mm: fix cache mode tracking in vm_insert_mixed()

BugLink: https://bugs.launchpad.net/bugs/1792174

commit 87744ab3 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@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

mm/memory.c

@@ -1657,10 +1657,14 @@ 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 (!pfn_modify_allowed(pfn, vma->vm_page_prot))
 		return -EACCES;
@@ -1676,10 +1680,10 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		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);