linux-kernel - Re: [PATCH v2 2/6] PCI/MSI: Factor out pci_get_msi

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]

Message-ID: <20131002072629.GB29860@dhcp-26-207.brq.redhat.com>
Date:	Wed, 2 Oct 2013 09:26:30 +0200
From:	Alexander Gordeev <agordeev@...hat.com>
To:	Mark Lord <kernel@...rt.ca>
Cc:	Michael Ellerman <michael@...erman.id.au>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Tejun Heo <tj@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-ide@...r.kernel.org" <linux-ide@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>, Joerg Roedel <joro@...tes.org>,
	Jan Beulich <JBeulich@...e.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH v2 2/6] PCI/MSI: Factor out pci_get_msi_cap() interface

On Tue, Oct 01, 2013 at 10:46:32PM -0400, Mark Lord wrote:
> >>> The last pattern makes most of sense to me and could be updated with a more
> >>> clear sequence - a call to (bit modified) pci_msix_table_size() followed
> >>> by a call to pci_enable_msix(). I think this pattern can effectively
> >>> supersede the currently recommended "loop" practice.
> >>
> >> The loop is still necessary, because there's a race between those two calls,
> >> so that pci_enable_msix() can still fail due to lack of MSIX slots.
> > 
> > Moreover, the existing loop pattern is racy and could fail just as easily ;)
> 
> Yes, but it then loops again to correct things.

No. If it failed it should exit the loop.

-- 
Regards,
Alexander Gordeev
agordeev@...hat.com
--
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/