Messages in this thread | | | Date | Fri, 03 Jun 2011 14:44:30 +0200 | From | Andreas Oberritter <> | Subject | Re: [PATCH] FE_GET_PROPERTY should be _IOW, because the associated structure is transferred from userspace to kernelspace. Keep the old ioctl around for compatibility so that existing code is not broken. |
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On 06/01/2011 11:15 PM, Mauro Carvalho Chehab wrote: > The dvb_usercopy will do the right thing, if we use _IOR or _IORW.
It only works, because _IOC_READ triggers a copy_from_user, as a workaround for wrongly marked ioctls like this, according to a code comment. It does not really do the right thing, because in this special case the later call to copy_to_user isn't required. But it doesn't do any real harm either.
> I prefer to not apply this patch, as it won't fix anything. Adding an _OLD means > that we'll need later to remove it, causing a regression. Ok, we may do like we did > with V4L _OLD ioctl's that were marked as _OLD at 2.6.5 and were removed on a late > 2.6.3x.
Either way is fine for me.
Regards, Andreas
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