Re: Re: [PATCH ftrace/core v3 2/3] ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2014/07/18 22:51), Steven Rostedt wrote:
> On Fri, 18 Jul 2014 16:09:07 +0900
> Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> 
> 
>>> "The ops can modify the IP register. This can only be set along with
>>> SAVE_REGS. If another ops is already registered for any of the
>>> functions that this ops will be registered for, then this ops will fail
>>> to register."
>>
>> Not only register, but also set_filter_ip ;)
>> "...will fail to register or set_filter_ip."
> 
> Sure.
> 
> 
>>>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
>>>> index 3214289..e52d86f 100644
>>>> --- a/kernel/kprobes.c
>>>> +++ b/kernel/kprobes.c
>>>
>>> I think this should be split into two patches. One that adds the ftrace
>>> infrastructure, and the other that adds the kprobes user of the
>>> IPMODIFY flag.
>>
>> Hmm, I thought that it was natural to introduce new feature and its user
>> together, so that we could use git-bisect safely.
> 
> It should still be bisect friendly. That is, the feature is added
> before the user, not the user before the feature ;-)

Ah, I see.

> I know some people like the feature and user in one patch, but for me,
> when the user is in a different sub system (here it's kprobes) from the
> infrastructure that is changing (ftrace), I prefer separate patches.
> 
> The user patch shows me where the users are. When they are one patch, I
> tend to have them get lost.

OK, then I'll decouple it :)

Thanks!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com