linux-kernel - Re: [RFC PATCH v3 2/5] powerpc: Exception hooks for context tracking subsystem

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: <1368435991.19924.35.camel@pasglop>
Date:	Mon, 13 May 2013 19:06:31 +1000
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Li Zhong <zhong@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
	paulmck@...ux.vnet.ibm.com, fweisbec@...il.com, paulus@...ba.org,
	michael@...erman.id.au
Subject: Re: [RFC PATCH v3 2/5] powerpc: Exception hooks for context
 tracking subsystem

On Mon, 2013-05-13 at 16:44 +0800, Li Zhong wrote:
> Yes, the above and hash_page() are two C functions for a same exception.
> And the exception hooks enable RCU usage in those C codes. But for asm
> codes, I think we could assume that there would be no RCU usage there,
> so we don't need wrap them in the hooks.

hash_page() won't start a new RCU, at least not in its current incarnation,
the only thing I can see it ever doing would be to take some RCU read locks one
day (it doesn't today).

low_hash_fault() is a different beast. It will typically kill things, thus
involving sending signals etc... RCU might well be involved.

Cheers,
Ben.


--
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/