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| author | Dan Williams <dan.j.williams@intel.com> | 2016-01-26 09:48:05 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-01-31 09:07:15 -0800 |
| commit | 03fc2da63b9a33dce784a2075c7e068bb97cbf69 (patch) | |
| tree | 7d8bbc192f8468a8427f6f4704749ab140dcc10e /mm/memory.c | |
| parent | d1a5f2b4d8a125943dcb6b032fc7eaefc2c78296 (diff) | |
| download | lwn-03fc2da63b9a33dce784a2075c7e068bb97cbf69.tar.gz lwn-03fc2da63b9a33dce784a2075c7e068bb97cbf69.zip | |
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/memory.c')
| -rw-r--r-- | mm/memory.c | 9 |
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); |