From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.14-rc1 commit 5981881d21dff612abf8fce484f8efa67f49aae4 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add libbpf_set_strict_mode() API that allows application to simulate libbpf 1.0 breaking changes before libbpf 1.0 is released. This will help users migrate gradually and with confidence.
For now only ALL or NONE options are available, subsequent patches will add more flags. This patch is preliminary for selftests/bpf changes.
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: John Fastabend john.fastabend@gmail.com Acked-by: Toke Høiland-Jørgensen toke@redhat.com Link: https://lore.kernel.org/bpf/20210525035935.1461796-2-andrii@kernel.org (cherry picked from commit 5981881d21dff612abf8fce484f8efa67f49aae4) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/Makefile | 1 + tools/lib/bpf/libbpf.c | 17 +++++++++++++ tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 5 ++++ tools/lib/bpf/libbpf_legacy.h | 47 +++++++++++++++++++++++++++++++++++ 5 files changed, 71 insertions(+) create mode 100644 tools/lib/bpf/libbpf_legacy.h
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 76cf5ab8d00c..914c0afff255 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -230,6 +230,7 @@ install_headers: $(BPF_HELPER_DEFS) $(call do_install,btf.h,$(prefix)/include/bpf,644); \ $(call do_install,libbpf_util.h,$(prefix)/include/bpf,644); \ $(call do_install,libbpf_common.h,$(prefix)/include/bpf,644); \ + $(call do_install,libbpf_legacy.h,$(prefix)/include/bpf,644); \ $(call do_install,xsk.h,$(prefix)/include/bpf,644); \ $(call do_install,bpf_helpers.h,$(prefix)/include/bpf,644); \ $(call do_install,$(BPF_HELPER_DEFS),$(prefix)/include/bpf,644); \ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2b01e60f4fc5..416fcb161ba8 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -151,6 +151,23 @@ static inline __u64 ptr_to_u64(const void *ptr) return (__u64) (unsigned long) ptr; }
+/* this goes away in libbpf 1.0 */ +enum libbpf_strict_mode libbpf_mode = LIBBPF_STRICT_NONE; + +int libbpf_set_strict_mode(enum libbpf_strict_mode mode) +{ + /* __LIBBPF_STRICT_LAST is the last power-of-2 value used + 1, so to + * get all possible values we compensate last +1, and then (2*x - 1) + * to get the bit mask + */ + if (mode != LIBBPF_STRICT_ALL + && (mode & ~((__LIBBPF_STRICT_LAST - 1) * 2 - 1))) + return errno = EINVAL, -EINVAL; + + libbpf_mode = mode; + return 0; +} + enum kern_feature_id { /* v4.14: kernel support for program & map names. */ FEAT_PROG_NAME, diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 2fee8d11cdd8..e3a6728e868a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -18,6 +18,7 @@ #include <linux/bpf.h>
#include "libbpf_common.h" +#include "libbpf_legacy.h"
#ifdef __cplusplus extern "C" { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 5355f67e97ff..6266317ef3a2 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -369,3 +369,8 @@ LIBBPF_0.4.0 { bpf_tc_hook_destroy; bpf_tc_query; } LIBBPF_0.3.0; + +LIBBPF_0.5.0 { + global: + libbpf_set_strict_mode; +} LIBBPF_0.4.0; diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h new file mode 100644 index 000000000000..7482cfe22ab2 --- /dev/null +++ b/tools/lib/bpf/libbpf_legacy.h @@ -0,0 +1,47 @@ +/* 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-ZESZ54n... + * + * 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, + + __LIBBPF_STRICT_LAST, +}; + +LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode); + + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __LIBBPF_LEGACY_BPF_H */