From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751866AbdBJXbj convert rfc822-to-8bit (ORCPT ); Fri, 10 Feb 2017 18:31:39 -0500 Received: from mga11.intel.com ([192.55.52.93]:15855 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136AbdBJXbi (ORCPT ); Fri, 10 Feb 2017 18:31:38 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,143,1484035200"; d="scan'208";a="1105866534" From: "Roberts, William C" To: Joe Perches , "linux-kernel@vger.kernel.org" , "apw@canonical.com" , Andew Morton CC: "keescook@chromium.org" , "kernel-hardening@lists.openwall.com" Subject: RE: [PATCH] checkpatch: add warning on %pk instead of %pK usage Thread-Topic: [PATCH] checkpatch: add warning on %pk instead of %pK usage Thread-Index: AQHSg9UvWAPxVS9whUiJ3t5Bad2kYaFjMnOA//+bwQCAAAERAIAAjywA//9+SKA= Date: Fri, 10 Feb 2017 23:31:35 +0000 Message-ID: <476DC76E7D1DF2438D32BFADF679FC562305DB22@ORSMSX103.amr.corp.intel.com> References: <1486755469-21573-1-git-send-email-william.c.roberts@intel.com> <1486757549.2192.20.camel@perches.com> <476DC76E7D1DF2438D32BFADF679FC562305C559@ORSMSX103.amr.corp.intel.com> <476DC76E7D1DF2438D32BFADF679FC562305C5BA@ORSMSX103.amr.corp.intel.com> <1486766996.2192.30.camel@perches.com> In-Reply-To: <1486766996.2192.30.camel@perches.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZDcxMjdjNTgtYjI3NC00MDMwLWE1MzYtNjY4NmNhZjgzMTYzIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IitVME5UeHAwNzJFYzNNWGl2WFp5Q052ZDNPWE9LaUNLYWhaSlpOQ2FxMU09In0= x-ctpclassification: CTP_IC x-originating-ip: [10.22.254.140] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Joe Perches [mailto:joe@perches.com] > Sent: Friday, February 10, 2017 2:50 PM > To: Roberts, William C ; linux- > kernel@vger.kernel.org; apw@canonical.com; Andew Morton foundation.org> > Cc: keescook@chromium.org; kernel-hardening@lists.openwall.com > Subject: Re: [PATCH] checkpatch: add warning on %pk instead of %pK usage > > On Fri, 2017-02-10 at 22:26 +0000, Roberts, William C wrote: > > > > > > > > > > > > On Fri, 2017-02-10 at 11:37 -0800, william.c.roberts@intel.com wrote: > > > > > From: William Roberts > > > > > > > > > > Sample output: > > > > > WARNING: %pk is close to %pK, did you mean %pK?. > > > > > \#20: FILE: drivers/char/applicom.c:230: > > > > > + printk(KERN_INFO "Could not allocate IRQ %d for > PCI > > > > > > > > Applicom > > > > > +device. %pk\n", dev->irq, pci_get_class); > > > > > > > > There isn't a single instance of this in the kernel tree. > > > > > > > > Maybe if this is really useful, then all the %p extensions > > > > should be enumerated and all unknown uses should have warnings. > > > > > > I was thinking of doing that, but I figured I would start with the > > > bare minimum patch. > > > > > > > > > > > Something like: > > > > > > > > --- > > > > scripts/checkpatch.pl | 9 +++++++++ > > > > 1 file changed, 9 insertions(+) > > > > > > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index > > > > ad5ea5c545b2..8a90b457e8b5 100755 > > > > --- a/scripts/checkpatch.pl > > > > +++ b/scripts/checkpatch.pl > > > > @@ -5305,6 +5305,15 @@ sub process { > > > > } > > > > } > > > > > > > > +# check for vsprintf extension %p misuses > > > > + if ($line =~ /\b$logFunctions\s*\(.*$String/) { > > > > I don't see the normal string formatting routines in that list... I think this is too > restrictive. > > I don't. There are no "normal" string formatting routines. By "normal" I'm referring to things that call into pointer(), just casually looking I see bstr_printf vsnprintf kvasprintf, which would be easy enough to add > What do you think is missing? sn?printf ? That's easy to add. The problem starts to get hairy when we think of how often folks roll their own logging macros (see some small sampling at the end). I think we would want to add DEBUG DBG and sn?printf and maybe consider dropping the \b on the regex so it's a bit more matchy but still shouldn't end up matching on any ASM as you pointed out in the V2 nack. Ill break this down into: 1. the patch as I know you'll take it, as you wrote it :-P 2. Adding to the logging macros 3. exploring making it less matchy Data: arch/alpha/kernel/pci_iommu.c:25:# define DBGA(args...) printk(KERN_DEBUG args) arch/alpha/kernel/pci_iommu.c:30:# define DBGA2(args...) printk(KERN_DEBUG args) arch/alpha/kernel/core_tsunami.c:50:# define DBG_CFG(args) printk args arch/alpha/kernel/core_titan.c:50:# define DBG_CFG(args) printk args arch/alpha/kernel/ptrace.c:34:#define DBG(fac,args) {if ((fac) & DEBUG) printk args;} arch/alpha/kernel/core_apecs.c:42:# define DBGC(args) printk args arch/alpha/kernel/core_irongate.c:38:# define DBG_CFG(args) printk args arch/alpha/kernel/core_wildfire.c:30:# define DBG_CFG(args) printk args arch/alpha/kernel/smc37c93x.c:18:# define DBG_DEVS(args) printk args arch/alpha/boot/misc.c:27:#define puts srm_printk arch/alpha/mm/numa.c:27:#define DBGDCONT(args...) printk(args) arch/powerpc/sysdev/tsi108_pci.c:43:#define DBG(x...) printk(x) arch/powerpc/sysdev/ge/ge_pic.c:31:#define DBG(fmt...) do { printk(KERN_DEBUG "gef_pic: " fmt); } while (0) arch/powerpc/sysdev/tsi108_dev.c:34:#define DBG(fmt...) do { printk(fmt); } while(0) arch/powerpc/sysdev/mpic.c:45:#define DBG(fmt...) printk(fmt) arch/powerpc/kernel/process.c:69:#define TM_DEBUG(x...) printk(KERN_INFO x) arch/powerpc/kernel/vdso.c:42:#define DBG(fmt...) printk(fmt) arch/powerpc/kernel/legacy_serial.c:21:#define DBG(fmt...) do { printk(fmt); } while(0) arch/powerpc/kernel/traps.c:89:#define TM_DEBUG(x...) printk(KERN_INFO x) arch/powerpc/kernel/prom.c:65:#define DBG(fmt...) printk(KERN_ERR fmt) arch/powerpc/kvm/book3s_paired_singles.c:33:#define dprintk printk