[PATCH] c/r: Fix arch-specific use of mm->context.vdso in v14-rc3

[Nathan Lynch]

Dan Smith <danms at us.ibm.com> wrote:

> On s390 and PPC, the mm_context does not have a void *vdso member, but
> rather an unsigned long vdso_base.  Since we cast the void * to an
> unsigned long anyway, add an arch-specific cr_arch_vdso() function to
> return the address.

Looks technically correct for powerpc at least, thanks.