Re: [patch 4/8] Immediate Value - i386 Optimization; kprobes

From: Andi Kleen
Date: Mon Jun 18 2007 - 15:33:22 EST


On Monday 18 June 2007 20:56:32 Andrew Morton wrote:
> On Mon, 18 Jun 2007 14:44:57 -0400
> Chuck Ebbert <cebbert@xxxxxxxxxx> wrote:
>
> > > I fancy it's done by the kprobe_page_fault handler, but I do not see
> > > clearly how writing the breakpoint from arch_arm_kprobe() in
> > > non-writeable memory is done.
> >
> > Looks like it's not merged yet:
> >
> > http://lkml.org/lkml/2007/6/7/2
> >
> > This needs to go in before 2.6.22-final
>
> Andi, I'll include the below two patches in the next batch, OK?

It won't work reliably unless some of the c_p_a() fixes get in first.

>
>
>
> +extern int kernel_text_is_ro;

No externs in .c files


I also don't like kernel_text_is_read_only() much, it would
be better to just lookup_address() it and check the write flag.

But for 2.6.22 as a quick fix it might be better to just
make KPROBES dependent on !DEBUG_RODATA. That would be a one liner.

-Andi
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