Wang Nan | e3ed2fe | 2015-07-01 02:14:03 +0000 | [diff] [blame] | 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 | |
Wang Nan | 7bf9836 | 2015-07-01 02:14:06 +0000 | [diff] [blame] | 32 | static __u64 ptr_to_u64(void *ptr) |
| 33 | { |
| 34 | return (__u64) (unsigned long) ptr; |
| 35 | } |
| 36 | |
Wang Nan | e3ed2fe | 2015-07-01 02:14:03 +0000 | [diff] [blame] | 37 | static 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 | |
| 43 | int 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 | } |
Wang Nan | 7bf9836 | 2015-07-01 02:14:06 +0000 | [diff] [blame] | 57 | |
| 58 | int 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 | } |