Re: kernel read/write
Quoting Michael Edward Christman (mec60@columbia.edu):
> I'm trying to write between the application level and the kernel. I am
> using version 2.0.34 and am attempting to use memcpy_tofs and
> memcpy_fromfs, but am having some trouble. If I use these functions in
> the application level, what do I use for the *to and *from variables. I
> assume that you can use a FILE for whatever is in the user space,
Yes, it's the second argument of the foo_read or foo_write.
> but
> where is the data stored in the kernel? Is it something like /dev/file?,
> and if so, how do I assign a pointer to it?
It's just an automatic (I think that's the jargon; ordinary) variable
declared in the routine. Or are you talking large transfers? Then
you'd have to kmalloc some memory.
One of the nice things about 2.2 kernels is that get/put_user do
all the VERIFY_... checking for you (assuming you're doing single
value read/writes).
> WBTE
> (Wet Behind The Ears)
ditto.
Cheers,
--
Email: d.wright@open.ac.uk Tel: +44 1908 653 739 Fax: +44 1908 655 151
Snail: David Wright, Earth Science Dept., Milton Keynes, England, MK7 6AA
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