From:   Alejandro Colomar <alx.manpages@gmail.com>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Alejandro Colomar <alx.manpages@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Kees Cook <keescook@chromium.org>,
        Joe Perches <joe@perches.com>
Subject: [PATCH v2 09/20] Implement offsetof(), sizeof_member(), typeof_member(), and container_of() in terms of memberof()
Date:   Sat, 20 Nov 2021 14:00:52 +0100
Message-Id: <20211120130104.185699-10-alx.manpages@gmail.com>
In-Reply-To: <20211120130104.185699-1-alx.manpages@gmail.com>
References: <20211119113644.1600-1-alx.manpages@gmail.com>
 <20211120130104.185699-1-alx.manpages@gmail.com>
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Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
---
 include/linux/container_of.h  | 3 ++-
 include/linux/offsetof.h      | 4 +++-
 include/linux/sizeof_field.h  | 5 ++++-
 include/linux/typeof_member.h | 5 ++++-
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/include/linux/container_of.h b/include/linux/container_of.h
index 03809348f333..d1a66e72d246 100644
--- a/include/linux/container_of.h
+++ b/include/linux/container_of.h
@@ -5,6 +5,7 @@
 
 #include <linux/build_bug.h>
 #include <linux/err.h>
+#include <linux/memberof.h>
 #include <linux/typeof_member.h>
 
 
@@ -17,7 +18,7 @@
  */
 #define container_of(ptr, type, member) ({				\
 	void *__mptr = (void *)(ptr);					\
-	static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\
+	static_assert(__same_type(*(ptr), memberof(type, member)) ||	\
 		      __same_type(*(ptr), void),			\
 		      "pointer type mismatch in container_of()");	\
 	((type *)(__mptr - offsetof(type, member))); })
diff --git a/include/linux/offsetof.h b/include/linux/offsetof.h
index 3db431197687..656c758479e8 100644
--- a/include/linux/offsetof.h
+++ b/include/linux/offsetof.h
@@ -5,12 +5,14 @@
 
 #include <uapi/linux/stddef.h>
 
+#include <linux/memberof.h>
+
 
 #undef offsetof
 #ifdef __compiler_offsetof
 #define offsetof(T, m)	__compiler_offsetof(T, m)
 #else
-#define offsetof(T, m)	((size_t)&((T *)0)->m)
+#define offsetof(T, m)	((size_t)&memberof(T, m))
 #endif
 
 
diff --git a/include/linux/sizeof_field.h b/include/linux/sizeof_field.h
index 15dc10fce8f3..a64accc76055 100644
--- a/include/linux/sizeof_field.h
+++ b/include/linux/sizeof_field.h
@@ -3,13 +3,16 @@
 #define _LINUX_SIZEOF_FIELD_H
 
 
+#include <linux/memberof.h>
+
+
 /**
  * sizeof_field() - Report the size of a struct field in bytes
  *
  * @T: The structure containing the field of interest
  * @m: The field (member) to return the size of
  */
-#define sizeof_field(T, m)  sizeof((((T *)0)->m))
+#define sizeof_field(T, m)  sizeof(memberof(T, m))
 
 
 #endif  /* _LINUX_SIZEOF_FIELD_H */
diff --git a/include/linux/typeof_member.h b/include/linux/typeof_member.h
index 1f3bfb3c17d2..529535a55d40 100644
--- a/include/linux/typeof_member.h
+++ b/include/linux/typeof_member.h
@@ -3,7 +3,10 @@
 #define _LINUX_TYPEOF_MEMBER_H
 
 
-#define typeof_member(T, m)  typeof(((T *)0)->m)
+#include <linux/memberof.h>
+
+
+#define typeof_member(T, m)  typeof(memberof(T, m))
 
 
 #endif	/* _LINUX_TYPEOF_MEMBER_H */
-- 
2.33.1