From patchwork Thu Jul 26 08:13:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 10545403 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2D7D414E0 for ; Thu, 26 Jul 2018 08:15:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 20C5F2AE2B for ; Thu, 26 Jul 2018 08:15:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 150B62AE42; Thu, 26 Jul 2018 08:15:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A93E42AE2B for ; Thu, 26 Jul 2018 08:15:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729270AbeGZJa5 (ORCPT ); Thu, 26 Jul 2018 05:30:57 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:38171 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728807AbeGZJa4 (ORCPT ); Thu, 26 Jul 2018 05:30:56 -0400 Received: from wuerfel.lan ([109.193.40.16]) by mrelayeu.kundenserver.de (mreue105 [212.227.15.145]) with ESMTPA (Nemesis) id 0LyUFS-1g6EdG1aA2-015sFb; Thu, 26 Jul 2018 10:14:52 +0200 From: Arnd Bergmann To: stable@vger.kernel.org Cc: gregkh@linuxfoundation.org, Arnd Bergmann , Michal Marek , Daniel Borkmann , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] [stable 4.9] turn off -Wattribute-alias Date: Thu, 26 Jul 2018 10:13:25 +0200 Message-Id: <20180726081358.3829157-4-arnd@arndb.de> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180726081358.3829157-1-arnd@arndb.de> References: <20180726081358.3829157-1-arnd@arndb.de> X-Provags-ID: V03:K1:XIn01yMgAsUVty1ujKZVURQ3gyuZoFxWA+hFwvMi6jmLQhkrEtq 450JtyqKYOjFus2V6Ilgt7lLmRb+qeLMbFm2OjH4zeEmqxvhxEwDdbpSNCpl+8n9t08cw4N uNzL5Ssm5WUH+WG8WpGQvsaTEPG/NgRqJXXYmVdqhBVpIzxJtx8oktCkOrTELV2RGSBI/xo sITQ78OOCJO2JtMwKHAQw== X-UI-Out-Filterresults: notjunk:1;V01:K0:a4bkbOUoQ/o=:3rSAKpvlZ2p5XMr59SE8A9 wizGn/exYCERnb0TRIkYaFW7qoozeWL6bHqhle2MUwjoaKDJjvqTrl7A2HnFkNVlR81WgZr8F YMVoes/n5FvYkBiE9OQfFtBKfdbPeAZUCXPYvjS/iRqVlnPa4p8pId1UvYFD3s9MccPTjjSQj 625KscfcGOkU+ow+yOSPuWGLkwXsM2gCqKya6KZ7k9ni1GTnkEInShFi7fwlu+cq2o2y24N/I Ix69xTuDvlHl2T3AAmZ2r8YDzd5f/zNnS1NsCfzjoZsaoIJJfgk1leb0t1/1jU8U3ee768x9L CxLZo7jN4WnxpnGQ/8WE73dJ5VDWvL/TA564p9oy1SduS7yk4EyoNizrK+JLLNogy56RmgMMm QkmvWtTpOjOUE4YcT3jEfY9T3/sZkWuTyG/XW2MW3r0DLjyAsTxzCsQDda0HFMEj4DtyrmFp/ RNwkE3mS4+2BgGQZznkV4Ry60KC2BesZyeC6h8kRKgMIRcgz+tFU06+WtmJQKRHwetw6z1JPy mSrNjzSX9HfIhSabmpFPQjRlsnCexdmgi2d5wc/f1hDOeeEwHdVqaikcV+GdF7Tk9L5mZHrT/ 57nJbZLXiF8ZVLH3MBEwlWbbBauMjJYpGj0cAfPBXBuhcp1TgaQDAv01F9Oeg1jWigoWddjR4 jd1QFT6ifN26MkqW3fg9WXUOcwCNBd3SFN2waikqQO/nnL/vQizI+BJPT0lqJsWt/URg= Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Starting with gcc-8.1, we get a warning about all system call definitions, which use an alias between functions with incompatible prototypes, e.g.: In file included from ../mm/process_vm_access.c:19: ../include/linux/syscalls.h:211:18: warning: 'sys_process_vm_readv' alias between functions of incompatible types 'long int(pid_t, const struct iovec *, long unsigned int, const struct iovec *, long unsigned int, long unsigned int)' {aka 'long int(int, const struct iovec *, long unsigned int, const struct iovec *, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ../include/linux/syscalls.h:207:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ ../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, ^~~~~~~~~~~~~~~ ../include/linux/syscalls.h:215:18: note: aliased declaration here asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~ ../include/linux/syscalls.h:207:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ ../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, This is really noisy and does not indicate a real problem. In the latest mainline kernel, this was addressed by commit bee20031772a ("disable -Wattribute-alias warning for SYSCALL_DEFINEx()"), which seems too invasive to backport. This takes a much simpler approach and just disables the warning across the kernel. Signed-off-by: Arnd Bergmann --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index f4cd42c9b940..41b9954dc0a9 100644 --- a/Makefile +++ b/Makefile @@ -635,6 +635,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context) +KBUILD_CFLAGS += $(call cc-disable-warning, attribute-alias) ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)