Re: [RFC PATCH 02/43] ptrace: cleanup ptrace_request()

From: Arnd Bergmann
Date: Fri Aug 27 2010 - 15:27:07 EST


On Friday 27 August 2010 18:13:35 Namhyung Kim wrote:
> Arnd Bergmann <arnd@xxxxxxxx> writes:
> > If you introduce two pointers, 'siginfo_t __user *usiginfo' and
> > 'unsigned long __user *datap' instead of just 'datap', you can use
> > get_user/put_user everywhere, which would make the code better readable
> > and faster.
> >
> > Otherwise this change looks good.
> >
>
> Despite I don't know how much it can run faster, I just want to keep it as is
> unless it would be a serious mistake. :-)

No, not a mistake, your code is fine as it is and not performance
critical at all.

However, in general using get_user/put_user is preferred over
copy_from_user/copy_to_user for scalar values.

Arnd
--
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/