linux-kernel - Re: [PATCH v7u1 26/31] x86: Don't enable swiotlb if there is not enough ram for it

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 Jan 2013 11:35:48 -0500
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	Yinghai Lu <yinghai@...nel.org>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Shuah Khan <shuahkhan@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Borislav Petkov <bp@...en8.de>, Jan Kiszka <jan.kiszka@....de>,
	Jason Wessel <jason.wessel@...driver.com>,
	linux-kernel@...r.kernel.org, Joerg Roedel <joro@...tes.org>
Subject: Re: [PATCH v7u1 26/31] x86: Don't enable swiotlb if there is not
 enough ram for it

On Thu, Jan 10, 2013 at 03:07:10PM -0800, Yinghai Lu wrote:
> On Wed, Jan 9, 2013 at 1:15 PM, Yinghai Lu <yinghai@...nel.org> wrote:
> > On Wed, Jan 9, 2013 at 1:00 PM, Eric W. Biederman <ebiederm@...ssion.com> wrote:
> >> Yinghai Lu <yinghai@...nel.org> writes:
> >>
> >>> please check updated attached. It should address all your request.
> >>
> >> There is one significant bug that I can see.
> >>
> >> swiotlb_print_info tests no_iotlb_memory but no_iotlb_memory is set
> >> after swiotlb_init_with_tlb returns.
> >
> > there is another swiotlb_print_info calling from
> > pci_swiotlb_late_init
> >
> > void __init pci_swiotlb_late_init(void)
> > {
> >         /* An IOMMU turned us off. */
> >         if (!swiotlb)
> >                 swiotlb_free();
> >         else {
> >                 printk(KERN_INFO "PCI-DMA: "
> >                        "Using software bounce buffering for IO (SWIOTLB)\n");
> >                 swiotlb_print_info();
> >         }
> > }
> >
> > so we need that checking when swiotlb == 1, but actually we can not
> > allocate that before.
> 
> Eric, so the code is right to put checking in swiotlb_print_info ?
> 
> I'd like to post the whole patchset again and ask HPA to put them in tip/next
> to catch -v3.9 merging window.

I'm the frontline maintainer of swiotlb and related stuff so if you want to follow
the proper protocol you should wait until I give you my Ack.

I need to check this patch out and then also test-run them on IA64, AMD-VI, Calgary-X
GART and Intel VT-d to make a sanity test.

However, this particular patch can go outside the mega-patchset you have. So you
could post the mega-patchset to hpa without this being in it and just mention
that there is this extra one that Konrad is handling.
--
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/