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Re: ioperm and pseudo devices
From: |
Roland McGrath |
Subject: |
Re: ioperm and pseudo devices |
Date: |
Tue, 19 Nov 2002 19:17:12 -0500 (EST) |
> I think we need a flag in the device structure to mark the type of the
> device more properly than the device ops does. In particular, I am worried
> about someone sending an io perm modify IPC to a non-io perm device port, it
> doesn't look to me as if I coded any guard against this into it.
That RPC goes to the task. You are talking about its argument.
convert_io_perm_to_port needs to check that it's really an io_perm port.
As it happens, I don't think that any other device uses no_device_ops (I
don't recall what it was there for in the first place). So you could use
ops==&no_device_ops as the test. Or to avoid the presumption you could
just make your own all-zeros io_perm_device_ops so that the address would
be unique.
It seems to me we might actually want a device_ops anyway, to have close.
Then io_perm.c could use the oskit interfaces for the global io bitmap,
to disallow an io_perm range that overlaps with a kernel driver.