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Commit e245c5c6 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller
Browse files

bpf: move fixup_bpf_calls() function 



no functional change.
move fixup_bpf_calls() to verifier.c
it's being refactored in the next patch

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4396e461

kernel/bpf/syscall.c

+0 −56
Original line number Diff line number Diff line
@@ -586,59 +586,6 @@ void bpf_register_prog_type(struct bpf_prog_type_list *tl) 
	list_add(&tl->list_node, &bpf_prog_types);

}



/* fixup insn->imm field of bpf_call instructions:

 * if (insn->imm == BPF_FUNC_map_lookup_elem)

 *      insn->imm = bpf_map_lookup_elem - __bpf_call_base;

 * else if (insn->imm == BPF_FUNC_map_update_elem)

 *      insn->imm = bpf_map_update_elem - __bpf_call_base;

 * else ...

 *

 * this function is called after eBPF program passed verification

 */

static void fixup_bpf_calls(struct bpf_prog *prog)

{

	const struct bpf_func_proto *fn;

	int i;



	for (i = 0; i < prog->len; i++) {

		struct bpf_insn *insn = &prog->insnsi[i];



		if (insn->code == (BPF_JMP | BPF_CALL)) {

			/* we reach here when program has bpf_call instructions

			 * and it passed bpf_check(), means that

			 * ops->get_func_proto must have been supplied, check it

			 */

			BUG_ON(!prog->aux->ops->get_func_proto);



			if (insn->imm == BPF_FUNC_get_route_realm)

				prog->dst_needed = 1;

			if (insn->imm == BPF_FUNC_get_prandom_u32)

				bpf_user_rnd_init_once();

			if (insn->imm == BPF_FUNC_xdp_adjust_head)

				prog->xdp_adjust_head = 1;

			if (insn->imm == BPF_FUNC_tail_call) {

				/* mark bpf_tail_call as different opcode

				 * to avoid conditional branch in

				 * interpeter for every normal call

				 * and to prevent accidental JITing by

				 * JIT compiler that doesn't support

				 * bpf_tail_call yet

				 */

				insn->imm = 0;

				insn->code |= BPF_X;

				continue;

			}



			fn = prog->aux->ops->get_func_proto(insn->imm);

			/* all functions that have prototype and verifier allowed

			 * programs to call them, must be real in-kernel functions

			 */

			BUG_ON(!fn->func);

			insn->imm = fn->func - __bpf_call_base;

		}

	}

}



/* drop refcnt on maps used by eBPF program and free auxilary data */

static void free_used_maps(struct bpf_prog_aux *aux)

{
@@ -892,9 +839,6 @@ static int bpf_prog_load(union bpf_attr *attr) 
	if (err < 0)

		goto free_used_maps;



	/* fixup BPF_CALL->imm field */

	fixup_bpf_calls(prog);



	/* eBPF program is ready to be JITed */

	prog = bpf_prog_select_runtime(prog, &err);

	if (err < 0)

kernel/bpf/verifier.c

+57 −0
Original line number Diff line number Diff line
@@ -3233,6 +3233,60 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) 
	return 0;

}



/* fixup insn->imm field of bpf_call instructions:

 * if (insn->imm == BPF_FUNC_map_lookup_elem)

 *      insn->imm = bpf_map_lookup_elem - __bpf_call_base;

 * else if (insn->imm == BPF_FUNC_map_update_elem)

 *      insn->imm = bpf_map_update_elem - __bpf_call_base;

 * else ...

 *

 * this function is called after eBPF program passed verification

 */

static void fixup_bpf_calls(struct bpf_prog *prog)

{

	const struct bpf_func_proto *fn;

	int i;



	for (i = 0; i < prog->len; i++) {

		struct bpf_insn *insn = &prog->insnsi[i];



		if (insn->code == (BPF_JMP | BPF_CALL)) {

			/* we reach here when program has bpf_call instructions

			 * and it passed bpf_check(), means that

			 * ops->get_func_proto must have been supplied, check it

			 */

			BUG_ON(!prog->aux->ops->get_func_proto);



			if (insn->imm == BPF_FUNC_get_route_realm)

				prog->dst_needed = 1;

			if (insn->imm == BPF_FUNC_get_prandom_u32)

				bpf_user_rnd_init_once();

			if (insn->imm == BPF_FUNC_xdp_adjust_head)

				prog->xdp_adjust_head = 1;

			if (insn->imm == BPF_FUNC_tail_call) {

				/* mark bpf_tail_call as different opcode

				 * to avoid conditional branch in

				 * interpeter for every normal call

				 * and to prevent accidental JITing by

				 * JIT compiler that doesn't support

				 * bpf_tail_call yet

				 */

				insn->imm = 0;

				insn->code |= BPF_X;

				continue;

			}



			fn = prog->aux->ops->get_func_proto(insn->imm);

			/* all functions that have prototype and verifier allowed

			 * programs to call them, must be real in-kernel functions

			 */

			BUG_ON(!fn->func);

			insn->imm = fn->func - __bpf_call_base;

		}

	}

}





static void free_states(struct bpf_verifier_env *env)

{

	struct bpf_verifier_state_list *sl, *sln;
@@ -3328,6 +3382,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) 
		/* program is valid, convert *(u32*)(ctx + off) accesses */

		ret = convert_ctx_accesses(env);



	if (ret == 0)

		fixup_bpf_calls(env->prog);



	if (log_level && log_len >= log_size - 1) {

		BUG_ON(log_len >= log_size);

		/* verifier log exceeded user supplied buffer */