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(-)
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
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
linux-stable-mirror@lists.linaro.org
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David Long -
Sasha Levin