linux-kernel - Re: [rfc] "fair" rw spinlocks

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:	Mon, 07 Dec 2009 15:19:59 -0800
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Andi Kleen <andi@...stfloor.org>
Cc:	paulmck@...ux.vnet.ibm.com,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...e.hu>,
	Christoph Hellwig <hch@...radead.org>,
	Nick Piggin <npiggin@...e.de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Oleg Nesterov <oleg@...hat.com>
Subject: Re: [rfc] "fair" rw spinlocks

Andi Kleen <andi@...stfloor.org> writes:

> ebiederm@...ssion.com (Eric W. Biederman) writes:
>
>> "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com> writes:
>>>
>>> Is it required that all of the processes see the signal before the
>>> corresponding interrupt handler returns?  (My guess is "no", which
>>> enables a trick or two, but thought I should ask.)
>>
>> Not that I recall.  I think it is just an I/O completed signal.
>
> Wasn't there the sysrq SAK too? That one definitely would need
> to be careful about synchronicity.

SAK from sysrq is done through schedule work, I seem to recall the
locking being impossible otherwise.  There is also send_sig_all and a
few others from sysrq.  I expect we could legitimately make them
schedule_work as well if needed.

Eric
--
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/