Makes sense to me.
.... Ken
On Fri, Feb 9, 2024, 10:44 PM Theo de Raadt <dera...@openbsd.org> wrote:
> Kenneth Westerback <kwesterb...@gmail.com> wrote:
>
> > Looks correct to me. The value returned by get_ucomnames() is only
> > passed to find_ucom() where it is checked against NULL.
>
> Alternative diff in the kernel, *in addition* to the other diff.
>
> On a ucom-supporting kernel, if there are no matching devices the
> sysctl returns the empty string.
>
> The correct value for the sysctl node should be "no ucom translations
> information".
>
> So lack of support should return the empty string, not EINVAL. From
> sysctl(2), EINVAL means either of these two conditions:
>
> [EINVAL] The name array is less than two or greater than
> CTL_MAXNAME.
>
> [EINVAL] A non-null newp pointer is given and its specified
> length in newlen is too large or too small.
>
> Neither of them apply. It's a made-up errno. Maybe some other error
> would be more suitable, but empty string works just as well.
>
> Compile tested on GENERIC and RAMDISK, I did not try more than that.
>
> Index: kern_sysctl.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/kern_sysctl.c,v
> diff -u -p -u -r1.424 kern_sysctl.c
> --- kern_sysctl.c 19 Jan 2024 01:43:27 -0000 1.424
> +++ kern_sysctl.c 10 Feb 2024 03:39:16 -0000
> @@ -771,14 +771,13 @@ hw_sysctl(int *name, u_int namelen, void
> case HW_ALLOWPOWERDOWN:
> return (sysctl_securelevel_int(oldp, oldlenp, newp, newlen,
> &allowpowerdown));
> -#if NUCOM > 0
> case HW_UCOMNAMES: {
> - const char *str = sysctl_ucominit();
> - if (str == NULL)
> - return EINVAL;
> + const char *str = "";
> +#if NUCOM > 0
> + str = sysctl_ucominit();
> +#endif /* NUCOM > 0 */
> return (sysctl_rdstring(oldp, oldlenp, newp, str));
> }
> -#endif /* NUCOM > 0 */
> #ifdef __HAVE_CPU_TOPOLOGY
> case HW_SMT:
> return (sysctl_hwsmt(oldp, oldlenp, newp, newlen));
>
