Generate vmlinux.h only from the in-tree vmlinux, and remove enum
declarations that would cause a build failure in case of version
mismatches.
There are now two options when building the samples:
1. Compile the kernel to use in-tree vmlinux for vmlinux.h
2. Override VMLINUX_BTF for samples using something like this:
make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
This change was tested with relative builds, e.g. cases like:
* make O=build -C samples/bpf
* make KBUILD_OUTPUT=build -C samples/bpf
* make -C samples/bpf
* cd samples/bpf && make
When a suitable VMLINUX_BTF is not found, the following message is
printed:
/home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
VMLINUX_BTF variable. Stop.
Fixes: 384b6b3bbf (samples: bpf: Add vmlinux.h generation support)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210928054608.1799021-1-memxor@gmail.com
571fa247ab