On Tue, 2018-08-14 at 19:18 +0200, Greg Kroah-Hartman wrote:
4.4-stable review patch. If anyone has any objections, please let me know.
From: Dan Williams dan.j.williams@intel.com
commit 87744ab3832b83ba71b931f86f9cfdb000d07da5 upstream
vm_insert_mixed() unlike vm_insert_pfn_prot() and vmf_insert_pfn_pmd(), fails to check the pgprot_t it uses for the mapping against the one recorded in the memtype tracking tree. Add the missing call to track_pfn_insert() to preclude cases where incompatible aliased mappings are established for a given physical address range.
[...]
This apparently breaks a number of DRM drivers. The upstream fixes are:
8ef4227615e1 x86/io: add interface to reserve io memtype for a resource range. (v1.1) 7cf321d118a8 drm/drivers: add support for using the arch wc mapping API.
They appear to apply cleanly to 4.4-stable. They are included in 4.9 so no other stable branch needs them.
Ben.