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authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>2009-03-12 17:45:27 -0700
committerIngo Molnar <mingo@elte.hu>2009-03-13 04:28:50 +0100
commit4bb9c5c02153dfc89a6c73a6f32091413805ad7d (patch)
tree408dee350cab80fbe7884b6640d651ef8ec44601 /mm
parent6a5c05f002c3e4f24887a5fe8e7df757d339d368 (diff)
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c
index baa999e87cd..d7df5babcba 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1665,9 +1665,10 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
* behaviour that some programs depend on. We mark the "original"
* un-COW'ed pages by matching them up with "vma->vm_pgoff".
*/
- if (addr == vma->vm_start && end == vma->vm_end)
+ if (addr == vma->vm_start && end == vma->vm_end) {
vma->vm_pgoff = pfn;
- else if (is_cow_mapping(vma->vm_flags))
+ vma->vm_flags |= VM_PFNMAP_AT_MMAP;
+ } else if (is_cow_mapping(vma->vm_flags))
return -EINVAL;
vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
@@ -1679,6 +1680,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
* needed from higher level routine calling unmap_vmas
*/
vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP);
+ vma->vm_flags &= ~VM_PFNMAP_AT_MMAP;
return -EINVAL;
}