VM, x86, PAT: Change is_linear_pfn_mapping to not use vm_pgoff
authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>
Fri, 13 Mar 2009 00:45:27 +0000 (17:45 -0700)
committerIngo Molnar <mingo@elte.hu>
Fri, 13 Mar 2009 03:28:50 +0000 (04:28 +0100)
commit4bb9c5c02153dfc89a6c73a6f32091413805ad7d
tree408dee350cab80fbe7884b6640d651ef8ec44601
parent6a5c05f002c3e4f24887a5fe8e7df757d339d368
VM, x86, PAT: Change is_linear_pfn_mapping to not use vm_pgoff

Impact: fix false positive PAT warnings - also fix VirtalBox hang

Use of vma->vm_pgoff to identify the pfnmaps that are fully
mapped at mmap time is broken. vm_pgoff is set by generic mmap
code even for cases where drivers are setting up the mappings
at the fault time.

The problem was originally reported here:

 http://marc.info/?l=linux-kernel&m=123383810628583&w=2

Change is_linear_pfn_mapping logic to overload VM_INSERTPAGE
flag along with VM_PFNMAP to mean full PFNMAP setup at mmap
time.

Problem also tracked at:

 http://bugzilla.kernel.org/show_bug.cgi?id=12800

Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha>@intel.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "ebiederm@xmission.com" <ebiederm@xmission.com>
Cc: <stable@kernel.org> # only for 2.6.29.1, not .28
LKML-Reference: <20090313004527.GA7176@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/mm/pat.c
include/linux/mm.h
mm/memory.c