linux-kernel - Re: [PATCH v3 01/17] hashtable: introduce a small and naive hashtable

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: <1346944293.1680.26.camel@gandalf.local.home>
Date:	Thu, 06 Sep 2012 11:11:33 -0400
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Josh Triplett <josh@...htriplett.org>
Cc:	Sasha Levin <levinsasha928@...il.com>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Pedro Alves <palves@...hat.com>, Tejun Heo <tj@...nel.org>,
	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	paul.gortmaker@...driver.com, davem@...emloft.net, mingo@...e.hu,
	ebiederm@...ssion.com, aarcange@...hat.com, ericvh@...il.com,
	netdev@...r.kernel.org, eric.dumazet@...il.com, axboe@...nel.dk,
	agk@...hat.com, dm-devel@...hat.com, neilb@...e.de,
	ccaulfie@...hat.com, teigland@...hat.com,
	Trond.Myklebust@...app.com, bfields@...ldses.org,
	fweisbec@...il.com, jesse@...ira.com,
	venkat.x.venkatsubra@...cle.com, ejt@...hat.com,
	snitzer@...hat.com, edumazet@...gle.com, linux-nfs@...r.kernel.org,
	dev@...nvswitch.org, rds-devel@....oracle.com, lw@...fujitsu.com
Subject: Re: [PATCH v3 01/17] hashtable: introduce a small and naive
 hashtable

On Thu, 2012-09-06 at 07:55 -0700, Josh Triplett wrote:

> > My solution to making 'break' work in the iterator is:
> > 
> > 	for (bkt = 0, node = NULL; bkt < HASH_SIZE(name) && node == NULL; bkt++)
> > 		hlist_for_each_entry(obj, node, &name[bkt], member)
> > 
> 
> Looks reasonable.  However, it would break (or rather, not break) on
> code like this:
> 
> 	hash_for_each_entry(...) {
> 		if (...) {
> 			foo(node);
> 			node = NULL;
> 			break;
> 		}
> 	}
> 
> Hiding the double loop still seems error-prone.

We've already had this conversation ;-)  A guess a big comment is in
order:

/*
 * NOTE!  Although this is a double loop, 'break' still works because of
 *        the 'node == NULL' condition in the outer loop. On break of
 *        the inner loop, node will be !NULL, and the outer loop will
 *        exit as well.
 */

-- Steve


--
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/