Makefile

CLANG   ?= clang
GCC     ?= gcc
BPFTOOL ?= bpftool
ARCH    := $(shell uname -m | sed 's/x86_64/x86/' | sed 's/aarch64/arm64/')

BPF_CFLAGS := -g -O2 -target bpf -D__TARGET_ARCH_$(ARCH)
CFLAGS     := -g -O2 -Wall
LDLIBS     := -lbpf -lelf -lz

.PHONY: all clean

all: kern_error_monitor

# Generate vmlinux.h from running kernel's BTF
vmlinux.h:
	$(BPFTOOL) btf dump file /sys/kernel/btf/vmlinux format c > $@

# Compile BPF program
kern_error_monitor.bpf.o: kern_error_monitor.bpf.c kern_error_monitor.h vmlinux.h
	$(CLANG) $(BPF_CFLAGS) -c $< -o $@

# Generate BPF skeleton header
kern_error_monitor.skel.h: kern_error_monitor.bpf.o
	$(BPFTOOL) gen skeleton $< > $@

# Compile userspace daemon
kern_error_monitor: kern_error_monitor.c kern_error_monitor.h kern_error_monitor.skel.h
	$(GCC) $(CFLAGS) -o $@ $< $(LDLIBS)

clean:
	rm -f kern_error_monitor kern_error_monitor.bpf.o \
	      kern_error_monitor.skel.h vmlinux.h