diff options
Diffstat (limited to 'runtime/exec_utils.cc')
-rw-r--r-- | runtime/exec_utils.cc | 124 |
1 files changed, 100 insertions, 24 deletions
diff --git a/runtime/exec_utils.cc b/runtime/exec_utils.cc index db1baa76f9..463d4580cf 100644 --- a/runtime/exec_utils.cc +++ b/runtime/exec_utils.cc @@ -30,18 +30,22 @@ namespace art { using android::base::StringPrintf; -int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_msg) { - const std::string command_line(android::base::Join(arg_vector, ' ')); - CHECK_GE(arg_vector.size(), 1U) << command_line; +namespace { + +std::string ToCommandLine(const std::vector<std::string>& args) { + return android::base::Join(args, ' '); +} +// Fork and execute a command specified in a subprocess. +// If there is a runtime (Runtime::Current != nullptr) then the subprocess is created with the +// same environment that existed when the runtime was started. +// Returns the process id of the child process on success, -1 otherwise. +pid_t ExecWithoutWait(std::vector<std::string>& arg_vector) { // Convert the args to char pointers. const char* program = arg_vector[0].c_str(); std::vector<char*> args; - for (size_t i = 0; i < arg_vector.size(); ++i) { - const std::string& arg = arg_vector[i]; - char* arg_str = const_cast<char*>(arg.c_str()); - CHECK(arg_str != nullptr) << i; - args.push_back(arg_str); + for (const auto& arg : arg_vector) { + args.push_back(const_cast<char*>(arg.c_str())); } args.push_back(nullptr); @@ -61,38 +65,110 @@ int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_m } else { execve(program, &args[0], envp); } - PLOG(ERROR) << "Failed to execve(" << command_line << ")"; + PLOG(ERROR) << "Failed to execve(" << ToCommandLine(arg_vector) << ")"; // _exit to avoid atexit handlers in child. _exit(1); } else { - if (pid == -1) { - *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s", - command_line.c_str(), strerror(errno)); + return pid; + } +} + +} // namespace + +int ExecAndReturnCode(std::vector<std::string>& arg_vector, std::string* error_msg) { + pid_t pid = ExecWithoutWait(arg_vector); + if (pid == -1) { + *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s", + ToCommandLine(arg_vector).c_str(), strerror(errno)); + return -1; + } + + // wait for subprocess to finish + int status = -1; + pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0)); + if (got_pid != pid) { + *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: " + "wanted %d, got %d: %s", + ToCommandLine(arg_vector).c_str(), pid, got_pid, strerror(errno)); + return -1; + } + if (WIFEXITED(status)) { + return WEXITSTATUS(status); + } + return -1; +} + +int ExecAndReturnCode(std::vector<std::string>& arg_vector, + time_t timeout_secs, + bool* timed_out, + std::string* error_msg) { + *timed_out = false; + + // Start subprocess. + pid_t pid = ExecWithoutWait(arg_vector); + if (pid == -1) { + *error_msg = StringPrintf("Failed to execv(%s) because fork failed: %s", + ToCommandLine(arg_vector).c_str(), strerror(errno)); + return -1; + } + + // Add SIGCHLD to the signal set. + sigset_t child_mask, original_mask; + sigemptyset(&child_mask); + sigaddset(&child_mask, SIGCHLD); + if (sigprocmask(SIG_BLOCK, &child_mask, &original_mask) == -1) { + *error_msg = StringPrintf("Failed to set sigprocmask(): %s", strerror(errno)); + return -1; + } + + // Wait for a SIGCHLD notification. + errno = 0; + timespec ts = {timeout_secs, 0}; + int wait_result = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, nullptr, &ts)); + int wait_errno = errno; + + // Restore the original signal set. + if (sigprocmask(SIG_SETMASK, &original_mask, nullptr) == -1) { + *error_msg = StringPrintf("Fail to restore sigprocmask(): %s", strerror(errno)); + if (wait_result == 0) { return -1; } + } - // wait for subprocess to finish - int status = -1; - pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0)); - if (got_pid != pid) { - *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: " - "wanted %d, got %d: %s", - command_line.c_str(), pid, got_pid, strerror(errno)); - return -1; + // Having restored the signal set, see if we need to terminate the subprocess. + if (wait_result == -1) { + if (wait_errno == EAGAIN) { + *error_msg = "Timed out."; + *timed_out = true; + } else { + *error_msg = StringPrintf("Failed to sigtimedwait(): %s", strerror(errno)); } - if (WIFEXITED(status)) { - return WEXITSTATUS(status); + if (kill(pid, SIGKILL) != 0) { + PLOG(ERROR) << "Failed to kill() subprocess: "; } + } + + // Wait for subprocess to finish. + int status = -1; + pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0)); + if (got_pid != pid) { + *error_msg = StringPrintf("Failed after fork for execv(%s) because waitpid failed: " + "wanted %d, got %d: %s", + ToCommandLine(arg_vector).c_str(), pid, got_pid, strerror(errno)); return -1; } + if (WIFEXITED(status)) { + return WEXITSTATUS(status); + } + return -1; } + bool Exec(std::vector<std::string>& arg_vector, std::string* error_msg) { int status = ExecAndReturnCode(arg_vector, error_msg); if (status != 0) { - const std::string command_line(android::base::Join(arg_vector, ' ')); *error_msg = StringPrintf("Failed execv(%s) because non-0 exit status", - command_line.c_str()); + ToCommandLine(arg_vector).c_str()); return false; } return true; |