From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Tue, 28 Sep 2021 11:16:08 +0530
Subject: samples: bpf: Fix vmlinux.h generation for XDP samples
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Patch-mainline: v5.15-rc5
Git-commit: 571fa247ab411f3233eeaaf837c6e646a513b9f8
References: jsc#PED-1377
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: 384b6b3bbf0d (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
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
samples/bpf/Makefile | 17 ++++++++---------
samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
2 files changed, 8 insertions(+), 14 deletions(-)
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -322,17 +322,11 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(sr
-include $(BPF_SAMPLES_PATH)/Makefile.target
-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_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux)) \
+ $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)) \
+ $(abspath ./vmlinux)
VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
-ifeq ($(VMLINUX_BTF),)
-$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
-endif
-
$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
ifeq ($(VMLINUX_H),)
$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
@@ -340,6 +334,11 @@ else
$(Q)cp "$(VMLINUX_H)" $@
endif
+ifeq ($(VMLINUX_BTF),)
+ $(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
+ build the kernel or set VMLINUX_BTF variable)
+endif
+
clean-files += vmlinux.h
# Get Clang's default includes on this system, as opposed to those seen by
--- a/samples/bpf/xdp_redirect_map_multi.bpf.c
+++ b/samples/bpf/xdp_redirect_map_multi.bpf.c
@@ -5,11 +5,6 @@
#include "xdp_sample.bpf.h"
#include "xdp_sample_shared.h"
-enum {
- BPF_F_BROADCAST = (1ULL << 3),
- BPF_F_EXCLUDE_INGRESS = (1ULL << 4),
-};
-
struct {
__uint(type, BPF_MAP_TYPE_DEVMAP_HASH);
__uint(key_size, sizeof(int));