Re: [PATCH v2 20/28] arm64: Save spsr in pt_regs

[Sean Anderson]

On 3/10/22 3:50 PM, Sean Anderson wrote:
> This register holds "pstate" which includes (among other things) the
> instruction mode the CPU was in when the exception was taken. This is
> necessary to correctly interpret instructions at elr.
> 
> Signed-off-by: Sean Anderson <sean.ander...@seco.com>
> ---
> 
> Changes in v2:
> - New
> 
>  arch/arm/cpu/armv8/exceptions.S         | 5 ++++-
>  arch/arm/include/asm/proc-armv/ptrace.h | 2 +-
>  2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/cpu/armv8/exceptions.S b/arch/arm/cpu/armv8/exceptions.S
> index 001913f429..270d9df518 100644
> --- a/arch/arm/cpu/armv8/exceptions.S
> +++ b/arch/arm/cpu/armv8/exceptions.S
> @@ -77,15 +77,18 @@ _save_el_regs:
>       switch_el x11, 3f, 2f, 1f
>  3:   mrs     x1, esr_el3
>       mrs     x2, elr_el3
> +     mrs     x3, spsr_el3
>       b       0f
>  2:   mrs     x1, esr_el2
>       mrs     x2, elr_el2
> +     mrs     x3, spsr_el3
>       b       0f
>  1:   mrs     x1, esr_el1
>       mrs     x2, elr_el1
> +     mrs     x3, spsr_el3

s/el3/el1/ (and the same thing for el2)

Will be fixed in v3

--Sean

>  0:
>       stp     x1, x0, [sp, #-16]!
> -     stp     xzr, x2, [sp, #-16]!
> +     stp     x3, x2, [sp, #-16]!
>       mov     x0, sp
>       ret
>  
> diff --git a/arch/arm/include/asm/proc-armv/ptrace.h 
> b/arch/arm/include/asm/proc-armv/ptrace.h
> index bebcaf6e33..3b8fe7aac0 100644
> --- a/arch/arm/include/asm/proc-armv/ptrace.h
> +++ b/arch/arm/include/asm/proc-armv/ptrace.h
> @@ -21,7 +21,7 @@
>   * on the stack during an exception.
>   */
>  struct pt_regs {
> -     unsigned long unused;
> +     unsigned long spsr;
>       unsigned long elr;
>       unsigned long esr;
>       unsigned long regs[31];
>