Messages in this thread | | | Date | Sun, 23 Jan 2000 23:10:44 +0100 | From | Jens Axboe <> | Subject | Re: Suspicious code in i2c-dev.c |
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On Sun, Jan 23 2000, Frodo Looijaard wrote: > > 2. copy_to_user may fault, and if this is the case, the user will > > never know (the user will not see the EFAULT error code returned). > > > There are more instances of point 2, including some with copy_from_user. > > Hmm. Can you elaborate on that? What exactly will happen when a > copy_{to,from}_user faults? And what does a fault in this instance > mean (cache miss?).
It means that copy_[to|from]_user tried to access memory that didn't belong in the current process address space. In this case they will return non-0 and -EFAULT should be returned to the process.
-- * Jens Axboe <axboe@suse.de> * Linux CD-ROM Maintainer * http://www.kernel.dk
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