Re: [PATCH] [RFC] Remove bdflush syscall stub

Cyril Hrubis
2019-05-28T11:20:32Z

Hi!
> >> > I've tested the patch on i386. Before the patch calling bdflush() with
> >> > attempt to tune a variable returned 0 and after the patch the syscall
> >> > fails with EINVAL.
> >>
> >> Should be ENOSYS, doesn't it?
> >
> > My bad, the LTP syscall wrapper handles ENOSYS and produces skipped
> > results based on that.
> >
> > EINVAL is what you get for not yet implemented syscalls, i.e. new
> > syscall on old kernel.
>
> EINVAL? Is that a bdflush-specific thing, test-specific, or is itmore
> general?
>
> glibc has fallback paths that test for ENOSYS only. EINVAL will be
> passed to the application, skipping fallback. For missing system calls,
> this is not what we want.

The syscall returns ENOSYS after this change, sorry for the confusion.

--
Cyril Hrubis
chrubis@suse.cz