From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755476AbcFQIpT (ORCPT ); Fri, 17 Jun 2016 04:45:19 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:64718 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752337AbcFQIpQ (ORCPT ); Fri, 17 Jun 2016 04:45:16 -0400 Subject: Re: [PATCH] MIPS: tools: Fix relocs tool compiler warnings To: Harvey Hunt , References: <20160616153539.10600-1-harvey.hunt@imgtec.com> CC: , From: Matt Redfearn Message-ID: <5763B898.7040502@imgtec.com> Date: Fri, 17 Jun 2016 09:45:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20160616153539.10600-1-harvey.hunt@imgtec.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [192.168.154.116] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/06/16 16:35, Harvey Hunt wrote: > When using clang as HOSTCC, the following warnings appear: > > In file included from arch/mips/boot/tools/relocs_64.c:27:0: > arch/mips/boot/tools/relocs.c: In function ‘read_relocs’: > arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info)); > ^~~~~~~~~ > arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > arch/mips/boot/tools/relocs.c: In function ‘walk_relocs’: > arch/mips/boot/tools/relocs.c:491:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; > ^~~~~~~ > arch/mips/boot/tools/relocs.c: In function ‘do_reloc’: > arch/mips/boot/tools/relocs.c:502:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > unsigned r_type = ELF_R_TYPE(rel->r_info); > ^~~~~~~~ > arch/mips/boot/tools/relocs.c: In function ‘do_reloc_info’: > arch/mips/boot/tools/relocs.c:641:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > rel_type(ELF_R_TYPE(rel->r_info)), > ^~~~~~~~ > > Fix them by making Elf64_Mips_Rela a union > > Signed-off-by: Harvey Hunt > Cc: Matt Redfearn > Cc: linux-mips@linux-mips.org > Cc: linux-kernel@vger.kernel.org > --- > arch/mips/boot/tools/relocs_64.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/arch/mips/boot/tools/relocs_64.c b/arch/mips/boot/tools/relocs_64.c > index b671b5e..06066e6a 100644 > --- a/arch/mips/boot/tools/relocs_64.c > +++ b/arch/mips/boot/tools/relocs_64.c > @@ -9,17 +9,20 @@ > > typedef uint8_t Elf64_Byte; > > -typedef struct { > - Elf64_Word r_sym; /* Symbol index. */ > - Elf64_Byte r_ssym; /* Special symbol. */ > - Elf64_Byte r_type3; /* Third relocation. */ > - Elf64_Byte r_type2; /* Second relocation. */ > - Elf64_Byte r_type; /* First relocation. */ > +typedef union { > + struct { > + Elf64_Word r_sym; /* Symbol index. */ > + Elf64_Byte r_ssym; /* Special symbol. */ > + Elf64_Byte r_type3; /* Third relocation. */ > + Elf64_Byte r_type2; /* Second relocation. */ > + Elf64_Byte r_type; /* First relocation. */ > + } fields; > + Elf64_Xword unused; > } Elf64_Mips_Rela; > > #define ELF_CLASS ELFCLASS64 > -#define ELF_R_SYM(val) (((Elf64_Mips_Rela *)(&val))->r_sym) > -#define ELF_R_TYPE(val) (((Elf64_Mips_Rela *)(&val))->r_type) > +#define ELF_R_SYM(val) (((Elf64_Mips_Rela *)(&val))->fields.r_sym) > +#define ELF_R_TYPE(val) (((Elf64_Mips_Rela *)(&val))->fields.r_type) > #define ELF_ST_TYPE(o) ELF64_ST_TYPE(o) > #define ELF_ST_BIND(o) ELF64_ST_BIND(o) > #define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o) Acked-by: Matt Redfearn