Date: Wed, 31 Dec 2003 14:02:04 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Robert Watson <rwatson@freebsd.org> Cc: William Michael Grim <wgrim@siue.edu> Subject: Re: pciconf -lv - /dev/pci error Message-ID: <XFMail.20031231140204.jhb@FreeBSD.org> In-Reply-To: <Pine.NEB.3.96L.1031231125153.54208A-100000@fledge.watson.org>
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On 31-Dec-2003 Robert Watson wrote: > > On Wed, 31 Dec 2003, William Michael Grim wrote: > >> I have 5.1-RELEASE installed on my system, and I've never needed to do a >> "pciconf -lv" to probe the system before. However, I tried doing it >> earlier today after logging in through SSH and doing "su -" to become >> superuser. I received this error: >> >> [root@snow 09:12:42 root]# pciconf -lv >> pciconf: /dev/pci: Operation not permitted >> >> [root@snow 09:15:41 root]# ls -l /dev/pci >> crw-r--r-- 1 root wheel 251, 0 Nov 2 05:09 /dev/pci >> >> So, as you can see, the permissions are correct. Perhaps I don't have >> something compiled into my kernel? I can attach a dmesg and kernel >> config if it's necessary. > > pciconf -lv appears to cause pciconf to open /dev/pci writable: > > 731 pciconf CALL open(0x8049a55,0x2,0) > 731 pciconf NAMI "/dev/pci" > 731 pciconf RET open -1 errno 13 Permission denied > > And, of course, it's not writable by non-root. The attached patch causes > pciconf to open /dev/pci read-only when listing devices (apply to > usr.sbin/pciconf/pciconf.c): > > Index: pciconf.c > =================================================================== > RCS file: /home/ncvs/src/usr.sbin/pciconf/pciconf.c,v > retrieving revision 1.19 > diff -u -r1.19 pciconf.c > --- pciconf.c 20 Jun 2003 23:59:25 -0000 1.19 > +++ pciconf.c 31 Dec 2003 17:58:45 -0000 > @@ -165,7 +165,7 @@ > if (verbose) > load_vendors(); > > - fd = open(_PATH_DEVPCI, O_RDWR, 0); > + fd = open(_PATH_DEVPCI, O_RDONLY, 0); > if (fd < 0) > err(1, "%s", _PATH_DEVPCI); > > > > The pci_user.c code in the kernel requires that the caller hold a writable > file descriptor for most of the ioctls; the exception is PCIOCGETCONF, > which is the only ioctl pciconf's list_devs() uses. We can probably just > go ahead and commit this patch, I think. The reason a check was added to > the kernel pci ioctl code is that unaligned writes to /dev/pci can cause > faults, I believe... History is in PR 32677. I do think your patch might be ok if it only applies to the -l case. If so, then it should probably be committed and MFC'd (along with the kernel pci_user.c change) so the PR can be closed. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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