resolve_btfids: Change in-place update with raw binary output
Currently resolve_btfids updates .BTF_ids section of an ELF file
in-place, based on the contents of provided BTF, usually within the
same input file, and optionally a BTF base.
Change resolve_btfids behavior to enable BTF transformations as part
of its main operation. To achieve this, in-place ELF write in
resolve_btfids is replaced with generation of the following binaries:
* ${1}.BTF with .BTF section data
* ${1}.BTF_ids with .BTF_ids section data if it existed in ${1}
* ${1}.BTF.base with .BTF.base section data for out-of-tree modules
The execution of resolve_btfids and consumption of its output is
orchestrated by scripts/gen-btf.sh introduced in this patch.
The motivation for emitting binary data is that it allows simplifying
resolve_btfids implementation by delegating ELF update to the $OBJCOPY
tool [1], which is already widely used across the codebase.
There are two distinct paths for BTF generation and resolve_btfids
application in the kernel build: for vmlinux and for kernel modules.
For the vmlinux binary a .BTF section is added in a roundabout way to
ensure correct linking. The patch doesn't change this approach, only
the implementation is a little different.
Before this patch it worked as follows:
* pahole consumed .tmp_vmlinux1 [2] and added .BTF section with
llvm-objcopy [3] to it
* then everything except the .BTF section was stripped from .tmp_vmlinux1
into a .tmp_vmlinux1.bpf.o object [2], later linked into vmlinux
* resolve_btfids was executed later on vmlinux.unstripped [4],
updating it in-place
After this patch gen-btf.sh implements the following:
* pahole consumes .tmp_vmlinux1 and produces a *detached* file with
raw BTF data
* resolve_btfids consumes .tmp_vmlinux1 and detached BTF to produce
(potentially modified) .BTF, and .BTF_ids sections data
* a .tmp_vmlinux1.bpf.o object is then produced with objcopy copying
BTF output of resolve_btfids
* .BTF_ids data gets embedded into vmlinux.unstripped in
link-vmlinux.sh by objcopy --update-section
For kernel modules, creating a special .bpf.o file is not necessary,
and so embedding of sections data produced by resolve_btfids is
straightforward with objcopy.
With this patch an ELF file becomes effectively read-only within
resolve_btfids, which allows deleting elf_update() call and satellite
code (like compressed_section_fix [5]).
Endianness handling of .BTF_ids data is also changed. Previously the
"flags" part of the section was bswapped in sets_patch() [6], and then
Elf_Type was modified before elf_update() to signal to libelf that
bswap may be necessary. With this patch we explicitly bswap entire
data buffer on load and on dump.
[1] https://lore.kernel.org/bpf/131b4190-9c49-4f79-a99d-c00fac97fa44@linux.dev/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/link-vmlinux.sh?h=v6.18#n110
[3] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/tree/btf_encoder.c?h=v1.31#n1803
[4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/link-vmlinux.sh?h=v6.18#n284
[5] https://lore.kernel.org/bpf/20200819092342.259004-1-jolsa@kernel.org/
[6] https://lore.kernel.org/bpf/cover.1707223196.git.vmalik@redhat.com/
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20251219181825.1289460-3-ihor.solodrai@linux.dev
master
Ihor Solodrai
Andrii Nakryiko
parent
014e1cdb5f
commit
522397d05e
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@ -4766,6 +4766,7 @@ F: net/sched/act_bpf.c
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F: net/sched/cls_bpf.c
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F: samples/bpf/
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F: scripts/bpf_doc.py
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F: scripts/gen-btf.sh
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F: scripts/Makefile.btf
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F: scripts/pahole-version.sh
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F: tools/bpf/
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@ -18,13 +18,15 @@ pahole-flags-$(call test-ge, $(pahole-ver), 126) = -j$(JOBS) --btf_features=enc
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pahole-flags-$(call test-ge, $(pahole-ver), 130) += --btf_features=attributes
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ifneq ($(KBUILD_EXTMOD),)
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module-pahole-flags-$(call test-ge, $(pahole-ver), 128) += --btf_features=distilled_base
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endif
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endif
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pahole-flags-$(CONFIG_PAHOLE_HAS_LANG_EXCLUDE) += --lang_exclude=rust
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export PAHOLE_FLAGS := $(pahole-flags-y)
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export MODULE_PAHOLE_FLAGS := $(module-pahole-flags-y)
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resolve-btfids-flags-y :=
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resolve-btfids-flags-$(CONFIG_WERROR) += --fatal_warnings
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resolve-btfids-flags-$(if $(KBUILD_EXTMOD),y) += --distill_base
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resolve-btfids-flags-$(if $(KBUILD_VERBOSE),y) += --verbose
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export RESOLVE_BTFIDS_FLAGS := $(resolve-btfids-flags-y)
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@ -42,9 +42,8 @@ quiet_cmd_btf_ko = BTF [M] $@
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cmd_btf_ko = \
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if [ ! -f $(objtree)/vmlinux ]; then \
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printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
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else \
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LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) $(MODULE_PAHOLE_FLAGS) --btf_base $(objtree)/vmlinux $@; \
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$(RESOLVE_BTFIDS) -b $(objtree)/vmlinux $@; \
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else \
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$(srctree)/scripts/gen-btf.sh --btf_base $(objtree)/vmlinux $@; \
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fi;
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# Same as newer-prereqs, but allows to exclude specified extra dependencies
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@ -71,7 +71,7 @@ targets += vmlinux.unstripped .vmlinux.export.o
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vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) FORCE
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+$(call if_changed_dep,link_vmlinux)
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ifdef CONFIG_DEBUG_INFO_BTF
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vmlinux.unstripped: $(RESOLVE_BTFIDS)
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vmlinux.unstripped: $(RESOLVE_BTFIDS) $(srctree)/scripts/gen-btf.sh
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endif
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ifdef CONFIG_BUILDTIME_TABLE_SORT
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@ -0,0 +1,157 @@
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#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0
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# Copyright (c) 2025 Meta Platforms, Inc. and affiliates.
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#
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# This script generates BTF data for the provided ELF file.
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#
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# Kernel BTF generation involves these conceptual steps:
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# 1. pahole generates BTF from DWARF data
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# 2. resolve_btfids applies kernel-specific btf2btf
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# transformations and computes data for .BTF_ids section
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# 3. the result gets linked/objcopied into the target binary
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#
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# How step (3) should be done differs between vmlinux, and
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# kernel modules, which is the primary reason for the existence
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# of this script.
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#
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# For modules the script expects vmlinux passed in as --btf_base.
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# Generated .BTF, .BTF.base and .BTF_ids sections become embedded
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# into the input ELF file with objcopy.
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#
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# For vmlinux the input file remains unchanged and two files are produced:
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# - ${1}.btf.o ready for linking into vmlinux
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# - ${1}.BTF_ids with .BTF_ids data blob
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# This output is consumed by scripts/link-vmlinux.sh
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set -e
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usage()
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{
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echo "Usage: $0 [--btf_base <file>] <target ELF file>"
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exit 1
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}
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BTF_BASE=""
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while [ $# -gt 0 ]; do
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case "$1" in
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--btf_base)
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BTF_BASE="$2"
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shift 2
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;;
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-*)
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echo "Unknown option: $1" >&2
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usage
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;;
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*)
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break
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;;
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esac
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done
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if [ $# -ne 1 ]; then
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usage
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fi
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ELF_FILE="$1"
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shift
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is_enabled() {
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grep -q "^$1=y" ${objtree}/include/config/auto.conf
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}
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info()
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{
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printf " %-7s %s\n" "${1}" "${2}"
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}
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case "${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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gen_btf_data()
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{
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info BTF "${ELF_FILE}"
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btf1="${ELF_FILE}.BTF.1"
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${PAHOLE} -J ${PAHOLE_FLAGS} \
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${BTF_BASE:+--btf_base ${BTF_BASE}} \
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--btf_encode_detached=${btf1} \
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"${ELF_FILE}"
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info BTFIDS "${ELF_FILE}"
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${RESOLVE_BTFIDS} ${RESOLVE_BTFIDS_FLAGS} \
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${BTF_BASE:+--btf_base ${BTF_BASE}} \
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--btf ${btf1} "${ELF_FILE}"
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}
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gen_btf_o()
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{
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local btf_data=${ELF_FILE}.btf.o
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# Create ${btf_data} which contains just .BTF section but no symbols. Add
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# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
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# deletes all symbols including __start_BTF and __stop_BTF, which will
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# be redefined in the linker script.
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info OBJCOPY "${btf_data}"
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echo "" | ${CC} ${CLANG_FLAGS} -c -x c -o ${btf_data} -
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${OBJCOPY} --add-section .BTF=${ELF_FILE}.BTF \
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--set-section-flags .BTF=alloc,readonly ${btf_data}
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${OBJCOPY} --only-section=.BTF --strip-all ${btf_data}
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# Change e_type to ET_REL so that it can be used to link final vmlinux.
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# GNU ld 2.35+ and lld do not allow an ET_EXEC input.
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if is_enabled CONFIG_CPU_BIG_ENDIAN; then
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et_rel='\0\1'
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else
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et_rel='\1\0'
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fi
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printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none
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}
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embed_btf_data()
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{
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info OBJCOPY "${ELF_FILE}.BTF"
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${OBJCOPY} --add-section .BTF=${ELF_FILE}.BTF ${ELF_FILE}
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# a module might not have a .BTF_ids or .BTF.base section
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local btf_base="${ELF_FILE}.BTF.base"
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if [ -f "${btf_base}" ]; then
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${OBJCOPY} --add-section .BTF.base=${btf_base} ${ELF_FILE}
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fi
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local btf_ids="${ELF_FILE}.BTF_ids"
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if [ -f "${btf_ids}" ]; then
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${OBJCOPY} --update-section .BTF_ids=${btf_ids} ${ELF_FILE}
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fi
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}
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cleanup()
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{
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rm -f "${ELF_FILE}.BTF.1"
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rm -f "${ELF_FILE}.BTF"
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if [ "${BTFGEN_MODE}" = "module" ]; then
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rm -f "${ELF_FILE}.BTF.base"
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rm -f "${ELF_FILE}.BTF_ids"
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fi
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}
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trap cleanup EXIT
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BTFGEN_MODE="vmlinux"
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if [ -n "${BTF_BASE}" ]; then
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BTFGEN_MODE="module"
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fi
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gen_btf_data
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case "${BTFGEN_MODE}" in
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vmlinux)
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gen_btf_o
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;;
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module)
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embed_btf_data
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;;
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esac
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exit 0
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@ -106,34 +106,6 @@ vmlinux_link()
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${kallsymso} ${btf_vmlinux_bin_o} ${arch_vmlinux_o} ${ldlibs}
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}
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# generate .BTF typeinfo from DWARF debuginfo
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# ${1} - vmlinux image
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gen_btf()
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{
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local btf_data=${1}.btf.o
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info BTF "${btf_data}"
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LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
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# Create ${btf_data} which contains just .BTF section but no symbols. Add
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# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
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# deletes all symbols including __start_BTF and __stop_BTF, which will
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# be redefined in the linker script. Add 2>/dev/null to suppress GNU
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# objcopy warnings: "empty loadable segment detected at ..."
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${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
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--strip-all ${1} "${btf_data}" 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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# GNU ld 2.35+ and lld do not allow an ET_EXEC input.
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if is_enabled CONFIG_CPU_BIG_ENDIAN; then
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et_rel='\0\1'
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else
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et_rel='\1\0'
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fi
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printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none
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btf_vmlinux_bin_o=${btf_data}
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}
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# Create ${2}.o file with all symbols from the ${1} object file
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kallsyms()
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{
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@ -205,6 +177,7 @@ if is_enabled CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX; then
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fi
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btf_vmlinux_bin_o=
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btfids_vmlinux=
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kallsymso=
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strip_debug=
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generate_map=
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@ -232,11 +205,13 @@ if is_enabled CONFIG_KALLSYMS || is_enabled CONFIG_DEBUG_INFO_BTF; then
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fi
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if is_enabled CONFIG_DEBUG_INFO_BTF; then
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if ! gen_btf .tmp_vmlinux1; then
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if ! ${srctree}/scripts/gen-btf.sh .tmp_vmlinux1; then
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echo >&2 "Failed to generate BTF for vmlinux"
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echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
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exit 1
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fi
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btf_vmlinux_bin_o=.tmp_vmlinux1.btf.o
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btfids_vmlinux=.tmp_vmlinux1.BTF_ids
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fi
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if is_enabled CONFIG_KALLSYMS; then
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@ -289,14 +264,9 @@ fi
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vmlinux_link "${VMLINUX}"
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# fill in BTF IDs
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if is_enabled CONFIG_DEBUG_INFO_BTF; then
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info BTFIDS "${VMLINUX}"
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RESOLVE_BTFIDS_ARGS=""
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if is_enabled CONFIG_WERROR; then
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RESOLVE_BTFIDS_ARGS=" --fatal_warnings "
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fi
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${RESOLVE_BTFIDS} ${RESOLVE_BTFIDS_ARGS} "${VMLINUX}"
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info OBJCOPY ${btfids_vmlinux}
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${OBJCOPY} --update-section .BTF_ids=${btfids_vmlinux} ${VMLINUX}
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fi
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mksysmap "${VMLINUX}" System.map
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@ -71,9 +71,11 @@
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#include <fcntl.h>
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#include <errno.h>
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#include <linux/btf_ids.h>
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#include <linux/kallsyms.h>
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#include <linux/rbtree.h>
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#include <linux/zalloc.h>
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#include <linux/err.h>
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#include <linux/limits.h>
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#include <bpf/btf.h>
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#include <bpf/libbpf.h>
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#include <subcmd/parse-options.h>
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@ -124,6 +126,7 @@ struct object {
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struct btf *btf;
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struct btf *base_btf;
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bool distill_base;
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struct {
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int fd;
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@ -324,42 +327,16 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
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return btf_id__add(root, id, BTF_ID_KIND_SYM);
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}
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/* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
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#ifndef SHF_COMPRESSED
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#define SHF_COMPRESSED (1 << 11) /* Section with compressed data. */
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#endif
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/*
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* The data of compressed section should be aligned to 4
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* (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
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* sets sh_addralign to 1, which makes libelf fail with
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* misaligned section error during the update:
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* FAILED elf_update(WRITE): invalid section alignment
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*
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* While waiting for ld fix, we fix the compressed sections
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* sh_addralign value manualy.
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*/
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static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
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static void bswap_32_data(void *data, u32 nr_bytes)
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{
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int expected = gelf_getclass(elf) == ELFCLASS32 ? 4 : 8;
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u32 cnt, i;
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u32 *ptr;
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if (!(sh->sh_flags & SHF_COMPRESSED))
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return 0;
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cnt = nr_bytes / sizeof(u32);
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ptr = data;
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if (sh->sh_addralign == expected)
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return 0;
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pr_debug2(" - fixing wrong alignment sh_addralign %u, expected %u\n",
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sh->sh_addralign, expected);
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sh->sh_addralign = expected;
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if (gelf_update_shdr(scn, sh) == 0) {
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pr_err("FAILED cannot update section header: %s\n",
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elf_errmsg(-1));
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return -1;
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}
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return 0;
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for (i = 0; i < cnt; i++)
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ptr[i] = bswap_32(ptr[i]);
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}
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static int elf_collect(struct object *obj)
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@ -380,7 +357,7 @@ static int elf_collect(struct object *obj)
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elf_version(EV_CURRENT);
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elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL);
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elf = elf_begin(fd, ELF_C_READ_MMAP_PRIVATE, NULL);
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if (!elf) {
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close(fd);
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pr_err("FAILED cannot create ELF descriptor: %s\n",
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@ -443,21 +420,20 @@ static int elf_collect(struct object *obj)
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obj->efile.symbols_shndx = idx;
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obj->efile.strtabidx = sh.sh_link;
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} else if (!strcmp(name, BTF_IDS_SECTION)) {
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/*
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* If target endianness differs from host, we need to bswap32
|
||||
* the .BTF_ids section data on load, because .BTF_ids has
|
||||
* Elf_Type = ELF_T_BYTE, and so libelf returns data buffer in
|
||||
* the target endianness. We repeat this on dump.
|
||||
*/
|
||||
if (obj->efile.encoding != ELFDATANATIVE) {
|
||||
pr_debug("bswap_32 .BTF_ids data from target to host endianness\n");
|
||||
bswap_32_data(data->d_buf, data->d_size);
|
||||
}
|
||||
obj->efile.idlist = data;
|
||||
obj->efile.idlist_shndx = idx;
|
||||
obj->efile.idlist_addr = sh.sh_addr;
|
||||
} else if (!strcmp(name, BTF_BASE_ELF_SEC)) {
|
||||
/* If a .BTF.base section is found, do not resolve
|
||||
* BTF ids relative to vmlinux; resolve relative
|
||||
* to the .BTF.base section instead. btf__parse_split()
|
||||
* will take care of this once the base BTF it is
|
||||
* passed is NULL.
|
||||
*/
|
||||
obj->base_btf_path = NULL;
|
||||
}
|
||||
|
||||
if (compressed_section_fix(elf, scn, &sh))
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
|
@ -587,11 +563,26 @@ static int load_btf(struct object *obj)
|
|||
obj->base_btf = base_btf;
|
||||
obj->btf = btf;
|
||||
|
||||
if (obj->base_btf && obj->distill_base) {
|
||||
err = btf__distill_base(obj->btf, &base_btf, &btf);
|
||||
if (err) {
|
||||
pr_err("FAILED to distill base BTF: %s\n", strerror(errno));
|
||||
goto out_err;
|
||||
}
|
||||
|
||||
btf__free(obj->base_btf);
|
||||
btf__free(obj->btf);
|
||||
obj->base_btf = base_btf;
|
||||
obj->btf = btf;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
out_err:
|
||||
btf__free(base_btf);
|
||||
btf__free(btf);
|
||||
obj->base_btf = NULL;
|
||||
obj->btf = NULL;
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -760,24 +751,6 @@ static int sets_patch(struct object *obj)
|
|||
*/
|
||||
BUILD_BUG_ON((u32 *)set8->pairs != &set8->pairs[0].id);
|
||||
qsort(set8->pairs, set8->cnt, sizeof(set8->pairs[0]), cmp_id);
|
||||
|
||||
/*
|
||||
* When ELF endianness does not match endianness of the
|
||||
* host, libelf will do the translation when updating
|
||||
* the ELF. This, however, corrupts SET8 flags which are
|
||||
* already in the target endianness. So, let's bswap
|
||||
* them to the host endianness and libelf will then
|
||||
* correctly translate everything.
|
||||
*/
|
||||
if (obj->efile.encoding != ELFDATANATIVE) {
|
||||
int i;
|
||||
|
||||
set8->flags = bswap_32(set8->flags);
|
||||
for (i = 0; i < set8->cnt; i++) {
|
||||
set8->pairs[i].flags =
|
||||
bswap_32(set8->pairs[i].flags);
|
||||
}
|
||||
}
|
||||
break;
|
||||
default:
|
||||
pr_err("Unexpected btf_id_kind %d for set '%s'\n", id->kind, id->name);
|
||||
|
|
@ -793,8 +766,6 @@ static int sets_patch(struct object *obj)
|
|||
|
||||
static int symbols_patch(struct object *obj)
|
||||
{
|
||||
off_t err;
|
||||
|
||||
if (__symbols_patch(obj, &obj->structs) ||
|
||||
__symbols_patch(obj, &obj->unions) ||
|
||||
__symbols_patch(obj, &obj->typedefs) ||
|
||||
|
|
@ -805,20 +776,90 @@ static int symbols_patch(struct object *obj)
|
|||
if (sets_patch(obj))
|
||||
return -1;
|
||||
|
||||
/* Set type to ensure endian translation occurs. */
|
||||
obj->efile.idlist->d_type = ELF_T_WORD;
|
||||
return 0;
|
||||
}
|
||||
|
||||
elf_flagdata(obj->efile.idlist, ELF_C_SET, ELF_F_DIRTY);
|
||||
static int dump_raw_data(const char *out_path, const void *data, u32 size)
|
||||
{
|
||||
size_t written;
|
||||
FILE *file;
|
||||
|
||||
err = elf_update(obj->efile.elf, ELF_C_WRITE);
|
||||
if (err < 0) {
|
||||
pr_err("FAILED elf_update(WRITE): %s\n",
|
||||
elf_errmsg(-1));
|
||||
file = fopen(out_path, "wb");
|
||||
if (!file) {
|
||||
pr_err("Couldn't open %s for writing\n", out_path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
pr_debug("update %s for %s\n",
|
||||
err >= 0 ? "ok" : "failed", obj->path);
|
||||
return err < 0 ? -1 : 0;
|
||||
written = fwrite(data, 1, size, file);
|
||||
if (written != size) {
|
||||
pr_err("Failed to write data to %s\n", out_path);
|
||||
fclose(file);
|
||||
unlink(out_path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
fclose(file);
|
||||
pr_debug("Dumped %lu bytes of data to %s\n", size, out_path);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int dump_raw_btf_ids(struct object *obj, const char *out_path)
|
||||
{
|
||||
Elf_Data *data = obj->efile.idlist;
|
||||
int err;
|
||||
|
||||
if (!data || !data->d_buf) {
|
||||
pr_debug("%s has no BTF_ids data to dump\n", obj->path);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* If target endianness differs from host, we need to bswap32 the
|
||||
* .BTF_ids section data before dumping so that the output is in
|
||||
* target endianness.
|
||||
*/
|
||||
if (obj->efile.encoding != ELFDATANATIVE) {
|
||||
pr_debug("bswap_32 .BTF_ids data from host to target endianness\n");
|
||||
bswap_32_data(data->d_buf, data->d_size);
|
||||
}
|
||||
|
||||
err = dump_raw_data(out_path, data->d_buf, data->d_size);
|
||||
if (err)
|
||||
return -1;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int dump_raw_btf(struct btf *btf, const char *out_path)
|
||||
{
|
||||
const void *raw_btf_data;
|
||||
u32 raw_btf_size;
|
||||
int err;
|
||||
|
||||
raw_btf_data = btf__raw_data(btf, &raw_btf_size);
|
||||
if (!raw_btf_data) {
|
||||
pr_err("btf__raw_data() failed\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
err = dump_raw_data(out_path, raw_btf_data, raw_btf_size);
|
||||
if (err)
|
||||
return -1;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int make_out_path(char *buf, u32 buf_sz, const char *in_path, const char *suffix)
|
||||
{
|
||||
int len = snprintf(buf, buf_sz, "%s%s", in_path, suffix);
|
||||
|
||||
if (len < 0 || len >= buf_sz) {
|
||||
pr_err("Output path is too long: %s%s\n", in_path, suffix);
|
||||
return -E2BIG;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const char * const resolve_btfids_usage[] = {
|
||||
|
|
@ -840,6 +881,8 @@ int main(int argc, const char **argv)
|
|||
.sets = RB_ROOT,
|
||||
};
|
||||
bool fatal_warnings = false;
|
||||
char out_path[PATH_MAX];
|
||||
|
||||
struct option btfid_options[] = {
|
||||
OPT_INCR('v', "verbose", &verbose,
|
||||
"be more verbose (show errors, etc)"),
|
||||
|
|
@ -849,6 +892,8 @@ int main(int argc, const char **argv)
|
|||
"path of file providing base BTF"),
|
||||
OPT_BOOLEAN(0, "fatal_warnings", &fatal_warnings,
|
||||
"turn warnings into errors"),
|
||||
OPT_BOOLEAN(0, "distill_base", &obj.distill_base,
|
||||
"distill --btf_base and emit .BTF.base section data"),
|
||||
OPT_END()
|
||||
};
|
||||
int err = -1;
|
||||
|
|
@ -860,6 +905,9 @@ int main(int argc, const char **argv)
|
|||
|
||||
obj.path = argv[0];
|
||||
|
||||
if (load_btf(&obj))
|
||||
goto out;
|
||||
|
||||
if (elf_collect(&obj))
|
||||
goto out;
|
||||
|
||||
|
|
@ -869,23 +917,37 @@ int main(int argc, const char **argv)
|
|||
*/
|
||||
if (obj.efile.idlist_shndx == -1 ||
|
||||
obj.efile.symbols_shndx == -1) {
|
||||
pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n");
|
||||
err = 0;
|
||||
goto out;
|
||||
pr_debug("Cannot find .BTF_ids or symbols sections, skip symbols resolution\n");
|
||||
goto dump_btf;
|
||||
}
|
||||
|
||||
if (symbols_collect(&obj))
|
||||
goto out;
|
||||
|
||||
if (load_btf(&obj))
|
||||
goto out;
|
||||
|
||||
if (symbols_resolve(&obj))
|
||||
goto out;
|
||||
|
||||
if (symbols_patch(&obj))
|
||||
goto out;
|
||||
|
||||
err = make_out_path(out_path, sizeof(out_path), obj.path, BTF_IDS_SECTION);
|
||||
err = err ?: dump_raw_btf_ids(&obj, out_path);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
dump_btf:
|
||||
err = make_out_path(out_path, sizeof(out_path), obj.path, BTF_ELF_SEC);
|
||||
err = err ?: dump_raw_btf(obj.btf, out_path);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
if (obj.base_btf && obj.distill_base) {
|
||||
err = make_out_path(out_path, sizeof(out_path), obj.path, BTF_BASE_ELF_SEC);
|
||||
err = err ?: dump_raw_btf(obj.base_btf, out_path);
|
||||
if (err)
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (!(fatal_warnings && warnings))
|
||||
err = 0;
|
||||
out:
|
||||
|
|
|
|||
|
|
@ -45,3 +45,6 @@ xdp_synproxy
|
|||
xdp_hw_metadata
|
||||
xdp_features
|
||||
verification_cert.h
|
||||
*.BTF
|
||||
*.BTF_ids
|
||||
*.BTF.base
|
||||
|
|
|
|||
|
|
@ -4,6 +4,7 @@ include ../../../scripts/Makefile.arch
|
|||
include ../../../scripts/Makefile.include
|
||||
|
||||
CXX ?= $(CROSS_COMPILE)g++
|
||||
OBJCOPY ?= $(CROSS_COMPILE)objcopy
|
||||
|
||||
CURDIR := $(abspath .)
|
||||
TOOLSDIR := $(abspath ../../..)
|
||||
|
|
@ -653,9 +654,10 @@ $(TRUNNER_TEST_OBJS): $(TRUNNER_OUTPUT)/%.test.o: \
|
|||
| $(TRUNNER_OUTPUT)/%.test.d
|
||||
$$(call msg,TEST-OBJ,$(TRUNNER_BINARY),$$@)
|
||||
$(Q)cd $$(@D) && $$(CC) -I. $$(CFLAGS) -MMD -MT $$@ -c $(CURDIR)/$$< $$(LDLIBS) -o $$(@F)
|
||||
$$(if $$(TEST_NEEDS_BTFIDS), \
|
||||
$$(call msg,BTFIDS,$(TRUNNER_BINARY),$$@) \
|
||||
$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@)
|
||||
$$(if $$(TEST_NEEDS_BTFIDS), \
|
||||
$$(call msg,BTFIDS,$(TRUNNER_BINARY),$$@) \
|
||||
$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@; \
|
||||
$(OBJCOPY) --update-section .BTF_ids=$$@.BTF_ids $$@)
|
||||
|
||||
$(TRUNNER_TEST_OBJS:.o=.d): $(TRUNNER_OUTPUT)/%.test.d: \
|
||||
$(TRUNNER_TESTS_DIR)/%.c \
|
||||
|
|
@ -894,6 +896,7 @@ EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR) \
|
|||
prog_tests/tests.h map_tests/tests.h verifier/tests.h \
|
||||
feature bpftool $(TEST_KMOD_TARGETS) \
|
||||
$(addprefix $(OUTPUT)/,*.o *.d *.skel.h *.lskel.h *.subskel.h \
|
||||
*.BTF *.BTF_ids *.BTF.base \
|
||||
no_alu32 cpuv4 bpf_gcc \
|
||||
liburandom_read.so) \
|
||||
$(OUTPUT)/FEATURE-DUMP.selftests \
|
||||
|
|
|
|||
|
|
@ -101,9 +101,9 @@ static int resolve_symbols(void)
|
|||
int type_id;
|
||||
__u32 nr;
|
||||
|
||||
btf = btf__parse_elf("btf_data.bpf.o", NULL);
|
||||
btf = btf__parse_raw("resolve_btfids.test.o.BTF");
|
||||
if (CHECK(libbpf_get_error(btf), "resolve",
|
||||
"Failed to load BTF from btf_data.bpf.o\n"))
|
||||
"Failed to load BTF from resolve_btfids.test.o.BTF\n"))
|
||||
return -1;
|
||||
|
||||
nr = btf__type_cnt(btf);
|
||||
|
|
|
|||
Loading…
Reference in New Issue