Re: [PATCH v6 1/8] x86: allow to handle errors in text_pokefunction family

From: Petr Mladek
Date: Tue Jan 21 2014 - 08:01:01 EST

On Tue, 2014-01-14 at 18:20 -0500, Steven Rostedt wrote:
> FYI, for future patches, start the subject with a capital letter. ie:
> x86: Allow to handle errors in text_poke function family
> On Tue, 10 Dec 2013 16:42:13 +0100
> Petr Mladek <pmladek@xxxxxxx> wrote:
> > The text_poke functions called BUG() in case of error. This was too strict.
> > There are situations when the system is still usable even when the patching
> > has failed, for example when enabling the dynamic ftrace.
> >
> > This commit modifies text_poke and text_poke_bp functions to return an error
> > code instead of calling BUG(). They used to return the patched address. But
> > the address was just copied from the first parameter. It was no extra
> > information and it has not been used anywhere yet.
> >
> > There are some situations where it is hard to recover from an error. Masami
> > Hiramatsu <> suggested to create
> > text_poke*_or_die() variants for this purpose.
> I don't like the "_or_die()". Although I don't care much about it, I'm
> thinking the x86 maintainers might not like it either.
> What about just doing the test in the places that would call "or_die"?
> ret = text_poke*();
> BUG_ON(ret);

Exactly this solution has been used in v5 of this patch set, see

Masami suggested to use the "or_die()" because BUG_ON() was used on most
locations, see

I personally do not have any strong opinion about it and will do
whatever makes x86 maintainers happy :-)

Best Regards,

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