diff options
Diffstat (limited to 'kernel/tools/lib/bpf/bpf.c')
-rw-r--r-- | kernel/tools/lib/bpf/bpf.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/tools/lib/bpf/bpf.c b/kernel/tools/lib/bpf/bpf.c new file mode 100644 index 000000000..a6331050a --- /dev/null +++ b/kernel/tools/lib/bpf/bpf.c @@ -0,0 +1,85 @@ +/* + * common eBPF ELF operations. + * + * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> + * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> + * Copyright (C) 2015 Huawei Inc. + */ + +#include <stdlib.h> +#include <memory.h> +#include <unistd.h> +#include <asm/unistd.h> +#include <linux/bpf.h> +#include "bpf.h" + +/* + * When building perf, unistd.h is override. Define __NR_bpf is + * required to be defined. + */ +#ifndef __NR_bpf +# if defined(__i386__) +# define __NR_bpf 357 +# elif defined(__x86_64__) +# define __NR_bpf 321 +# elif defined(__aarch64__) +# define __NR_bpf 280 +# else +# error __NR_bpf not defined. libbpf does not support your arch. +# endif +#endif + +static __u64 ptr_to_u64(void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + +static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, + unsigned int size) +{ + return syscall(__NR_bpf, cmd, attr, size); +} + +int bpf_create_map(enum bpf_map_type map_type, int key_size, + int value_size, int max_entries) +{ + union bpf_attr attr; + + memset(&attr, '\0', sizeof(attr)); + + attr.map_type = map_type; + attr.key_size = key_size; + attr.value_size = value_size; + attr.max_entries = max_entries; + + return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); +} + +int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, + size_t insns_cnt, char *license, + u32 kern_version, char *log_buf, size_t log_buf_sz) +{ + int fd; + union bpf_attr attr; + + bzero(&attr, sizeof(attr)); + attr.prog_type = type; + attr.insn_cnt = (__u32)insns_cnt; + attr.insns = ptr_to_u64(insns); + attr.license = ptr_to_u64(license); + attr.log_buf = ptr_to_u64(NULL); + attr.log_size = 0; + attr.log_level = 0; + attr.kern_version = kern_version; + + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + if (fd >= 0 || !log_buf || !log_buf_sz) + return fd; + + /* Try again with log */ + attr.log_buf = ptr_to_u64(log_buf); + attr.log_size = log_buf_sz; + attr.log_level = 1; + log_buf[0] = 0; + return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); +} |