linux-kernel - Re: unchecked_isa_dma and BusLogic SCSI controller

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] [day] [month] [year] [list]

Message-ID: <20061102133548.GA27715@infradead.org>
Date:	Thu, 2 Nov 2006 13:35:48 +0000
From:	Christoph Hellwig <hch@...radead.org>
To:	Matthew Wilcox <matthew@....cx>
Cc:	Randy Dunlap <randy.dunlap@...cle.com>, Jun Sun <jsun@...sun.net>,
	linux-scsi@...r.kernel.org, lkml <linux-kernel@...r.kernel.org>
Subject: Re: unchecked_isa_dma and BusLogic SCSI controller

On Thu, Nov 02, 2006 at 05:41:28AM -0700, Matthew Wilcox wrote:
> On Wed, Nov 01, 2006 at 05:33:58PM -0800, Randy Dunlap wrote:
> >     unchecked_isa_dma - 1=>only use bottom 16 MB of ram (ISA DMA addressing
> >                    restriction), 0=>can use full 32 bit (or better) DMA
> >                    address space
> > 
> > > It is hard for me to see why BusLogic controller would only do DMA
> > > in low 16MB.  Is there a fix for this?
> > 
> > Does anyone know that controller hardware and its limitations?
> 
> I don't, but:
> 
> 		if (pci_set_dma_mask(PCI_Device, DMA_32BIT_MASK ))
> 			continue;
> 
> So somebody thinks the device can do 32-bit addressing.  I would expect
> that setting unchecked_isa_dma is a historical mistake.  However, I
> don't have any cards of this type to test.

The buslogic driver also supports non-PCI devices, and at least the
ISA boards have the obvious limitiation that unchecked_isa_dma = 1
caters to.  Now someone would have to audit the driver whether it's
enough to only set this on the actual isa hosts instead of the host
template.
-
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/