linux_dsm_epyc7002/include/linux/build_bug.h
Arnd Bergmann 14dc3983b5 kbuild: avoid static_assert for genksyms
genksyms does not know or care about the _Static_assert() built-in, and
sometimes falls back to ignoring the later symbols, which causes
undefined behavior such as

  WARNING: modpost: EXPORT symbol "ethtool_set_ethtool_phy_ops" [vmlinux] version generation failed, symbol will not be versioned.
  ld: net/ethtool/common.o: relocation R_AARCH64_ABS32 against `__crc_ethtool_set_ethtool_phy_ops' can not be used when making a shared object
  net/ethtool/common.o:(_ftrace_annotated_branch+0x0): dangerous relocation: unsupported relocation

Redefine static_assert for genksyms to avoid that.

Link: https://lkml.kernel.org/r/20201203230955.1482058-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:02:14 -08:00

86 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BUILD_BUG_H
#define _LINUX_BUILD_BUG_H
#include <linux/compiler.h>
#ifdef __CHECKER__
#define BUILD_BUG_ON_ZERO(e) (0)
#else /* __CHECKER__ */
/*
* Force a compilation error if condition is true, but also produce a
* result (of value 0 and type int), so the expression can be used
* e.g. in a structure initializer (or where-ever else comma expressions
* aren't permitted).
*/
#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
#endif /* __CHECKER__ */
/* Force a compilation error if a constant expression is not a power of 2 */
#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
/*
* BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
* expression but avoids the generation of any code, even if that expression
* has side-effects.
*/
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
/**
* BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
* error message.
* @condition: the condition which the compiler should know is false.
*
* See BUILD_BUG_ON for description.
*/
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
/**
* BUILD_BUG_ON - break compile if a condition is true.
* @condition: the condition which the compiler should know is false.
*
* If you have some code which relies on certain constants being equal, or
* some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
* detect if someone changes it.
*/
#define BUILD_BUG_ON(condition) \
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
/**
* BUILD_BUG - break compile if used.
*
* If you have some code that you expect the compiler to eliminate at
* build time, you should use BUILD_BUG to detect if it is
* unexpectedly used.
*/
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
/**
* static_assert - check integer constant expression at build time
*
* static_assert() is a wrapper for the C11 _Static_assert, with a
* little macro magic to make the message optional (defaulting to the
* stringification of the tested expression).
*
* Contrary to BUILD_BUG_ON(), static_assert() can be used at global
* scope, but requires the expression to be an integer constant
* expression (i.e., it is not enough that __builtin_constant_p() is
* true for expr).
*
* Also note that BUILD_BUG_ON() fails the build if the condition is
* true, while static_assert() fails the build if the expression is
* false.
*/
#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
#ifdef __GENKSYMS__
/* genksyms gets confused by _Static_assert */
#define _Static_assert(expr, ...)
#endif
#endif /* _LINUX_BUILD_BUG_H */