svn commit: r291937 - in head: lib/libc/aarch64/sys lib/libc/arm/sys sys/arm/arm sys/arm/include sys/arm64/arm64 sys/arm64/include sys/conf sys/kern

[Warner Losh]

I'm running Atmel hardware with this change built on amd64.
I'm not sure what the issue here is.

Warner
On Dec 24, 2015 8:40 AM, "Ian Lepore" <ian at freebsd.org> wrote:

> On Mon, 2015-12-07 at 12:20 +0000, Konstantin Belousov wrote:
> > Author: kib
> > Date: Mon Dec  7 12:20:26 2015
> > New Revision: 291937
> > URL: https://svnweb.freebsd.org/changeset/base/291937
> >
> > Log:
> >   Add support for usermode (vdso-like) gettimeofday(2) and
> >   clock_gettime(2) on ARMv7 and ARMv8 systems which have architectural
> >   generic timer hardware. It is similar how the RDTSC timer is used in
> >   userspace on x86.
> >
> >   Fix a permission problem where generic timer access from EL0 (or
> >   userspace on v7) was not properly initialized on APs.
> >
> >   For ARMv7, mark the stack non-executable. The shared page is added for
> >   all arms (including ARMv8 64bit), and the signal trampoline code is
> >   moved to the page.
> >
> >   Reviewed by:>       > andrew
> >   Discussed with:>    > emaste, mmel
> >   Sponsored by:>      > The FreeBSD Foundation
> >   Differential revision:>     https://reviews.freebsd.org/D4209
>
> I've just discovered this change breaks buildworld on armv4/5 systems.
>  Those systems don't have the counter hardware that can be read from
> userland (they don't have any common timer hardware at all, every
> system is different).  Also, they don't support the 'mrrc' instruction,
> so the buildworld fails to compile libc.
>
> -- Ian
>
>