linux-kernel - Re: [PATCH] markers: bit-field is not thread-safe nor smp-safe

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Fri, 10 Oct 2008 09:35:21 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Cc:	Lai Jiangshan <laijs@...fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] markers: bit-field is not thread-safe nor smp-safe


* Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca> wrote:

> * Lai Jiangshan (laijs@...fujitsu.com) wrote:
> > 
> > bit-field is not thread-safe nor smp-safe.
> > 
> > struct marker_entry.rcu_pending is not protected by any lock
> > in rcu-callback free_old_closure().
> > so we must turn it into a safe type.
> > 
> 
> 
> hrm, yes, you are right. I first test for 
> 
>         if (entry->rcu_pending)
>            rcu_barrier_sched();
> 
> To check if I must execute the rcu callback, and _this_ races against
> the entry->rcu_pending = 0; within the callback.
> 
> Your fix is therefore needed.
> 
> Thanks !
> 
> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>

applied to tip/tracing/markers, thanks guys!

	Ingo
--
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/