[PATCH] ARM: kexec: drop invalid assembly argument

[Stefan Agner]

The tst menomic has only a single #<const> argument in Thumb mode. There
is an ARM variant which allows to write #<const> as #<byte>, #<rot>
which probably is where the current syntax comes from.

It seems that binutils does not care about the additional parameter.
Clang however complains in Thumb2 mode:
arch/arm/kernel/relocate_kernel.S:28:12: error: too many operands for
instruction
tst r3,#1,0
^

Drop the unnecessary parameter. This fixes building this file in Thumb2
mode with the Clang integrated assembler.

Link: https://github.com/ClangBuiltLinux/linux/issues/770
Signed-off-by: Stefan Agner <ste...@agner.ch>
---
arch/arm/kernel/relocate_kernel.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S
index 7eaa2ae7aff5..72a08786e16e 100644
--- a/arch/arm/kernel/relocate_kernel.S
+++ b/arch/arm/kernel/relocate_kernel.S
@@ -25,26 +25,26 @@ ENTRY(relocate_new_kernel)
ldr r3, [r0],#4

/* Is it a destination page. Put destination address to r4 */
- tst r3,#1,0
+ tst r3,#1
beq 1f
bic r4,r3,#1
b 0b
1:
/* Is it an indirection page */
- tst r3,#2,0
+ tst r3,#2
beq 1f
bic r0,r3,#2
b 0b
1:

/* are we done ? */
- tst r3,#4,0
+ tst r3,#4
beq 1f
b 2f

1:
/* is it source ? */
- tst r3,#8,0
+ tst r3,#8
beq 0b
bic r3,r3,#8
mov r6,#1024
--
2.25.0

[Russell King - ARM Linux admin]

On Wed, Feb 05, 2020 at 11:59:26PM +0100, Stefan Agner wrote:
> The tst menomic has only a single #<const> argument in Thumb mode. There
> is an ARM variant which allows to write #<const> as #<byte>, #<rot>
> which probably is where the current syntax comes from.
>
> It seems that binutils does not care about the additional parameter.
> Clang however complains in Thumb2 mode:
> arch/arm/kernel/relocate_kernel.S:28:12: error: too many operands for
> instruction
> tst r3,#1,0
> ^
>
> Drop the unnecessary parameter. This fixes building this file in Thumb2
> mode with the Clang integrated assembler.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/770
> Signed-off-by: Stefan Agner <ste...@agner.ch>

Please drop it in the patch system, thanks.

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

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[Nick Desaulniers]

On Wed, Feb 5, 2020 at 3:54 PM Russell King - ARM Linux admin
<li...@armlinux.org.uk> wrote:
>
> On Wed, Feb 05, 2020 at 11:59:26PM +0100, Stefan Agner wrote:
> > The tst menomic has only a single #<const> argument in Thumb mode. There
> > is an ARM variant which allows to write #<const> as #<byte>, #<rot>
> > which probably is where the current syntax comes from.
> >
> > It seems that binutils does not care about the additional parameter.
> > Clang however complains in Thumb2 mode:
> > arch/arm/kernel/relocate_kernel.S:28:12: error: too many operands for
> > instruction
> > tst r3,#1,0
> > ^
> >
> > Drop the unnecessary parameter. This fixes building this file in Thumb2
> > mode with the Clang integrated assembler.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/770
> > Signed-off-by: Stefan Agner <ste...@agner.ch>
>
> Please drop it in the patch system, thanks.

Hi Stefan, did you add this to the patch tracking system? Looks like a
bunch got accepted, but I didn't see it in:
https://www.armlinux.org.uk/developer/patches/section.php?section=20&page=132

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--
Thanks,
~Nick Desaulniers