From: Alexei Starovoitov ast@kernel.org
mainline inclusion from mainline-5.15-rc1 commit 301ba4d710284e088d278adc477b7edad834577f 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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In order to make a clean split of CO-RE logic move its types into independent header file.
Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20210721000822.40958-4-alexei.starovoitov@gmail.... (cherry picked from commit 301ba4d710284e088d278adc477b7edad834577f) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/libbpf.c | 32 ++++-------- tools/lib/bpf/libbpf_internal.h | 71 +------------------------ tools/lib/bpf/relo_core.h | 92 +++++++++++++++++++++++++++++++++ 3 files changed, 102 insertions(+), 93 deletions(-) create mode 100644 tools/lib/bpf/relo_core.h
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 423844b07ef2..74d786ad4e13 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5036,34 +5036,20 @@ static size_t bpf_core_essential_name_len(const char *name) return n; }
-struct core_cand -{ - const struct btf *btf; - const struct btf_type *t; - const char *name; - __u32 id; -}; - -/* dynamically sized list of type IDs and its associated struct btf */ -struct core_cand_list { - struct core_cand *cands; - int len; -}; - -static void bpf_core_free_cands(struct core_cand_list *cands) +static void bpf_core_free_cands(struct bpf_core_cand_list *cands) { free(cands->cands); free(cands); }
-static int bpf_core_add_cands(struct core_cand *local_cand, +static int bpf_core_add_cands(struct bpf_core_cand *local_cand, size_t local_essent_len, const struct btf *targ_btf, const char *targ_btf_name, int targ_start_id, - struct core_cand_list *cands) + struct bpf_core_cand_list *cands) { - struct core_cand *new_cands, *cand; + struct bpf_core_cand *new_cands, *cand; const struct btf_type *t; const char *targ_name; size_t targ_essent_len; @@ -5199,11 +5185,11 @@ static int load_module_btfs(struct bpf_object *obj) return 0; }
-static struct core_cand_list * +static struct bpf_core_cand_list * bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 local_type_id) { - struct core_cand local_cand = {}; - struct core_cand_list *cands; + struct bpf_core_cand local_cand = {}; + struct bpf_core_cand_list *cands; const struct btf *main_btf; size_t local_essent_len; int err, i; @@ -6232,7 +6218,7 @@ static int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn const struct bpf_core_relo *relo, int relo_idx, const struct btf *local_btf, - struct core_cand_list *cands) + struct bpf_core_cand_list *cands) { struct bpf_core_spec local_spec, cand_spec, targ_spec = {}; struct bpf_core_relo_res cand_res, targ_res; @@ -6386,7 +6372,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog, struct hashmap *cand_cache) { const void *type_key = u32_as_hash_key(relo->type_id); - struct core_cand_list *cands = NULL; + struct bpf_core_cand_list *cands = NULL; const char *prog_name = prog->name; const struct btf_type *local_type; const char *local_name; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 016ca7cb4f8a..3178d5685dce 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -14,6 +14,7 @@ #include <errno.h> #include <linux/err.h> #include "libbpf_legacy.h" +#include "relo_core.h"
/* make sure libbpf doesn't use kernel-only integer typedefs */ #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 @@ -366,76 +367,6 @@ struct bpf_line_info_min { __u32 line_col; };
-/* bpf_core_relo_kind encodes which aspect of captured field/type/enum value - * has to be adjusted by relocations. - */ -enum bpf_core_relo_kind { - BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */ - BPF_FIELD_BYTE_SIZE = 1, /* field size in bytes */ - BPF_FIELD_EXISTS = 2, /* field existence in target kernel */ - BPF_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */ - BPF_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */ - BPF_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */ - BPF_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */ - BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */ - BPF_TYPE_EXISTS = 8, /* type existence in target kernel */ - BPF_TYPE_SIZE = 9, /* type size in bytes */ - BPF_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ - BPF_ENUMVAL_VALUE = 11, /* enum value integer value */ -}; - -/* The minimum bpf_core_relo checked by the loader - * - * CO-RE relocation captures the following data: - * - insn_off - instruction offset (in bytes) within a BPF program that needs - * its insn->imm field to be relocated with actual field info; - * - type_id - BTF type ID of the "root" (containing) entity of a relocatable - * type or field; - * - access_str_off - offset into corresponding .BTF string section. String - * interpretation depends on specific relocation kind: - * - for field-based relocations, string encodes an accessed field using - * a sequence of field and array indices, separated by colon (:). It's - * conceptually very close to LLVM's getelementptr ([0]) instruction's - * arguments for identifying offset to a field. - * - for type-based relocations, strings is expected to be just "0"; - * - for enum value-based relocations, string contains an index of enum - * value within its enum type; - * - * Example to provide a better feel. - * - * struct sample { - * int a; - * struct { - * int b[10]; - * }; - * }; - * - * struct sample *s = ...; - * int x = &s->a; // encoded as "0:0" (a is field #0) - * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1, - * // b is field #0 inside anon struct, accessing elem #5) - * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array) - * - * type_id for all relocs in this example will capture BTF type id of - * `struct sample`. - * - * Such relocation is emitted when using __builtin_preserve_access_index() - * Clang built-in, passing expression that captures field address, e.g.: - * - * bpf_probe_read(&dst, sizeof(dst), - * __builtin_preserve_access_index(&src->a.b.c)); - * - * In this case Clang will emit field relocation recording necessary data to - * be able to find offset of embedded `a.b.c` field within `src` struct. - * - * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction - */ -struct bpf_core_relo { - __u32 insn_off; - __u32 type_id; - __u32 access_str_off; - enum bpf_core_relo_kind kind; -};
typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h new file mode 100644 index 000000000000..ddf20151fe41 --- /dev/null +++ b/tools/lib/bpf/relo_core.h @@ -0,0 +1,92 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ +/* Copyright (c) 2019 Facebook */ + +#ifndef __RELO_CORE_H +#define __RELO_CORE_H + +/* bpf_core_relo_kind encodes which aspect of captured field/type/enum value + * has to be adjusted by relocations. + */ +enum bpf_core_relo_kind { + BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */ + BPF_FIELD_BYTE_SIZE = 1, /* field size in bytes */ + BPF_FIELD_EXISTS = 2, /* field existence in target kernel */ + BPF_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */ + BPF_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */ + BPF_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */ + BPF_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */ + BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */ + BPF_TYPE_EXISTS = 8, /* type existence in target kernel */ + BPF_TYPE_SIZE = 9, /* type size in bytes */ + BPF_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ + BPF_ENUMVAL_VALUE = 11, /* enum value integer value */ +}; + +/* The minimum bpf_core_relo checked by the loader + * + * CO-RE relocation captures the following data: + * - insn_off - instruction offset (in bytes) within a BPF program that needs + * its insn->imm field to be relocated with actual field info; + * - type_id - BTF type ID of the "root" (containing) entity of a relocatable + * type or field; + * - access_str_off - offset into corresponding .BTF string section. String + * interpretation depends on specific relocation kind: + * - for field-based relocations, string encodes an accessed field using + * a sequence of field and array indices, separated by colon (:). It's + * conceptually very close to LLVM's getelementptr ([0]) instruction's + * arguments for identifying offset to a field. + * - for type-based relocations, strings is expected to be just "0"; + * - for enum value-based relocations, string contains an index of enum + * value within its enum type; + * + * Example to provide a better feel. + * + * struct sample { + * int a; + * struct { + * int b[10]; + * }; + * }; + * + * struct sample *s = ...; + * int x = &s->a; // encoded as "0:0" (a is field #0) + * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1, + * // b is field #0 inside anon struct, accessing elem #5) + * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array) + * + * type_id for all relocs in this example will capture BTF type id of + * `struct sample`. + * + * Such relocation is emitted when using __builtin_preserve_access_index() + * Clang built-in, passing expression that captures field address, e.g.: + * + * bpf_probe_read(&dst, sizeof(dst), + * __builtin_preserve_access_index(&src->a.b.c)); + * + * In this case Clang will emit field relocation recording necessary data to + * be able to find offset of embedded `a.b.c` field within `src` struct. + * + * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction + */ +struct bpf_core_relo { + __u32 insn_off; + __u32 type_id; + __u32 access_str_off; + enum bpf_core_relo_kind kind; +}; + +struct bpf_core_cand +{ + const struct btf *btf; + const struct btf_type *t; + const char *name; + __u32 id; +}; + +/* dynamically sized list of type IDs and its associated struct btf */ +struct bpf_core_cand_list { + struct bpf_core_cand *cands; + int len; +}; + +#endif