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* [PATCH bpf-next 1/2] tools/bpftool: allow substituting custom vmlinux.h for the build
@ 2020-06-30  0:47 Andrii Nakryiko
  2020-06-30  0:47 ` [PATCH bpf-next 2/2] selftests/bpf: allow substituting custom vmlinux.h for selftests build Andrii Nakryiko
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2020-06-30  0:47 UTC (permalink / raw)
  To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko

In some build contexts (e.g., Travis CI build for outdated kernel), vmlinux.h,
generated from available kernel, doesn't contain all the types necessary for
BPF program compilation. For such set up, the most maintainable way to deal
with this problem is to keep pre-generated (almost up-to-date) vmlinux.h
checked in and use it for compilation purposes. bpftool after that can deal
with kernel missing some of the features in runtime with no problems.

To that effect, allow to specify path to custom vmlinux.h to bpftool's
Makefile with VMLINUX_H variable.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/bpf/bpftool/Makefile | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 8c6563e56ffc..273da1615503 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -122,20 +122,24 @@ BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstr
 BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o)
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
 
-VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux)				\
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux)				\
 		     $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)	\
 		     ../../../vmlinux					\
 		     /sys/kernel/btf/vmlinux				\
 		     /boot/vmlinux-$(shell uname -r)
-VMLINUX_BTF := $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
 
-ifneq ($(VMLINUX_BTF),)
+ifneq ($(VMLINUX_BTF)$(VMLINUX_H),)
 ifeq ($(feature-clang-bpf-co-re),1)
 
 BUILD_BPF_SKELS := 1
 
 $(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP)
+ifeq ($(VMLINUX_H),)
 	$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) btf dump file $< format c > $@
+else
+	$(Q)cp "$(VMLINUX_H)" $@
+endif
 
 $(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF)
 	$(QUIET_CLANG)$(CLANG) \
-- 
2.24.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-06-30 14:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-30  0:47 [PATCH bpf-next 1/2] tools/bpftool: allow substituting custom vmlinux.h for the build Andrii Nakryiko
2020-06-30  0:47 ` [PATCH bpf-next 2/2] selftests/bpf: allow substituting custom vmlinux.h for selftests build Andrii Nakryiko
2020-06-30  4:51   ` Yonghong Song
2020-06-30  3:12 ` [PATCH bpf-next 1/2] tools/bpftool: allow substituting custom vmlinux.h for the build Yonghong Song
2020-06-30 14:12 ` Daniel Borkmann

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