linux-kernel - Re: Oops in a driver while using SLUB as a SLAB allocator

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: <Pine.LNX.4.64.0706220628420.6142@blonde.wat.veritas.com>
Date:	Fri, 22 Jun 2007 06:37:03 +0100 (BST)
From:	Hugh Dickins <hugh@...itas.com>
To:	Christoph Lameter <clameter@....com>
cc:	Nicolas Ferre <nicolas.ferre@....atmel.com>,
	ARM Linux Mailing List 
	<linux-arm-kernel@...ts.arm.linux.org.uk>,
	Linux Kernel list <linux-kernel@...r.kernel.org>,
	Marc Pignat <marc.pignat@...s.ch>,
	Andrew Victor <andrew@...people.com>,
	Pierre Ossman <drzeus@...eus.cx>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Russell King <rmk@....linux.org.uk>
Subject: Re: Oops in a driver while using SLUB as a SLAB allocator

On Thu, 21 Jun 2007, Christoph Lameter wrote:
> On Fri, 22 Jun 2007, Hugh Dickins wrote:
> 
> > However... what gives you confidence that flush_dcache_page is
> > never applied to other slab pages?
> 
> Flush dcache page is supposed to run on pages not objects of varying 
> length. It is suprising that this has not lead to earlier problems.
> Objects allocated this way may straddle a page boundary under some 
> conditions and in that case virt_to_page may not lead to a page that 
> covers the complete object that is supposed to be flushed. Hopefully the 
> "size" of the allocated object were whole pages.

No, that's the wrong way round.  Neither ARM nor PA-RISC expects
flush_dcache_page to flush any dcache when given a slab allocation:
they just expect it to pass through, not to oops.

Hugh
-
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/