linux_dsm_epyc7002/tools/lib/bpf/bpf_helpers.h
Ian Rogers da7a35062b libbpf bpf_helpers: Use __builtin_offsetof for offsetof
The non-builtin route for offsetof has a dependency on size_t from
stdlib.h/stdint.h that is undeclared and may break targets.
The offsetof macro in bpf_helpers may disable the same macro in other
headers that have a #ifdef offsetof guard. Rather than add additional
dependencies improve the offsetof macro declared here to use the
builtin that is available since llvm 3.7 (the first with a BPF backend).

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200720061741.1514673-1-irogers@google.com
2020-07-21 13:26:25 -07:00

81 lines
1.8 KiB
C

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __BPF_HELPERS__
#define __BPF_HELPERS__
/*
* Note that bpf programs need to include either
* vmlinux.h (auto-generated from BTF) or linux/types.h
* in advance since bpf_helper_defs.h uses such types
* as __u64.
*/
#include "bpf_helper_defs.h"
#define __uint(name, val) int (*name)[val]
#define __type(name, val) typeof(val) *name
#define __array(name, val) typeof(val) *name[]
/* Helper macro to print out debug messages */
#define bpf_printk(fmt, ...) \
({ \
char ____fmt[] = fmt; \
bpf_trace_printk(____fmt, sizeof(____fmt), \
##__VA_ARGS__); \
})
/*
* Helper macro to place programs, maps, license in
* different sections in elf_bpf file. Section names
* are interpreted by elf_bpf loader
*/
#define SEC(NAME) __attribute__((section(NAME), used))
#ifndef __always_inline
#define __always_inline __attribute__((always_inline))
#endif
#ifndef __weak
#define __weak __attribute__((weak))
#endif
/*
* Helper macro to manipulate data structures
*/
#ifndef offsetof
#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
#endif
#ifndef container_of
#define container_of(ptr, type, member) \
({ \
void *__mptr = (void *)(ptr); \
((type *)(__mptr - offsetof(type, member))); \
})
#endif
/*
* Helper structure used by eBPF C program
* to describe BPF map attributes to libbpf loader
*/
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
};
enum libbpf_pin_type {
LIBBPF_PIN_NONE,
/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
LIBBPF_PIN_BY_NAME,
};
enum libbpf_tristate {
TRI_NO = 0,
TRI_YES = 1,
TRI_MODULE = 2,
};
#define __kconfig __attribute__((section(".kconfig")))
#define __ksym __attribute__((section(".ksyms")))
#endif