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authorDan Williams <dan.j.williams@intel.com>2016-01-26 09:48:05 -0800
committerDan Williams <dan.j.williams@intel.com>2016-01-31 09:07:15 -0800
commit03fc2da63b9a33dce784a2075c7e068bb97cbf69 (patch)
tree7d8bbc192f8468a8427f6f4704749ab140dcc10e /mm
parentd1a5f2b4d8a125943dcb6b032fc7eaefc2c78296 (diff)
mm: fix pfn_t to page conversion in vm_insert_mixed
pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid(). Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Cc: Dave Hansen <dave@sr71.net> Cc: David Airlie <airlied@linux.ie> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 30991f83d0bf..93ce37989471 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
* than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP
* without pte special, it would there be refcounted as a normal page.
*/
- if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) {
+ if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
struct page *page;
- page = pfn_t_to_page(pfn);
+ /*
+ * At this point we are committed to insert_page()
+ * regardless of whether the caller specified flags that
+ * result in pfn_t_has_page() == false.
+ */
+ page = pfn_to_page(pfn_t_to_pfn(pfn));
return insert_page(vma, addr, page, vma->vm_page_prot);
}
return insert_pfn(vma, addr, pfn, vma->vm_page_prot);