[PATCH] PPC: sstep.c: Add modsw, moduw instruction emulation

[Naveen N. Rao]

On 2016/12/04 10:25PM, PrasannaKumar Muralidharan wrote:
> Add modsw and moduw instruction emulation support to analyse_instr.
> 
> Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar at gmail.com>

Hi Prasanna,
Thanks for the patch! A few minor comments below...

> ---
>  arch/powerpc/lib/sstep.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index 9c78a9c..5acef72 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -1148,6 +1148,15 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
>  				(int) regs->gpr[rb];
>  			goto arith_done;
> 
> +		case 779:	/* modsw */
> +			regs->gpr[rd] = (int) regs->gpr[ra] %
> +				(int) regs->gpr[rb];
> +			goto arith_done;

Since these instructions don't update CR, you can directly goto 
instr_done.

> +
> +		case 267:	/* moduw */

Please move this case further up so that the extended opcodes are in 
numerical order.


- Naveen