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29500f15b5
Stephen Rothwell reported a build error on ppc64 when
CONFIG_TRIM_UNUSED_KSYMS is enabled.
Jessica Yu pointed out the cause of the error with the reference to the
ppc64 ELF ABI:
"Symbol names with a dot (.) prefix are reserved for holding entry
point addresses. The value of a symbol named ".FN", if it exists,
is the entry point of the function "FN".
As it turned out, CONFIG_TRIM_UNUSED_KSYMS has never worked for ppc64,
but this issue has been unnoticed until recently because this option
depends on !UNUSED_SYMBOLS hence is disabled by all{mod,yes}config.
(Then, it was uncovered by another patch removing UNUSED_SYMBOLS.)
Removing the dot prefix in scripts/gen_autoksyms.sh fixes the issue.
Please note it must be done before 'sort -u' because modules have
both ._mcount and _mcount undefined when CONFIG_FUNCTION_TRACER=y.
Link: https://lore.kernel.org/lkml/20210209210843.3af66662@canb.auug.org.au/
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
56 lines
1.4 KiB
Bash
Executable File
56 lines
1.4 KiB
Bash
Executable File
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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# Create an autoksyms.h header file from the list of all module's needed symbols
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# as recorded on the second line of *.mod files and the user-provided symbol
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# whitelist.
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set -e
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output_file="$1"
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# Use "make V=1" to debug this script.
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case "$KBUILD_VERBOSE" in
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*1*)
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set -x
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;;
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esac
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# We need access to CONFIG_ symbols
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. include/config/auto.conf
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ksym_wl=/dev/null
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if [ -n "$CONFIG_UNUSED_KSYMS_WHITELIST" ]; then
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# Use 'eval' to expand the whitelist path and check if it is relative
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eval ksym_wl="$CONFIG_UNUSED_KSYMS_WHITELIST"
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[ "${ksym_wl}" != "${ksym_wl#/}" ] || ksym_wl="$abs_srctree/$ksym_wl"
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if [ ! -f "$ksym_wl" ] || [ ! -r "$ksym_wl" ]; then
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echo "ERROR: '$ksym_wl' whitelist file not found" >&2
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exit 1
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fi
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fi
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# Generate a new ksym list file with symbols needed by the current
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# set of modules.
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cat > "$output_file" << EOT
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/*
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* Automatically generated file; DO NOT EDIT.
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*/
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EOT
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[ -f modules.order ] && modlist=modules.order || modlist=/dev/null
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sed 's/ko$/mod/' $modlist |
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xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- |
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cat - "$ksym_wl" |
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# Remove the dot prefix for ppc64; symbol names with a dot (.) hold entry
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# point addresses.
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sed -e 's/^\.//' |
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sort -u |
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sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file"
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# Special case for modversions (see modpost.c)
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if [ -n "$CONFIG_MODVERSIONS" ]; then
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echo "#define __KSYM_module_layout 1" >> "$output_file"
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fi
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