1/* 2 * common eBPF ELF operations. 3 * 4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 6 * Copyright (C) 2015 Huawei Inc. 7 */ 8 9#include <stdlib.h> 10#include <memory.h> 11#include <unistd.h> 12#include <asm/unistd.h> 13#include <linux/bpf.h> 14#include "bpf.h" 15 16/* 17 * When building perf, unistd.h is override. Define __NR_bpf is 18 * required to be defined. 19 */ 20#ifndef __NR_bpf 21# if defined(__i386__) 22# define __NR_bpf 357 23# elif defined(__x86_64__) 24# define __NR_bpf 321 25# elif defined(__aarch64__) 26# define __NR_bpf 280 27# else 28# error __NR_bpf not defined. libbpf does not support your arch. 29# endif 30#endif 31 32static __u64 ptr_to_u64(void *ptr) 33{ 34 return (__u64) (unsigned long) ptr; 35} 36 37static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 38 unsigned int size) 39{ 40 return syscall(__NR_bpf, cmd, attr, size); 41} 42 43int bpf_create_map(enum bpf_map_type map_type, int key_size, 44 int value_size, int max_entries) 45{ 46 union bpf_attr attr; 47 48 memset(&attr, '\0', sizeof(attr)); 49 50 attr.map_type = map_type; 51 attr.key_size = key_size; 52 attr.value_size = value_size; 53 attr.max_entries = max_entries; 54 55 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 56} 57 58int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, 59 size_t insns_cnt, char *license, 60 u32 kern_version, char *log_buf, size_t log_buf_sz) 61{ 62 int fd; 63 union bpf_attr attr; 64 65 bzero(&attr, sizeof(attr)); 66 attr.prog_type = type; 67 attr.insn_cnt = (__u32)insns_cnt; 68 attr.insns = ptr_to_u64(insns); 69 attr.license = ptr_to_u64(license); 70 attr.log_buf = ptr_to_u64(NULL); 71 attr.log_size = 0; 72 attr.log_level = 0; 73 attr.kern_version = kern_version; 74 75 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 76 if (fd >= 0 || !log_buf || !log_buf_sz) 77 return fd; 78 79 /* Try again with log */ 80 attr.log_buf = ptr_to_u64(log_buf); 81 attr.log_size = log_buf_sz; 82 attr.log_level = 1; 83 log_buf[0] = 0; 84 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 85} 86