linux-kernel - Re: SCSI breakage on non-cache coherent architectures

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, 20 Nov 2007 11:34:24 +1100
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	David Miller <davem@...emloft.net>
Cc:	James.Bottomley@...senPartnership.com,
	linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org,
	rmk@....linux.org.uk
Subject: Re: SCSI breakage on non-cache coherent architectures

On Mon, 2007-11-19 at 14:31 -0800, David Miller wrote:
> From: Benjamin Herrenschmidt <benh@...nel.crashing.org>
> Date: Tue, 20 Nov 2007 06:51:14 +1100
> 
> > On Mon, 2007-11-19 at 00:38 -0800, David Miller wrote:
> > > From: Benjamin Herrenschmidt <benh@...nel.crashing.org>
> > > Date: Mon, 19 Nov 2007 16:35:23 +1100
> > > 
> > > You could make a ____dma_cacheline_aligned and use that.
> > > It seems pretty reasonable.
> > 
> > I was thinking about that. What archs would need it ? arm, mips, what
> > else ?
> 
> The sparc32 port would need it too.

James preference seem to go for a revert of the patch that removed the
kmalloc of the buffer instead. Sounds definitely like an easier plan
for .24 (and maybe even backport to stable).

I'll produce a patch for that later today or tomorrow.

Do you still think we should introduce this __dma_cacheline_aligned ? Do
you see other cases of drivers where it would be useful ? It tend to
agree with your earlier statement that drivers doing that are broken and
should be using a separate allocator for DMA'ble objects (in fact, on
non-cache coherent archs, kmalloc is just fine).

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/