Messages in this thread Patch in this message | | | From | Yongji Xie <> | Subject | [PATCH v2] mm: fix incorrect pfn passed to untrack_pfn() in remap_pfn_range() | Date | Sun, 24 Apr 2016 12:01:41 +0800 |
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We use generic hooks in remap_pfn_range() to help archs to track pfnmap regions. The code is something like:
int remap_pfn_range() { ... track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); ... pfn -= addr >> PAGE_SHIFT; ... untrack_pfn(vma, pfn, PAGE_ALIGN(size)); ... }
Here we can easily find the pfn is changed but not recovered before untrack_pfn() is called. That's incorrect.
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> --- mm/memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 098f00d..eee75ed 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1711,6 +1711,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long next; unsigned long end = addr + PAGE_ALIGN(size); struct mm_struct *mm = vma->vm_mm; + unsigned long remap_pfn = pfn; int err; /* @@ -1737,7 +1738,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, vma->vm_pgoff = pfn; } - err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); + err = track_pfn_remap(vma, &prot, remap_pfn, addr, PAGE_ALIGN(size)); if (err) return -EINVAL; @@ -1756,7 +1757,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, } while (pgd++, addr = next, addr != end); if (err) - untrack_pfn(vma, pfn, PAGE_ALIGN(size)); + untrack_pfn(vma, remap_pfn, PAGE_ALIGN(size)); return err; } -- 1.7.9.5
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