linux-kernel - Re: [PATCH 18 of 38] x86: unify pci iommu setup and allow swiotlb to compile for 32 bit

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:	Wed, 26 Nov 2008 09:36:49 +0000
From:	Ian Campbell <Ian.Campbell@...rix.com>
To:	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>
Cc:	jeremy@...p.org, mingo@...e.hu, linux-kernel@...r.kernel.org,
	xen-devel@...ts.xensource.com, x86@...nel.org
Subject: Re: [PATCH 18 of 38] x86: unify pci iommu setup and allow swiotlb
	to	compile for 32 bit

On Wed, 2008-11-26 at 11:53 +0900, FUJITA Tomonori wrote:
> 
> > +     BUG_ON(max_slots > 1UL << (BITS_PER_LONG - IO_TLB_SHIFT));
> 
> How can this BUG_ON happen? Using u64 for the mask is fine though.

It covers the cases where the previous code would have overflowed. It
can't happen right now because although mask is 64 bits the value
assigned to it is currently sizeof(unsigned long). If someone changes
the type of that field then we would start seeing unexpected values.

Ian.

--
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/