On Wed, Apr 07, 2021 at 10:55:14PM +0300, Alexey Dobriyan wrote: > Now that ->proc_lseek has been made mandatory it would be nice to test > that nothing has been forgotten. > @@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *filename) > fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); > if (fd == -1) > return; > + /* struct proc_ops::proc_lseek is mandatory if file is seekable. */ > + (void)lseek(fd, 0, SEEK_SET); > rv = read(fd, buf, sizeof(buf)); > assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); > close(fd); why throw away the return value? if it returns an error seeking to offset 0, something is terribly wrong.