we do have to do |
+ // will be ok... |
+ bool use_vfork = (environ.size() == 0); |
agl
2009/08/20 20:35:16
const
agl
2009/08/20 20:35:16
Comment about why we can't modify the environment
|
+ |
+ InjectiveMultimap fd_shuffle; |
+ for (file_handle_mapping_vector::const_iterator |
+ it = fds_to_remap.begin(); it != fds_to_remap.end(); ++it) { |
+ fd_shuffle.push_back(InjectionArc(it->first, it->second, false)); |
+ } |
+ |
+ scoped_array<char*> argv_cstr(new char*[argv.size() + 1]); |
+ for (size_t i = 0; i < argv.size(); i++) |
+ argv_cstr[i] = const_cast<char*>(argv[i].c_str()); |
+ argv_cstr[argv.size()] = NULL; |
+ |
+ pid_t pid = use_vfork ? vfork() : fork(); |
if (pid < 0) |
return false; |
if (pid == 0) { |
// Child process |
- InjectiveMultimap fd_shuffle; |
- for (file_handle_mapping_vector::const_iterator |
- it = fds_to_remap.begin(); it != fds_to_remap.end(); ++it) { |
- fd_shuffle.push_back(InjectionArc(it->first, it->second, false)); |
- } |
- for (environment_vector::const_iterator it = environ.begin(); |
- it != environ.end(); ++it) { |
- if (it->first) { |
- if (it->second) { |
- setenv(it->first, it->second, 1); |
- } else { |
- unsetenv(it->first); |
+ if (!use_vfork) { |
+ for (environment_vector::const_iterator it = environ.begin(); |
+ it != environ.end(); ++it) { |
+ if (it->first) { |
+ if (it->second) { |
+ setenv(it->first, it->second, 1); |
+ } else { |
+ unsetenv(it->first); |
+ } |
} |
} |
} |
@@ -255,17 +270,8 @@ bool LaunchApp(const std::vector<std::string>& argv, |
if (!ShuffleFileDescriptors(fd_shuffle)) |
_exit(127); |
- // If we are using the SUID sandbox, it sets a magic environment variable |
- // ("SBX_D"), so we remove that variable from the environment here on the |
- // off chance that it's already set. |
- unsetenv("SBX_D"); |
- |
CloseSuperfluousFds(fd_shuffle); |
- scoped_array<char*> argv_cstr(new char*[argv.size() + 1]); |
- 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()); |
LOG(ERROR) << "LaunchApp: exec failed!, argv_cstr[0] " << argv_cstr[0] |
<< ", errno " << errno; |