From: Paul Mackerras <paulus@samba.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Arjan van de Ven <arjan@linux.intel.com>,
hans.rosenfeld@amd.com, linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: bisected boot regression post 2.6.25-rc3.. please revert
Date: Mon, 10 Mar 2008 15:35:41 +1100 [thread overview]
Message-ID: <18388.47773.77106.664217@cargo.ozlabs.ibm.com> (raw)
In-Reply-To: <alpine.LFD.1.00.0803091007560.5896@woody.linux-foundation.org>
Linus Torvalds writes:
> But even for PAGE_MASK, we literally have code like this:
>
> if ((size_avail & PAGE_MASK) < rg.size) {
>
> where it so _happens_ that "size_avail" is unsigned, but what if it
> wasn't? It could turn a unsigned comparison into a signed one, and
> introduce any number of security bugs etc.
We have had PAGE_MASK being signed on powerpc for ages, so if you do
find any such bugs, please let me know. :) I'm not aware of any at
present, though.
The expression you quoted will be ok as long as either size_avail or
rg.size is unsigned, as far as I can see.
Our PAGE_SIZE is unsigned long.
Paul.
next prev parent reply other threads:[~2008-03-10 4:35 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-01 18:56 bisected boot regression post 2.6.25-rc3.. please revert Arjan van de Ven
2008-03-03 7:46 ` Ingo Molnar
2008-03-03 9:13 ` Ingo Molnar
2008-03-03 16:41 ` Arjan van de Ven
2008-03-03 17:40 ` Ingo Molnar
2008-03-03 17:51 ` Nish Aravamudan
2008-03-03 17:55 ` Ingo Molnar
2008-03-03 17:58 ` H. Peter Anvin
2008-03-03 18:36 ` Arjan van de Ven
2008-03-03 18:44 ` Linus Torvalds
2008-03-03 22:00 ` Arjan van de Ven
2008-03-04 1:05 ` Arjan van de Ven
2008-03-04 6:53 ` Ingo Molnar
2008-03-05 15:35 ` Arjan van de Ven
2008-03-09 11:56 ` Ingo Molnar
2008-03-09 17:27 ` Linus Torvalds
2008-03-09 18:57 ` Ingo Molnar
2008-03-10 2:45 ` Jeremy Fitzhardinge
2008-03-10 4:35 ` Paul Mackerras [this message]
2008-03-03 21:13 ` Segher Boessenkool
2008-03-03 21:22 ` Segher Boessenkool
2008-03-03 22:33 ` Segher Boessenkool
2008-03-03 22:55 ` H. Peter Anvin
2008-03-03 22:56 ` Jeremy Fitzhardinge
2008-03-03 23:04 ` H. Peter Anvin
2008-03-04 6:58 ` Ingo Molnar
2008-03-03 17:15 ` Nish Aravamudan
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