chore(btfhack): add kprobe.c for btfhack test

bpf/headers/common.h

@@ -0,0 +1,148 @@
+// This is a compact version of `vmlinux.h` to be used in the examples using C code.
+
+#pragma once
+
+typedef unsigned char __u8;
+typedef short int __s16;
+typedef short unsigned int __u16;
+typedef int __s32;
+typedef unsigned int __u32;
+typedef long long int __s64;
+typedef long long unsigned int __u64;
+typedef __u8 u8;
+typedef __s16 s16;
+typedef __u16 u16;
+typedef __s32 s32;
+typedef __u32 u32;
+typedef __s64 s64;
+typedef __u64 u64;
+typedef __u16 __le16;
+typedef __u16 __be16;
+typedef __u32 __be32;
+typedef __u64 __be64;
+typedef __u32 __wsum;
+
+#include "bpf_helpers.h"
+
+enum bpf_map_type {
+	BPF_MAP_TYPE_UNSPEC                = 0,
+	BPF_MAP_TYPE_HASH                  = 1,
+	BPF_MAP_TYPE_ARRAY                 = 2,
+	BPF_MAP_TYPE_PROG_ARRAY            = 3,
+	BPF_MAP_TYPE_PERF_EVENT_ARRAY      = 4,
+	BPF_MAP_TYPE_PERCPU_HASH           = 5,
+	BPF_MAP_TYPE_PERCPU_ARRAY          = 6,
+	BPF_MAP_TYPE_STACK_TRACE           = 7,
+	BPF_MAP_TYPE_CGROUP_ARRAY          = 8,
+	BPF_MAP_TYPE_LRU_HASH              = 9,
+	BPF_MAP_TYPE_LRU_PERCPU_HASH       = 10,
+	BPF_MAP_TYPE_LPM_TRIE              = 11,
+	BPF_MAP_TYPE_ARRAY_OF_MAPS         = 12,
+	BPF_MAP_TYPE_HASH_OF_MAPS          = 13,
+	BPF_MAP_TYPE_DEVMAP                = 14,
+	BPF_MAP_TYPE_SOCKMAP               = 15,
+	BPF_MAP_TYPE_CPUMAP                = 16,
+	BPF_MAP_TYPE_XSKMAP                = 17,
+	BPF_MAP_TYPE_SOCKHASH              = 18,
+	BPF_MAP_TYPE_CGROUP_STORAGE        = 19,
+	BPF_MAP_TYPE_REUSEPORT_SOCKARRAY   = 20,
+	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE = 21,
+	BPF_MAP_TYPE_QUEUE                 = 22,
+	BPF_MAP_TYPE_STACK                 = 23,
+	BPF_MAP_TYPE_SK_STORAGE            = 24,
+	BPF_MAP_TYPE_DEVMAP_HASH           = 25,
+	BPF_MAP_TYPE_STRUCT_OPS            = 26,
+	BPF_MAP_TYPE_RINGBUF               = 27,
+	BPF_MAP_TYPE_INODE_STORAGE         = 28,
+};
+
+enum xdp_action {
+	XDP_ABORTED = 0,
+	XDP_DROP = 1,
+	XDP_PASS = 2,
+	XDP_TX = 3,
+	XDP_REDIRECT = 4,
+};
+
+struct xdp_md {
+	__u32 data;
+	__u32 data_end;
+	__u32 data_meta;
+	__u32 ingress_ifindex;
+	__u32 rx_queue_index;
+	__u32 egress_ifindex;
+};
+
+typedef __u16 __sum16;
+
+#define ETH_P_IP 0x0800
+
+struct ethhdr {
+	unsigned char h_dest[6];
+	unsigned char h_source[6];
+	__be16 h_proto;
+};
+
+struct iphdr {
+	__u8 ihl: 4;
+	__u8 version: 4;
+	__u8 tos;
+	__be16 tot_len;
+	__be16 id;
+	__be16 frag_off;
+	__u8 ttl;
+	__u8 protocol;
+	__sum16 check;
+	__be32 saddr;
+	__be32 daddr;
+};
+
+enum {
+	BPF_ANY     = 0,
+	BPF_NOEXIST = 1,
+	BPF_EXIST   = 2,
+	BPF_F_LOCK  = 4,
+};
+
+/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
+ * BPF_FUNC_perf_event_read_value flags.
+ */
+#define BPF_F_INDEX_MASK 0xffffffffULL
+#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
+
+#if defined(__TARGET_ARCH_x86)
+struct pt_regs {
+	/*
+	 * C ABI says these regs are callee-preserved. They aren't saved on kernel entry
+	 * unless syscall needs a complete, fully filled "struct pt_regs".
+	 */
+	unsigned long r15;
+	unsigned long r14;
+	unsigned long r13;
+	unsigned long r12;
+	unsigned long rbp;
+	unsigned long rbx;
+	/* These regs are callee-clobbered. Always saved on kernel entry. */
+	unsigned long r11;
+	unsigned long r10;
+	unsigned long r9;
+	unsigned long r8;
+	unsigned long rax;
+	unsigned long rcx;
+	unsigned long rdx;
+	unsigned long rsi;
+	unsigned long rdi;
+	/*
+	 * On syscall entry, this is syscall#. On CPU exception, this is error code.
+	 * On hw interrupt, it's IRQ number:
+	 */
+	unsigned long orig_rax;
+	/* Return frame for iretq */
+	unsigned long rip;
+	unsigned long cs;
+	unsigned long eflags;
+	unsigned long rsp;
+	unsigned long ss;
+	/* top of stack page */
+};
+#endif /* __TARGET_ARCH_x86 */

bpf/kprobe.c

@@ -0,0 +1,27 @@
+// +build ignore
+
+#include "common.h"
+
+char __license[] SEC("license") = "Dual MIT/GPL";
+
+struct bpf_map_def SEC("maps") kprobe_map = {
+	.type        = BPF_MAP_TYPE_ARRAY,
+	.key_size    = sizeof(u32),
+	.value_size  = sizeof(u64),
+	.max_entries = 1,
+};
+
+SEC("kprobe/sys_execve")
+int kprobe_execve() {
+	u32 key     = 0;
+	u64 initval = 1, *valp;
+
+	valp = bpf_map_lookup_elem(&kprobe_map, &key);
+	if (!valp) {
+		bpf_map_update_elem(&kprobe_map, &key, &initval, BPF_ANY);
+		return 0;
+	}
+	__sync_fetch_and_add(valp, 1);
+
+	return 0;
+}

pkg/exporter/testbtf/btf.go

@@ -11,7 +11,7 @@ import (
 
 const mapKey uint32 = 0
 
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang bpf ../../bpf/kprobe.c -- -I../../bpf/headers
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang-16 bpf ../../../bpf/kprobe.c -- -I../../../bpf/headers
 
 func btfTest(btf *btf.Spec) error {
 	fn := "sys_execve"