From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f175.google.com (mail-io0-f175.google.com [209.85.223.175]) by kanga.kvack.org (Postfix) with ESMTP id 96F4C6B0038 for ; Thu, 10 Sep 2015 18:01:02 -0400 (EDT) Received: by iofb144 with SMTP id b144so78143695iof.1 for ; Thu, 10 Sep 2015 15:01:02 -0700 (PDT) Received: from resqmta-po-08v.sys.comcast.net (resqmta-po-08v.sys.comcast.net. [2001:558:fe16:19:96:114:154:167]) by mx.google.com with ESMTPS id qm8si95834igb.65.2015.09.10.15.00.58 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 10 Sep 2015 15:00:58 -0700 (PDT) Date: Thu, 10 Sep 2015 17:00:56 -0500 (CDT) From: Christoph Lameter Subject: Re: Is it OK to pass non-acquired objects to kfree? In-Reply-To: Message-ID: References: <20150909184415.GJ4029@linux.vnet.ibm.com> <20150909203642.GO4029@linux.vnet.ibm.com> <20150910171333.GD4029@linux.vnet.ibm.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dmitry Vyukov Cc: "Paul E. McKenney" , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , "linux-mm@kvack.org" , Andrey Konovalov , Alexander Potapenko On Thu, 10 Sep 2015, Dmitry Vyukov wrote: > > It changes the first word of the object after the barrier. The first word > > is used in SLUB as the pointer to the next free object. > > User can also write to this object after it is reallocated. It is > equivalent to kmalloc writing to the object. > And barrier is not the kind of barrier that would make it correct. > So I do not see how it is relevant. This is a compiler barrier so nothing can be moved below that into the code where the freelist pointer is handled. That was the issue from what I heard? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org