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

From: Steven Rostedt
Date: Tue Jan 14 2014 - 18:20:46 EST



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 <masami.hiramatsu.pt@xxxxxxxxxxx> 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);

?

-- Steve

>
> Last but not least, we modify return value of the text_poke_early() function.
> It is not capable of returning an error code. Let's return void to make
> it clear.
>
> Finally, we also need to modify the few locations where text_poke functions
> were used and the error code has to be handled now.
>
> Signed-off-by: Petr Mladek <pmladek@xxxxxxx>
> ---

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/