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  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, 16 Jan 2017 16:13:19 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Byungchul Park <byungchul.park@....com>
Cc:     mingo@...nel.org, tglx@...utronix.de, walken@...gle.com,
        boqun.feng@...il.com, kirill@...temov.name,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        iamjoonsoo.kim@....com, akpm@...ux-foundation.org,
        npiggin@...il.com
Subject: Re: [PATCH v4 07/15] lockdep: Implement crossrelease feature

On Fri, Dec 09, 2016 at 02:12:03PM +0900, Byungchul Park wrote:
> +	/*
> +	 * We assign class_idx here redundantly even though following
> +	 * memcpy will cover it, in order to ensure a rcu reader can
> +	 * access the class_idx atomically without lock.
> +	 *
> +	 * Here we assume setting a word-sized variable is atomic.

which one, where?

> +	 */
> +	xlock->hlock.class_idx = hlock->class_idx;
> +	gen_id = (unsigned int)atomic_inc_return(&cross_gen_id);
> +	WRITE_ONCE(xlock->gen_id, gen_id);
> +	memcpy(&xlock->hlock, hlock, sizeof(struct held_lock));
> +	INIT_LIST_HEAD(&xlock->xlock_entry);
> +	list_add_tail_rcu(&xlock->xlock_entry, &xlocks_head);


Powered by blists - more mailing lists