linux-kernel - Re: [PATCH 1/2] PCI: Split pci_assign_unassigned

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:	Tue, 07 May 2013 10:50:26 +1000
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Yinghai Lu <yinghai@...nel.org>
Cc:	Bjorn Helgaas <bhelgaas@...gle.com>,
	Gavin Shan <shangw@...ux.vnet.ibm.com>,
	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] PCI: Split pci_assign_unassigned_resources to per
 root bus

On Mon, 2013-05-06 at 16:15 -0700, Yinghai Lu wrote:
> BenH reported that there is some assign unassigned resource problem
> in powerpc.
> 
> It turns out after
> | commit 0c5be0cb0edfe3b5c4b62eac68aa2aa15ec681af
> | Date:   Thu Feb 23 19:23:29 2012 -0800
> |
> |    PCI: Retry on IORESOURCE_IO type allocations
> 
> even the root bus does not have io port range, it will keep retrying
> to realloc with mmio.
> 
> Current retry logic is : try with must+optional at first, and if
> it fails will try must then try to extend must with optional.
> That will fail as mmio-non-pref and mmio-pref for bridge will
> be next to each other. So we have no chance to extend mmio-non-pref.

Shouldn't you do completely separate passes for IO and MMIO through the
whole lot instead since they are completely separate address spaces ?

IE. Even a legit setup with IOs, in case of failures on the IO side
(resource exhaustion, FW bugs, ...) we shouldn't retry the memory side
and vice-versa.

Note that I'm a bit worried by how invasive your proposed patch is. I
will let Gavin test it and if it works I'm happy but keep in mind that I
really need that fixed in 3.10 ... (especially since there are noises
around about a certain enterprise distro using that version...)

Cheers,
Ben.

--
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/