Commit a4fa885b authored by Ihor Solodrai's avatar Ihor Solodrai Committed by Andrii Nakryiko
Browse files

resolve_btfids: Introduce enum btf_id_kind 



Instead of using multiple flags, make struct btf_id tagged with an
enum value indicating its kind in the context of resolve_btfids.

Signed-off-by: default avatarIhor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Tested-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Acked-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20251219181321.1283664-4-ihor.solodrai@linux.dev
parent 5f347a0f

tools/bpf/resolve_btfids/main.c

+60 −23
Original line number Diff line number Diff line
@@ -98,6 +98,13 @@ 
# error "Unknown machine endianness!"

#endif



enum btf_id_kind {

	BTF_ID_KIND_NONE,

	BTF_ID_KIND_SYM,

	BTF_ID_KIND_SET,

	BTF_ID_KIND_SET8

};



struct btf_id {

	struct rb_node	 rb_node;

	char		*name;
@@ -105,9 +112,8 @@ struct btf_id { 
		int	 id;

		int	 cnt;

	};

	enum btf_id_kind kind;

	int		 addr_cnt;

	bool		 is_set;

	bool		 is_set8;

	Elf64_Addr	 addr[ADDR_CNT];

};
@@ -197,8 +203,10 @@ static struct btf_id *btf_id__find(struct rb_root *root, const char *name) 
	return NULL;

}



static struct btf_id *

btf_id__add(struct rb_root *root, char *name, bool unique)

static struct btf_id *__btf_id__add(struct rb_root *root,

				    char *name,

				    enum btf_id_kind kind,

				    bool unique)

{

	struct rb_node **p = &root->rb_node;

	struct rb_node *parent = NULL;
@@ -221,12 +229,23 @@ btf_id__add(struct rb_root *root, char *name, bool unique) 
	if (id) {

		pr_debug("adding symbol %s\n", name);

		id->name = name;

		id->kind = kind;

		rb_link_node(&id->rb_node, parent, p);

		rb_insert_color(&id->rb_node, root);

	}

	return id;

}



static inline struct btf_id *btf_id__add(struct rb_root *root, char *name, enum btf_id_kind kind)

{

	return __btf_id__add(root, name, kind, false);

}



static inline struct btf_id *btf_id__add_unique(struct rb_root *root, char *name, enum btf_id_kind kind)

{

	return __btf_id__add(root, name, kind, true);

}



static char *get_id(const char *prefix_end)

{

	/*
@@ -260,22 +279,36 @@ static char *get_id(const char *prefix_end) 
	return id;

}



static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)

static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind kind)

{

	int len = strlen(name);

	int prefixlen;

	char *id;



	/*

	 * __BTF_ID__set__name

	 * name =    ^

	 * id   =         ^

	 */

	char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;

	int len = strlen(name);

	switch (kind) {

	case BTF_ID_KIND_SET:

		prefixlen = sizeof(BTF_SET "__") - 1;

		break;

	case BTF_ID_KIND_SET8:

		prefixlen = sizeof(BTF_SET8 "__") - 1;

		break;

	default:

		pr_err("Unexpected kind %d passed to %s() for symbol %s\n", kind, __func__, name);

		return NULL;

	}



	id = name + prefixlen;

	if (id >= name + len) {

		pr_err("FAILED to parse set name: %s\n", name);

		return NULL;

	}



	return btf_id__add(&obj->sets, id, true);

	return btf_id__add_unique(&obj->sets, id, kind);

}



static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
@@ -288,7 +321,7 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size) 
		return NULL;

	}



	return btf_id__add(root, id, false);

	return btf_id__add(root, id, BTF_ID_KIND_SYM);

}



/* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
@@ -491,35 +524,31 @@ static int symbols_collect(struct object *obj) 
			id = add_symbol(&obj->funcs, prefix, sizeof(BTF_FUNC) - 1);

		/* set8 */

		} else if (!strncmp(prefix, BTF_SET8, sizeof(BTF_SET8) - 1)) {

			id = add_set(obj, prefix, true);

			id = add_set(obj, prefix, BTF_ID_KIND_SET8);

			/*

			 * SET8 objects store list's count, which is encoded

			 * in symbol's size, together with 'cnt' field hence

			 * that - 1.

			 */

			if (id) {

			if (id)

				id->cnt = sym.st_size / sizeof(uint64_t) - 1;

				id->is_set8 = true;

			}

		/* set */

		} else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) {

			id = add_set(obj, prefix, false);

			id = add_set(obj, prefix, BTF_ID_KIND_SET);

			/*

			 * SET objects store list's count, which is encoded

			 * in symbol's size, together with 'cnt' field hence

			 * that - 1.

			 */

			if (id) {

			if (id)

				id->cnt = sym.st_size / sizeof(int) - 1;

				id->is_set = true;

			}

		} else {

			pr_err("FAILED unsupported prefix %s\n", prefix);

			return -1;

		}



		if (!id)

			return -ENOMEM;

			return -EINVAL;



		if (id->addr_cnt >= ADDR_CNT) {

			pr_err("FAILED symbol %s crossed the number of allowed lists\n",
@@ -643,7 +672,7 @@ static int id_patch(struct object *obj, struct btf_id *id) 
	int i;



	/* For set, set8, id->id may be 0 */

	if (!id->id && !id->is_set && !id->is_set8) {

	if (!id->id && id->kind != BTF_ID_KIND_SET && id->kind != BTF_ID_KIND_SET8) {

		pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);

		warnings++;

	}
@@ -696,6 +725,7 @@ static int sets_patch(struct object *obj) 
{

	Elf_Data *data = obj->efile.idlist;

	struct rb_node *next;

	int cnt;



	next = rb_first(&obj->sets);

	while (next) {
@@ -715,11 +745,15 @@ static int sets_patch(struct object *obj) 
			return -1;

		}



		if (id->is_set) {

		switch (id->kind) {

		case BTF_ID_KIND_SET:

			set = data->d_buf + off;

			cnt = set->cnt;

			qsort(set->ids, set->cnt, sizeof(set->ids[0]), cmp_id);

		} else {

			break;

		case BTF_ID_KIND_SET8:

			set8 = data->d_buf + off;

			cnt = set8->cnt;

			/*

			 * Make sure id is at the beginning of the pairs

			 * struct, otherwise the below qsort would not work.
@@ -744,10 +778,13 @@ static int sets_patch(struct object *obj) 
						bswap_32(set8->pairs[i].flags);

				}

			}

			break;

		default:

			pr_err("Unexpected btf_id_kind %d for set '%s'\n", id->kind, id->name);

			return -1;

		}



		pr_debug("sorting  addr %5lu: cnt %6d [%s]\n",

			 off, id->is_set ? set->cnt : set8->cnt, id->name);

		pr_debug("sorting  addr %5lu: cnt %6d [%s]\n", off, cnt, id->name);



		next = rb_next(next);

	}