From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [PATCH ckpt-v15] allocate checkpoint headers with kzalloc Date: Thu, 14 May 2009 12:32:43 -0400 Message-ID: <4A0C47AB.9060803@cs.columbia.edu> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Nathan Lynch Cc: Linux Containers List-Id: containers.vger.kernel.org Pushed on ckpt-v15-dev. Thanks, Oren. Nathan Lynch wrote: > In a checkpoint image I noticed a lot of 0x6b (POISON_FREE) bytes > corresponding to checkpoint_restart_block -- this indicates that we > would write uninitialized kernel memory to the image in cases where > slab allocator debugging is not enabled[1]. > > Use kzalloc in ckpt_hdr_get. > > [1] slub's debug mode apparently initializes allocated buffers to > POISON_FREE instead of POISON_INUSE, which confused me for a bit. > Maybe I don't understand the intended meanings of the poison values. > > Signed-off-by: Nathan Lynch > --- > checkpoint/sys.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/checkpoint/sys.c b/checkpoint/sys.c > index 255ebc1..34a226c 100644 > --- a/checkpoint/sys.c > +++ b/checkpoint/sys.c > @@ -117,7 +117,7 @@ int ckpt_kread(struct ckpt_ctx *ctx, void *addr, int count) > */ > void *ckpt_hdr_get(struct ckpt_ctx *ctx, int len) > { > - return kmalloc(len, GFP_KERNEL); > + return kzalloc(len, GFP_KERNEL); > } > > /**