The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f23ab3efb1b30cc5c5ef5ae4ef294ed467f30675 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 10 Nov 2017 12:15:00 +1100
Subject: [PATCH] powerpc: Fix DABR match on hash based systems
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>
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 6879aed47377..445137e2d0ca 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1498,7 +1498,7 @@ USE_TEXT_SECTION()
.balign IFETCH_ALIGN_BYTES
do_hash_page:
#ifdef CONFIG_PPC_BOOK3S_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 */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 8c54166491e7..29b2fed93289 100644
--- 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 */