Merge "Set groups before dropping privileges." into nyc-dev

}

static bool drop_privileges() {

  // AID_LOG: for reading the logs data associated with the crashing process.

  // AID_READPROC: for reading /proc/<PID>/{comm,cmdline}.

  gid_t groups[] = { AID_DEBUGGERD, AID_LOG, AID_READPROC };

  if (setgroups(sizeof(groups)/sizeof(groups[0]), groups) != 0) {

    ALOGE("debuggerd: failed to setgroups: %s", strerror(errno));

    return false;

  }

  if (setresgid(AID_DEBUGGERD, AID_DEBUGGERD, AID_DEBUGGERD) != 0) {

    ALOGE("debuggerd: failed to setresgid");

    ALOGE("debuggerd: failed to setresgid: %s", strerror(errno));

    return false;

  }

  if (setresuid(AID_DEBUGGERD, AID_DEBUGGERD, AID_DEBUGGERD) != 0) {

    ALOGE("debuggerd: failed to setresuid");

    ALOGE("debuggerd: failed to setresuid: %s", strerror(errno));

    return false;

  }