Re: [PATCH Dovetail v3 3/6] arm: irq_pipeline: Fix dovetail_fault_{entry,exit} bypass in hw_breakpoint_pending

Hi Florian,

Florian Bezdeka <[email protected]> writes:

> HW breakpoint / watchpoint handling was bypassing the
> dovetail_fault_{entry,exit} machinery. As a result it could happen that
> the inband IRQ mask was touched from the OOB stage.
>
> There is one more problem in the HW bp/wp handling related to
> interrupts_enabled(). This one will be fixed in a separate patch.
>
> Signed-off-by: Florian Bezdeka <[email protected]>
> ---
>  arch/arm/include/asm/dovetail.h         | 1 +
>  arch/arm/include/asm/trace/exceptions.h | 3 ++-
>  arch/arm/kernel/hw_breakpoint.c         | 6 ++++++
>  3 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/include/asm/dovetail.h b/arch/arm/include/asm/dovetail.h
> index 795a1fb903ec29f4c2fb7b25e70980796804acc0..eeb5d16ad032044a2587822f6b35074d664a9bbc 100644
> --- a/arch/arm/include/asm/dovetail.h
> +++ b/arch/arm/include/asm/dovetail.h
> @@ -16,6 +16,7 @@
>  #define ARM_TRAP_VFP		6	/* VFP floating point exception */
>  #define ARM_TRAP_UNDEFINSTR	7	/* Undefined instruction */
>  #define ARM_TRAP_ALIGNMENT	8	/* Unaligned access exception */
> +#define ARM_TRAP_HW_BREAK	9	/* HW break or watchpoint exception */
>

ARM_TRAP_HW_BREAK would not be caught by xnarch_fault_bp_p() and friends
without fixing them up. What is the expected upside of differentiating
ARM_TRAP_BREAK from ARM_TRAP_HW_BREAK?

-- 
Philippe.