While looking at xor_xc_2() I realized that its inline assembly constraints
are incorrect. Also the inline assembly constraints for the other xor()
function look incorrect, but are not (execute instruction vs register
zero). However that revealed another real bug on __stackleak_poison() with
another incorrect inline assembly constraint.

Fix and improve all of them.

Heiko Carstens (3):
  s390/xor: Fix xor_xc_2() inline assembly constraints
  s390/xor: Improve inline assembly constraints
  s390/stackleak: Fix __stackleak_poison() inline assembly constraint

 arch/s390/include/asm/processor.h |  2 +-
 arch/s390/lib/xor.c               | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

-- 
2.51.0

On Mon, Mar 02, 2026 at 02:34:57PM +0100, Heiko Carstens wrote:
> While looking at xor_xc_2() I realized that its inline assembly constraints
> are incorrect. Also the inline assembly constraints for the other xor()
> function look incorrect, but are not (execute instruction vs register
> zero). However that revealed another real bug on __stackleak_poison() with
> another incorrect inline assembly constraint.
> 
> Fix and improve all of them.
> 
> Heiko Carstens (3):
>   s390/xor: Fix xor_xc_2() inline assembly constraints
>   s390/xor: Improve inline assembly constraints
>   s390/stackleak: Fix __stackleak_poison() inline assembly constraint
> 
>  arch/s390/include/asm/processor.h |  2 +-
>  arch/s390/lib/xor.c               | 10 +++++-----
>  2 files changed, 6 insertions(+), 6 deletions(-)

Applied, thank you!

On Mon, Mar 02, 2026 at 02:34:57PM +0100, Heiko Carstens wrote:
> While looking at xor_xc_2() I realized that its inline assembly constraints
> are incorrect. Also the inline assembly constraints for the other xor()
> function look incorrect, but are not (execute instruction vs register
> zero). However that revealed another real bug on __stackleak_poison() with
> another incorrect inline assembly constraint.

No expert on the constraints, but have you considered to just convert
this code to pure assembly?

Otherwise please try to get it into Linus' tree ASAP so that I easily
rebase on that for the XOR series.

On Mon, Mar 02, 2026 at 02:47:51PM +0100, Christoph Hellwig wrote:
> On Mon, Mar 02, 2026 at 02:34:57PM +0100, Heiko Carstens wrote:
> > While looking at xor_xc_2() I realized that its inline assembly constraints
> > are incorrect. Also the inline assembly constraints for the other xor()
> > function look incorrect, but are not (execute instruction vs register
> > zero). However that revealed another real bug on __stackleak_poison() with
> > another incorrect inline assembly constraint.
> 
> No expert on the constraints, but have you considered to just convert
> this code to pure assembly?

In general I don't like pure assembly files, since they come without any
instrumentation. Of course you could (correctly) argue that's the case for the
current inline assembly as well (except for ftrace). However the rest can be
easily fixed/addressed.

But I don't want to rush in even more code to make your life more complicated.

> Otherwise please try to get it into Linus' tree ASAP so that I easily
> rebase on that for the XOR series.

Sure, that should happen before rc3 comes out.