From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E33993FC2 for ; Fri, 27 Aug 2021 15:27:27 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id CF09160232; Fri, 27 Aug 2021 15:27:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1630078047; bh=YcuO1NmAv8VjO+U1iC07eG0TGAhra6EY6qYLzMjAgaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ytgMCOlbA8xS9fK9fADxvgDVtHAxdZZdYbdHl8d9L3G439mhJbneI4c0KYZuBASB3 SMTgmLPBYH9WPgyZhav/y7Pi7t5xq8ceOTnJbwi5Ymf7CnygBMjEO0Lgu4t5qfY6ko siwjxk2LH/DxcEJaereaBerz4SWfaS5AN1/TGkZQ= Date: Fri, 27 Aug 2021 17:27:20 +0200 From: Greg Kroah-Hartman To: Joe Perches Cc: linux-kernel@vger.kernel.org, Larry Finger , Phillip Potter , linux-staging@lists.linux.dev Subject: Re: [PATCH 5/5] staging: r8188eu: Use vsprintf extension %phCX to format a copy_to_user string Message-ID: References: <152e1b8f84c4686ea38182ca55344ed7f2cede65.1630003183.git.joe@perches.com> <903a73b791466918ca72c8fc62406acb86e93018.camel@perches.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <903a73b791466918ca72c8fc62406acb86e93018.camel@perches.com> On Fri, Aug 27, 2021 at 08:23:31AM -0700, Joe Perches wrote: > On Fri, 2021-08-27 at 10:42 +0200, Greg Kroah-Hartman wrote: > > On Thu, Aug 26, 2021 at 11:43:05AM -0700, Joe Perches wrote: > > > This reduces object size without changing the string content. > > > > > > compiled x86-64 defconfig w/ r8188eu and gcc 10.3.0 > > > > > > $ size drivers/staging/r8188eu/os_dep/ioctl_linux.o* > > >    text data bss dec hex filename > > >   72556 1548 0 74104 12178 drivers/staging/r8188eu/os_dep/ioctl_linux.o.new > > >   72758 1548 0 74306 12242 drivers/staging/r8188eu/os_dep/ioctl_linux.o.old > > > > > > Signed-off-by: Joe Perches > > > --- > > >  drivers/staging/r8188eu/os_dep/ioctl_linux.c | 9 +++------ > > >  1 file changed, 3 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c > > > index ab4a9200f0791..048164659d872 100644 > > > --- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c > > > +++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c > > > @@ -2907,10 +2907,8 @@ static int rtw_p2p_get_groupid(struct net_device *dev, > > >   struct adapter *padapter = (struct adapter *)rtw_netdev_priv(dev); > > >   struct wifidirect_info *pwdinfo = &padapter->wdinfo; > > >   > > > > > > - sprintf(extra, "\n%.2X:%.2X:%.2X:%.2X:%.2X:%.2X %s", > > > - pwdinfo->groupid_info.go_device_addr[0], pwdinfo->groupid_info.go_device_addr[1], > > > - pwdinfo->groupid_info.go_device_addr[2], pwdinfo->groupid_info.go_device_addr[3], > > > - pwdinfo->groupid_info.go_device_addr[4], pwdinfo->groupid_info.go_device_addr[5], > > > + sprintf(extra, "\n%pM %s", > > > + pwdinfo->groupid_info.go_device_addr, > > >   pwdinfo->groupid_info.ssid); > > > > We can just use the lower-case one here, no need for a new modifier just > > for something like this (i.e. log file output) > > That was just a trivial conversion of log file output and is lower case > as log file output is not ABI. > > The copy_to_user bit (2nd diff block) is nominally an ABI and is upper case. > IMO at a minimum, it's bad form to change it. > > @@ -3075,8 +3073,7 @@ static int rtw_p2p_get_go_device_address(struct net_device *dev, > if (!blnMatch) > sprintf(go_devadd_str, "\n\ndev_add = NULL"); > else > - sprintf(go_devadd_str, "\ndev_add =%.2X:%.2X:%.2X:%.2X:%.2X:%.2X", > - attr_content[0], attr_content[1], attr_content[2], attr_content[3], attr_content[4], attr_content[5]); > + sprintf(go_devadd_str, "\ndev_add =%6phCX", attr_content); > > if (copy_to_user(wrqu->data.pointer, go_devadd_str, 10 + 17)) > return -EFAULT; That looks like a horrible driver-specific api that no one will really be using and will be removed from the tree soon. So it can be changed, no need to worry about any "compatibility" issues here. thanks, greg k-h