On Mon, Nov 19, 2012 at 02:48:06PM +0000, Russell King - ARM Linux wrote:
On Mon, Nov 19, 2012 at 04:32:36PM +0200, Ville Syrjälä wrote:
On Thu, Nov 15, 2012 at 02:39:41PM +0000, Arnd Bergmann wrote:
On Thursday 15 November 2012, Rob Clark wrote:
I still haven't heard a conclusive argument why we need to use get_user() rather than copy_from_user() in the DRM code. Is this about a fast path where you want to shave off a few cycles for each call, or does this simplify the code structure, or something else?
well, it is mostly because it seemed like a good idea to first try to solve the root issue, rather than having to fix things up in each driver when someone from x86-world introduces a 64b get_user()..
As pointed out by hpa earlier, x86-32 doesn't have a 64b get_user either. I don't think we have a lot of drivers that are used only on 64-bit x86 and on 32-bit ARM but not on 32-bit x86.
Ouch. I didn't realize that x86-32 doesn't have it. All the systems where I've run the new code are 64bit so I never noticed the problem.
I see there was a patch [1] posted a long time ago to implement 64bit get_user() on x86-32. I wonder what happened to it?
Wonderful lkml.org after four "Negotiating SSL connection..." messages gives me under elinks...
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what a wonderful site... please choose another LKML archive, preferably one which works. Thanks.
This one look like the same thing: http://article.gmane.org/gmane.linux.kernel/198823