From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: Sami Tolvanen <samitolvanen@google.com>,
linux-kernel@vger.kernel.org,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH 05/13] kbuild: remove stale *.symversions
Date: Thu, 19 Aug 2021 09:57:36 +0900 [thread overview]
Message-ID: <20210819005744.644908-6-masahiroy@kernel.org> (raw)
In-Reply-To: <20210819005744.644908-1-masahiroy@kernel.org>
cmd_update_lto_symversions merges all the existing *.symversions, but
some of them might be stale.
If the last EXPORT_SYMBOL is removed from a C file, the *.symversions
file is not deleted or updated. It contains stale CRCs, which will be
used for linking the vmlinux or modules.
It is not a big deal when the EXPORT_SYMBOL is really removed. However,
when the EXPORT_SYMBOL is moved to another file, the same __crc_<symbol>
will appear twice in the merged *.symversions, possibly with different
CRCs if the function argument is changed at the same time. It would
cause potential breakage of module versioning.
If no EXPORT_SYMBOL is found, let's remove *.symversions explicitly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/Makefile.build | 2 ++
1 file changed, 2 insertions(+)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 279363266455..585dae34746a 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -177,6 +177,8 @@ cmd_modversions_c = \
if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
> $@.symversions; \
+ else \
+ rm -f $@.symversions; \
fi;
else
cmd_modversions_c = \
--
2.30.2
next prev parent reply other threads:[~2021-08-19 0:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-19 0:57 [PATCH 00/13] kbuild: refactoring after Clang LTO Masahiro Yamada
2021-08-19 0:57 ` [PATCH 01/13] kbuild: move objtool_args back to scripts/Makefile.build Masahiro Yamada
2021-08-19 2:45 ` Kees Cook
2021-08-19 0:57 ` [PATCH 02/13] gen_compile_commands: extract compiler command from a series of commands Masahiro Yamada
2021-08-19 6:48 ` Kees Cook
2021-08-19 0:57 ` [PATCH 03/13] kbuild: detect objtool changes correctly and remove .SECONDEXPANSION Masahiro Yamada
2021-08-19 2:55 ` Kees Cook
2021-08-19 3:18 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 04/13] kbuild: remove unused quiet_cmd_update_lto_symversions Masahiro Yamada
2021-08-19 6:19 ` Kees Cook
2021-08-19 0:57 ` Masahiro Yamada [this message]
2021-08-19 6:29 ` [PATCH 05/13] kbuild: remove stale *.symversions Kees Cook
2021-08-19 0:57 ` [PATCH 06/13] kbuild: merge vmlinux_link() between the ordinary link and Clang LTO Masahiro Yamada
2021-08-19 2:42 ` Kees Cook
2021-08-19 0:57 ` [PATCH 07/13] kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh Masahiro Yamada
2021-08-19 6:32 ` Kees Cook
2021-08-19 0:57 ` [PATCH 08/13] kbuild: merge vmlinux_link() between ARCH=um and other architectures Masahiro Yamada
2021-08-19 2:43 ` Kees Cook
2021-08-19 0:57 ` [PATCH 09/13] kbuild: do not create built-in.a.symversions or lib.a.symversions Masahiro Yamada
2021-08-19 6:41 ` Kees Cook
2021-08-28 11:57 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 10/13] kbuild: build modules in the same way with/without Clang LTO Masahiro Yamada
2021-08-19 6:59 ` Kees Cook
2021-08-19 8:11 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 11/13] kbuild: always postpone CRC links for module versioning Masahiro Yamada
2021-08-19 6:43 ` Kees Cook
2021-08-19 0:57 ` [PATCH 12/13] kbuild: merge cmd_modversions_c and cmd_modversions_S Masahiro Yamada
2021-08-19 3:06 ` Kees Cook
2021-08-19 0:57 ` [PATCH 13/13] kbuild: merge cmd_ar_builtin and cmd_ar_module Masahiro Yamada
2021-08-19 3:01 ` Kees Cook
2021-08-25 4:57 ` [PATCH 00/13] kbuild: refactoring after Clang LTO Masahiro Yamada
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