From: Lecopzer Chen lecopzer.chen@mediatek.com
[ Upstream commit 1d11053dc63094075bf9e4809fffd3bb5e72f9a6 ]
When building modules(CONFIG_...=m), I found some of module versions are incorrect and set to 0. This can be found in build log for first clean build which shows
WARNING: EXPORT symbol "XXXX" [drivers/XXX/XXX.ko] version generation failed, symbol will not be versioned.
But in second build(incremental build), the WARNING disappeared and the module version becomes valid CRC and make someone who want to change modules without updating kernel image can't insert their modules.
The problematic code is + $(foreach n, $(filter-out FORCE,$^), \ + $(if $(wildcard $(n).symversions), \ + ; cat $(n).symversions >> $@.symversions))
For example: rm -f fs/notify/built-in.a.symversions ; rm -f fs/notify/built-in.a; \ llvm-ar cDPrST fs/notify/built-in.a fs/notify/fsnotify.o \ fs/notify/notification.o fs/notify/group.o ...
`foreach n` shows nothing to `cat` into $(n).symversions because `if $(wildcard $(n).symversions)` return nothing, but actually they do exist during this line was executed.
-rw-r--r-- 1 root root 168580 Jun 13 19:10 fs/notify/fsnotify.o -rw-r--r-- 1 root root 111 Jun 13 19:10 fs/notify/fsnotify.o.symversions
The reason is the $(n).symversions are generated at runtime, but Makefile wildcard function expends and checks the file exist or not during parsing the Makefile.
Thus fix this by use `test` shell command to check the file existence in runtime.
Rebase from both: 1. [https://lore.kernel.org/lkml/20210616080252.32046-1-lecopzer.chen@mediatek.c...] 2. [https://lore.kernel.org/lkml/20210702032943.7865-1-lecopzer.chen@mediatek.co...]
Fixes: 38e891849003 ("kbuild: lto: fix module versioning") Co-developed-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Lecopzer Chen lecopzer.chen@mediatek.com Signed-off-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 34d257653fb4..c6bd62f518ff 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -388,7 +388,7 @@ ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y) cmd_update_lto_symversions = \ rm -f $@.symversions \ $(foreach n, $(filter-out FORCE,$^), \ - $(if $(wildcard $(n).symversions), \ + $(if $(shell test -s $(n).symversions && echo y), \ ; cat $(n).symversions >> $@.symversions)) else cmd_update_lto_symversions = echo >/dev/null