From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 13 Jul 2017 17:43:54 +0200 (CEST) Received: from mail.linuxfoundation.org ([140.211.169.12]:41418 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992568AbdGMPnqGk4U6 (ORCPT ); Thu, 13 Jul 2017 17:43:46 +0200 Received: from localhost (LFbn-1-12253-150.w90-92.abo.wanadoo.fr [90.92.67.150]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 1ABCBAE1; Thu, 13 Jul 2017 15:43:38 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yousong Zhou , "Maciej W. Rozycki" , linux-mips@linux-mips.org, Ralf Baechle , Amit Pundir Subject: [PATCH 3.18 02/22] MIPS: UAPI: Ignore __arch_swab{16,32,64} when using MIPS16 Date: Thu, 13 Jul 2017 17:42:42 +0200 Message-Id: <20170713153934.228855979@linuxfoundation.org> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170713153934.089183081@linuxfoundation.org> References: <20170713153934.089183081@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 59107 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yousong Zhou commit 71a0a72456b48de972d7ed613b06a22a3aa9057f upstream. Some GCC versions (e.g. 4.8.3) can incorrectly inline a function with MIPS32 instructions into another function with MIPS16 code [1], causing the assembler to genereate incorrect binary code or fail right away complaining about unrecognized opcode. In the case of __arch_swab{16,32}, when inlined by the compiler with flags `-mips32r2 -mips16 -Os', the assembler can fail with the following error. {standard input}:79: Error: unrecognized opcode `wsbh $2,$2' For performance concerns and to workaround the issue already existing in older compilers, just ignore these 2 functions when compiling with mips16 enabled. [1] Inlining nomips16 function into mips16 function can result in undefined builtins, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55777 Signed-off-by: Yousong Zhou Cc: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11241/ Signed-off-by: Ralf Baechle Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/uapi/asm/swab.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/arch/mips/include/uapi/asm/swab.h +++ b/arch/mips/include/uapi/asm/swab.h @@ -13,8 +13,9 @@ #define __SWAB_64_THRU_32__ -#if (defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) || \ - defined(_MIPS_ARCH_LOONGSON3A) +#if !defined(__mips16) && \ + ((defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) || \ + defined(_MIPS_ARCH_LOONGSON3A)) static inline __attribute_const__ __u16 __arch_swab16(__u16 x) { @@ -65,5 +66,5 @@ static inline __attribute_const__ __u64 } #define __arch_swab64 __arch_swab64 #endif /* __mips64 */ -#endif /* MIPS R2 or newer or Loongson 3A */ +#endif /* (not __mips16) and (MIPS R2 or newer or Loongson 3A) */ #endif /* _ASM_SWAB_H */