[RFC 2/2] powerpc/kprobes: Move kprobes over to patch_instruction

[Naveen N. Rao]

On 2017/05/17 11:40AM, Balbir Singh wrote:
> On Tue, 2017-05-16 at 19:05 +0530, Naveen N. Rao wrote:
> > On 2017/05/16 01:49PM, Balbir Singh wrote:
> > > arch_arm/disarm_probe use direct assignment for copying
> > > instructions, replace them with patch_instruction
> > 
> > Thanks for doing this!
> > 
> > We will also have to convert optprobes and ftrace to use 
> > patch_instruction, but that can be done once the basic infrastructure is 
> > in.
> >
> 
> I think these patches can go in without even patch 1. I looked quickly at
> optprobes and ftrace and thought they were already using patch_instruction
> (ftrace_modify_code() and arch_optimize_kprobes()), are there other paths
> I missed?

[Sorry for the delay...]

Yes, all the patch_*_insns() functions need to be converted since the 
area they patch comes from .text. There is also a memcpy() where we copy 
the instruction template in, so perhaps a patch_instructions() helper 
may be useful too.

- Naveen