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Re: Unifying /dev/{mem,kmem,zero,null} implementations



Joerg Sonnenberger wrote:
Hi all,
http://www.netbsd.org/~joerg/common-mem.diff
unifies the implementation of /dev/{mem,kmem,zero,null} in MI code and
makes it MPsafe. This is useful as writing to /dev/null is not that
unknown :-)

This needs quite a bit attention from portmasters and testing:
- the address returned by mmap of /dev/mem is not consistent on all
ports, I have no idea if it works on those where atop() doesn't exist.
- on i386, the special /dev/io semantic for COMPAT_10 and COMPAT_FREEBSD
is lost at the moment -- do we want to keep that? It would mean another
platform hook.
- the access permissions for raw memory are inconsistent and should be
changed to use kauth on all platforms.

Over all, the patch adds 1419 lines and removes 6271.

Comments?

Joerg

In dev_mem_readwrite() pmap_kenter_pa and pmap_kremove calls require a pmap_update(pmap_kernel()) after them otherwise the updates may not have been sync'd into the hardware.

Thanks,
Chris


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