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* [PATCH 4.20 0/1] Fix regression from arm spectre patch series
@ 2019-01-25 22:40 David Long
  2019-01-25 22:40 ` [PATCH 4.20 1/1] ARM: fix the cockup in the previous patch David Long
  0 siblings, 1 reply; 3+ messages in thread
From: David Long @ 2019-01-25 22:40 UTC (permalink / raw)
  To: stable, Russell King - ARM Linux, Florian Fainelli,
	Julien Thierry, Tony Lindgren, Marc Zyngier
  Cc: Greg KH, Mark Brown

From: "David A. Long" <dave.long@linaro.org>

Backport upstream patch for regression introduced from spectre patch series.
This was run through kernelci testing. Also the kernel was built
with and without BIG_LITTLE and the symbol table was examined to verify
the processor tables do not go into .rodata when BIG_LITTLE=n.

Russell King (1):
  ARM: fix the cockup in the previous patch

 arch/arm/mm/proc-macros.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.17.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH 4.20 1/1] ARM: fix the cockup in the previous patch
  2019-01-25 22:40 [PATCH 4.20 0/1] Fix regression from arm spectre patch series David Long
@ 2019-01-25 22:40 ` David Long
  2019-01-26 17:57   ` Sasha Levin
  0 siblings, 1 reply; 3+ messages in thread
From: David Long @ 2019-01-25 22:40 UTC (permalink / raw)
  To: stable, Russell King - ARM Linux, Florian Fainelli,
	Julien Thierry, Tony Lindgren, Marc Zyngier
  Cc: Greg KH, Mark Brown

From: Russell King <rmk+kernel@armlinux.org.uk>

Commit d6951f582cc50ba0ad22ef46b599740966599b14 upstream.

The intention in the previous patch was to only place the processor
tables in the .rodata section if big.Little was being built and we
wanted the branch target hardening, but instead (due to the way it
was tested) it ended up always placing the tables into the .rodata
section.

Although harmless, let's correct this anyway.

Fixes: 3a4d0c2172bc ("ARM: ensure that processor vtables is not lost after boot")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
---
 arch/arm/mm/proc-macros.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 19516fbc2c55..5461d589a1e2 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -278,7 +278,7 @@
  * If we are building for big.Little with branch predictor hardening,
  * we need the processor function tables to remain available after boot.
  */
-#if 1 // defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+#if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
 	.section ".rodata"
 #endif
 	.type	\name\()_processor_functions, #object
@@ -316,7 +316,7 @@ ENTRY(\name\()_processor_functions)
 	.endif
 
 	.size	\name\()_processor_functions, . - \name\()_processor_functions
-#if 1 // defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+#if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
 	.previous
 #endif
 .endm
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH 4.20 1/1] ARM: fix the cockup in the previous patch
  2019-01-25 22:40 ` [PATCH 4.20 1/1] ARM: fix the cockup in the previous patch David Long
@ 2019-01-26 17:57   ` Sasha Levin
  0 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2019-01-26 17:57 UTC (permalink / raw)
  To: David Long
  Cc: stable, Russell King - ARM Linux, Florian Fainelli,
	Julien Thierry, Tony Lindgren, Marc Zyngier, Greg KH, Mark Brown

On Fri, Jan 25, 2019 at 05:40:37PM -0500, David Long wrote:
>From: Russell King <rmk+kernel@armlinux.org.uk>
>
>Commit d6951f582cc50ba0ad22ef46b599740966599b14 upstream.
>
>The intention in the previous patch was to only place the processor
>tables in the .rodata section if big.Little was being built and we
>wanted the branch target hardening, but instead (due to the way it
>was tested) it ended up always placing the tables into the .rodata
>section.
>
>Although harmless, let's correct this anyway.
>
>Fixes: 3a4d0c2172bc ("ARM: ensure that processor vtables is not lost after boot")
>Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
>Signed-off-by: David A. Long <dave.long@linaro.org>

Queued for 4.20, thank you.

--
Thanks,
Sasha

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2019-01-25 22:40 [PATCH 4.20 0/1] Fix regression from arm spectre patch series David Long
2019-01-25 22:40 ` [PATCH 4.20 1/1] ARM: fix the cockup in the previous patch David Long
2019-01-26 17:57   ` Sasha Levin

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