path: root/scripts
diff options
authorStanislav Fomichev <sdf@google.com>2019-11-27 08:14:10 -0800
committerAlexei Starovoitov <ast@kernel.org>2019-11-27 11:11:42 -0800
commitda5fb18225b49b97bb37c51bcbbb2990a507c364 (patch)
tree2d8c17dcb803aee714dd523ceacea53824021fdb /scripts
parentbpf: Fix static checker warning (diff)
bpf: Support pre-2.25-binutils objcopy for vmlinux BTF
If vmlinux BTF generation fails, but CONFIG_DEBUG_INFO_BTF is set, .BTF section of vmlinux is empty and kernel will prohibit BPF loading and return "in-kernel BTF is malformed". --dump-section argument to binutils' objcopy was added in version 2.25. When using pre-2.25 binutils, BTF generation silently fails. Convert to --only-section which is present on pre-2.25 binutils. Documentation/process/changes.rst states that binutils 2.21+ is supported, not sure those standards apply to BPF subsystem. v2: * exit and print an error if gen_btf fails (John Fastabend) v3: * resend with Andrii's Acked-by/Tested-by tags Fixes: 341dfcf8d78ea ("btf: expose BTF info through sysfs") Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20191127161410.57327-1-sdf@google.com
Diffstat (limited to 'scripts')
1 files changed, 6 insertions, 1 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 06495379fcd8..2998ddb323e3 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -127,7 +127,8 @@ gen_btf()
cut -d, -f1 | cut -d' ' -f2)
bin_format=$(LANG=C ${OBJDUMP} -f ${1} | grep 'file format' | \
awk '{print $4}')
- ${OBJCOPY} --dump-section .BTF=.btf.vmlinux.bin ${1} 2>/dev/null
+ ${OBJCOPY} --set-section-flags .BTF=alloc -O binary \
+ --only-section=.BTF ${1} .btf.vmlinux.bin 2>/dev/null
${OBJCOPY} -I binary -O ${bin_format} -B ${bin_arch} \
--rename-section .data=.BTF .btf.vmlinux.bin ${2}
@@ -253,6 +254,10 @@ btf_vmlinux_bin_o=""
if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
if gen_btf .tmp_vmlinux.btf .btf.vmlinux.bin.o ; then
+ else
+ echo >&2 "Failed to generate BTF for vmlinux"
+ echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
+ exit 1