From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752071AbdEMIGK (ORCPT ); Sat, 13 May 2017 04:06:10 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:34232 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731AbdEMIGI (ORCPT ); Sat, 13 May 2017 04:06:08 -0400 Date: Sat, 13 May 2017 11:05:30 +0300 From: Dan Carpenter To: Geliang Tang Cc: Felipe Balbi , Greg Kroah-Hartman , Michal Nazarewicz , Vincent Pelletier , Felix =?iso-8859-1?Q?H=E4dicke?= , Jim Lin , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: gadget: f_fs: use memdup_user Message-ID: <20170513080530.2rsqs3apd6w3psve@mwanda> References: <908fa521decaf3703e172c3734c0d498741f3ddb.1494580404.git.geliangtang@gmail.com> <694b8a4beb2ec1e087321bc423e5cd0c69e5a717.1494576863.git.geliangtang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <694b8a4beb2ec1e087321bc423e5cd0c69e5a717.1494576863.git.geliangtang@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 13, 2017 at 11:15:59AM +0800, Geliang Tang wrote: > Use memdup_user() helper instead of open-coding to simplify the code. > > Signed-off-by: Geliang Tang > --- > drivers/usb/gadget/function/f_fs.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c > index 71dd27c..5754538 100644 > --- a/drivers/usb/gadget/function/f_fs.c > +++ b/drivers/usb/gadget/function/f_fs.c > @@ -3692,14 +3692,9 @@ static char *ffs_prepare_buffer(const char __user *buf, size_t len) > if (unlikely(!len)) > return NULL; > > - data = kmalloc(len, GFP_KERNEL); > - if (unlikely(!data)) > - return ERR_PTR(-ENOMEM); > - > - if (unlikely(copy_from_user(data, buf, len))) { > - kfree(data); > - return ERR_PTR(-EFAULT); > - } > + data = memdup_user(buf, len); > + if (unlikely(IS_ERR(data))) Don't use likely/unlikely() here. It's not a fast path. regards, dan carpenter