x86 PAT: remove PFNMAP type on track_pfn_vma_new() error

Impact: fix (harmless) double-free of memtype entries and avoid warning

On track_pfn_vma_new() failure, reset the vm_flags so that there will be
no second cleanup happening when upper level routines call unmap_vmas().

This patch fixes part of the bug reported here:

  http://marc.info/?l=linux-kernel&m=123108883716357&w=2

Specifically the error message:

  X:5010 freeing invalid memtype d0000000-d0101000

Is due to multiple frees on error path, will not happen with the patch below.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 7 insertions, 1 deletions

diff --git a/mm/memory.c b/mm/memory.c
index c2d4c477e5bb..d3ee2ea5615c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1672,8 +1672,14 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
         vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
 
         err = track_pfn_vma_new(vma, prot, pfn, PAGE_ALIGN(size));
-        if (err)
+        if (err) {
+                /*
+                 * To indicate that track_pfn related cleanup is not
+                 * needed from higher level routine calling unmap_vmas
+                 */
+                vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP);
                 return -EINVAL;
+        }
 
         BUG_ON(addr >= end);
         pfn -= addr >> PAGE_SHIFT;