[LTP] [PATCH 1/1] lib: dirtyc0w_shmem: userfaultfd01: Add safe_userfaultfd()

[Cyril Hrubis]

Hi!
> > +	} else if (ret < 0) {
> > +		tst_brk_(file, lineno, TBROK | TERRNO,
> > +			 "Invalid syscall(__NR_userfaultfd, %d) return value %d", flags, ret);
> > +	}
> I suppose main error handle if (ret == -1) already cover standard syscall
> error, why still need check ret < 0 ?

We are testing kernel and we have to check for situation that are
impossible under normal operation. There have been cases when a bug in a
kernel patch caused the syscall to return invalid return values, so we
are making extra sure that this does not happen.

-- 
Cyril Hrubis
chrubis@suse.cz