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author | Masahiro Yamada <masahiroy@kernel.org> | 2021-08-19 03:01:14 +0300 |
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committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-09-03 02:17:20 +0300 |
commit | 52d83df682c82055961531853c066f4f16e234ea (patch) | |
tree | 9b11534aad6da013ba7432efc03a496d9fbbc632 | |
parent | 2185a7e4b0ade86c2c57fc63d4a7535c40254bd0 (diff) | |
download | linux-52d83df682c82055961531853c066f4f16e234ea.tar.xz |
kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
When CONFIG_TRIM_UNUSED_KSYMS is enabled, I see some warnings like this:
nm: arch/x86/entry/vdso/vdso32/note.o: no symbols
$NM (both GNU nm and llvm-nm) warns when no symbol is found in the
object. Suppress the stderr.
Fangrui Song mentioned binutils>=2.37 `nm -q` can be used to suppress
"no symbols" [1], and llvm-nm>=13.0.0 supports -q as well.
We cannot use it for now, but note it as a TODO.
[1]: https://sourceware.org/bugzilla/show_bug.cgi?id=27408
Fixes: bbda5ec671d3 ("kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
-rwxr-xr-x | scripts/gen_ksymdeps.sh | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh index 1324986e1362..725e8c9c1b53 100755 --- a/scripts/gen_ksymdeps.sh +++ b/scripts/gen_ksymdeps.sh @@ -4,7 +4,13 @@ set -e # List of exported symbols -ksyms=$($NM $1 | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z) +# +# If the object has no symbol, $NM warns 'no symbols'. +# Suppress the stderr. +# TODO: +# Use -q instead of 2>/dev/null when we upgrade the minimum version of +# binutils to 2.37, llvm to 13.0.0. +ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z) if [ -z "$ksyms" ]; then exit 0 |