| //===-- sanitizer_symbolizer_process_libcdep.cc ---------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Implementation of SymbolizerProcess used by external symbolizers. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_platform.h" |
| #if SANITIZER_POSIX |
| #include "sanitizer_posix.h" |
| #include "sanitizer_symbolizer_internal.h" |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #if SANITIZER_MAC |
| #include <util.h> // for forkpty() |
| #endif // SANITIZER_MAC |
| |
| namespace __sanitizer { |
| |
| SymbolizerProcess::SymbolizerProcess(const char *path, bool use_forkpty) |
| : path_(path), |
| input_fd_(kInvalidFd), |
| output_fd_(kInvalidFd), |
| times_restarted_(0), |
| failed_to_start_(false), |
| reported_invalid_path_(false), |
| use_forkpty_(use_forkpty) { |
| CHECK(path_); |
| CHECK_NE(path_[0], '\0'); |
| } |
| |
| const char *SymbolizerProcess::SendCommand(const char *command) { |
| for (; times_restarted_ < kMaxTimesRestarted; times_restarted_++) { |
| // Start or restart symbolizer if we failed to send command to it. |
| if (const char *res = SendCommandImpl(command)) |
| return res; |
| Restart(); |
| } |
| if (!failed_to_start_) { |
| Report("WARNING: Failed to use and restart external symbolizer!\n"); |
| failed_to_start_ = true; |
| } |
| return 0; |
| } |
| |
| bool SymbolizerProcess::Restart() { |
| if (input_fd_ != kInvalidFd) |
| internal_close(input_fd_); |
| if (output_fd_ != kInvalidFd) |
| internal_close(output_fd_); |
| return StartSymbolizerSubprocess(); |
| } |
| |
| const char *SymbolizerProcess::SendCommandImpl(const char *command) { |
| if (input_fd_ == kInvalidFd || output_fd_ == kInvalidFd) |
| return 0; |
| if (!WriteToSymbolizer(command, internal_strlen(command))) |
| return 0; |
| if (!ReadFromSymbolizer(buffer_, kBufferSize)) |
| return 0; |
| return buffer_; |
| } |
| |
| bool SymbolizerProcess::ReadFromSymbolizer(char *buffer, uptr max_length) { |
| if (max_length == 0) |
| return true; |
| uptr read_len = 0; |
| while (true) { |
| uptr just_read = internal_read(input_fd_, buffer + read_len, |
| max_length - read_len - 1); |
| // We can't read 0 bytes, as we don't expect external symbolizer to close |
| // its stdout. |
| if (just_read == 0 || just_read == (uptr)-1) { |
| Report("WARNING: Can't read from symbolizer at fd %d\n", input_fd_); |
| return false; |
| } |
| read_len += just_read; |
| if (ReachedEndOfOutput(buffer, read_len)) |
| break; |
| } |
| buffer[read_len] = '\0'; |
| return true; |
| } |
| |
| bool SymbolizerProcess::WriteToSymbolizer(const char *buffer, uptr length) { |
| if (length == 0) |
| return true; |
| uptr write_len = internal_write(output_fd_, buffer, length); |
| if (write_len == 0 || write_len == (uptr)-1) { |
| Report("WARNING: Can't write to symbolizer at fd %d\n", output_fd_); |
| return false; |
| } |
| return true; |
| } |
| |
| bool SymbolizerProcess::StartSymbolizerSubprocess() { |
| if (!FileExists(path_)) { |
| if (!reported_invalid_path_) { |
| Report("WARNING: invalid path to external symbolizer!\n"); |
| reported_invalid_path_ = true; |
| } |
| return false; |
| } |
| |
| int pid; |
| if (use_forkpty_) { |
| #if SANITIZER_MAC |
| fd_t fd = kInvalidFd; |
| // Use forkpty to disable buffering in the new terminal. |
| pid = forkpty(&fd, 0, 0, 0); |
| if (pid == -1) { |
| // forkpty() failed. |
| Report("WARNING: failed to fork external symbolizer (errno: %d)\n", |
| errno); |
| return false; |
| } else if (pid == 0) { |
| // Child subprocess. |
| ExecuteWithDefaultArgs(path_); |
| internal__exit(1); |
| } |
| |
| // Continue execution in parent process. |
| input_fd_ = output_fd_ = fd; |
| |
| // Disable echo in the new terminal, disable CR. |
| struct termios termflags; |
| tcgetattr(fd, &termflags); |
| termflags.c_oflag &= ~ONLCR; |
| termflags.c_lflag &= ~ECHO; |
| tcsetattr(fd, TCSANOW, &termflags); |
| #else // SANITIZER_MAC |
| UNIMPLEMENTED(); |
| #endif // SANITIZER_MAC |
| } else { |
| int *infd = NULL; |
| int *outfd = NULL; |
| // The client program may close its stdin and/or stdout and/or stderr |
| // thus allowing socketpair to reuse file descriptors 0, 1 or 2. |
| // In this case the communication between the forked processes may be |
| // broken if either the parent or the child tries to close or duplicate |
| // these descriptors. The loop below produces two pairs of file |
| // descriptors, each greater than 2 (stderr). |
| int sock_pair[5][2]; |
| for (int i = 0; i < 5; i++) { |
| if (pipe(sock_pair[i]) == -1) { |
| for (int j = 0; j < i; j++) { |
| internal_close(sock_pair[j][0]); |
| internal_close(sock_pair[j][1]); |
| } |
| Report("WARNING: Can't create a socket pair to start " |
| "external symbolizer (errno: %d)\n", errno); |
| return false; |
| } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) { |
| if (infd == NULL) { |
| infd = sock_pair[i]; |
| } else { |
| outfd = sock_pair[i]; |
| for (int j = 0; j < i; j++) { |
| if (sock_pair[j] == infd) continue; |
| internal_close(sock_pair[j][0]); |
| internal_close(sock_pair[j][1]); |
| } |
| break; |
| } |
| } |
| } |
| CHECK(infd); |
| CHECK(outfd); |
| |
| // Real fork() may call user callbacks registered with pthread_atfork(). |
| pid = internal_fork(); |
| if (pid == -1) { |
| // Fork() failed. |
| internal_close(infd[0]); |
| internal_close(infd[1]); |
| internal_close(outfd[0]); |
| internal_close(outfd[1]); |
| Report("WARNING: failed to fork external symbolizer " |
| " (errno: %d)\n", errno); |
| return false; |
| } else if (pid == 0) { |
| // Child subprocess. |
| internal_close(STDOUT_FILENO); |
| internal_close(STDIN_FILENO); |
| internal_dup2(outfd[0], STDIN_FILENO); |
| internal_dup2(infd[1], STDOUT_FILENO); |
| internal_close(outfd[0]); |
| internal_close(outfd[1]); |
| internal_close(infd[0]); |
| internal_close(infd[1]); |
| for (int fd = sysconf(_SC_OPEN_MAX); fd > 2; fd--) |
| internal_close(fd); |
| ExecuteWithDefaultArgs(path_); |
| internal__exit(1); |
| } |
| |
| // Continue execution in parent process. |
| internal_close(outfd[0]); |
| internal_close(infd[1]); |
| input_fd_ = infd[0]; |
| output_fd_ = outfd[1]; |
| } |
| |
| // Check that symbolizer subprocess started successfully. |
| int pid_status; |
| SleepForMillis(kSymbolizerStartupTimeMillis); |
| int exited_pid = waitpid(pid, &pid_status, WNOHANG); |
| if (exited_pid != 0) { |
| // Either waitpid failed, or child has already exited. |
| Report("WARNING: external symbolizer didn't start up correctly!\n"); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| } // namespace __sanitizer |
| |
| #endif // SANITIZER_POSIX |