Commit efc68158 authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Alexei Starovoitov
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bpf: change logging calls from verbose() to bpf_log() and use log pointer 



In preparation for moving code around, change a bunch of references to
env->log (and the verbose() logging helper) to use bpf_log() and a direct
pointer to struct bpf_verifier_log. While we're touching the function
signature, mark the 'prog' argument to bpf_check_type_match() as const.

Also enhance the bpf_verifier_log_needed() check to handle NULL pointers
for the log struct so we can re-use the code with logging disabled.

Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 1af9270e

include/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -1420,7 +1420,7 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, 
			     struct bpf_reg_state *regs);

int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,

			  struct bpf_reg_state *reg);

int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog,

int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,

			 struct btf *btf, const struct btf_type *t);



struct bpf_prog *bpf_prog_by_id(u32 id);

include/linux/bpf_verifier.h

+3 −2
Original line number Diff line number Diff line
@@ -347,8 +347,9 @@ static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log) 


static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)

{

	return (log->level && log->ubuf && !bpf_verifier_log_full(log)) ||

		log->level == BPF_LOG_KERNEL;

	return log &&

		((log->level && log->ubuf && !bpf_verifier_log_full(log)) ||

		 log->level == BPF_LOG_KERNEL);

}



#define BPF_MAX_SUBPROGS 256

kernel/bpf/btf.c

+3 −3
Original line number Diff line number Diff line
@@ -4388,7 +4388,7 @@ static int btf_check_func_type_match(struct bpf_verifier_log *log, 
}



/* Compare BTFs of given program with BTF of target program */

int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog,

int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,

			 struct btf *btf2, const struct btf_type *t2)

{

	struct btf *btf1 = prog->aux->btf;
@@ -4396,7 +4396,7 @@ int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog, 
	u32 btf_id = 0;



	if (!prog->aux->func_info) {

		bpf_log(&env->log, "Program extension requires BTF\n");

		bpf_log(log, "Program extension requires BTF\n");

		return -EINVAL;

	}
@@ -4408,7 +4408,7 @@ int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog, 
	if (!t1 || !btf_type_is_func(t1))

		return -EFAULT;



	return btf_check_func_type_match(&env->log, btf1, t1, btf2, t2);

	return btf_check_func_type_match(log, btf1, t1, btf2, t2);

}



/* Compare BTF of a function with given bpf_reg_state.

kernel/bpf/verifier.c

+25 −25
Original line number Diff line number Diff line
@@ -11249,6 +11249,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
	struct bpf_prog *prog = env->prog;

	bool prog_extension = prog->type == BPF_PROG_TYPE_EXT;

	struct bpf_prog *tgt_prog = prog->aux->linked_prog;

	struct bpf_verifier_log *log = &env->log;

	u32 btf_id = prog->aux->attach_btf_id;

	const char prefix[] = "btf_trace_";

	struct btf_func_model fmodel;
@@ -11276,23 +11277,23 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
		return 0;



	if (!btf_id) {

		verbose(env, "Tracing programs must provide btf_id\n");

		bpf_log(log, "Tracing programs must provide btf_id\n");

		return -EINVAL;

	}

	btf = bpf_prog_get_target_btf(prog);

	if (!btf) {

		verbose(env,

		bpf_log(log,

			"FENTRY/FEXIT program can only be attached to another program annotated with BTF\n");

		return -EINVAL;

	}

	t = btf_type_by_id(btf, btf_id);

	if (!t) {

		verbose(env, "attach_btf_id %u is invalid\n", btf_id);

		bpf_log(log, "attach_btf_id %u is invalid\n", btf_id);

		return -EINVAL;

	}

	tname = btf_name_by_offset(btf, t->name_off);

	if (!tname) {

		verbose(env, "attach_btf_id %u doesn't have a name\n", btf_id);

		bpf_log(log, "attach_btf_id %u doesn't have a name\n", btf_id);

		return -EINVAL;

	}

	if (tgt_prog) {
@@ -11304,18 +11305,18 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
				break;

			}

		if (subprog == -1) {

			verbose(env, "Subprog %s doesn't exist\n", tname);

			bpf_log(log, "Subprog %s doesn't exist\n", tname);

			return -EINVAL;

		}

		conservative = aux->func_info_aux[subprog].unreliable;

		if (prog_extension) {

			if (conservative) {

				verbose(env,

				bpf_log(log,

					"Cannot replace static functions\n");

				return -EINVAL;

			}

			if (!prog->jit_requested) {

				verbose(env,

				bpf_log(log,

					"Extension programs should be JITed\n");

				return -EINVAL;

			}
@@ -11323,7 +11324,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
			prog->expected_attach_type = tgt_prog->expected_attach_type;

		}

		if (!tgt_prog->jited) {

			verbose(env, "Can attach to only JITed progs\n");

			bpf_log(log, "Can attach to only JITed progs\n");

			return -EINVAL;

		}

		if (tgt_prog->type == prog->type) {
@@ -11331,7 +11332,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
			 * Cannot attach program extension to another extension.

			 * It's ok to attach fentry/fexit to extension program.

			 */

			verbose(env, "Cannot recursively attach\n");

			bpf_log(log, "Cannot recursively attach\n");

			return -EINVAL;

		}

		if (tgt_prog->type == BPF_PROG_TYPE_TRACING &&
@@ -11353,13 +11354,13 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
			 * reasonable stack size. Hence extending fentry is not

			 * allowed.

			 */

			verbose(env, "Cannot extend fentry/fexit\n");

			bpf_log(log, "Cannot extend fentry/fexit\n");

			return -EINVAL;

		}

		key = ((u64)aux->id) << 32 | btf_id;

	} else {

		if (prog_extension) {

			verbose(env, "Cannot replace kernel functions\n");

			bpf_log(log, "Cannot replace kernel functions\n");

			return -EINVAL;

		}

		key = btf_id;
@@ -11368,17 +11369,17 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
	switch (prog->expected_attach_type) {

	case BPF_TRACE_RAW_TP:

		if (tgt_prog) {

			verbose(env,

			bpf_log(log,

				"Only FENTRY/FEXIT progs are attachable to another BPF prog\n");

			return -EINVAL;

		}

		if (!btf_type_is_typedef(t)) {

			verbose(env, "attach_btf_id %u is not a typedef\n",

			bpf_log(log, "attach_btf_id %u is not a typedef\n",

				btf_id);

			return -EINVAL;

		}

		if (strncmp(prefix, tname, sizeof(prefix) - 1)) {

			verbose(env, "attach_btf_id %u points to wrong type name %s\n",

			bpf_log(log, "attach_btf_id %u points to wrong type name %s\n",

				btf_id, tname);

			return -EINVAL;

		}
@@ -11401,7 +11402,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
		return 0;

	case BPF_TRACE_ITER:

		if (!btf_type_is_func(t)) {

			verbose(env, "attach_btf_id %u is not a function\n",

			bpf_log(log, "attach_btf_id %u is not a function\n",

				btf_id);

			return -EINVAL;

		}
@@ -11412,8 +11413,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
		prog->aux->attach_func_proto = t;

		if (!bpf_iter_prog_supported(prog))

			return -EINVAL;

		ret = btf_distill_func_proto(&env->log, btf, t,

					     tname, &fmodel);

		ret = btf_distill_func_proto(log, btf, t, tname, &fmodel);

		return ret;

	default:

		if (!prog_extension)
@@ -11425,18 +11425,18 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
	case BPF_TRACE_FEXIT:

		prog->aux->attach_func_name = tname;

		if (prog->type == BPF_PROG_TYPE_LSM) {

			ret = bpf_lsm_verify_prog(&env->log, prog);

			ret = bpf_lsm_verify_prog(log, prog);

			if (ret < 0)

				return ret;

		}



		if (!btf_type_is_func(t)) {

			verbose(env, "attach_btf_id %u is not a function\n",

			bpf_log(log, "attach_btf_id %u is not a function\n",

				btf_id);

			return -EINVAL;

		}

		if (prog_extension &&

		    btf_check_type_match(env, prog, btf, t))

		    btf_check_type_match(log, prog, btf, t))

			return -EINVAL;

		t = btf_type_by_id(btf, t->type);

		if (!btf_type_is_func_proto(t))
@@ -11455,7 +11455,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
			prog->aux->attach_func_proto = NULL;

			t = NULL;

		}

		ret = btf_distill_func_proto(&env->log, btf, t,

		ret = btf_distill_func_proto(log, btf, t,

					     tname, &tr->func.model);

		if (ret < 0)

			goto out;
@@ -11467,7 +11467,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
		} else {

			addr = kallsyms_lookup_name(tname);

			if (!addr) {

				verbose(env,

				bpf_log(log,

					"The address of function %s cannot be found\n",

					tname);

				ret = -ENOENT;
@@ -11497,17 +11497,17 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
				break;

			}

			if (ret)

				verbose(env, "%s is not sleepable\n",

				bpf_log(log, "%s is not sleepable\n",

					prog->aux->attach_func_name);

		} else if (prog->expected_attach_type == BPF_MODIFY_RETURN) {

			if (tgt_prog) {

				verbose(env, "can't modify return codes of BPF programs\n");

				bpf_log(log, "can't modify return codes of BPF programs\n");

				ret = -EINVAL;

				goto out;

			}

			ret = check_attach_modify_return(prog, addr);

			if (ret)

				verbose(env, "%s() is not modifiable\n",

				bpf_log(log, "%s() is not modifiable\n",

					prog->aux->attach_func_name);

		}

		if (ret)