[PATCH bpf-next] bpftoo: Support user defined vmlinux path

[Jianlin Lv]

From: Jianlin Lv <iecedge@xxxxxxxxx>

Add EXTERNAL_PATH variable that define unconventional vmlinux path

Signed-off-by: Jianlin Lv <iecedge@xxxxxxxxx>
---
When building Ubuntu-5.15.0 kernel, '../../../vmlinux' cannot locate
compiled vmlinux image. Incorrect vmlinux generated vmlinux.h missing some
structure definitions that broken compiling pipe.
---
 tools/bpf/bpftool/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index c6d2c77d0252..fefa3b763eb7 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -160,6 +160,7 @@ $(OBJS): $(LIBBPF) $(LIBBPF_INTERNAL_HDRS)
 VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux)				\
 		     $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)	\
 		     ../../../vmlinux					\
+		     $(if $(EXTERNAL_PATH),$(EXTERNAL_PATH)/vmlinux)	\
 		     /sys/kernel/btf/vmlinux				\
 		     /boot/vmlinux-$(shell uname -r)
 VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
-- 
2.25.1