This is a note to let you know that I've just added the patch titled
powerpc: Fix DABR match on hash based systems
to the 4.14-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:
powerpc-fix-dabr-match-on-hash-based-systems.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f23ab3efb1b30cc5c5ef5ae4ef294ed467f30675 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 10 Nov 2017 12:15:00 +1100
Subject: powerpc: Fix DABR match on hash based systems
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
commit f23ab3efb1b30cc5c5ef5ae4ef294ed467f30675 upstream.
Commit 398a719d34a1 ("powerpc/mm: Update bits used to skip hash_page")
mistakenly dropped the DSISR_DABRMATCH bit from the mask of bit tested
to skip trying to hash a page.
As a result, the DABR matches would no longer be detected.
This adds it back. We open code it in the 2 places where it matters
rather than fold it into DSISR_BAD_FAULT_32S/64S because this isn't
technically a bad fault and while we would never hit it with the
current code, I prefer if page_fault_is_bad() didn't trigger on these.
Fixes: 398a719d34a1 ("powerpc/mm: Update bits used to skip hash_page")
Cc: stable@xxxxxxxxxxxxxxx # v4.14
Tested-by: Pedro Miraglia Franco de Carvalho <pedromfc@xxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/exceptions-64s.S | 2 +-
arch/powerpc/kernel/head_32.S | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1617,7 +1617,7 @@ USE_TEXT_SECTION()
.balign IFETCH_ALIGN_BYTES
do_hash_page:
#ifdef CONFIG_PPC_STD_MMU_64
- lis r0,DSISR_BAD_FAULT_64S@h
+ lis r0,(DSISR_BAD_FAULT_64S|DSISR_DABRMATCH)@h
ori r0,r0,DSISR_BAD_FAULT_64S@l
and. r0,r4,r0 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -388,7 +388,7 @@ DataAccess:
EXCEPTION_PROLOG
mfspr r10,SPRN_DSISR
stw r10,_DSISR(r11)
- andis. r0,r10,DSISR_BAD_FAULT_32S@h
+ andis. r0,r10,(DSISR_BAD_FAULT_32S|DSISR_DABRMATCH)@h
bne 1f /* if not, try to put a PTE */
mfspr r4,SPRN_DAR /* into the hash table */
rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
Patches currently in stable-queue which might be from benh@xxxxxxxxxxxxxxxxxxx are
queue-4.14/powerpc-fix-dabr-match-on-hash-based-systems.patch