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| author | Masahiro Yamada <masahiroy@kernel.org> | 2024-09-14 02:37:53 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-09-13 20:03:29 -0700 |
| commit | 42450f7a9086cf38e97c3aeeaabd229af7abbbad (patch) | |
| tree | 9105296ff0cbc99f62a39d4a9646c3c5174cb07e | |
| parent | c980dc9c67a94ab716ffc06767cb435480bda09d (diff) | |
| download | lwn-42450f7a9086cf38e97c3aeeaabd229af7abbbad.tar.gz lwn-42450f7a9086cf38e97c3aeeaabd229af7abbbad.zip | |
btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
When DEBUG_INFO_DWARF5 is selected, pahole 1.21+ is required to enable
DEBUG_INFO_BTF.
When DEBUG_INFO_DWARF4 or DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT is selected,
DEBUG_INFO_BTF can be enabled without pahole installed, but a build error
will occur in scripts/link-vmlinux.sh:
LD .tmp_vmlinux1
BTF: .tmp_vmlinux1: pahole (pahole) is not available
Failed to generate BTF for vmlinux
Try to disable CONFIG_DEBUG_INFO_BTF
We did not guard DEBUG_INFO_BTF by PAHOLE_VERSION when previously
discussed [1].
However, commit 613fe1692377 ("kbuild: Add CONFIG_PAHOLE_VERSION")
added CONFIG_PAHOLE_VERSION after all. Now several CONFIG options, as
well as the combination of DEBUG_INFO_BTF and DEBUG_INFO_DWARF5, are
guarded by PAHOLE_VERSION.
The remaining compile-time check in scripts/link-vmlinux.sh now appears
to be an awkward inconsistency.
This commit adopts Nathan's original work.
[1]: https://lore.kernel.org/lkml/20210111180609.713998-1-natechancellor@gmail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240913173759.1316390-2-masahiroy@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | lib/Kconfig.debug | 6 | ||||
| -rwxr-xr-x | scripts/link-vmlinux.sh | 12 |
2 files changed, 4 insertions, 14 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a30c03a66172..f627147d6c25 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -379,13 +379,15 @@ config DEBUG_INFO_BTF depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST depends on BPF_SYSCALL + depends on PAHOLE_VERSION >= 116 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121 # pahole uses elfutils, which does not have support for Hexagon relocations depends on !HEXAGON help Generate deduplicated BTF type information from DWARF debug info. - Turning this on expects presence of pahole tool, which will convert - DWARF type info into equivalent deduplicated BTF type info. + Turning this on requires pahole v1.16 or later (v1.21 or later to + support DWARF 5), which will convert DWARF type info into equivalent + deduplicated BTF type info. config PAHOLE_HAS_SPLIT_BTF def_bool PAHOLE_VERSION >= 119 diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 8a06907fea32..069d34112e6a 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -107,20 +107,8 @@ vmlinux_link() # ${1} - vmlinux image gen_btf() { - local pahole_ver local btf_data=${1}.btf.o - if ! [ -x "$(command -v ${PAHOLE})" ]; then - echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available" - return 1 - fi - - pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/') - if [ "${pahole_ver}" -lt "116" ]; then - echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16" - return 1 - fi - info BTF "${btf_data}" LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1} |