am 191fe44c: Merge "run-as: Don\'t require CAP_DAC_READ_SEARCH"

    struct stat  st;

    size_t  length = 0;

    void*   address = NULL;

    gid_t   oldegid;

    *filesize = 0;

    /*

     * Temporarily switch effective GID to allow us to read

     * the packages file

     */

    oldegid = getegid();

    if (setegid(AID_SYSTEM) < 0) {

        return NULL;

    }

    /* open the file for reading */

    fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

    if (fd < 0)

    if (fd < 0) {

        return NULL;

    }

    /* restore back to our old egid */

    if (setegid(oldegid) < 0) {

        goto EXIT;

    }

    /* get its size */

    ret = TEMP_FAILURE_RETRY(fstat(fd, &st));