Messages in this thread | | | Date | Fri, 23 May 2008 13:00:17 +0100 | From | "Tom Spink" <> | Subject | Re: [PATCH 1/1] UIO: Add a write() function to enable/disable interrupts |
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2008/5/23 Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>: > Hello Tom, > >> > Tom Spink wrote: >> >> The added benefit is that the code becomes less complex, as you don't >> >> have to check buffer sizes and copy the integer from userspace. >> > AFAIK this is wrong. You need to copy the integer from userspace in >> > uio_ioctl. Actually it's a value coming from user space, so you need to >> > do it somewhere. >> >> Not really in this case. It's not a *pointer* to a value in >> userspace, so you don't need to copy anything. If it was being used >> to point to a memory location holding a value, then yes, it would need >> to be copied across. But in this case, it's just being used to pass >> across 1 or 0. > ah, OK, you're right. Thanks for correcting my correction :-)
Heh, no problem. My initial idea was just a thought anyway, just to maintain a bit of extensibility if .write is ever needed for something else. :-)
> Uwe
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