Messages in this thread | | | Date | Wed, 28 Apr 1999 17:04:02 -0400 (EDT) | From | Denis Gerasimov <> | Subject | Re: verify_area(...) possible problem. |
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On Mon, 12 Apr 1999, Linus Torvalds wrote: .... > Basically, you should always use a kernel-space buffer. Just accept that > as a fundamental notion, and your life suddenly turns a lot easier. > > Now, I know about zero-copy. I'm not a big believer in it, but I certainly > know about it. And having a kernel buffer does not imply that you can't do > zero-copy. It just means that you can' tdo the initial copy to user space. > > Sounds contradictory? Think "mmap()". It works, it's there, and magically > all the problems go away. Don't make the mountain go to Mohammed. Instead, > think of your problem the other way around: instead of the kernel writing > to user space, think of it as user space asking to see a window of a > kernel buffer. You make a device driver that has a mmap() function, and > suddenly the device driver can write to kernel memory, and whatever it > writes magically shows up in user space too.
Can some kind soul point me in the right direction here? I mean a code example or a page which describes this in detail. Basically I need to have a buffer shared between a kernel space and user space.
Thanks!
Dennis Gerasimov
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