From: Arnd Bergmann <a...@arndb.de>

commit 14dc3983b5dff513a90bd5a8cc90acaf7867c3d0 upstream.

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-a...@kernel.org
Signed-off-by: Arnd Bergmann <a...@arndb.de>
Suggested-by: Ard Biesheuvel <a...@kernel.org>
Cc: Masahiro Yamada <masahi...@kernel.org>
Cc: Michal Marek <michal.l...@markovi.net>
Cc: Kees Cook <keesc...@chromium.org>
Cc: Rikard Falkeborn <rikard.falkeb...@gmail.com>
Cc: Marco Elver <el...@google.com>
Cc: <sta...@vger.kernel.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 include/linux/build_bug.h |    5 +++++
 1 file changed, 5 insertions(+)

--- a/include/linux/build_bug.h
+++ b/include/linux/build_bug.h
@@ -77,4 +77,9 @@
 #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 */


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