Re: [PATCH v4 1/8] arm64: Do not enable IRQs for ct_user_exit

[Mark Rutland]

On Tue, Jun 11, 2019 at 10:38:06AM +0100, Julien Thierry wrote:
> For el0_dbg and el0_error, DAIF bits get explicitly cleared before
> calling ct_user_exit.
> 
> When context tracking is disabled, DAIF gets set (almost) immediately
> after. When context tracking is enabled, among the first things done
> is disabling IRQs.
> 
> What is actually needed is:
> - PSR.D = 0 so the system can be debugged (should be already the case)
> - PSR.A = 0 so async error can be handled during context tracking
> 
> Do not clear PSR.I in those two locations.
> 
> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
> Reviewed-by: James Morse <james.morse@xxxxxxx>
> Cc:Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Marc Zyngier <marc.zyngier@xxxxxxx>

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

Mark.

> ---
>  arch/arm64/kernel/entry.S | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index cd0c7af..89ab6bd 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -870,7 +870,7 @@ el0_dbg:
>  	mov	x1, x25
>  	mov	x2, sp
>  	bl	do_debug_exception
> -	enable_daif
> +	enable_da_f
>  	ct_user_exit
>  	b	ret_to_user
>  el0_inv:
> @@ -922,7 +922,7 @@ el0_error_naked:
>  	enable_dbg
>  	mov	x0, sp
>  	bl	do_serror
> -	enable_daif
> +	enable_da_f
>  	ct_user_exit
>  	b	ret_to_user
>  ENDPROC(el0_error)
> --
> 1.9.1