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Subject: Re: [hwloc-devel] pcilib error messages w/ rhl8 and hwloc-1.3.1rc1
From: Paul H. Hargrove (PHHargrove_at_[hidden])
Date: 2011-12-14 15:56:20


On 12/14/2011 12:45 PM, Paul H. Hargrove wrote:
> Here is a portion of proc_bus_pci_read() from my
> /usr/src/linux-2.4.21-60.EL/drivers/pci/proc.c:
> /*
> * Normal users can read only the standardized portion of the
> * configuration space as several chips lock up when trying to
> read
> * undefined locations (think of Intel PIIX4 as a typical
> example).
> */
> if (capable(CAP_SYS_ADMIN))
> size = PCI_CFG_SPACE_SIZE;
> else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
> size = 128;
> else
> size = 64;
>
> I find that this exact code is still present in linux-2.6.39. So, the
> kernel behavior has not changed in this respect and I suspect
> therefore that more recent libpci is simply masking the short read.

Now that I think of it, this situation seems to imply that running the
code in topology-libpci.c as root on a system w/ a Intel PIIX4
controller could lock-up ones machine. Thoughts?

-Paul

-- 
Paul H. Hargrove                          PHHargrove_at_[hidden]
Future Technologies Group
HPC Research Department                   Tel: +1-510-495-2352
Lawrence Berkeley National Laboratory     Fax: +1-510-486-6900