Re: [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set

From: Jisheng Zhang
Date: Tue Aug 20 2019 - 05:03:04 EST


Hi Thomas,

On Tue, 20 Aug 2019 10:53:58 +0200 (CEST) Thomas Gleixner wrote:

>
>
> On Tue, 20 Aug 2019, Jisheng Zhang wrote:
>
> > This is to make the x86 kprobe_ftrace_handler() more common so that
> > the code could be reused in future.
>
> While I agree with the change in general, I can't find anything which
> reuses that code. So the change log is pretty useless and I have no idea
> how this is related to the rest of the series.

In v1, this code is moved from x86 to common kprobes.c [1]
But I agree with Masami, consolidation could be done when arm64 kprobes
on ftrace is stable.

In v2, actually, the arm64 version's kprobe_ftrace_handler() is the same
as x86's, the only difference is comment, e.g

/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */

while in arm64

/* Kprobe handler expects regs->pc = ip + 1 as breakpoint hit */


W/ above, any suggestion about the suitable change log?

Thanks

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2019-August/674417.html