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:	Sun, 10 Nov 2013 18:06:26 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Joe Perches <joe@...ches.com>,
	linux-arch <linux-arch@...r.kernel.org>
CC:	mingo@...nel.org, linux-kernel@...r.kernel.org, tglx@...utronix.de,
	james.t.kukunas@...el.com, hpa@...ux.intel.com,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	David Miller <davem@...emloft.net>
Subject: Re: [tip:x86/asm] x86, bitops:  Change bitops to be native operand
 size

On 11/10/2013 02:44 PM, Joe Perches wrote:
> (adding linux-arch, and possible patch below)
> 
> On Sun, 2013-11-10 at 14:10 -0800, H. Peter Anvin wrote:
>> Yes, on the generic it is int.
>>
>> The problem is in part that some architectures have bitop
>> instructions with specific behavior.
> 
> I think that all bitop indices should be changed
> to unsigned (int or long, probably long) for all
> arches.
> 
> Is there any impediment to that?
> 

It is at the very best misleading.  On x86 bit indicies will be signed
no matter what the data type says, and having an unsigned data type
being interpreted as signed seems like really dangerous.

On the other hand, for the generic implementation unsigned long makes sense.

We might need a bitindex_t or something like that for it to be clean.

	-hpa

--
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/

Powered by blists - more mailing lists