Patch "ARC: mm: PAE40: Fix crash at munmap" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

ARC: mm: PAE40: Fix crash at munmap

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arc-mm-pae40-fix-crash-at-munmap.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Yuriy Kolerov <[email protected]>
Date: Mon, 28 Nov 2016 07:07:17 +0300
Subject: ARC: mm: PAE40: Fix crash at munmap

From: Yuriy Kolerov <[email protected]>

commit 6a8b2ca702b279bea0e8f0363056439352e2081c upstream.

commit 1c3c90930392 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr from pfn, but the page shift was getting truncated to 32 bits since we lost the proper cast to 64 bits (for PAE400

Instead of reverting that commit, use a better helper which is 32/64 bits safe just like ARM implementation.

---
 arch/arc/include/asm/pgtable.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -280,7 +280,7 @@ static inline void pmd_set(pmd_t *pmdp,
 
 #define pte_page(pte)		pfn_to_page(pte_pfn(pte))
 #define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
-#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define pfn_pte(pfn, prot)	__pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 
 /* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/
 #define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/arc-mm-pae40-fix-crash-at-munmap.patch