linux/scripts/gen_autoksyms.sh

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#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-only
# Create an autoksyms.h header file from the list of all module's needed symbols
# as recorded on the second line of *.mod files and the user-provided symbol
# whitelist.
set -e
output_file="$1"
# Use "make V=1" to debug this script.
case "$KBUILD_VERBOSE" in
*1*)
set -x
;;
esac
needed_symbols=
# Special case for modversions (see modpost.c)
kbuild: do not include include/config/auto.conf from shell scripts 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@nod.at/ [3]: https://lore.kernel.org/all/20210920213957.1064-2-richard@nod.at/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2021-12-14 10:53:52 +08:00
if grep -q "^CONFIG_MODVERSIONS=y$" include/config/auto.conf; then
needed_symbols="$needed_symbols module_layout"
fi
kbuild: do not include include/config/auto.conf from shell scripts 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@nod.at/ [3]: https://lore.kernel.org/all/20210920213957.1064-2-richard@nod.at/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2021-12-14 10:53:52 +08:00
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: '$ksym_wl' whitelist file not found" >&2
exit 1
fi
fi
# Generate a new ksym list file with symbols needed by the current
# set of modules.
cat > "$output_file" << EOT
/*
* Automatically generated file; DO NOT EDIT.
*/
EOT
[ -f modules.order ] && modlist=modules.order || modlist=/dev/null
{
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"