6.10-stable review patch. If anyone has any objections, please let me know.
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From: Masahiro Yamada masahiroy@kernel.org
[ Upstream commit b1a9a5e04767e2a78783e19c9e55c25812ceccc3 ]
CONFIG_DEBUG_INFO_BTF=y requires one additional link step. (.tmp_vmlinux.btf)
CONFIG_KALLSYMS=y requires two additional link steps. (.tmp_vmlinux.kallsyms1 and .tmp_vmlinux.kallsyms2)
Enabling both requires three additional link steps.
When CONFIG_DEBUG_INFO_BTF=y and CONFIG_KALLSYMS=y, the current build process is as follows:
KSYMS .tmp_vmlinux.kallsyms0.S AS .tmp_vmlinux.kallsyms0.o LD .tmp_vmlinux.btf # temporary vmlinux for BTF BTF .btf.vmlinux.bin.o LD .tmp_vmlinux.kallsyms1 # temporary vmlinux for kallsyms step 1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.o LD .tmp_vmlinux.kallsyms2 # temporary vmlinux for kallsyms step 2 NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.o LD vmlinux # final vmlinux
This is redundant because the BTF generation and the kallsyms step 1 can be performed against the same temporary vmlinux.
When both CONFIG_DEBUG_INFO_BTF and CONFIG_KALLSYMS are enabled, we can reduce the number of link steps by one.
This commit changes the build process as follows:
KSYMS .tmp_vmlinux0.kallsyms.S AS .tmp_vmlinux0.kallsyms.o LD .tmp_vmlinux1 # temporary vmlinux for BTF and kallsyms step 1 BTF .tmp_vmlinux1.btf.o NM .tmp_vmlinux1.syms KSYMS .tmp_vmlinux1.kallsyms.S AS .tmp_vmlinux1.kallsyms.o LD .tmp_vmlinux2 # temporary vmlinux for kallsyms step 2 NM .tmp_vmlinux2.syms KSYMS .tmp_vmlinux2.kallsyms.S AS .tmp_vmlinux2.kallsyms.o LD vmlinux # final vmlinux
Signed-off-by: Masahiro Yamada masahiroy@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Stable-dep-of: 1472464c6248 ("kbuild: avoid scripts/kallsyms parsing /dev/null") Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/link-vmlinux.sh | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 1e41b330550e6..22d0bc8439863 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -105,11 +105,10 @@ vmlinux_link()
# generate .BTF typeinfo from DWARF debuginfo # ${1} - vmlinux image -# ${2} - file to dump raw BTF data into gen_btf() { local pahole_ver - local btf_data=${2} + local btf_data=${1}.btf.o
if ! [ -x "$(command -v ${PAHOLE})" ]; then echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available" @@ -122,8 +121,6 @@ gen_btf() return 1 fi
- vmlinux_link ${1} - info BTF "${btf_data}" LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
@@ -169,15 +166,13 @@ kallsyms() kallsymso=${2}.o }
-# Perform one step in kallsyms generation, including temporary linking of -# vmlinux. -kallsyms_step() +# Perform kallsyms for the given temporary vmlinux. +sysmap_and_kallsyms() { - kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1} + mksysmap "${1}" "${1}.syms" + kallsyms "${1}.syms" "${1}.kallsyms"
- vmlinux_link "${kallsyms_vmlinux}" - mksysmap "${kallsyms_vmlinux}" "${kallsyms_vmlinux}.syms" - kallsyms "${kallsyms_vmlinux}.syms" "${kallsyms_vmlinux}" + kallsyms_sysmap=${1}.syms }
# Create map file with all symbols from ${1} @@ -220,11 +215,21 @@ kallsymso= strip_debug=
if is_enabled CONFIG_KALLSYMS; then - kallsyms /dev/null .tmp_vmlinux.kallsyms0 + kallsyms /dev/null .tmp_vmlinux0.kallsyms +fi + +if is_enabled CONFIG_KALLSYMS || is_enabled CONFIG_DEBUG_INFO_BTF; then + + # The kallsyms linking does not need debug symbols, but the BTF does. + if ! is_enabled CONFIG_DEBUG_INFO_BTF; then + strip_debug=1 + fi + + vmlinux_link .tmp_vmlinux1 fi
if is_enabled CONFIG_DEBUG_INFO_BTF; then - if ! gen_btf .tmp_vmlinux.btf .btf.vmlinux.bin.o ; then + if ! gen_btf .tmp_vmlinux1; then echo >&2 "Failed to generate BTF for vmlinux" echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF" exit 1 @@ -260,14 +265,16 @@ if is_enabled CONFIG_KALLSYMS; then # The kallsyms linking does not need debug symbols included. strip_debug=1
- kallsyms_step 1 + sysmap_and_kallsyms .tmp_vmlinux1 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
- kallsyms_step 2 + vmlinux_link .tmp_vmlinux2 + sysmap_and_kallsyms .tmp_vmlinux2 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then - kallsyms_step 3 + vmlinux_link .tmp_vmlinux3 + sysmap_and_kallsyms .tmp_vmlinux3 fi fi
@@ -293,7 +300,7 @@ fi
# step a (see comment above) if is_enabled CONFIG_KALLSYMS; then - if ! cmp -s System.map ${kallsyms_vmlinux}.syms; then + if ! cmp -s System.map "${kallsyms_sysmap}"; then echo >&2 Inconsistent kallsyms data echo >&2 'Try "make KALLSYMS_EXTRA_PASS=1" as a workaround' exit 1