Subject: Re: mmap() from kernel to user
To: Kamal R. Prasad <email@example.com>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
Date: 11/21/2004 15:52:45
> I have a device driver in the works for a usb device. I want to
> mmap(ANON_MAP) and pass the fd to userspace
...what fd? mmap doesn't create fds.
> and have it read the fd for the bulk data obtained by the kernel.
Sounds as though you want the kernel to create a file descriptor for
userland to read. How you get it to userland is a minor detail.
If I wanted to do this, I'd create a socketpair - in modern NetBSD you
could also use a pipe, maybe - and hand one end to userland, keeping
the other end for the driver's use.
I don't know enough about USB to speak to the other questions.
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