[PATCH 0/2] powerpc: Disable syscall emulation and stepping

[Nicholas Piggin]

+Naveen (sorry missed cc'ing you at first)

Excerpts from Christophe Leroy's message of January 24, 2022 4:39 pm:
> 
> 
> Le 24/01/2022 à 06:57, Nicholas Piggin a écrit :
>> As discussed previously
>> 
>> https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/238946.html
>> 
>> I'm wondering whether PPC32 should be returning -1 for syscall
>> instructions too here? That could be done in another patch anyway.
>> 
> 
> The 'Programming Environments Manual for 32-Bit Implementations of the 
> PowerPC™ Architecture' says:
> 
> The following are not traced:
> • rfi instruction
> • sc and trap instructions that trap
> • Other instructions that cause interrupts (other than trace interrupts)
> • The first instruction of any interrupt handler
> • Instructions that are emulated by software
> 
> 
> So I think PPC32 should return -1 as well.

I agree.

What about the trap instructions? analyse_instr returns 0 for them
which falls through to return 0 for emulate_step, should they
return -1 as well or am I missing something?

Thanks,
Nick