Commit 30465003 authored by Dave Marchevsky's avatar Dave Marchevsky Committed by Alexei Starovoitov
Browse files

bpf: rename list_head -> graph_root in field info types 



Many of the structs recently added to track field info for linked-list
head are useful as-is for rbtree root. So let's do a mechanical renaming
of list_head-related types and fields:

include/linux/bpf.h:
  struct btf_field_list_head -> struct btf_field_graph_root
  list_head -> graph_root in struct btf_field union
kernel/bpf/btf.c:
  list_head -> graph_root in struct btf_field_info

This is a nonfunctional change, functionality to actually use these
fields for rbtree will be added in further patches.

Signed-off-by: default avatarDave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20221217082506.1570898-5-davemarchevsky@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 07453245

include/linux/bpf.h

+2 −2
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ struct btf_field_kptr { 
	u32 btf_id;

};



struct btf_field_list_head {

struct btf_field_graph_root {

	struct btf *btf;

	u32 value_btf_id;

	u32 node_offset;
@@ -201,7 +201,7 @@ struct btf_field { 
	enum btf_field_type type;

	union {

		struct btf_field_kptr kptr;

		struct btf_field_list_head list_head;

		struct btf_field_graph_root graph_root;

	};

};

kernel/bpf/btf.c

+11 −10
Original line number Diff line number Diff line
@@ -3228,7 +3228,7 @@ struct btf_field_info { 
		struct {

			const char *node_name;

			u32 value_btf_id;

		} list_head;

		} graph_root;

	};

};
@@ -3335,8 +3335,8 @@ static int btf_find_list_head(const struct btf *btf, const struct btf_type *pt, 
		return -EINVAL;

	info->type = BPF_LIST_HEAD;

	info->off = off;

	info->list_head.value_btf_id = id;

	info->list_head.node_name = list_node;

	info->graph_root.value_btf_id = id;

	info->graph_root.node_name = list_node;

	return BTF_FIELD_FOUND;

}
@@ -3604,13 +3604,14 @@ static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, 
	u32 offset;

	int i;



	t = btf_type_by_id(btf, info->list_head.value_btf_id);

	t = btf_type_by_id(btf, info->graph_root.value_btf_id);

	/* We've already checked that value_btf_id is a struct type. We

	 * just need to figure out the offset of the list_node, and

	 * verify its type.

	 */

	for_each_member(i, t, member) {

		if (strcmp(info->list_head.node_name, __btf_name_by_offset(btf, member->name_off)))

		if (strcmp(info->graph_root.node_name,

			   __btf_name_by_offset(btf, member->name_off)))

			continue;

		/* Invalid BTF, two members with same name */

		if (n)
@@ -3627,9 +3628,9 @@ static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, 
		if (offset % __alignof__(struct bpf_list_node))

			return -EINVAL;



		field->list_head.btf = (struct btf *)btf;

		field->list_head.value_btf_id = info->list_head.value_btf_id;

		field->list_head.node_offset = offset;

		field->graph_root.btf = (struct btf *)btf;

		field->graph_root.value_btf_id = info->graph_root.value_btf_id;

		field->graph_root.node_offset = offset;

	}

	if (!n)

		return -ENOENT;
@@ -3736,11 +3737,11 @@ int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) 


		if (!(rec->fields[i].type & BPF_LIST_HEAD))

			continue;

		btf_id = rec->fields[i].list_head.value_btf_id;

		btf_id = rec->fields[i].graph_root.value_btf_id;

		meta = btf_find_struct_meta(btf, btf_id);

		if (!meta)

			return -EFAULT;

		rec->fields[i].list_head.value_rec = meta->record;

		rec->fields[i].graph_root.value_rec = meta->record;



		if (!(rec->field_mask & BPF_LIST_NODE))

			continue;

kernel/bpf/helpers.c

+2 −2
Original line number Diff line number Diff line
@@ -1756,12 +1756,12 @@ void bpf_list_head_free(const struct btf_field *field, void *list_head, 
	while (head != orig_head) {

		void *obj = head;



		obj -= field->list_head.node_offset;

		obj -= field->graph_root.node_offset;

		head = head->next;

		/* The contained type can also have resources, including a

		 * bpf_list_head which needs to be freed.

		 */

		bpf_obj_free_fields(field->list_head.value_rec, obj);

		bpf_obj_free_fields(field->graph_root.value_rec, obj);

		/* bpf_mem_free requires migrate_disable(), since we can be

		 * called from map free path as well apart from BPF program (as

		 * part of map ops doing bpf_obj_free_fields).

kernel/bpf/verifier.c

+11 −10
Original line number Diff line number Diff line
@@ -8776,21 +8776,22 @@ static int process_kf_arg_ptr_to_list_node(struct bpf_verifier_env *env, 


	field = meta->arg_list_head.field;



	et = btf_type_by_id(field->list_head.btf, field->list_head.value_btf_id);

	et = btf_type_by_id(field->graph_root.btf, field->graph_root.value_btf_id);

	t = btf_type_by_id(reg->btf, reg->btf_id);

	if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, 0, field->list_head.btf,

				  field->list_head.value_btf_id, true)) {

	if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, 0, field->graph_root.btf,

				  field->graph_root.value_btf_id, true)) {

		verbose(env, "operation on bpf_list_head expects arg#1 bpf_list_node at offset=%d "

			"in struct %s, but arg is at offset=%d in struct %s\n",

			field->list_head.node_offset, btf_name_by_offset(field->list_head.btf, et->name_off),

			field->graph_root.node_offset,

			btf_name_by_offset(field->graph_root.btf, et->name_off),

			list_node_off, btf_name_by_offset(reg->btf, t->name_off));

		return -EINVAL;

	}



	if (list_node_off != field->list_head.node_offset) {

	if (list_node_off != field->graph_root.node_offset) {

		verbose(env, "arg#1 offset=%d, but expected bpf_list_node at offset=%d in struct %s\n",

			list_node_off, field->list_head.node_offset,

			btf_name_by_offset(field->list_head.btf, et->name_off));

			list_node_off, field->graph_root.node_offset,

			btf_name_by_offset(field->graph_root.btf, et->name_off));

		return -EINVAL;

	}

	/* Set arg#1 for expiration after unlock */
@@ -9232,9 +9233,9 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, 


				mark_reg_known_zero(env, regs, BPF_REG_0);

				regs[BPF_REG_0].type = PTR_TO_BTF_ID | MEM_ALLOC;

				regs[BPF_REG_0].btf = field->list_head.btf;

				regs[BPF_REG_0].btf_id = field->list_head.value_btf_id;

				regs[BPF_REG_0].off = field->list_head.node_offset;

				regs[BPF_REG_0].btf = field->graph_root.btf;

				regs[BPF_REG_0].btf_id = field->graph_root.value_btf_id;

				regs[BPF_REG_0].off = field->graph_root.node_offset;

			} else if (meta.func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx]) {

				mark_reg_known_zero(env, regs, BPF_REG_0);

				regs[BPF_REG_0].type = PTR_TO_BTF_ID | PTR_TRUSTED;