error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().
Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are
mapped in kmem with execute permissions. Use this flag to determine which
arena the kmem virtual addresses are returned to.
Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it
redundant.
Update the nearby comment for UMA_SLAB_KERNEL.
Reviewed by: kib, markj
Discussed with: jeff
Approved by: re (marius)
Differential Revision: https://reviews.freebsd.org/D16845
I imagine that the module would be useful only to a very limited number
of developers, so that's my excuse for not writing any documentation.
On a more serious note, please see DRAM Error Injection section of BKDGs
for families 10h - 16h. E.g. section 2.13.3.1 of BKDG for AMD Family 15h
Models 00h-0Fh Processors.
Many thanks to kib for his suggestions and comments.
Discussed with: kib
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D9824
