Re: [PATCH v3] powerpc/uprobes: Validation for prefixed instruction

[Ravi Bangoria]

> > @@ -41,6 +41,14 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
> >   	if (addr & 0x03)
> >   		return -EINVAL;
> >   
> > +	if (!IS_ENABLED(CONFIG_PPC64) || !cpu_has_feature(CPU_FTR_ARCH_31))
> > +		return 0;
>
> Sorry, I missed this last time, but I think we can drop the above
> checks. ppc_inst_prefixed() already factors in the dependency on
> CONFIG_PPC64,

Yeah, makes sense. I initially added CONFIG_PPC64 check because
I was using ppc_inst_prefix(x, y) macro which is not available
for !CONFIG_PPC64.

> and I don't think we need to confirm if we're running on a
> ISA V3.1 for the below check.

Prefixed instructions would be supported only when ARCH_31 is set.
(Ignoring insane scenario where user probes on prefixed instruction
on p10 predecessors). So I guess I still need ARCH_31 check?

Ravi