linux-kernel - Re: x86: PCI multi domain/segment config access

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 11 Jul 2008 15:21:17 -0600
From:	Matthew Wilcox <matthew@....cx>
To:	John Keller <jpk@....com>
Cc:	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: x86: PCI multi domain/segment config access

On Fri, Jul 11, 2008 at 04:13:47PM -0500, John Keller wrote:
> On x86 PCI Config space access to domains/segments > 0 appears to be broken.
> The noted patch related to PCI ext config space has all config accesses
> to offsets < 256 using conf1 if available, which is most likely the case.
> 
> This would force usage of conf1 for non-extended config access (< 256) on
> PCI domains > 0.
> 
> Am I missing something, or how would a conf1 access reference a domain
> other than zero?

You're correct.  Sorry about that, I wasn't thinking about domains at
the time I wrote the patch.  Try this:

[X86] Fix PCI config space for domains > 0

John Keller reports that PCI config space access is broken on machines
with more than one domain.  conf1 accesses only work for domain 0.

Signed-off-by: Matthew Wilcox <willy@...ux.intel.com>

diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 6e64aaf..fe33533 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -31,7 +31,7 @@ struct pci_raw_ops *raw_pci_ext_ops;
 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 						int reg, int len, u32 *val)
 {
-	if (reg < 256 && raw_pci_ops)
+	if (domain == 0 && reg < 256 && raw_pci_ops)
 		return raw_pci_ops->read(domain, bus, devfn, reg, len, val);
 	if (raw_pci_ext_ops)
 		return raw_pci_ext_ops->read(domain, bus, devfn, reg, len, val);
@@ -41,7 +41,7 @@ int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
 						int reg, int len, u32 val)
 {
-	if (reg < 256 && raw_pci_ops)
+	if (domain == 0 && reg < 256 && raw_pci_ops)
 		return raw_pci_ops->write(domain, bus, devfn, reg, len, val);
 	if (raw_pci_ext_ops)
 		return raw_pci_ext_ops->write(domain, bus, devfn, reg, len, val);

-- 
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/