linux-kernel - Re: [RFC PATCH 02/11] refcount: Implement inc/decrement-and-return functions

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:   Fri, 01 Sep 2017 23:51:53 +0100
From:   David Howells <dhowells@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     dhowells@...hat.com, linux-afs@...ts.infradead.org,
        linux-fsdevel@...r.kernel.org, Kees Cook <keescook@...omium.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH 02/11] refcount: Implement inc/decrement-and-return functions

Peter Zijlstra <peterz@...radead.org> wrote:

> 	if (obj) {
> 	  /* use obj */
> 	  refcount_dec(&obj->refs); /* should never hit 0 */
> 	}

You've missed a bit: We need to tell the gc to run when we reduce the refcount
to 1:

	if (obj) {
		...
		if (refcount_dec_return(&obj->refs) == 1)
			schedule_gc();
	}

David