linux/tools/lib/bpf/libbpf_legacy.h
Delyan Kratunov bc380eb9d0 libbpf: .text routines are subprograms in strict mode
Currently, libbpf considers a single routine in .text to be a program. This
is particularly confusing when it comes to library objects - a single routine
meant to be used as an extern will instead be considered a bpf_program.

This patch hides this compatibility behavior behind the pre-existing
SEC_NAME strict mode flag.

Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/018de8d0d67c04bf436055270d35d394ba393505.1647473511.git.delyank@fb.com
2022-03-17 23:11:15 -07:00

115 lines
3.8 KiB
C

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/*
* Libbpf legacy APIs (either discouraged or deprecated, as mentioned in [0])
*
* [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY
*
* Copyright (C) 2021 Facebook
*/
#ifndef __LIBBPF_LEGACY_BPF_H
#define __LIBBPF_LEGACY_BPF_H
#include <linux/bpf.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "libbpf_common.h"
#ifdef __cplusplus
extern "C" {
#endif
enum libbpf_strict_mode {
/* Turn on all supported strict features of libbpf to simulate libbpf
* v1.0 behavior.
* This will be the default behavior in libbpf v1.0.
*/
LIBBPF_STRICT_ALL = 0xffffffff,
/*
* Disable any libbpf 1.0 behaviors. This is the default before libbpf
* v1.0. It won't be supported anymore in v1.0, please update your
* code so that it handles LIBBPF_STRICT_ALL mode before libbpf v1.0.
*/
LIBBPF_STRICT_NONE = 0x00,
/*
* Return NULL pointers on error, not ERR_PTR(err).
* Additionally, libbpf also always sets errno to corresponding Exx
* (positive) error code.
*/
LIBBPF_STRICT_CLEAN_PTRS = 0x01,
/*
* Return actual error codes from low-level APIs directly, not just -1.
* Additionally, libbpf also always sets errno to corresponding Exx
* (positive) error code.
*/
LIBBPF_STRICT_DIRECT_ERRS = 0x02,
/*
* Enforce strict BPF program section (SEC()) names.
* E.g., while prefiously SEC("xdp_whatever") or SEC("perf_event_blah") were
* allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
* unrecognized by libbpf and would have to be just SEC("xdp") and
* SEC("xdp") and SEC("perf_event").
*
* Note, in this mode the program pin path will be based on the
* function name instead of section name.
*
* Additionally, routines in the .text section are always considered
* sub-programs. Legacy behavior allows for a single routine in .text
* to be a program.
*/
LIBBPF_STRICT_SEC_NAME = 0x04,
/*
* Disable the global 'bpf_objects_list'. Maintaining this list adds
* a race condition to bpf_object__open() and bpf_object__close().
* Clients can maintain it on their own if it is valuable for them.
*/
LIBBPF_STRICT_NO_OBJECT_LIST = 0x08,
/*
* Automatically bump RLIMIT_MEMLOCK using setrlimit() before the
* first BPF program or map creation operation. This is done only if
* kernel is too old to support memcg-based memory accounting for BPF
* subsystem. By default, RLIMIT_MEMLOCK limit is set to RLIM_INFINITY,
* but it can be overriden with libbpf_set_memlock_rlim_max() API.
* Note that libbpf_set_memlock_rlim_max() needs to be called before
* the very first bpf_prog_load(), bpf_map_create() or bpf_object__load()
* operation.
*/
LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK = 0x10,
/*
* Error out on any SEC("maps") map definition, which are deprecated
* in favor of BTF-defined map definitions in SEC(".maps").
*/
LIBBPF_STRICT_MAP_DEFINITIONS = 0x20,
__LIBBPF_STRICT_LAST,
};
LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode);
#define DECLARE_LIBBPF_OPTS LIBBPF_OPTS
/* "Discouraged" APIs which don't follow consistent libbpf naming patterns.
* They are normally a trivial aliases or wrappers for proper APIs and are
* left to minimize unnecessary disruption for users of libbpf. But they
* shouldn't be used going forward.
*/
struct bpf_program;
struct bpf_map;
struct btf;
struct btf_ext;
LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
LIBBPF_API enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* __LIBBPF_LEGACY_BPF_H */