From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751157AbdBBIPK (ORCPT ); Thu, 2 Feb 2017 03:15:10 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:36380 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750903AbdBBIPI (ORCPT ); Thu, 2 Feb 2017 03:15:08 -0500 Subject: Re: [PATCH v3 1/1] x86, relocs: add printf attribute to die() To: hpa@zytor.com, Thomas Gleixner , Ingo Molnar , x86@kernel.org References: <20161218194752.32367-1-nicolas.iooss_linux@m4x.org> <594529be-1083-bfc2-0f36-220ac3165f9e@m4x.org> <4A4B8F8B-8097-4240-9CA1-B1D009E5861D@zytor.com> Cc: linux-kernel@vger.kernel.org From: Nicolas Iooss Message-ID: Date: Thu, 2 Feb 2017 09:15:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <4A4B8F8B-8097-4240-9CA1-B1D009E5861D@zytor.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/02/17 02:39, hpa@zytor.com wrote: > On January 31, 2017 10:52:11 AM PST, Nicolas Iooss wrote: >> Hello, >> >> As I have not received any comment on the patch I sent in December, I >> am >> wondering whether I did anything wrong with it. How can I get it queued >> for the next merge window? >> >> Thanks, >> Nicolas >> >> On 18/12/16 20:47, Nicolas Iooss wrote: >>> Adding such an attribute helps to detect errors in the format string >> at >>> build time. After doing this, the compiler complains about such >> issues: >>> >>> arch/x86/tools/relocs.c:460:5: error: format specifies type 'int' >>> but the argument has type 'Elf64_Xword' (aka 'unsigned long') >>> [-Werror,-Wformat] >>> sec->shdr.sh_size); >>> ^~~~~~~~~~~~~~~~~ >>> arch/x86/tools/relocs.c:464:5: error: format specifies type 'int' >>> but the argument has type 'Elf64_Off' (aka 'unsigned long') >>> [-Werror,-Wformat] >>> sec->shdr.sh_offset, >> strerror(errno)); >>> ^~~~~~~~~~~~~~~~~~~ >>> >>> When relocs.c is included by relocs_32.c, sec->shdr.sh_size and >>> sec->shdr.sh_offset are 32-bit unsigned integers. When the file is >>> included by relocs_64.c, these expressions are 64-bit unsigned >> integers. >>> >>> Introduce a PRIuELF macro to define the right format to use when >>> printing sh_size and sh_offset values. >>> >>> While at it, constify the format attribute of die(). >>> >>> Signed-off-by: Nicolas Iooss >>> --- >>> I sent the first versions of this patch in September (cf. >>> https://patchwork.kernel.org/patch/9312665/) but it has not been >>> applied. >>> >>> As commit adee8705d251 ("x86/build: Annotate die() with noreturn to >> fix >>> build warning on clang") introduced the noreturn attribute to die(), >>> this patch now only adds the printf attribute. >>> >>> arch/x86/tools/relocs.c | 14 +++++++------- >>> arch/x86/tools/relocs.h | 3 ++- >>> arch/x86/tools/relocs_32.c | 3 +++ >>> arch/x86/tools/relocs_64.c | 3 +++ >>> arch/x86/tools/relocs_common.c | 2 +- >>> 5 files changed, 16 insertions(+), 9 deletions(-) >>> >>> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c >>> index 0c2fae8d929d..4cad603b8d58 100644 >>> --- a/arch/x86/tools/relocs.c >>> +++ b/arch/x86/tools/relocs.c >>> @@ -397,7 +397,7 @@ static void read_shdrs(FILE *fp) >>> ehdr.e_shnum); >>> } >>> if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { >>> - die("Seek to %d failed: %s\n", >>> + die("Seek to %"PRIuELF" failed: %s\n", >>> ehdr.e_shoff, strerror(errno)); >>> } >>> for (i = 0; i < ehdr.e_shnum; i++) { >>> @@ -431,11 +431,11 @@ static void read_strtabs(FILE *fp) >>> } >>> sec->strtab = malloc(sec->shdr.sh_size); >>> if (!sec->strtab) { >>> - die("malloc of %d bytes for strtab failed\n", >>> + die("malloc of %"PRIuELF" bytes for strtab failed\n", >>> sec->shdr.sh_size); >>> } >>> if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { >>> - die("Seek to %d failed: %s\n", >>> + die("Seek to %"PRIuELF" failed: %s\n", >>> sec->shdr.sh_offset, strerror(errno)); >>> } >>> if (fread(sec->strtab, 1, sec->shdr.sh_size, fp) >>> @@ -456,11 +456,11 @@ static void read_symtabs(FILE *fp) >>> } >>> sec->symtab = malloc(sec->shdr.sh_size); >>> if (!sec->symtab) { >>> - die("malloc of %d bytes for symtab failed\n", >>> + die("malloc of %"PRIuELF" bytes for symtab failed\n", >>> sec->shdr.sh_size); >>> } >>> if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { >>> - die("Seek to %d failed: %s\n", >>> + die("Seek to %"PRIuELF" failed: %s\n", >>> sec->shdr.sh_offset, strerror(errno)); >>> } >>> if (fread(sec->symtab, 1, sec->shdr.sh_size, fp) >>> @@ -489,11 +489,11 @@ static void read_relocs(FILE *fp) >>> } >>> sec->reltab = malloc(sec->shdr.sh_size); >>> if (!sec->reltab) { >>> - die("malloc of %d bytes for relocs failed\n", >>> + die("malloc of %"PRIuELF" bytes for relocs failed\n", >>> sec->shdr.sh_size); >>> } >>> if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { >>> - die("Seek to %d failed: %s\n", >>> + die("Seek to %"PRIuELF" failed: %s\n", >>> sec->shdr.sh_offset, strerror(errno)); >>> } >>> if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) >>> diff --git a/arch/x86/tools/relocs.h b/arch/x86/tools/relocs.h >>> index 1d23bf953a4a..f41416c31608 100644 >>> --- a/arch/x86/tools/relocs.h >>> +++ b/arch/x86/tools/relocs.h >>> @@ -16,7 +16,8 @@ >>> #include >>> #include >>> >>> -void die(char *fmt, ...) __attribute__((noreturn)); >>> +void die(const char *fmt, ...) __attribute__((noreturn)) >>> + __attribute__((format(printf, 1, 2))); >>> >>> #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) >>> >>> diff --git a/arch/x86/tools/relocs_32.c b/arch/x86/tools/relocs_32.c >>> index b2ade2bb4162..8024ec473e6a 100644 >>> --- a/arch/x86/tools/relocs_32.c >>> +++ b/arch/x86/tools/relocs_32.c >>> @@ -14,4 +14,7 @@ >>> #define ELF_ST_BIND(o) ELF32_ST_BIND(o) >>> #define ELF_ST_VISIBILITY(o) ELF32_ST_VISIBILITY(o) >>> >>> +/* printf format for Elf32_Off */ >>> +#define PRIuELF PRIu32 >>> + >>> #include "relocs.c" >>> diff --git a/arch/x86/tools/relocs_64.c b/arch/x86/tools/relocs_64.c >>> index 56b61b743c4c..2cf4de5c9d99 100644 >>> --- a/arch/x86/tools/relocs_64.c >>> +++ b/arch/x86/tools/relocs_64.c >>> @@ -14,4 +14,7 @@ >>> #define ELF_ST_BIND(o) ELF64_ST_BIND(o) >>> #define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o) >>> >>> +/* printf format for Elf64_Off */ >>> +#define PRIuELF PRIu64 >>> + >>> #include "relocs.c" >>> diff --git a/arch/x86/tools/relocs_common.c >> b/arch/x86/tools/relocs_common.c >>> index acab636bcb34..30adb44eff79 100644 >>> --- a/arch/x86/tools/relocs_common.c >>> +++ b/arch/x86/tools/relocs_common.c >>> @@ -1,6 +1,6 @@ >>> #include "relocs.h" >>> >>> -void die(char *fmt, ...) >>> +void die(const char *fmt, ...) >>> { >>> va_list ap; >>> va_start(ap, fmt); >>> > > Both are wrong... either PRIu64 or add a cast. I described in a previous email (https://lkml.org/lkml/2016/9/3/200) the types which are used. Here is a part of this email: * When compiling relocs_32.c, sec->shdr.sh_size is of type Elf32_Word (unsigned int) and sec->shdr.sh_offset is Elf32_Off (unsigned int). * When compiling relocs_64.c, sec->shdr.sh_size is Elf64_Xword (long long unsigned int when the compiler is in 32-bit mode, long unsigned int in 64-bit mode) and sec->shdr.sh_offset is Elf64_Off (same real type as sec->shdr.sh_size). With this in mind, would you accept a patch which casts everything to 64-bit integers (uint64_t) and uses PRIu64 (which is %llu on 32-bit x86 and %lu on 64-bit x86)? Nicolas