summaryrefslogtreecommitdiff
path: root/mm/memory.c
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2016-05-04 07:52:29 +0300
committerDavid S. Miller <davem@davemloft.net>2016-05-04 07:52:29 +0300
commitcba653210056cf47cc1969f831f05ddfb99ee2bd (patch)
tree92d93a3eee5b12d77af3696b9da8026e71df5752 /mm/memory.c
parent26879da58711aa604a1b866cbeedd7e0f78f90ad (diff)
parent7391daf2ffc780679d6ab3fad1db2619e5dd2c2a (diff)
downloadlinux-cba653210056cf47cc1969f831f05ddfb99ee2bd.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: net/ipv4/ip_gre.c Minor conflicts between tunnel bug fixes in net and ipv6 tunnel cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 93897f23cc11..305537fc8640 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -789,6 +789,46 @@ out:
return pfn_to_page(pfn);
}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t pmd)
+{
+ unsigned long pfn = pmd_pfn(pmd);
+
+ /*
+ * There is no pmd_special() but there may be special pmds, e.g.
+ * in a direct-access (dax) mapping, so let's just replicate the
+ * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+ */
+ if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+ if (vma->vm_flags & VM_MIXEDMAP) {
+ if (!pfn_valid(pfn))
+ return NULL;
+ goto out;
+ } else {
+ unsigned long off;
+ off = (addr - vma->vm_start) >> PAGE_SHIFT;
+ if (pfn == vma->vm_pgoff + off)
+ return NULL;
+ if (!is_cow_mapping(vma->vm_flags))
+ return NULL;
+ }
+ }
+
+ if (is_zero_pfn(pfn))
+ return NULL;
+ if (unlikely(pfn > highest_memmap_pfn))
+ return NULL;
+
+ /*
+ * NOTE! We still have PageReserved() pages in the page tables.
+ * eg. VDSO mappings can cause them to exist.
+ */
+out:
+ return pfn_to_page(pfn);
+}
+#endif
+
/*
* copy one vm_area from one task to the other. Assumes the page tables
* already present in the new task to be cleared in the whole range