* [PATCH v4.14 stable] powerpc: Fix DABR match on hash based
@ 2018-02-16 9:54 Naveen N. Rao
2018-02-16 10:21 ` Naveen N. Rao
0 siblings, 1 reply; 3+ messages in thread
From: Naveen N. Rao @ 2018-02-16 9:54 UTC (permalink / raw)
To: Greg KH; +Cc: Benjamin Herrenschmidt, Michael Ellerman, stable
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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@vger.kernel.org # v4.14
Tested-by: Pedro Miraglia Franco de Carvalho <pedromfc@br.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
Hi Greg,
This is a backport of commit f23ab3efb1b30 ("powerpc: Fix DABR match on
hash based systems") to v4.14. This wasn't applying on v4.14 due to
commit 4e003747043d5 ("powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with
CONFIG_PPC_BOOK3S_64"), which renamed CONFIG_PPC_STD_MMU_64. Kindly
apply this for v4.14-stable.
- Naveen
arch/powerpc/kernel/exceptions-64s.S | 2 +-
arch/powerpc/kernel/head_32.S | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e9f72abc52b7..e91b40aa5417 100644
--- 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 */
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 */
--
2.16.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v4.14 stable] powerpc: Fix DABR match on hash based
2018-02-16 9:54 [PATCH v4.14 stable] powerpc: Fix DABR match on hash based Naveen N. Rao
@ 2018-02-16 10:21 ` Naveen N. Rao
2018-02-19 16:26 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Naveen N. Rao @ 2018-02-16 10:21 UTC (permalink / raw)
To: Greg KH; +Cc: Benjamin Herrenschmidt, Michael Ellerman, stable
Naveen N. Rao wrote:
> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>
> 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@vger.kernel.org # v4.14
> Tested-by: Pedro Miraglia Franco de Carvalho <pedromfc@br.ibm.com>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Not quite sure if this is required, but:
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Thanks,
Naveen
> ---
> Hi Greg,
> This is a backport of commit f23ab3efb1b30 ("powerpc: Fix DABR match on
> hash based systems") to v4.14. This wasn't applying on v4.14 due to
> commit 4e003747043d5 ("powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with
> CONFIG_PPC_BOOK3S_64"), which renamed CONFIG_PPC_STD_MMU_64. Kindly
> apply this for v4.14-stable.
>
> - Naveen
>
> arch/powerpc/kernel/exceptions-64s.S | 2 +-
> arch/powerpc/kernel/head_32.S | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index e9f72abc52b7..e91b40aa5417 100644
> --- 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 */
> 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 */
> --
> 2.16.1
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v4.14 stable] powerpc: Fix DABR match on hash based
2018-02-16 10:21 ` Naveen N. Rao
@ 2018-02-19 16:26 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2018-02-19 16:26 UTC (permalink / raw)
To: Naveen N. Rao; +Cc: Benjamin Herrenschmidt, Michael Ellerman, stable
On Fri, Feb 16, 2018 at 03:51:40PM +0530, Naveen N. Rao wrote:
> Naveen N. Rao wrote:
> > From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> >
> > 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@vger.kernel.org # v4.14
> > Tested-by: Pedro Miraglia Franco de Carvalho <pedromfc@br.ibm.com>
> > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>
> Not quite sure if this is required, but:
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Thanks, now queued up.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-02-16 9:54 [PATCH v4.14 stable] powerpc: Fix DABR match on hash based Naveen N. Rao
2018-02-16 10:21 ` Naveen N. Rao
2018-02-19 16:26 ` Greg KH
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