From bd054102a8c7f36ff03446cc41822601180241f3 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 27 Jun 2022 14:15:26 -0700 Subject: libbpf: enforce strict libbpf 1.0 behaviors Remove support for legacy features and behaviors that previously had to be disabled by calling libbpf_set_strict_mode(): - legacy BPF map definitions are not supported now; - RLIMIT_MEMLOCK auto-setting, if necessary, is always on (but see libbpf_set_memlock_rlim()); - program name is used for program pinning (instead of section name); - cleaned up error returning logic; - entry BPF programs should have SEC() always. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220627211527.2245459-15-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf_legacy.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'tools/lib/bpf/libbpf_legacy.h') diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h index d7bcbd01f66f..863f49df8bf4 100644 --- a/tools/lib/bpf/libbpf_legacy.h +++ b/tools/lib/bpf/libbpf_legacy.h @@ -20,6 +20,11 @@ extern "C" { #endif +/* 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. @@ -88,6 +93,25 @@ enum libbpf_strict_mode { LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode); +/** + * @brief **libbpf_get_error()** extracts the error code from the passed + * pointer + * @param ptr pointer returned from libbpf API function + * @return error code; or 0 if no error occured + * + * Note, as of libbpf 1.0 this function is not necessary and not recommended + * to be used. Libbpf doesn't return error code embedded into the pointer + * itself. Instead, NULL is returned on error and error code is passed through + * thread-local errno variable. **libbpf_get_error()** is just returning -errno + * value if it receives NULL, which is correct only if errno hasn't been + * modified between libbpf API call and corresponding **libbpf_get_error()** + * call. Prefer to check return for NULL and use errno directly. + * + * This API is left in libbpf 1.0 to allow applications that were 1.0-ready + * before final libbpf 1.0 without needing to change them. + */ +LIBBPF_API long libbpf_get_error(const void *ptr); + #define DECLARE_LIBBPF_OPTS LIBBPF_OPTS /* "Discouraged" APIs which don't follow consistent libbpf naming patterns. -- cgit v1.2.3