linux-kernel - Re: [GIT PULL v2] Early SLAB fixes for 2.6.31

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, 17 Jun 2009 09:01:16 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Nick Piggin <npiggin@...e.de>
cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Pekka Enberg <penberg@...helsinki.fi>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
	cl@...ux-foundation.org, kamezawa.hiroyu@...fujitsu.com,
	lizf@...fujitsu.com, mingo@...e.hu, yinghai@...nel.org
Subject: Re: [GIT PULL v2] Early SLAB fixes for 2.6.31

On Wed, 17 Jun 2009, Nick Piggin wrote:
> 
> In some cases perhaps it is difficult. In others it should be
> pretty natural. Lots of memory allocating paths pass gfp
> a long way down the stack.

I agree that some cases would be pretty natural. In fact, that's what we 
started out doing. On the x86 side, we didn't have a lot of issues in 
testing, and we fixed them up by using GFP_NOWAIT (see for example 
cpupri_init() in kernel/sched_cpupri.c, or init_irq_default_affinity() in 
kernel/irq/handle.c - both of which were fixed up in that phase).

Those paths, in fact, in general already had "bootmem" flags etc. And x86 
doesn't need to initialize a lot of state at bootup. 

Then Ben happened, and crazy PPC ioremap crap. 

So the problem is exactly that it was perfectly natural to pass down a gfp 
or other flag in _some_ cases. And then in a few cases it's much more 
painful.

		Linus
--
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/