linux-kernel - Re: [crash] Re: Latest brk patchset

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]

Message-ID: <49BED431.5070201@zytor.com>
Date:	Mon, 16 Mar 2009 15:35:29 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
CC:	Yinghai Lu <yinghai@...nel.org>, Ingo Molnar <mingo@...e.hu>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [crash] Re: Latest brk patchset

Jeremy Fitzhardinge wrote:
> H. Peter Anvin wrote:
>> Or simplified:
>>
>> PAGE_TABLE_SIZE(((1 << 32)-PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT
> 
> Was worried about 1<<32 overflowing.  Never really sure what gas's type 
> system is.
> 

It's bignum-based.

You could also write:

PAGE_TABLE_SIZE((-PAGE_OFFSET & 0xffffffff) >> PAGE_SHIFT) << PAGE_SHIFT

(the & 0xffffffff is necessary, or you'll get a signed shift.)

	-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/