[PATCH 3.16 101/131] mm: fix cache mode tracking in vm_insert_mixed()

[Ben Hutchings]

3.16.59-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams <dan.j.williams@xxxxxxxxx>

commit 87744ab3832b83ba71b931f86f9cfdb000d07da5 upstream.

vm_insert_mixed() unlike vm_insert_pfn_prot() and vmf_insert_pfn_pmd(),
fails to check the pgprot_t it uses for the mapping against the one
recorded in the memtype tracking tree.  Add the missing call to
track_pfn_insert() to preclude cases where incompatible aliased mappings
are established for a given physical address range.

[groeck: Backport to v4.4.y]

Link: http://lkml.kernel.org/r/147328717909.35069.14256589123570653697.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 mm/memory.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1623,10 +1623,14 @@ EXPORT_SYMBOL(vm_insert_pfn_prot);
 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 			unsigned long pfn)
 {
+	pgprot_t pgprot = vma->vm_page_prot;
+
 	BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
 
 	if (addr < vma->vm_start || addr >= vma->vm_end)
 		return -EFAULT;
+	if (track_pfn_insert(vma, &pgprot, pfn))
+		return -EINVAL;
 
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
@@ -1639,9 +1643,9 @@ int vm_insert_mixed(struct vm_area_struc
 		struct page *page;
 
 		page = pfn_to_page(pfn);
-		return insert_page(vma, addr, page, vma->vm_page_prot);
+		return insert_page(vma, addr, page, pgprot);
 	}
-	return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+	return insert_pfn(vma, addr, pfn, pgprot);
 }
 EXPORT_SYMBOL(vm_insert_mixed);