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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Zhen Lei](/assets/img/avatar_default.png)
LLVM appends various suffixes for local functions and variables, suffixes observed: - foo.llvm.[0-9a-f]+ - foo.[0-9a-f]+ Therefore, when CONFIG_LTO_CLANG=y, kallsyms_lookup_name() needs to truncate the suffix of the symbol name before comparing the local function or variable name. Old implementation code: - if (strcmp(namebuf, name) == 0) - return kallsyms_sym_address(i); - if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0) - return kallsyms_sym_address(i); The preceding process is traversed by address from low to high. That is, for those with the same name after the suffix is removed, the one with the smallest address is returned first. Therefore, when sorting in the tool, if the raw names are the same, they should be sorted by address in ascending order. ASCII[.] = 2e ASCII[0-9] = 30,39 ASCII[A-Z] = 41,5a ASCII[_] = 5f ASCII[a-z] = 61,7a According to the preceding ASCII code values, the following sorting result is strictly followed. --------------------------------- | main-key | sub-key | |---------------------------------| | | addr_lowest | | <name> | ... | | <name>.<suffix> | ... | | | addr_highest | |---------------------------------| | <name>?<others> | | //? is [_A-Za-z0-9] --------------------------------- Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
300 lines
7.5 KiB
Bash
Executable file
300 lines
7.5 KiB
Bash
Executable file
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0
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#
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# link vmlinux
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#
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# vmlinux is linked from the objects in vmlinux.a and $(KBUILD_VMLINUX_LIBS).
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# vmlinux.a contains objects that are linked unconditionally.
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# $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
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# (not within --whole-archive), and do not require symbol indexes added.
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#
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# vmlinux
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# ^
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# |
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# +--< vmlinux.a
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# |
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# +--< $(KBUILD_VMLINUX_LIBS)
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# | +--< lib/lib.a + more
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# |
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# +-< ${kallsymso} (see description in KALLSYMS section)
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#
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# vmlinux version (uname -v) cannot be updated during normal
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# descending-into-subdirs phase since we do not yet know if we need to
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# update vmlinux.
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# Therefore this step is delayed until just before final link of vmlinux.
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#
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# System.map is generated to document addresses of all kernel symbols
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# Error out on error
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set -e
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LD="$1"
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KBUILD_LDFLAGS="$2"
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LDFLAGS_vmlinux="$3"
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is_enabled() {
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grep -q "^$1=y" include/config/auto.conf
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}
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# Nice output in kbuild format
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# Will be supressed by "make -s"
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info()
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{
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printf " %-7s %s\n" "${1}" "${2}"
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}
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# Link of vmlinux
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# ${1} - output file
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# ${2}, ${3}, ... - optional extra .o files
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vmlinux_link()
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{
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local output=${1}
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local objs
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local libs
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local ld
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local ldflags
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local ldlibs
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info LD ${output}
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# skip output file argument
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shift
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if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
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# Use vmlinux.o instead of performing the slow LTO link again.
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objs=vmlinux.o
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libs=
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else
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objs=vmlinux.a
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libs="${KBUILD_VMLINUX_LIBS}"
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fi
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if is_enabled CONFIG_MODULES; then
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objs="${objs} .vmlinux.export.o"
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fi
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objs="${objs} init/version-timestamp.o"
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if [ "${SRCARCH}" = "um" ]; then
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wl=-Wl,
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ld="${CC}"
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ldflags="${CFLAGS_vmlinux}"
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ldlibs="-lutil -lrt -lpthread"
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else
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wl=
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ld="${LD}"
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ldflags="${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux}"
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ldlibs=
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fi
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ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}"
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# The kallsyms linking does not need debug symbols included.
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if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
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ldflags="${ldflags} ${wl}--strip-debug"
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fi
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if is_enabled CONFIG_VMLINUX_MAP; then
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ldflags="${ldflags} ${wl}-Map=${output}.map"
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fi
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${ld} ${ldflags} -o ${output} \
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${wl}--whole-archive ${objs} ${wl}--no-whole-archive \
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${wl}--start-group ${libs} ${wl}--end-group \
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$@ ${ldlibs}
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}
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# generate .BTF typeinfo from DWARF debuginfo
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# ${1} - vmlinux image
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# ${2} - file to dump raw BTF data into
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gen_btf()
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{
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local pahole_ver
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if ! [ -x "$(command -v ${PAHOLE})" ]; then
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echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
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return 1
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fi
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pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
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if [ "${pahole_ver}" -lt "116" ]; then
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echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
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return 1
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fi
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vmlinux_link ${1}
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info "BTF" ${2}
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LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
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# Create ${2} which contains just .BTF section but no symbols. Add
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# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
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# deletes all symbols including __start_BTF and __stop_BTF, which will
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# be redefined in the linker script. Add 2>/dev/null to suppress GNU
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# objcopy warnings: "empty loadable segment detected at ..."
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${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
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--strip-all ${1} ${2} 2>/dev/null
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# Change e_type to ET_REL so that it can be used to link final vmlinux.
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# Unlike GNU ld, lld does not allow an ET_EXEC input.
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printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
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}
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# Create ${2} .S file with all symbols from the ${1} object file
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kallsyms()
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{
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local kallsymopt;
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if is_enabled CONFIG_KALLSYMS_ALL; then
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kallsymopt="${kallsymopt} --all-symbols"
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fi
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if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
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kallsymopt="${kallsymopt} --absolute-percpu"
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fi
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if is_enabled CONFIG_KALLSYMS_BASE_RELATIVE; then
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kallsymopt="${kallsymopt} --base-relative"
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fi
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if is_enabled CONFIG_LTO_CLANG; then
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kallsymopt="${kallsymopt} --lto-clang"
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fi
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info KSYMS ${2}
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scripts/kallsyms ${kallsymopt} ${1} > ${2}
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}
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# Perform one step in kallsyms generation, including temporary linking of
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# vmlinux.
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kallsyms_step()
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{
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kallsymso_prev=${kallsymso}
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kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
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kallsymso=${kallsyms_vmlinux}.o
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kallsyms_S=${kallsyms_vmlinux}.S
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vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
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mksysmap ${kallsyms_vmlinux} ${kallsyms_vmlinux}.syms
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kallsyms ${kallsyms_vmlinux}.syms ${kallsyms_S}
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info AS ${kallsyms_S}
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${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
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${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
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-c -o ${kallsymso} ${kallsyms_S}
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}
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# Create map file with all symbols from ${1}
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# See mksymap for additional details
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mksysmap()
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{
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info NM ${2}
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${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
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}
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sorttable()
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{
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${objtree}/scripts/sorttable ${1}
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}
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# Delete output files in case of error
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cleanup()
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{
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rm -f .btf.*
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rm -f System.map
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rm -f vmlinux
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rm -f vmlinux.map
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}
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# Use "make V=1" to debug this script
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case "${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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if [ "$1" = "clean" ]; then
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cleanup
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exit 0
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fi
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${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init init/version-timestamp.o
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btf_vmlinux_bin_o=""
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if is_enabled CONFIG_DEBUG_INFO_BTF; then
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btf_vmlinux_bin_o=.btf.vmlinux.bin.o
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if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
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echo >&2 "Failed to generate BTF for vmlinux"
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echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
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exit 1
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fi
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fi
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kallsymso=""
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kallsymso_prev=""
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kallsyms_vmlinux=""
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if is_enabled CONFIG_KALLSYMS; then
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# kallsyms support
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# Generate section listing all symbols and add it into vmlinux
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# It's a three step process:
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# 1) Link .tmp_vmlinux.kallsyms1 so it has all symbols and sections,
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# but __kallsyms is empty.
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# Running kallsyms on that gives us .tmp_kallsyms1.o with
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# the right size
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# 2) Link .tmp_vmlinux.kallsyms2 so it now has a __kallsyms section of
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# the right size, but due to the added section, some
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# addresses have shifted.
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# From here, we generate a correct .tmp_vmlinux.kallsyms2.o
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# 3) That link may have expanded the kernel image enough that
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# more linker branch stubs / trampolines had to be added, which
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# introduces new names, which further expands kallsyms. Do another
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# pass if that is the case. In theory it's possible this results
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# in even more stubs, but unlikely.
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# KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
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# other bugs.
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# 4) The correct ${kallsymso} is linked into the final vmlinux.
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#
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# a) Verify that the System.map from vmlinux matches the map from
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# ${kallsymso}.
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kallsyms_step 1
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kallsyms_step 2
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# step 3
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size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
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size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
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if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
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kallsyms_step 3
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fi
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fi
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vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
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# fill in BTF IDs
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if is_enabled CONFIG_DEBUG_INFO_BTF && is_enabled CONFIG_BPF; then
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info BTFIDS vmlinux
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${RESOLVE_BTFIDS} vmlinux
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fi
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mksysmap vmlinux System.map
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if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then
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info SORTTAB vmlinux
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if ! sorttable vmlinux; then
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echo >&2 Failed to sort kernel tables
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exit 1
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fi
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fi
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# step a (see comment above)
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if is_enabled CONFIG_KALLSYMS; then
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if ! cmp -s System.map ${kallsyms_vmlinux}.syms; then
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echo >&2 Inconsistent kallsyms data
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echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
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exit 1
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fi
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fi
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# For fixdep
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echo "vmlinux: $0" > .vmlinux.d
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