Function execGdb

lib/exceptionhandler/exceptionhandler.cpp:414–496

* Spawn a new GDB process and attach it to the current process. * * @param dumpFile a POSIX file descriptor to write GDB's output to, * it will also be used to write failure messages to. * @param[out] gdbWritePipe a POSIX file descriptor linked to GDB's stdin. * * @return 0 if we failed to spawn a new process, a non-zero process ID if we * success

 *       be unchanged.
 */
static pid_t execGdb(int const dumpFile, int *gdbWritePipe)
{
	int gdbPipe[2];
	pid_t pid;
	char *gdbArgv[] = { gdbPath, programPath, programPID, nullptr };
	char *gdbEnv[] = { nullptr };
	/* Check if the "bare minimum" is available: GDB and an absolute path
	 * to our program's binary.
	 */
	if (!programIsAvailable
	    || !gdbIsAvailable)
	{
		writeAll(dumpFile, "No extended backtrace dumped:\n");

		if (!programIsAvailable)
		{
			writeAll(dumpFile, "- Program path not available\n");
		}
		if (!gdbIsAvailable)
		{
			writeAll(dumpFile, "- GDB not available\n");
		}

		return 0;
	}

	// Create a pipe to use for communication with 'gdb'
	if (pipe(gdbPipe) == -1)
	{
		writeAll(dumpFile, "Pipe failed\n");

		printf("Pipe failed\n");

		return 0;
	}

	// Fork a new child process
	pid = fork();
	if (pid == -1)
	{
		writeAll(dumpFile, "Fork failed\n");

		printf("Fork failed\n");

		// Clean up our pipe
		close(gdbPipe[0]);
		close(gdbPipe[1]);

		return 0;
	}

	// Check to see if we're the parent
	if (pid != 0)
	{
#ifdef WZ_OS_LINUX
		// Allow tracing the process, some hardened kernel configurations disallow this.
		prctl(PR_SET_PTRACER, pid, 0, 0, 0);
#endif