On Thu, Jul 15, 2021 at 4:37 PM Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx> wrote: > > 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@xxxxxxxxxxxx/] > 2. [https://lore.kernel.org/lkml/20210702032943.7865-1-lecopzer.chen@xxxxxxxxxxxx/] > > Fixes: 38e89184900385 ("kbuild: lto: fix module versioning") > Sign-off-byed: Sami Tolvanen <samitolvanen@xxxxxxxxxx> This Signed-off-by is not correct usage, I think. I replaced it with Co-developed-by. I usually use 'for ... do ... done' instead of $(foreach ...), and 'if ... then ... fi' instead of $(if ...). But, this is the minimal change without causing too long command line. Applied to linux-kbuild. Thanks. > Signed-off-by: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx> > --- > scripts/Makefile.build | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > index 10b2f2380d6f..02197cb8e3a7 100644 > --- a/scripts/Makefile.build > +++ b/scripts/Makefile.build > @@ -386,7 +386,7 @@ ifeq ($(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 > -- > 2.18.0 > -- Best Regards Masahiro Yamada
