linux-hardened/include/linux/stddef.h
Kees Cook 4229a47017 stddef.h: Introduce sizeof_field()
The size of fields within a structure is needed in a few places in the
kernel already, and will be needed for the usercopy whitelisting when
declaring whitelist regions within structures. This creates a dedicated
macro and redefines offsetofend() to use it.

Existing usage, ignoring the 1200+ lustre assert uses:

$ git grep -E 'sizeof\(\(\((struct )?[a-zA-Z_]+ \*\)0\)->' | \
	grep -v staging/lustre | wc -l
65

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-15 12:07:46 -08:00

39 lines
827 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_STDDEF_H
#define _LINUX_STDDEF_H
#include <uapi/linux/stddef.h>
#undef NULL
#define NULL ((void *)0)
enum {
false = 0,
true = 1
};
#undef offsetof
#ifdef __compiler_offsetof
#define offsetof(TYPE, MEMBER) __compiler_offsetof(TYPE, MEMBER)
#else
#define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER)
#endif
/**
* sizeof_field(TYPE, MEMBER)
*
* @TYPE: The structure containing the field of interest
* @MEMBER: The field to return the size of
*/
#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
/**
* offsetofend(TYPE, MEMBER)
*
* @TYPE: The type of the structure
* @MEMBER: The member within the structure to get the end offset of
*/
#define offsetofend(TYPE, MEMBER) \
(offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
#endif