Re: [PATCH 1/2] error-injection: Simplify arch specific helpers

From: Masami Hiramatsu
Date: Fri Jun 01 2018 - 19:13:09 EST


On Thu, 31 May 2018 15:39:03 +0530
"Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx> wrote:

> Masami Hiramatsu wrote:
> > On Tue, 29 May 2018 18:06:02 +0530
> > "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx> wrote:
> >
> >> We already have an arch-independent way to set the instruction pointer
> >> with instruction_pointer_set(). Using this allows us to get rid of the
> >> need for override_function_with_return() that each architecture has to
> >> implement.
> >>
> >> Furthermore, just_return_func() only has to encode arch-specific
> >> assembly instructions to return from a function. Introduce a macro
> >> ARCH_FUNC_RET to provide the arch-specific instruction and move over
> >> just_return_func() to generic code.
> >>
> >> With these changes, architectures that already support kprobes, only
> >> just need to ensure they provide regs_set_return_value(), GET_IP() (for
> >> instruction_pointer_set()), and ARCH_FUNC_RET to support error
> >> injection.
> >
> > Nice! the code basically good to me. Just one comment, ARCH_FUNC_RET sounds
> > like a function. Maybe ARCH_RETURN_INSTRUCTION will be better name, isn't it? :)
>
> Sure -- I thought of writing ARCH_FUNCTION_RETURN, but felt that was too
> verbose. How about ARCH_FUNC_RET_INST?

It is OK if we can recognize it is an instruction.

Thank you,

--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>