Re: [PATCH -tip] [BUGFIX] kprobes/x86: Do not jump-optimize kprobes on irq entry code

From: Masami Hiramatsu
Date: Mon Jul 24 2017 - 21:47:04 EST


On Tue, 25 Jul 2017 09:15:29 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> > arch/x86/kernel/unwind_frame.c is only compiled when CONFIG_FRAME_POINTER
> > is enabled, but CONFIG_KPROBES does not depend on it.
> >
> > Is unwind_frame.c really where in_entry_code() should be implemented, now
> > that its symbol becomes exposed to other compile units ?
>
> At least kprobes needs it. (as far
> It seems we can move it in arch/x86/entry/common.c or
> somewhere in header. (arm has arch/arm/include/asm/traps.h for
> that purpose)

As far as I can see, that code is only for unwinder or kprobes,
and only arm/arm64 has similar code.

I've decided to make this fix kprobe/opt.c local, since this fix
is also needed for stable. I'll send v2 patch soon.

Thanks,

--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>