Re: [PATCH v9 3.2 2/9] uprobes: handle breakpoint and signal step exception.

From: Mike Frysinger
Date: Fri Jan 20 2012 - 17:58:14 EST


On Wed, Jan 18, 2012 at 06:01, Mike Frysinger wrote:
> On Wednesday 18 January 2012 05:47:49 Srikar Dronamraju wrote:
>> > On Wednesday 18 January 2012 04:02:32 Srikar Dronamraju wrote:
>> > > > Â Can we use existing SET_IP() instead of set_instruction_pointer() ?
>> > >
>> > > Oleg had already commented about this in one his uprobes reviews.
>> > >
>> > > The GET_IP/SET_IP available in include/asm-generic/ptrace.h doesnt work
>> > > on all archs. Atleast it doesnt work on powerpc when I tried it.
>> >
>> > so migrate the arches you need over to it.
>>
>> One question that could be asked is why arent we using instruction_pointer
>> instead of GET_IP since instruction_pointer is being defined in 25
>> places and with references in 120 places.
>
> i think you misunderstand the point. Â{G,S}ET_IP() is the glue between the
> arch's pt_regs struct and the public facing API. Âthe only people who should
> be touching those macros are the ptrace core. Âinstruction_pointer() and
> instruction_pointer_set() are the API that asm/ptrace.h exports to the rest of
> the tree.

Srikar: does that make sense ? i'm happy to help with improving
asm-generic/ptrace.h.
-mike
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