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| author | Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com> | 2009-03-12 17:45:27 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-13 04:28:50 +0100 |
| commit | 4bb9c5c02153dfc89a6c73a6f32091413805ad7d (patch) | |
| tree | 408dee350cab80fbe7884b6640d651ef8ec44601 /mm/memory.c | |
| parent | 6a5c05f002c3e4f24887a5fe8e7df757d339d368 (diff) | |
| download | lwn-4bb9c5c02153dfc89a6c73a6f32091413805ad7d.tar.gz lwn-4bb9c5c02153dfc89a6c73a6f32091413805ad7d.zip | |
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/memory.c')
| -rw-r--r-- | mm/memory.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index baa999e87cd2..d7df5babcba9 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; } |