Messages in this thread Patch in this message |  | | Subject | Re: [PATCH v2 10/13] kprobes: Remove uneeded kernel dependency on struct arch_specific_insn | From | "Jon Medhurst (Tixy)" <> | Date | Wed, 13 Nov 2013 17:13:53 +0000 |
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On Tue, 2013-10-15 at 17:04 -0400, David Long wrote: > From: "David A. Long" <dave.long@linaro.org> > > Instead of depending on include/asm/kprobes.h to provide a dummy definition > for struct arch_specific_insn, do so in include/linux/kprobes.h.
That change description doesn't quite seem to quite make sense to me.
Anyway, what we're trying to do with this patch is to allow us to use arch_specific_insn for purposes additional to implementing kprobes. This patch enables that but I'm wary that the kprobes code assumes that ainsn is a struct arch_specific_insn, e.g. in linux/kernel/kprobes.c we have:
memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn));
Now, that code isn't compiled when kprobes isn't configured, but it seams to me to be safer if that was also changed to
memcpy(&p->ainsn, &ap->ainsn, sizeof(p->ainsn));
However, I also wonder if we should instead leave arch_specific_insn as a kprobes specific structure and on ARM define it in terms of a new more generic 'struct probe_insn'? The drawback with that is that we'd probably end up with a struct just containing a single member which seems a bit redundant:
struct arch_specific_insn { struct probe_insn pinsn; };
Thought's anyone?
> > Signed-off-by: David A. Long <dave.long@linaro.org> > --- > include/linux/kprobes.h | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h > index 925eaf2..4b5a74d 100644 > --- a/include/linux/kprobes.h > +++ b/include/linux/kprobes.h > @@ -52,9 +52,6 @@ > > #else /* CONFIG_KPROBES */ > typedef int kprobe_opcode_t; > -struct arch_specific_insn { > - int dummy; > -}; > #endif /* CONFIG_KPROBES */ > > struct kprobe; > @@ -110,7 +107,11 @@ struct kprobe { > kprobe_opcode_t opcode; > > /* copy of the original instruction */ > +#ifdef CONFIG_KPROBES > struct arch_specific_insn ainsn; > +#else > + int ainsn; > +#endif > > /* > * Indicates various status flags.
-- Tixy
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