[PATCH 5/5] kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols

From: Masahiro Yamada
Date: Mon Sep 26 2022 - 05:04:17 EST


Every EXPORT_SYMBOL creates __kstrtab_* and __kstrtabns_*, which
consumes 15-20% of the kallsyms entries.

For x86_64 defconfig,

$ cat /proc/kallsyms | wc
129527 388581 5685465
$ cat /proc/kallsyms | grep __kstrtab | wc
23489 70467 1187932

We already ignore __crc_* symbols populated by EXPORT_SYMBOL, so it
should be fine to ignore __kstrtab_* and __kstrtabns_* as well.

This makes vmlinux a bit smaller.

$ size vmlinux.before vmlinux.after
text data bss dec hex filename
22785374 8559694 1413328 32758396 1f3da7c vmlinux.before
22785374 8137806 1413328 32336508 1ed6a7c vmlinux.after

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

scripts/mksysmap | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/scripts/mksysmap b/scripts/mksysmap
index 75f3dfd1c156..16a08b8ef2f8 100755
--- a/scripts/mksysmap
+++ b/scripts/mksysmap
@@ -43,6 +43,8 @@
# $ - local symbols for ARM, MIPS, etc.
# .L - local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc.
# __crc_ - modversions
+# __kstrtab_ - EXPORT_SYMBOL (symbol name)
+# __kstrtabns_ - EXPORT_SYMBOL (namespace)
#
# Ignored symbols:
# L0 - for LoongArch?
@@ -52,5 +54,7 @@ $NM -n $1 | grep -v \
-e ' \$' \
-e ' \.L' \
-e ' __crc_' \
+ -e ' __kstrtab_' \
+ -e ' __kstrtabns_' \
-e ' L0$' \
> $2
--
2.34.1