From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v3 2/3] linux/stddef.h: Add sizeof_member() macro Date: Tue, 29 Oct 2019 15:47:55 -0700 Message-ID: <20191029224756.28618-3-keescook@chromium.org> References: <20191029224756.28618-1-keescook@chromium.org> Return-path: In-Reply-To: <20191029224756.28618-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Linus Torvalds Cc: Kees Cook , Pankaj Bharadiya , Alexey Dobriyan , "David S. Miller" , Randy Dunlap , Andrew Morton , netdev@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-arch.vger.kernel.org From: Pankaj Bharadiya At present we have 2 different macros to calculate the size of a member of a struct: FIELD_SIZEOF() and sizeof_field(). As a prerequisite to bringing uniformity to the entire kernel source tree, add sizeof_member() macro as it is both more pleasant (not upper case) and more correct (sizeof()-family cannot operate on bit fields; this is meant to operate on struct members), as discussed[1]. Future patches will replace all occurrences of above macros with sizeof_member(). [1] https://www.openwall.com/lists/kernel-hardening/2019/07/02/2 Signed-off-by: Pankaj Bharadiya Link: https://lore.kernel.org/r/20190924105839.110713-2-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/stddef.h | 13 ++++++++++++- tools/testing/selftests/bpf/bpf_util.h | 6 +++--- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/include/linux/stddef.h b/include/linux/stddef.h index 998a4ba28eba..ecadb736c853 100644 --- a/include/linux/stddef.h +++ b/include/linux/stddef.h @@ -27,6 +27,17 @@ enum { */ #define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) +/** + * sizeof_member(TYPE, MEMBER) - get the size of a struct's member + * + * @TYPE: the target struct + * @MEMBER: the target struct's member + * + * Return: the size of @MEMBER in the struct definition without having a + * declared instance of @TYPE. + */ +#define sizeof_member(TYPE, MEMBER) (sizeof(((TYPE *)0)->MEMBER)) + /** * offsetofend(TYPE, MEMBER) * @@ -34,6 +45,6 @@ enum { * @MEMBER: The member within the structure to get the end offset of */ #define offsetofend(TYPE, MEMBER) \ - (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) + (offsetof(TYPE, MEMBER) + sizeof_member(TYPE, MEMBER)) #endif diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h index ec219f84e041..6b4b3e24ba9f 100644 --- a/tools/testing/selftests/bpf/bpf_util.h +++ b/tools/testing/selftests/bpf/bpf_util.h @@ -31,13 +31,13 @@ static inline unsigned int bpf_num_possible_cpus(void) # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) #endif -#ifndef sizeof_field -#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) +#ifndef sizeof_member +#define sizeof_member(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) #endif #ifndef offsetofend #define offsetofend(TYPE, MEMBER) \ - (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) + (offsetof(TYPE, MEMBER) + sizeof_member(TYPE, MEMBER)) #endif #endif /* __BPF_UTIL__ */ -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f193.google.com ([209.85.214.193]:39708 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726321AbfJ2WsH (ORCPT ); Tue, 29 Oct 2019 18:48:07 -0400 Received: by mail-pl1-f193.google.com with SMTP id t12so21086plo.6 for ; Tue, 29 Oct 2019 15:48:06 -0700 (PDT) From: Kees Cook Subject: [PATCH v3 2/3] linux/stddef.h: Add sizeof_member() macro Date: Tue, 29 Oct 2019 15:47:55 -0700 Message-ID: <20191029224756.28618-3-keescook@chromium.org> In-Reply-To: <20191029224756.28618-1-keescook@chromium.org> References: <20191029224756.28618-1-keescook@chromium.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Linus Torvalds Cc: Kees Cook , Pankaj Bharadiya , Alexey Dobriyan , "David S. Miller" , Randy Dunlap , Andrew Morton , netdev@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20191029224755.zd1Y7sGr4D8Yni7jUHXsivnUPsE8LzuVMj1sXusBCak@z> From: Pankaj Bharadiya At present we have 2 different macros to calculate the size of a member of a struct: FIELD_SIZEOF() and sizeof_field(). As a prerequisite to bringing uniformity to the entire kernel source tree, add sizeof_member() macro as it is both more pleasant (not upper case) and more correct (sizeof()-family cannot operate on bit fields; this is meant to operate on struct members), as discussed[1]. Future patches will replace all occurrences of above macros with sizeof_member(). [1] https://www.openwall.com/lists/kernel-hardening/2019/07/02/2 Signed-off-by: Pankaj Bharadiya Link: https://lore.kernel.org/r/20190924105839.110713-2-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/stddef.h | 13 ++++++++++++- tools/testing/selftests/bpf/bpf_util.h | 6 +++--- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/include/linux/stddef.h b/include/linux/stddef.h index 998a4ba28eba..ecadb736c853 100644 --- a/include/linux/stddef.h +++ b/include/linux/stddef.h @@ -27,6 +27,17 @@ enum { */ #define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) +/** + * sizeof_member(TYPE, MEMBER) - get the size of a struct's member + * + * @TYPE: the target struct + * @MEMBER: the target struct's member + * + * Return: the size of @MEMBER in the struct definition without having a + * declared instance of @TYPE. + */ +#define sizeof_member(TYPE, MEMBER) (sizeof(((TYPE *)0)->MEMBER)) + /** * offsetofend(TYPE, MEMBER) * @@ -34,6 +45,6 @@ enum { * @MEMBER: The member within the structure to get the end offset of */ #define offsetofend(TYPE, MEMBER) \ - (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) + (offsetof(TYPE, MEMBER) + sizeof_member(TYPE, MEMBER)) #endif diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h index ec219f84e041..6b4b3e24ba9f 100644 --- a/tools/testing/selftests/bpf/bpf_util.h +++ b/tools/testing/selftests/bpf/bpf_util.h @@ -31,13 +31,13 @@ static inline unsigned int bpf_num_possible_cpus(void) # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) #endif -#ifndef sizeof_field -#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) +#ifndef sizeof_member +#define sizeof_member(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) #endif #ifndef offsetofend #define offsetofend(TYPE, MEMBER) \ - (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) + (offsetof(TYPE, MEMBER) + sizeof_member(TYPE, MEMBER)) #endif #endif /* __BPF_UTIL__ */ -- 2.17.1