mm, x86, pat: rework linear pfn-mmap tracking

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 6bef278ad3033868deebcb4256d64349e02aa380..655e1429388a364014899b4a84ea59e97500a5ea 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1055,7 +1055,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
        if (is_vm_hugetlb_page(vma))
                return copy_hugetlb_page_range(dst_mm, src_mm, vma);
 
-       if (unlikely(is_pfn_mapping(vma))) {
+       if (unlikely(vma->vm_flags & VM_PFNMAP)) {
                /*
                 * We do not free on error cases below as remove_vma
                 * gets called on error from higher level routine
@@ -1327,7 +1327,7 @@ static void unmap_single_vma(struct mmu_gather *tlb,
        if (vma->vm_file)
                uprobe_munmap(vma, start, end);
 
-       if (unlikely(is_pfn_mapping(vma)))
+       if (unlikely(vma->vm_flags & VM_PFNMAP))
                untrack_pfn(vma, 0, 0);
 
        if (start != end) {
@@ -2299,26 +2299,20 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
         * There's a horrible special case to handle copy-on-write
         * behaviour that some programs depend on. We mark the "original"
         * un-COW'ed pages by matching them up with "vma->vm_pgoff".
+        * See vm_normal_page() for details.
         */
-       if (addr == vma->vm_start && end == vma->vm_end) {
+       if (is_cow_mapping(vma->vm_flags)) {
+               if (addr != vma->vm_start || end != vma->vm_end)
+                       return -EINVAL;
                vma->vm_pgoff = pfn;
-               vma->vm_flags |= VM_PFN_AT_MMAP;
-       } else if (is_cow_mapping(vma->vm_flags))
+       }
+
+       err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size));
+       if (err)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
 
-       err = track_pfn_remap(vma, &prot, pfn, PAGE_ALIGN(size));
-       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);
-               vma->vm_flags &= ~VM_PFN_AT_MMAP;
-               return -EINVAL;
-       }
-
        BUG_ON(addr >= end);
        pfn -= addr >> PAGE_SHIFT;
        pgd = pgd_offset(mm, addr);