linux-kernel - Re: [RFC][PATCH] dma-mapping: align default segment_boundary_mask with dma

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: <20200316214506.GC18970@Asurada-Nvidia.nvidia.com>
Date:   Mon, 16 Mar 2020 14:45:06 -0700
From:   Nicolin Chen <nicoleotsuka@...il.com>
To:     Christoph Hellwig <hch@....de>
Cc:     robin.murphy@....com, m.szyprowski@...sung.com,
        linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org
Subject: Re: [RFC][PATCH] dma-mapping: align default segment_boundary_mask
 with dma_mask

Hi Christoph,

On Mon, Mar 16, 2020 at 01:48:50PM +0100, Christoph Hellwig wrote:
> On Fri, Mar 13, 2020 at 05:00:07PM -0700, Nicolin Chen wrote:
> > @@ -736,7 +736,7 @@ static inline unsigned long dma_get_seg_boundary(struct device *dev)
> >  {
> >  	if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
> >  		return dev->dma_parms->segment_boundary_mask;
> > -	return DMA_BIT_MASK(32);
> > +	return (unsigned long)dma_get_mask(dev);
> 
> Just thinking out loud after my reply - shouldn't we just return ULONG_MAX
> by default here to mark this as no limit?

Yea, ULONG_MAX (saying no limit) sounds good to me.