Date: Mon, 16 Jun 2003 11:42:04 -0700 From: John-Mark Gurney <gurney_j@efn.org> To: Robert Watson <rwatson@freebsd.org> Cc: arch@freebsd.org Subject: Re: make /dev/pci really readable Message-ID: <20030616184204.GL73854@funkthat.com> In-Reply-To: <Pine.NEB.3.96L.1030616135002.8726B-100000@fledge.watson.org> References: <20030616074122.GF73854@funkthat.com> <Pine.NEB.3.96L.1030616135002.8726B-100000@fledge.watson.org>
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Robert Watson wrote this message on Mon, Jun 16, 2003 at 13:54 -0400:
>
> On Mon, 16 Jun 2003, John-Mark Gurney wrote:
>
> > Does anyone have an objection to making /dev/pci really honor the
> > permissions, and giving normal users (or just group wheel) premission to
> > run pciconf -l. Right now the code requires the write bit set for any
> > operation.
>
> I seem to recall that there was a problem wherein user processes could
> cause cause unaligned accesses using /dev/pci. There's also some rather
again, I just proposed -l, not -r to become user readable. I know that -r
has problems. I've crashed the sparc box a number of times by specifing
pciconf -r pci1:5:0 0x0:0xf.
> odd use of useracc(), printf(), etc, in the ioctl code. I suspect this
well, do you mean odd use of printf as in providing diagnostics to catch
mismatched userland/kernel?
for useracc, it checks to make sure that various pointers passed to it
are either readable or writable. I don't see this as odd. Or is there
another better method of checking user data when accessing user space
buffers?
other than a minor bug that could hit if there was more pci_devinfo's in
the list than pci_numdevs (which should never happen, but will prevent a
NULL deref), I didn't see anything wrong with -l.
> code needs some fairly thorough review and cleanup before we should reduce
> the level of privilege required to use the device (note that we make it
> world readable by default, so changes in the semantics of read permissions
> will affect all users in the system). Could you do that cleanup in the
> first pass, then revisit the permissions change?
sure, no problem.
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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