libbpf: Update BTF reloc support to latest Clang format (511bb008) · Commits · 戴 / test

tools/lib/bpf/btf.c

+8 −8

Original line number	Original line	Diff line number	Diff line
	@@ -888,14 +888,14 @@ static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
	return btf_ext_setup_info(btf_ext, &param);		return btf_ext_setup_info(btf_ext, &param);
	}		}

	static int btf_ext_setup_offset_reloc(struct btf_ext *btf_ext)		static int btf_ext_setup_field_reloc(struct btf_ext *btf_ext)
	{		{
	struct btf_ext_sec_setup_param param = {		struct btf_ext_sec_setup_param param = {
	.off = btf_ext->hdr->offset_reloc_off,		.off = btf_ext->hdr->field_reloc_off,
	.len = btf_ext->hdr->offset_reloc_len,		.len = btf_ext->hdr->field_reloc_len,
	.min_rec_size = sizeof(struct bpf_offset_reloc),		.min_rec_size = sizeof(struct bpf_field_reloc),
	.ext_info = &btf_ext->offset_reloc_info,		.ext_info = &btf_ext->field_reloc_info,
	.desc = "offset_reloc",		.desc = "field_reloc",
	};		};

	return btf_ext_setup_info(btf_ext, &param);		return btf_ext_setup_info(btf_ext, &param);
	@@ -975,9 +975,9 @@ struct btf_ext btf_ext__new(__u8 data, __u32 size)
	goto done;		goto done;

	if (btf_ext->hdr->hdr_len <		if (btf_ext->hdr->hdr_len <
	offsetofend(struct btf_ext_header, offset_reloc_len))		offsetofend(struct btf_ext_header, field_reloc_len))
	goto done;		goto done;
	err = btf_ext_setup_offset_reloc(btf_ext);		err = btf_ext_setup_field_reloc(btf_ext);
	if (err)		if (err)
	goto done;		goto done;

tools/lib/bpf/btf.h

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -60,8 +60,8 @@ struct btf_ext_header {
	__u32 line_info_len;		__u32 line_info_len;

	/* optional part of .BTF.ext header */		/* optional part of .BTF.ext header */
	__u32 offset_reloc_off;		__u32 field_reloc_off;
	__u32 offset_reloc_len;		__u32 field_reloc_len;
	};		};

	LIBBPF_API void btf__free(struct btf *btf);		LIBBPF_API void btf__free(struct btf *btf);

tools/lib/bpf/libbpf.c

+12 −12

Original line number	Original line	Diff line number	Diff line
	@@ -2326,7 +2326,7 @@ static bool str_is_empty(const char *s)
	}		}

	/*		/*
	* Turn bpf_offset_reloc into a low- and high-level spec representation,		* Turn bpf_field_reloc into a low- and high-level spec representation,
	* validating correctness along the way, as well as calculating resulting		* validating correctness along the way, as well as calculating resulting
	* field offset (in bytes), specified by accessor string. Low-level spec		* field offset (in bytes), specified by accessor string. Low-level spec
	* captures every single level of nestedness, including traversing anonymous		* captures every single level of nestedness, including traversing anonymous
	@@ -2977,7 +2977,7 @@ static void *u32_as_hash_key(__u32 x)
	* types should be compatible (see bpf_core_fields_are_compat for details).		* types should be compatible (see bpf_core_fields_are_compat for details).
	* 3. It is supported and expected that there might be multiple flavors		* 3. It is supported and expected that there might be multiple flavors
	* matching the spec. As long as all the specs resolve to the same set of		* matching the spec. As long as all the specs resolve to the same set of
	* offsets across all candidates, there is not error. If there is any		* offsets across all candidates, there is no error. If there is any
	* ambiguity, CO-RE relocation will fail. This is necessary to accomodate		* ambiguity, CO-RE relocation will fail. This is necessary to accomodate
	* imprefection of BTF deduplication, which can cause slight duplication of		* imprefection of BTF deduplication, which can cause slight duplication of
	* the same BTF type, if some directly or indirectly referenced (by		* the same BTF type, if some directly or indirectly referenced (by
	@@ -2992,12 +2992,12 @@ static void *u32_as_hash_key(__u32 x)
	* CPU-wise compared to prebuilding a map from all local type names to		* CPU-wise compared to prebuilding a map from all local type names to
	* a list of candidate type names. It's also sped up by caching resolved		* a list of candidate type names. It's also sped up by caching resolved
	* list of matching candidates per each local "root" type ID, that has at		* list of matching candidates per each local "root" type ID, that has at
	* least one bpf_offset_reloc associated with it. This list is shared		* least one bpf_field_reloc associated with it. This list is shared
	* between multiple relocations for the same type ID and is updated as some		* between multiple relocations for the same type ID and is updated as some
	* of the candidates are pruned due to structural incompatibility.		* of the candidates are pruned due to structural incompatibility.
	*/		*/
	static int bpf_core_reloc_offset(struct bpf_program *prog,		static int bpf_core_reloc_field(struct bpf_program *prog,
	const struct bpf_offset_reloc *relo,		const struct bpf_field_reloc *relo,
	int relo_idx,		int relo_idx,
	const struct btf *local_btf,		const struct btf *local_btf,
	const struct btf *targ_btf,		const struct btf *targ_btf,
	@@ -3106,10 +3106,10 @@ static int bpf_core_reloc_offset(struct bpf_program *prog,
	}		}

	static int		static int
	bpf_core_reloc_offsets(struct bpf_object obj, const char targ_btf_path)		bpf_core_reloc_fields(struct bpf_object obj, const char targ_btf_path)
	{		{
	const struct btf_ext_info_sec *sec;		const struct btf_ext_info_sec *sec;
	const struct bpf_offset_reloc *rec;		const struct bpf_field_reloc *rec;
	const struct btf_ext_info *seg;		const struct btf_ext_info *seg;
	struct hashmap_entry *entry;		struct hashmap_entry *entry;
	struct hashmap *cand_cache = NULL;		struct hashmap *cand_cache = NULL;
	@@ -3134,7 +3134,7 @@ bpf_core_reloc_offsets(struct bpf_object obj, const char targ_btf_path)
	goto out;		goto out;
	}		}

	seg = &obj->btf_ext->offset_reloc_info;		seg = &obj->btf_ext->field_reloc_info;
	for_each_btf_ext_sec(seg, sec) {		for_each_btf_ext_sec(seg, sec) {
	sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);		sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
	if (str_is_empty(sec_name)) {		if (str_is_empty(sec_name)) {
	@@ -3153,7 +3153,7 @@ bpf_core_reloc_offsets(struct bpf_object obj, const char targ_btf_path)
	sec_name, sec->num_info);		sec_name, sec->num_info);

	for_each_btf_ext_rec(seg, sec, i, rec) {		for_each_btf_ext_rec(seg, sec, i, rec) {
	err = bpf_core_reloc_offset(prog, rec, i, obj->btf,		err = bpf_core_reloc_field(prog, rec, i, obj->btf,
	targ_btf, cand_cache);		targ_btf, cand_cache);
	if (err) {		if (err) {
	pr_warning("prog '%s': relo #%d: failed to relocate: %d\n",		pr_warning("prog '%s': relo #%d: failed to relocate: %d\n",
	@@ -3179,8 +3179,8 @@ bpf_object__relocate_core(struct bpf_object obj, const char targ_btf_path)
	{		{
	int err = 0;		int err = 0;

	if (obj->btf_ext->offset_reloc_info.len)		if (obj->btf_ext->field_reloc_info.len)
	err = bpf_core_reloc_offsets(obj, targ_btf_path);		err = bpf_core_reloc_fields(obj, targ_btf_path);

	return err;		return err;
	}		}

tools/lib/bpf/libbpf_internal.h

+18 −7

Original line number	Original line	Diff line number	Diff line
	@@ -110,7 +110,7 @@ struct btf_ext {
	};		};
	struct btf_ext_info func_info;		struct btf_ext_info func_info;
	struct btf_ext_info line_info;		struct btf_ext_info line_info;
	struct btf_ext_info offset_reloc_info;		struct btf_ext_info field_reloc_info;
	__u32 data_size;		__u32 data_size;
	};		};

	@@ -135,13 +135,23 @@ struct bpf_line_info_min {
	__u32 line_col;		__u32 line_col;
	};		};

	/* The minimum bpf_offset_reloc checked by the loader		/* bpf_field_info_kind encodes which aspect of captured field has to be
			* adjusted by relocations. Currently supported values are:
			* - BPF_FIELD_BYTE_OFFSET: field offset (in bytes);
			* - BPF_FIELD_EXISTS: field existence (1, if field exists; 0, otherwise);
			*/
			enum bpf_field_info_kind {
			BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */
			BPF_FIELD_EXISTS = 2, /* field existence in target kernel */
			};

			/* The minimum bpf_field_reloc checked by the loader
	*		*
	* Offset relocation captures the following data:		* Field relocation captures the following data:
	* - insn_off - instruction offset (in bytes) within a BPF program that needs		* - insn_off - instruction offset (in bytes) within a BPF program that needs
	* its insn->imm field to be relocated with actual offset;		* 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_id - BTF type ID of the "root" (containing) entity of a relocatable
	* offset;		* field;
	* - access_str_off - offset into corresponding .BTF string section. String		* - access_str_off - offset into corresponding .BTF string section. String
	* itself encodes an accessed field using a sequence of field and array		* itself encodes an accessed field using a sequence of field and array
	* indicies, separated by colon (:). It's conceptually very close to LLVM's		* indicies, separated by colon (:). It's conceptually very close to LLVM's
	@@ -172,15 +182,16 @@ struct bpf_line_info_min {
	* bpf_probe_read(&dst, sizeof(dst),		* bpf_probe_read(&dst, sizeof(dst),
	* __builtin_preserve_access_index(&src->a.b.c));		* __builtin_preserve_access_index(&src->a.b.c));
	*		*
	* In this case Clang will emit offset relocation recording necessary data to		* 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.		* be able to find offset of embedded `a.b.c` field within `src` struct.
	*		*
	* [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction		* [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
	*/		*/
	struct bpf_offset_reloc {		struct bpf_field_reloc {
	__u32 insn_off;		__u32 insn_off;
	__u32 type_id;		__u32 type_id;
	__u32 access_str_off;		__u32 access_str_off;
			enum bpf_field_info_kind kind;
	};		};

	#endif /* __LIBBPF_LIBBPF_INTERNAL_H */		#endif /* __LIBBPF_LIBBPF_INTERNAL_H */

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