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* arm64: Fix size of __early_cpu_boot_status
@ 2019-04-30 10:35 Arun KS
  2019-04-30 11:06 ` Will Deacon
  2019-05-01 11:01 ` Mark Rutland
  0 siblings, 2 replies; 4+ messages in thread
From: Arun KS @ 2019-04-30 10:35 UTC (permalink / raw)
  To: Catalin Marinas, Will Deacon, James Morse, Mark Rutland, Jun Yao,
	Steve Capper, Arun KS, Vladimir Murzin, linux-arm-kernel,
	linux-kernel

__early_cpu_boot_status is of type long. Use quad
assembler directive to allocate proper size.

Signed-off-by: Arun KS <arunks@codeaurora.org>
---
 arch/arm64/kernel/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index eecf792..115f332 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -684,7 +684,7 @@ ENTRY(__boot_cpu_mode)
  * with MMU turned off.
  */
 ENTRY(__early_cpu_boot_status)
-	.long 	0
+	.quad 	0
 
 	.popsection
 
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: arm64: Fix size of __early_cpu_boot_status
  2019-04-30 10:35 arm64: Fix size of __early_cpu_boot_status Arun KS
@ 2019-04-30 11:06 ` Will Deacon
  2019-05-01  4:57   ` Arun KS
  2019-05-01 11:01 ` Mark Rutland
  1 sibling, 1 reply; 4+ messages in thread
From: Will Deacon @ 2019-04-30 11:06 UTC (permalink / raw)
  To: Arun KS
  Cc: Catalin Marinas, James Morse, Mark Rutland, Jun Yao,
	Steve Capper, Vladimir Murzin, linux-arm-kernel, linux-kernel

On Tue, Apr 30, 2019 at 04:05:04PM +0530, Arun KS wrote:
> __early_cpu_boot_status is of type long. Use quad
> assembler directive to allocate proper size.
> 
> Signed-off-by: Arun KS <arunks@codeaurora.org>
> ---
>  arch/arm64/kernel/head.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index eecf792..115f332 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -684,7 +684,7 @@ ENTRY(__boot_cpu_mode)
>   * with MMU turned off.
>   */
>  ENTRY(__early_cpu_boot_status)
> -	.long 	0
> +	.quad 	0

Yikes. How did you spot this? Did we end up corrupting an adjacent variable,
or does the alignment in the linker script save us in practice?

Will

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: arm64: Fix size of __early_cpu_boot_status
  2019-04-30 11:06 ` Will Deacon
@ 2019-05-01  4:57   ` Arun KS
  0 siblings, 0 replies; 4+ messages in thread
From: Arun KS @ 2019-05-01  4:57 UTC (permalink / raw)
  To: Will Deacon
  Cc: Arun KS, Catalin Marinas, James Morse, Mark Rutland, Jun Yao,
	Steve Capper, Vladimir Murzin, linux-arm-kernel, linux-kernel

On Tue, Apr 30, 2019 at 4:39 PM Will Deacon <will.deacon@arm.com> wrote:
>
> On Tue, Apr 30, 2019 at 04:05:04PM +0530, Arun KS wrote:
> > __early_cpu_boot_status is of type long. Use quad
> > assembler directive to allocate proper size.
> >
> > Signed-off-by: Arun KS <arunks@codeaurora.org>
> > ---
> >  arch/arm64/kernel/head.S | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> > index eecf792..115f332 100644
> > --- a/arch/arm64/kernel/head.S
> > +++ b/arch/arm64/kernel/head.S
> > @@ -684,7 +684,7 @@ ENTRY(__boot_cpu_mode)
> >   * with MMU turned off.
> >   */
> >  ENTRY(__early_cpu_boot_status)
> > -     .long   0
> > +     .quad   0
>
> Yikes. How did you spot this? Did we end up corrupting an adjacent variable,
> or does the alignment in the linker script save us in practice?

Rite now there is no adjacent variable. But I was adding one and it
was getting corrupted.

Regards,
Arun
>
> Will

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: arm64: Fix size of __early_cpu_boot_status
  2019-04-30 10:35 arm64: Fix size of __early_cpu_boot_status Arun KS
  2019-04-30 11:06 ` Will Deacon
@ 2019-05-01 11:01 ` Mark Rutland
  1 sibling, 0 replies; 4+ messages in thread
From: Mark Rutland @ 2019-05-01 11:01 UTC (permalink / raw)
  To: Arun KS
  Cc: Catalin Marinas, Will Deacon, James Morse, Jun Yao, Steve Capper,
	Vladimir Murzin, linux-arm-kernel, linux-kernel

On Tue, Apr 30, 2019 at 04:05:04PM +0530, Arun KS wrote:
> __early_cpu_boot_status is of type long. Use quad
> assembler directive to allocate proper size.
> 
> Signed-off-by: Arun KS <arunks@codeaurora.org>
> ---
>  arch/arm64/kernel/head.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index eecf792..115f332 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -684,7 +684,7 @@ ENTRY(__boot_cpu_mode)
>   * with MMU turned off.
>   */
>  ENTRY(__early_cpu_boot_status)
> -	.long 	0
> +	.quad 	0

This is the last element in .mmuoff.data.write, which is padded to 2K,
so luckily we don't clobber anything else (and don't need a backport).

For consistency with __boot_cpu_mode, we could instead change the c
declaration to int, and fix up the calls to
update_early_cpu_boot_status, to use a w register, but either way:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

>  
>  	.popsection
>  
> -- 
> 1.9.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-05-01 11:01 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-04-30 10:35 arm64: Fix size of __early_cpu_boot_status Arun KS
2019-04-30 11:06 ` Will Deacon
2019-05-01  4:57   ` Arun KS
2019-05-01 11:01 ` Mark Rutland

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