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twx-linux/tools/lib/bpf/bpf.h
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Daniel T. Lee a0356372f4 libbpf: fix samples/bpf build failure due to undefined UINT32_MAX
[ Upstream commit 32e621e554 ]

Currently, building bpf samples will cause the following error.

    ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
     #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
                               ^
    ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
     extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
                             ^~~~~~~~~~~~~~~~

Due to commit 4519efa6f8 ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.

Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)

    clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
    -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
    -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
    llc -march=bpf -mcpu=generic  -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o

But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.

    gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
    -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
    -I./tools/  lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;

This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31 06:47:22 -07:00

71 lines
2.8 KiB
C

/*
* 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.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License (not later!)
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses>
*/
#ifndef __BPF_BPF_H
#define __BPF_BPF_H
#include <linux/bpf.h>
#include <stddef.h>
#include <stdint.h>
int bpf_create_map_node(enum bpf_map_type map_type, int key_size,
int value_size, int max_entries, __u32 map_flags,
int node);
int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries, __u32 map_flags);
int bpf_create_map_in_map_node(enum bpf_map_type map_type, int key_size,
int inner_map_fd, int max_entries,
__u32 map_flags, int node);
int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
int inner_map_fd, int max_entries, __u32 map_flags);
/* Recommend log buffer size */
#define BPF_LOG_BUF_SIZE 65536
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
size_t log_buf_sz);
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, int strict_alignment,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz, int log_level);
int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags);
int bpf_map_lookup_elem(int fd, const void *key, void *value);
int bpf_map_delete_elem(int fd, const void *key);
int bpf_map_get_next_key(int fd, const void *key, void *next_key);
int bpf_obj_pin(int fd, const char *pathname);
int bpf_obj_get(const char *pathname);
int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type,
unsigned int flags);
int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
void *data_out, __u32 *size_out, __u32 *retval,
__u32 *duration);
int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id);
int bpf_map_get_next_id(__u32 start_id, __u32 *next_id);
int bpf_prog_get_fd_by_id(__u32 id);
int bpf_map_get_fd_by_id(__u32 id);
int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
#endif