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authorMasahiro Yamada <masahiroy@kernel.org>2021-08-19 03:01:14 +0300
committerMasahiro Yamada <masahiroy@kernel.org>2021-09-03 02:17:20 +0300
commit52d83df682c82055961531853c066f4f16e234ea (patch)
tree9b11534aad6da013ba7432efc03a496d9fbbc632
parent2185a7e4b0ade86c2c57fc63d4a7535c40254bd0 (diff)
downloadlinux-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 $NM (both GNU nm and llvm-nm) warns when no symbol is found in the object. Suppress the stderr. Fangrui Song mentioned binutils>=2.37 `nm -q` can be used to suppress "no symbols" [1], and llvm-nm>=13.0.0 supports -q as well. We cannot use it for now, but note it as a TODO. [1]: https://sourceware.org/bugzilla/show_bug.cgi?id=27408 Fixes: bbda5ec671d3 ("kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
-rwxr-xr-xscripts/gen_ksymdeps.sh8
1 files changed, 7 insertions, 1 deletions
diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh
index 1324986e1362..725e8c9c1b53 100755
--- a/scripts/gen_ksymdeps.sh
+++ b/scripts/gen_ksymdeps.sh
@@ -4,7 +4,13 @@
set -e
# List of exported symbols
-ksyms=$($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