The patch titled
Subject: Revert "kbuild: avoid static_assert for genksyms"
has been added to the -mm tree. Its filename is
revert-kbuild-avoid-static_assert-for-genksyms.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/revert-kbuild-avoid-static_assert-for-genksyms.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/revert-kbuild-avoid-static_assert-for-genksyms.patch
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------------------------------------------------------
From: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Subject: Revert "kbuild: avoid static_assert for genksyms"
This reverts commit 14dc3983b5dff513a90bd5a8cc90acaf7867c3d0.
Macro Elver had sent a fix proper fix earlier, and also pointed out
corner cases:
"I guess what you propose is simpler, but might still have corner cases
where we still get warnings. In particular, if some file (for whatever
reason) does not include build_bug.h and uses a raw _Static_assert(),
then we still get warnings. E.g. I see 1 user of raw _Static_assert()
(drivers/gpu/drm/amd/amdgpu/amdgv_sriovmsg.h )."
I believe the raw use of _Static_assert() should be allowed, so this
should be fixed in genksyms.
Even after commit 14dc3983b5df ("kbuild: avoid static_assert for
genksyms"), I confirmed the following test code emits the warning.
---------------->8----------------
#include <linux/export.h>
_Static_assert((1 ?: 0), "");
void foo(void) { }
EXPORT_SYMBOL(foo);
---------------->8----------------
WARNING: modpost: EXPORT symbol "foo" [vmlinux] version generation failed, symbol will not be versioned.
Now that commit 869b91992bce ("genksyms: Ignore module scoped
_Static_assert()") fixed this issue properly, the workaround should
be reverted.
Link: https://lkml.org/lkml/2020/12/10/845
Link: https://lkml.kernel.org/r/20201219183911.181442-1-masahiroy@xxxxxxxxxx
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/build_bug.h | 5 -----
1 file changed, 5 deletions(-)
--- a/include/linux/build_bug.h~revert-kbuild-avoid-static_assert-for-genksyms
+++ a/include/linux/build_bug.h
@@ -77,9 +77,4 @@
#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 */
_
Patches currently in -mm which might be from masahiroy@xxxxxxxxxx are
revert-kbuild-avoid-static_assert-for-genksyms.patch
