From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: a suspected race at __posix_lock_file() Date: Sun, 26 Jul 2009 16:20:02 -0600 Message-ID: <20090726222002.GB3711@parisc-linux.org> References: <2014bcab0907232256y18f98816r15464c024a934ae7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org To: ?????? shin hong Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:46375 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754007AbZGZWUC (ORCPT ); Sun, 26 Jul 2009 18:20:02 -0400 Content-Disposition: inline In-Reply-To: <2014bcab0907232256y18f98816r15464c024a934ae7@mail.gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Jul 24, 2009 at 02:56:24PM +0900, ?????? shin hong wrote: > Hi. I found a suspected race condition bug at fs/locks/__posix_lock_file() > in recent Linux kernel. > > This bug is similar to the one reported in ChangeLog 2.6.24 ( commit > 85c59580b30c82aa771aa33b37217a6b6851bc14 ). > > Big Kernel Lock(BKL) might be released and re-taken > at the call site of locks_delete_lock() > since Releasing-On-Block semantics of BKL. > Locks_delete_lock() may be blocked by kmem_cache_alloc() invocation. Could you explain to me how locks_delete_lock() calls kmem_cache_alloc()? > Please examine the possbility of race condition of this code > and let me know your opinion. > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."