Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 24 Jun 2003 12:01:31 +0100 | From | Russell King <> | Subject | Re: Provide example copy_in_user implementation |
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On Tue, Jun 24, 2003 at 12:25:51PM +0200, Pavel Machek wrote: > On Út 24-06-03 11:18:20, Russell King wrote: > > On Tue, Jun 24, 2003 at 12:06:10PM +0200, Pavel Machek wrote: > > > This patch adds example copy_in_user implementation (copy_in_user is > > > needed for new ioctl32 implementation, all 64bit archs will need > > > it)... Please apply, > > > > get_user / put_user on byte quantities may be faster than using > > copy_from_user/copy_to_user on byte quantities. Yes, it may be > > a generic implementation, but there's no point in purposely making > > it inefficient. > > Actually, it seems that most architectures do... > > static inline unsigned long > __copy_from_user(void *to, const void __user *from, unsigned long n) > { > if (__builtin_constant_p(n)) { > unsigned long ret; > > switch (n) { > case 1: > > > ...so it should be exactly as fast. Ahha, not arm.
Note that ARM isn't 64 bit, I'm not worried about it. Given that code does get cut'n'pasted about the place, I still think its a good idea. But its your code...
-- Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html
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