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| author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2021-06-03 20:05:16 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-08 22:59:08 +0300 |
| commit | 0779890fed7817725f399d6ec85730e08ebfdeee (patch) | |
| tree | a7323161645afc4cf70eaa8f85f58e96ce44b6a9 /tools/bpf | |
| parent | 56b8b7f9533b5c40cbc1266b5cc6a3b19dfd2aad (diff) | |
| download | linux-0779890fed7817725f399d6ec85730e08ebfdeee.tar.xz | |
tools/bpftool: Fix cross-build
When the bootstrap and final bpftool have different architectures, we
need to build two distinct disasm.o objects. Add a recipe for the
bootstrap disasm.o.
After commit d510296d331a ("bpftool: Use syscall/loader program in
"prog load" and "gen skeleton" command.") cross-building bpftool didn't
work anymore, because the bootstrap bpftool was linked using objects
from different architectures:
$ make O=/tmp/bpftool ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/bpftool/ V=1
[...]
aarch64-linux-gnu-gcc ... -c -MMD -o /tmp/bpftool/disasm.o /home/z/src/linux/kernel/bpf/disasm.c
gcc ... -c -MMD -o /tmp/bpftool//bootstrap/main.o main.c
gcc ... -o /tmp/bpftool//bootstrap/bpftool /tmp/bpftool//bootstrap/main.o ... /tmp/bpftool/disasm.o
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/bpftool/disasm.o: error adding symbols: file in wrong format
collect2: error: ld returned 1 exit status
[...]
The final bpftool was built for e.g. arm64, while the bootstrap bpftool,
executed on the host, was built for x86. The problem here was that disasm.o
linked into the bootstrap bpftool was arm64 rather than x86. With the fix
we build two disasm.o, one for the target bpftool in arm64, and one for
the bootstrap bpftool in x86.
Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210603170515.1854642-1-jean-philippe@linaro.org
Diffstat (limited to 'tools/bpf')
| -rw-r--r-- | tools/bpf/bpftool/Makefile | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index d16d289ade7a..d73232be1e99 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -136,7 +136,7 @@ endif BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool -BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o xlated_dumper.o btf_dumper.o) $(OUTPUT)disasm.o +BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o xlated_dumper.o btf_dumper.o disasm.o) OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ @@ -180,6 +180,9 @@ endif CFLAGS += $(if $(BUILD_BPF_SKELS),,-DBPFTOOL_WITHOUT_SKELETONS) +$(BOOTSTRAP_OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c + $(QUIET_CC)$(HOSTCC) $(CFLAGS) -c -MMD -o $@ $< + $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< |