Richard Weinberger pointed out the risk of sourcing the kernel config
from shell scripts [1], and proposed some patches [2], [3]. It is a good
point, but it took a long time because I was wondering how to fix this.
This commit goes with simple grep approach because there are only a few
scripts including the kernel configuration.
scripts/link_vmlinux.sh has references to a bunch of CONFIG options,
all of which are boolean. I added is_enabled() helper as
scripts/package/{mkdebian,builddeb} do.
scripts/gen_autoksyms.sh uses 'eval', stating "to expand the whitelist
path". I removed it since it is the issue we are trying to fix.
I was a bit worried about the cost of invoking the grep command over
again. I extracted the grep parts from it, and measured the cost. It
was approximately 0.03 sec, which I hope is acceptable.
[test code]
$ cat test-grep.sh
#!/bin/sh
is_enabled() {
grep -q "^$1=y" include/config/auto.conf
}
is_enabled CONFIG_LTO_CLANG
is_enabled CONFIG_LTO_CLANG
is_enabled CONFIG_STACK_VALIDATION
is_enabled CONFIG_UNWINDER_ORC
is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
is_enabled CONFIG_VMLINUX_VALIDATION
is_enabled CONFIG_FRAME_POINTER
is_enabled CONFIG_GCOV_KERNEL
is_enabled CONFIG_LTO_CLANG
is_enabled CONFIG_RETPOLINE
is_enabled CONFIG_X86_SMAP
is_enabled CONFIG_LTO_CLANG
is_enabled CONFIG_VMLINUX_MAP
is_enabled CONFIG_KALLSYMS_ALL
is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU
is_enabled CONFIG_KALLSYMS_BASE_RELATIVE
is_enabled CONFIG_DEBUG_INFO_BTF
is_enabled CONFIG_KALLSYMS
is_enabled CONFIG_DEBUG_INFO_BTF
is_enabled CONFIG_BPF
is_enabled CONFIG_BUILDTIME_TABLE_SORT
is_enabled CONFIG_KALLSYMS
$ time ./test-grep.sh
real 0m0.036s
user 0m0.027s
sys m0.009s
[1]: https://lore.kernel.org/all/1919455.eZKeABUfgV@blindfold/
[2]: https://lore.kernel.org/all/20180219092245.26404-1-richard@xxxxxx/
[3]: https://lore.kernel.org/all/20210920213957.1064-2-richard@xxxxxx/
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Reviewed-by: Nicolas Schier <n.schier@xxxxxx>
---
Changes in v2:
- complete the fixes of gen_autoksyms.sh
scripts/gen_autoksyms.sh | 11 +++-------
scripts/link-vmlinux.sh | 47 ++++++++++++++++++++--------------------
scripts/setlocalversion | 9 ++++----
3 files changed, 31 insertions(+), 36 deletions(-)
diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh
index 6ed0d225c8b1..949d6a054034 100755
--- a/scripts/gen_autoksyms.sh
+++ b/scripts/gen_autoksyms.sh
@@ -16,20 +16,15 @@ case "$KBUILD_VERBOSE" in
;;
esac
-# We need access to CONFIG_ symbols
-. include/config/auto.conf
-
needed_symbols=
# Special case for modversions (see modpost.c)
-if [ -n "$CONFIG_MODVERSIONS" ]; then
+if grep -q "^CONFIG_MODVERSIONS=y$" include/config/auto.conf; then
needed_symbols="$needed_symbols module_layout"
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"
+ksym_wl=$(sed -n 's/^CONFIG_UNUSED_KSYMS_WHITELIST="\(.*\)"$/\1/p' include/config/auto.conf)
+if [ -n "$ksym_wl" ]; then
[ "${ksym_wl}" != "${ksym_wl#/}" ] || ksym_wl="$abs_srctree/$ksym_wl"
if [ ! -f "$ksym_wl" ] || [ ! -r "$ksym_wl" ]; then
echo "ERROR: '$ksym_wl' whitelist file not found" >&2
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 5cdd9bc5c385..a4b61a2f65db 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -34,6 +34,10 @@ LD="$1"
KBUILD_LDFLAGS="$2"
LDFLAGS_vmlinux="$3"
+is_enabled() {
+ grep -q "^$1=y" include/config/auto.conf
+}
+
# Nice output in kbuild format
# Will be supressed by "make -s"
info()
@@ -80,11 +84,11 @@ modpost_link()
${KBUILD_VMLINUX_LIBS} \
--end-group"
- if [ -n "${CONFIG_LTO_CLANG}" ]; then
+ if is_enabled CONFIG_LTO_CLANG; then
gen_initcalls
lds="-T .tmp_initcalls.lds"
- if [ -n "${CONFIG_MODVERSIONS}" ]; then
+ if is_enabled CONFIG_MODVERSIONS; then
gen_symversions
lds="${lds} -T .tmp_symversions.lds"
fi
@@ -104,21 +108,21 @@ objtool_link()
local objtoolcmd;
local objtoolopt;
- if [ "${CONFIG_LTO_CLANG} ${CONFIG_STACK_VALIDATION}" = "y y" ]; then
+ if is_enabled CONFIG_LTO_CLANG && is_enabled CONFIG_STACK_VALIDATION; then
# Don't perform vmlinux validation unless explicitly requested,
# but run objtool on vmlinux.o now that we have an object file.
- if [ -n "${CONFIG_UNWINDER_ORC}" ]; then
+ if is_enabled CONFIG_UNWINDER_ORC; then
objtoolcmd="orc generate"
fi
objtoolopt="${objtoolopt} --duplicate"
- if [ -n "${CONFIG_FTRACE_MCOUNT_USE_OBJTOOL}" ]; then
+ if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then
objtoolopt="${objtoolopt} --mcount"
fi
fi
- if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then
+ if is_enabled CONFIG_VMLINUX_VALIDATION; then
objtoolopt="${objtoolopt} --noinstr"
fi
@@ -127,16 +131,16 @@ objtool_link()
objtoolcmd="check"
fi
objtoolopt="${objtoolopt} --vmlinux"
- if [ -z "${CONFIG_FRAME_POINTER}" ]; then
+ if ! is_enabled CONFIG_FRAME_POINTER; then
objtoolopt="${objtoolopt} --no-fp"
fi
- if [ -n "${CONFIG_GCOV_KERNEL}" ] || [ -n "${CONFIG_LTO_CLANG}" ]; then
+ if is_enabled CONFIG_GCOV_KERNEL || is_enabled CONFIG_LTO_CLANG; then
objtoolopt="${objtoolopt} --no-unreachable"
fi
- if [ -n "${CONFIG_RETPOLINE}" ]; then
+ if is_enabled CONFIG_RETPOLINE; then
objtoolopt="${objtoolopt} --retpoline"
fi
- if [ -n "${CONFIG_X86_SMAP}" ]; then
+ if is_enabled CONFIG_X86_SMAP; then
objtoolopt="${objtoolopt} --uaccess"
fi
info OBJTOOL ${1}
@@ -161,7 +165,7 @@ vmlinux_link()
# skip output file argument
shift
- if [ -n "${CONFIG_LTO_CLANG}" ]; then
+ if is_enabled CONFIG_LTO_CLANG; then
# Use vmlinux.o instead of performing the slow LTO link again.
objs=vmlinux.o
libs=
@@ -189,7 +193,7 @@ vmlinux_link()
ldflags="${ldflags} ${wl}--strip-debug"
fi
- if [ -n "${CONFIG_VMLINUX_MAP}" ]; then
+ if is_enabled CONFIG_VMLINUX_MAP; then
ldflags="${ldflags} ${wl}-Map=${output}.map"
fi
@@ -239,15 +243,15 @@ kallsyms()
{
local kallsymopt;
- if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
+ if is_enabled CONFIG_KALLSYMS_ALL; then
kallsymopt="${kallsymopt} --all-symbols"
fi
- if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
+ if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
kallsymopt="${kallsymopt} --absolute-percpu"
fi
- if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
+ if is_enabled CONFIG_KALLSYMS_BASE_RELATIVE; then
kallsymopt="${kallsymopt} --base-relative"
fi
@@ -312,9 +316,6 @@ if [ "$1" = "clean" ]; then
exit 0
fi
-# We need access to CONFIG_ symbols
-. include/config/auto.conf
-
# Update version
info GEN .version
if [ -r .version ]; then
@@ -343,7 +344,7 @@ tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
btf_vmlinux_bin_o=""
-if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
+if is_enabled CONFIG_DEBUG_INFO_BTF; then
btf_vmlinux_bin_o=.btf.vmlinux.bin.o
if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
echo >&2 "Failed to generate BTF for vmlinux"
@@ -355,7 +356,7 @@ fi
kallsymso=""
kallsymso_prev=""
kallsyms_vmlinux=""
-if [ -n "${CONFIG_KALLSYMS}" ]; then
+if is_enabled CONFIG_KALLSYMS; then
# kallsyms support
# Generate section listing all symbols and add it into vmlinux
@@ -395,12 +396,12 @@ fi
vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
# fill in BTF IDs
-if [ -n "${CONFIG_DEBUG_INFO_BTF}" -a -n "${CONFIG_BPF}" ]; then
+if is_enabled CONFIG_DEBUG_INFO_BTF && is_enabled CONFIG_BPF; then
info BTFIDS vmlinux
${RESOLVE_BTFIDS} vmlinux
fi
-if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
+if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then
info SORTTAB vmlinux
if ! sorttable vmlinux; then
echo >&2 Failed to sort kernel tables
@@ -412,7 +413,7 @@ info SYSMAP System.map
mksysmap vmlinux System.map
# step a (see comment above)
-if [ -n "${CONFIG_KALLSYMS}" ]; then
+if is_enabled CONFIG_KALLSYMS; then
mksysmap ${kallsyms_vmlinux} .tmp_System.map
if ! cmp -s System.map .tmp_System.map; then
diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 6b54e46a0f12..d06137405190 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -111,9 +111,7 @@ if $scm_only; then
exit
fi
-if test -e include/config/auto.conf; then
- . include/config/auto.conf
-else
+if ! test -e include/config/auto.conf; then
echo "Error: kernelrelease not valid - run 'make prepare' to update it" >&2
exit 1
fi
@@ -125,10 +123,11 @@ if test ! "$srctree" -ef .; then
fi
# CONFIG_LOCALVERSION and LOCALVERSION (if set)
-res="${res}${CONFIG_LOCALVERSION}${LOCALVERSION}"
+config_localversion=$(sed -n 's/^CONFIG_LOCALVERSION="\(.*\)"$/\1/p' include/config/auto.conf)
+res="${res}${config_localversion}${LOCALVERSION}"
# scm version string if not at a tagged commit
-if test "$CONFIG_LOCALVERSION_AUTO" = "y"; then
+if grep -q "^CONFIG_LOCALVERSION_AUTO=y$" include/config/auto.conf; then
# full scm version string
res="$res$(scm_version)"
elif [ "${LOCALVERSION+set}" != "set" ]; then
--
2.32.0
