From: venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com>
Date: Sat, 10 Jan 2009 00:13:09 +0000 (-0800)
Subject: x86 PAT: remove PFNMAP type on track_pfn_vma_new() error
X-Git-Tag: v2.6.29-rc2~84^2~4
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=a36706131182f5507d1e2cfbf391b0fa8d72203c;p=linux-2.6-omap-h63xx.git

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>
---

diff --git a/mm/memory.c b/mm/memory.c
index c2d4c477e5b..d3ee2ea5615 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;