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| author | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-26 15:25:48 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-28 15:19:21 +0900 |
| commit | a6aaeb841198016083663ae56c568de4e065d090 (patch) | |
| tree | 12339f936fba7c5c2c152ce3dcd0dd427cfaeee4 | |
| parent | da83616bcd3fa84233f6e37e2cf8cbfa979c6927 (diff) | |
| download | linux-stable-a6aaeb841198016083663ae56c568de4e065d090.tar.gz linux-stable-a6aaeb841198016083663ae56c568de4e065d090.tar.bz2 linux-stable-a6aaeb841198016083663ae56c568de4e065d090.zip | |
kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO
Commit fbe078d397b4 ("kbuild: lto: add a default list of used symbols")
does not work as expected if the .config file has already specified
CONFIG_UNUSED_KSYMS_WHITELIST="my/own/white/list" before enabling
CONFIG_LTO_CLANG.
So, the user-supplied whitelist and LTO-specific white list must be
independent of each other.
I refactored the shell script so CONFIG_MODVERSIONS and CONFIG_CLANG_LTO
handle whitelists in the same way.
Fixes: fbe078d397b4 ("kbuild: lto: add a default list of used symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
| -rw-r--r-- | init/Kconfig | 1 | ||||
| -rwxr-xr-x | scripts/gen_autoksyms.sh | 35 | ||||
| -rw-r--r-- | scripts/lto-used-symbollist.txt | 6 |
3 files changed, 26 insertions, 16 deletions
diff --git a/init/Kconfig b/init/Kconfig index efdc35abccb6..22946fe5ded9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2283,7 +2283,6 @@ config TRIM_UNUSED_KSYMS config UNUSED_KSYMS_WHITELIST string "Whitelist of symbols to keep in ksymtab" depends on TRIM_UNUSED_KSYMS - default "scripts/lto-used-symbollist.txt" if LTO_CLANG help By default, all unused exported symbols will be un-exported from the build when TRIM_UNUSED_KSYMS is selected. diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh index d54dfba15bf2..da320151e7c3 100755 --- a/scripts/gen_autoksyms.sh +++ b/scripts/gen_autoksyms.sh @@ -19,7 +19,26 @@ esac # We need access to CONFIG_ symbols . include/config/auto.conf -ksym_wl=/dev/null +needed_symbols= + +# Special case for modversions (see modpost.c) +if [ -n "$CONFIG_MODVERSIONS" ]; then + needed_symbols="$needed_symbols module_layout" +fi + +# With CONFIG_LTO_CLANG, LLVM bitcode has not yet been compiled into a binary +# when the .mod files are generated, which means they don't yet contain +# references to certain symbols that will be present in the final binaries. +if [ -n "$CONFIG_LTO_CLANG" ]; then + # intrinsic functions + needed_symbols="$needed_symbols memcpy memmove memset" + # ftrace + needed_symbols="$needed_symbols _mcount" + # stack protector symbols + needed_symbols="$needed_symbols __stack_chk_fail __stack_chk_guard" +fi + +ksym_wl= if [ -n "$CONFIG_UNUSED_KSYMS_WHITELIST" ]; then # Use 'eval' to expand the whitelist path and check if it is relative eval ksym_wl="$CONFIG_UNUSED_KSYMS_WHITELIST" @@ -40,16 +59,14 @@ cat > "$output_file" << EOT EOT [ -f modules.order ] && modlist=modules.order || modlist=/dev/null -sed 's/ko$/mod/' $modlist | -xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- | -cat - "$ksym_wl" | + +{ + sed 's/ko$/mod/' $modlist | xargs -n1 sed -n -e '2p' + echo "$needed_symbols" + [ -n "$ksym_wl" ] && cat "$ksym_wl" +} | sed -e 's/ /\n/g' | sed -n -e '/^$/!p' | # Remove the dot prefix for ppc64; symbol names with a dot (.) hold entry # point addresses. sed -e 's/^\.//' | sort -u | sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file" - -# Special case for modversions (see modpost.c) -if [ -n "$CONFIG_MODVERSIONS" ]; then - echo "#define __KSYM_module_layout 1" >> "$output_file" -fi diff --git a/scripts/lto-used-symbollist.txt b/scripts/lto-used-symbollist.txt deleted file mode 100644 index 406ada65e926..000000000000 --- a/scripts/lto-used-symbollist.txt +++ /dev/null @@ -1,6 +0,0 @@ -memcpy -memmove -memset -_mcount -__stack_chk_fail -__stack_chk_guard |