Libbpf userspace function `libbpf_set_strict_mode`

0.5.0

Set the "strict mode" of libbpf.

Definition

int libbpf_set_strict_mode(enum libbpf_strict_mode mode);

Parameters

mode: strict mode to set

Return

0, on success; negative error code, otherwise

`enum libbpf_strict_mode`

/* As of libbpf 1.0 libbpf_set_strict_mode() and enum libbpf_struct_mode have
 * no effect. But they are left in libbpf_legacy.h so that applications that
 * prepared for libbpf 1.0 before final release by using
 * libbpf_set_strict_mode() still work with libbpf 1.0+ without any changes.
 */
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 overridden with libbpf_set_memlock_rlim() API.
     * Note that libbpf_set_memlock_rlim() 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,
};

Usage

Warning

as of v1.0 libbpf_set_strict_mode is a no-op

Example

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Libbpf userspace function libbpf_set_strict_mode