Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753696AbdHIPrs (ORCPT ); Wed, 9 Aug 2017 11:47:48 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:36722 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753679AbdHIPrp (ORCPT ); Wed, 9 Aug 2017 11:47:45 -0400 Message-ID: <1502293662.1439.12.camel@gmail.com> Subject: Re: drivers/tty/serial/8250/8250_fintek.c:364: warning: 'probe_data' is used uninitialized in this function From: Daniel Micay To: Arnd Bergmann , kbuild test robot Cc: kbuild-all@01.org, Linux Kernel Mailing List , Kees Cook , Andrew Morton , Linux Memory Management List Date: Wed, 09 Aug 2017 11:47:42 -0400 In-Reply-To: References: <201708092333.gJ53XSff%fengguang.wu@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.24.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2952 Lines: 62 On Wed, 2017-08-09 at 17:32 +0200, Arnd Bergmann wrote: > On Wed, Aug 9, 2017 at 5:07 PM, kbuild test robot > wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin > > ux.git master > > head: bfa738cf3dfae2111626650f86135f93c5ff0a22 > > commit: 6974f0c4555e285ab217cee58b6e874f776ff409 > > include/linux/string.h: add the option of fortified string.h > > functions > > date: 4 weeks ago > > config: x86_64-randconfig-v0-08092220 (attached as .config) > > compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7 > > reproduce: > > git checkout 6974f0c4555e285ab217cee58b6e874f776ff409 > > # save the attached .config to linux build tree > > make ARCH=x86_64 > > > > All warnings (new ones prefixed by >>): > > > > In file included from include/linux/bitmap.h:8, > > from include/linux/cpumask.h:11, > > from arch/x86/include/asm/cpumask.h:4, > > from arch/x86/include/asm/msr.h:10, > > from arch/x86/include/asm/processor.h:20, > > from arch/x86/include/asm/cpufeature.h:4, > > from arch/x86/include/asm/thread_info.h:52, > > from include/linux/thread_info.h:37, > > from arch/x86/include/asm/preempt.h:6, > > from include/linux/preempt.h:80, > > from include/linux/spinlock.h:50, > > from include/linux/seqlock.h:35, > > from include/linux/time.h:5, > > from include/linux/stat.h:18, > > from include/linux/module.h:10, > > from drivers/tty/serial/8250/8250_fintek.c:11: > > include/linux/string.h: In function 'strcpy': > > include/linux/string.h:209: warning: '______f' is static but > > declared in inline function 'strcpy' which is not static > > include/linux/string.h:211: warning: '______f' is static but > > declared in inline function 'strcpy' which is not static > > > This clearly comes from __trace_if() when CONFIG_PROFILE_ALL_BRANCHES > is enabled. I did not see the warning with gcc-7.1.1, and I guess this > only > happens on older compilers like the gcc-4.4 that was used here. > > What is the reason for __FORTIFY_INLINE to be "extern __always_inline" > rather than "static __always_inline"? If they cannot just be 'static', > maybe > this can be changed to depend on the compiler version. > > Arnd It's important to get the semantics of using extern. It means if you do something like &memcpy, it resolves to the address of the direct symbol instead of generating a useless thunk for that object file. It might also be required for Clang compatibility, I don't remember. It could have a compiler version dependency or maybe one specifically tied to old compiler && CONFIG_PROFILE_ALL_BRANCHES / other options that conflict with it like that.