Commit 22b769bb authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

bpf: emit more dynptr information in verifier log 



Emit dynptr type for CONST_PTR_TO_DYNPTR register. Also emit id,
ref_obj_id, and dynptr_id fields for STACK_DYNPTR stack slots.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231204233931.49758-3-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 1e68485d

kernel/bpf/log.c

+16 −9
Original line number Diff line number Diff line
@@ -628,6 +628,12 @@ static bool type_is_map_ptr(enum bpf_reg_type t) { 
	}

}



/*

 * _a stands for append, was shortened to avoid multiline statements below.

 * This macro is used to output a comma separated list of attributes.

 */

#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; })



static void print_reg_state(struct bpf_verifier_env *env,

			    const struct bpf_func_state *state,

			    const struct bpf_reg_state *reg)
@@ -643,11 +649,6 @@ static void print_reg_state(struct bpf_verifier_env *env, 
		verbose_snum(env, reg->var_off.value + reg->off);

		return;

	}

/*

 * _a stands for append, was shortened to avoid multiline statements below.

 * This macro is used to output a comma separated list of attributes.

 */

#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; })



	verbose(env, "%s", reg_type_str(env, t));

	if (t == PTR_TO_STACK) {
@@ -686,6 +687,8 @@ static void print_reg_state(struct bpf_verifier_env *env, 
		verbose_a("sz=");

		verbose_unum(env, reg->mem_size);

	}

	if (t == CONST_PTR_TO_DYNPTR)

		verbose_a("type=%s",  dynptr_type_str(reg->dynptr.type));

	if (tnum_is_const(reg->var_off)) {

		/* a pointer register with fixed offset */

		if (reg->var_off.value) {
@@ -702,8 +705,6 @@ static void print_reg_state(struct bpf_verifier_env *env, 
		}

	}

	verbose(env, ")");



#undef verbose_a

}



void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state,
@@ -727,6 +728,7 @@ void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_st 
	}

	for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {

		char types_buf[BPF_REG_SIZE + 1];

		const char *sep = "";

		bool valid = false;

		u8 slot_type;

		int j;
@@ -765,9 +767,14 @@ void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_st 


			verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);

			print_liveness(env, reg->live);

			verbose(env, "=dynptr_%s", dynptr_type_str(reg->dynptr.type));

			verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type));

			if (reg->id)

				verbose_a("id=%d", reg->id);

			if (reg->ref_obj_id)

				verbose(env, "(ref_id=%d)", reg->ref_obj_id);

				verbose_a("ref_id=%d", reg->ref_obj_id);

			if (reg->dynptr_id)

				verbose_a("dynptr_id=%d", reg->dynptr_id);

			verbose(env, ")");

			break;

		case STACK_ITER:

			/* only main slot has ref_obj_id set; skip others */