diff options
| -rw-r--r-- | content/browser/zygote_main_linux.cc | 65 |
1 files changed, 34 insertions, 31 deletions
diff --git a/content/browser/zygote_main_linux.cc b/content/browser/zygote_main_linux.cc index 1f38c30..eca8d68 100644 --- a/content/browser/zygote_main_linux.cc +++ b/content/browser/zygote_main_linux.cc @@ -377,52 +377,54 @@ class Zygote { return -1; } - // Handle a 'fork' request from the browser: this means that the browser - // wishes to start a new renderer. - bool HandleForkRequest(int fd, const Pickle& pickle, - void* iter, std::vector<int>& fds) { + // Unpacks process type and arguments from |pickle| and forks a new process. + // Returns -1 on error, otherwise returns twice, returning 0 to the child + // process and the child process ID to the parent process, like fork(). + base::ProcessId ReadArgsAndFork(const Pickle& pickle, + void* iter, + std::vector<int>& fds) { std::vector<std::string> args; - int argc, numfds; + int argc = 0; + int numfds = 0; base::GlobalDescriptors::Mapping mapping; - base::ProcessId child; std::string process_type; std::string channel_id; const std::string channel_id_prefix = std::string("--") + switches::kProcessChannelID + std::string("="); if (!pickle.ReadString(&iter, &process_type)) - goto error; - + return -1; if (!pickle.ReadInt(&iter, &argc)) - goto error; + return -1; for (int i = 0; i < argc; ++i) { std::string arg; if (!pickle.ReadString(&iter, &arg)) - goto error; + return -1; args.push_back(arg); if (arg.compare(0, channel_id_prefix.length(), channel_id_prefix) == 0) channel_id = arg; } if (!pickle.ReadInt(&iter, &numfds)) - goto error; + return -1; if (numfds != static_cast<int>(fds.size())) - goto error; + return -1; for (int i = 0; i < numfds; ++i) { base::GlobalDescriptors::Key key; if (!pickle.ReadUInt32(&iter, &key)) - goto error; + return -1; mapping.push_back(std::make_pair(key, fds[i])); } mapping.push_back(std::make_pair( static_cast<uint32_t>(kSandboxIPCChannel), kMagicSandboxIPCDescriptor)); - child = ForkWithRealPid(process_type, fds, channel_id); - - if (!child) { + // Returns twice, once per process. + base::ProcessId child_pid = ForkWithRealPid(process_type, fds, channel_id); + if (!child_pid) { + // This is the child process. #if defined(SECCOMP_SANDBOX) if (SeccompSandboxEnabled() && g_proc_fd >= 0) { // Try to open /proc/self/maps as the seccomp sandbox needs access to it @@ -455,28 +457,29 @@ class Zygote { // SetProcessTitleFromCommandLine in ChromeMain, so we can pass NULL here // (we don't have the original argv at this point). SetProcessTitleFromCommandLine(NULL); - - // The fork() request is handled further up the call stack. - return true; - } else if (child < 0) { - LOG(ERROR) << "Zygote could not fork: " << errno; - goto error; + } else if (child_pid < 0) { + LOG(ERROR) << "Zygote could not fork: process_type " << process_type + << " numfds " << numfds << " child_pid " << child_pid; } + return child_pid; + } + // Handle a 'fork' request from the browser: this means that the browser + // wishes to start a new renderer. Returns true if we are in a new process, + // otherwise writes the child_pid back to the browser via |fd|. Writes a + // child_pid of -1 on error. + bool HandleForkRequest(int fd, const Pickle& pickle, + void* iter, std::vector<int>& fds) { + base::ProcessId child_pid = ReadArgsAndFork(pickle, iter, fds); + if (child_pid == 0) + return true; for (std::vector<int>::const_iterator i = fds.begin(); i != fds.end(); ++i) close(*i); - - if (HANDLE_EINTR(write(fd, &child, sizeof(child))) < 0) + // Must always send reply, as ZygoteHost blocks while waiting for it. + if (HANDLE_EINTR(write(fd, &child_pid, sizeof(child_pid))) < 0) PLOG(ERROR) << "write"; return false; - - error: - LOG(ERROR) << "Error parsing fork request from browser"; - for (std::vector<int>::const_iterator - i = fds.begin(); i != fds.end(); ++i) - close(*i); - return false; } bool HandleGetSandboxStatus(int fd, const Pickle& pickle, void* iter) { |