From e3ed2fef22b694cf07b06abaa6481a9e6f868e1f Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 1 Jul 2015 02:14:03 +0000 Subject: bpf tools: Add bpf.c/h for common bpf operations This patch introduces bpf.c and bpf.h, which hold common functions issuing bpf syscall. The goal of these two files is to hide syscall completely from user. Note that bpf.c and bpf.h deal with kernel interface only. Things like structure of 'map' section in the ELF object is not cared by of bpf.[ch]. We first introduce bpf_create_map(). Note that, since functions in bpf.[ch] are wrapper of sys_bpf, they don't use OO style naming. Signed-off-by: Wang Nan Acked-by: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-16-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/bpf.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 tools/lib/bpf/bpf.c (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c new file mode 100644 index 000000000000..208de7c31e60 --- /dev/null +++ b/tools/lib/bpf/bpf.c @@ -0,0 +1,51 @@ +/* + * common eBPF ELF operations. + * + * Copyright (C) 2013-2015 Alexei Starovoitov + * Copyright (C) 2015 Wang Nan + * Copyright (C) 2015 Huawei Inc. + */ + +#include +#include +#include +#include +#include +#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 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)); +} -- cgit v1.2.3 From 7bf98369a73a9a84c56b3f2b247ea8f0eaf8668b Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 1 Jul 2015 02:14:06 +0000 Subject: bpf tools: Introduce bpf_load_program() to bpf.c bpf_load_program() can be used to load bpf program into kernel. To make loading faster, first try to load without logbuf. Try again with logbuf if the first try failed. Signed-off-by: Wang Nan Acked-by: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-19-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/bpf.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 208de7c31e60..a6331050ab79 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -29,6 +29,11 @@ # 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) { @@ -49,3 +54,32 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, 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)); +} -- cgit v1.2.3