| //===-- sanitizer_symbolizer_posix_libcdep.cc -----------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is shared between AddressSanitizer and ThreadSanitizer |
| // run-time libraries. |
| // POSIX-specific implementation of symbolizer parts. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_platform.h" |
| #if SANITIZER_POSIX |
| #include "sanitizer_common.h" |
| #include "sanitizer_internal_defs.h" |
| #include "sanitizer_symbolizer.h" |
| |
| #include <errno.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| namespace __sanitizer { |
| |
| bool StartSymbolizerSubprocess(const char *path_to_symbolizer, |
| int *input_fd, int *output_fd) { |
| if (!FileExists(path_to_symbolizer)) { |
| Report("WARNING: invalid path to external symbolizer!\n"); |
| return false; |
| } |
| |
| 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); |
| |
| int pid = 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 = getdtablesize(); fd > 2; fd--) |
| internal_close(fd); |
| execl(path_to_symbolizer, path_to_symbolizer, (char*)0); |
| 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 |