Commit a06aef4e authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'bpf_func_info-improvements' 



Martin KaFai Lau says:

====================
The patchset has a few improvements on bpf_func_info:
1. Improvements on the behaviors of info.func_info, info.func_info_cnt
   and info.func_info_rec_size.
2. Name change: s/insn_offset/insn_off/

Please see individual patch for details.
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 30da46b5 84ecc1f9

include/uapi/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -2991,7 +2991,7 @@ struct bpf_flow_keys { 
};



struct bpf_func_info {

	__u32	insn_offset;

	__u32	insn_off;

	__u32	type_id;

};

kernel/bpf/core.c

+1 −1
Original line number Diff line number Diff line
@@ -410,7 +410,7 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) 
	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));



	/* prog->aux->name will be ignored if full btf name is available */

	if (prog->aux->btf) {

	if (prog->aux->func_info_cnt) {

		type = btf_type_by_id(prog->aux->btf,

				      prog->aux->func_info[prog->aux->func_idx].type_id);

		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);

kernel/bpf/syscall.c

+20 −26
Original line number Diff line number Diff line
@@ -2083,6 +2083,12 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
				return -EFAULT;

	}



	if ((info.func_info_cnt || info.func_info_rec_size) &&

	    info.func_info_rec_size != sizeof(struct bpf_func_info))

		return -EINVAL;



	info.func_info_rec_size = sizeof(struct bpf_func_info);



	if (!capable(CAP_SYS_ADMIN)) {

		info.jited_prog_len = 0;

		info.xlated_prog_len = 0;
@@ -2226,35 +2232,23 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
		}

	}



	if (prog->aux->btf) {

		u32 krec_size = sizeof(struct bpf_func_info);

		u32 ucnt, urec_size;



	if (prog->aux->btf)

		info.btf_id = btf_id(prog->aux->btf);



		ucnt = info.func_info_cnt;

	ulen = info.func_info_cnt;

	info.func_info_cnt = prog->aux->func_info_cnt;

		urec_size = info.func_info_rec_size;

		info.func_info_rec_size = krec_size;

		if (ucnt) {

			/* expect passed-in urec_size is what the kernel expects */

			if (urec_size != info.func_info_rec_size)

				return -EINVAL;



	if (info.func_info_cnt && ulen) {

		if (bpf_dump_raw_ok()) {

			char __user *user_finfo;



			user_finfo = u64_to_user_ptr(info.func_info);

				ucnt = min_t(u32, info.func_info_cnt, ucnt);

			ulen = min_t(u32, info.func_info_cnt, ulen);

			if (copy_to_user(user_finfo, prog->aux->func_info,

						 krec_size * ucnt))

					 info.func_info_rec_size * ulen))

				return -EFAULT;

		} else {

				info.func_info_cnt = 0;

			}

			info.func_info = 0;

		}

	} else {

		info.func_info_cnt = 0;

	}



done:

kernel/bpf/verifier.c

+9 −9
Original line number Diff line number Diff line
@@ -4707,24 +4707,24 @@ static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, 
			goto free_btf;

		}



		/* check insn_offset */

		/* check insn_off */

		if (i == 0) {

			if (krecord[i].insn_offset) {

			if (krecord[i].insn_off) {

				verbose(env,

					"nonzero insn_offset %u for the first func info record",

					krecord[i].insn_offset);

					"nonzero insn_off %u for the first func info record",

					krecord[i].insn_off);

				ret = -EINVAL;

				goto free_btf;

			}

		} else if (krecord[i].insn_offset <= prev_offset) {

		} else if (krecord[i].insn_off <= prev_offset) {

			verbose(env,

				"same or smaller insn offset (%u) than previous func info record (%u)",

				krecord[i].insn_offset, prev_offset);

				krecord[i].insn_off, prev_offset);

			ret = -EINVAL;

			goto free_btf;

		}



		if (env->subprog_info[i].start != krecord[i].insn_offset) {

		if (env->subprog_info[i].start != krecord[i].insn_off) {

			verbose(env, "func_info BTF section doesn't match subprog layout in BPF program\n");

			ret = -EINVAL;

			goto free_btf;
@@ -4739,7 +4739,7 @@ static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, 
			goto free_btf;

		}



		prev_offset = krecord[i].insn_offset;

		prev_offset = krecord[i].insn_off;

		urecord += urec_size;

	}
@@ -4762,7 +4762,7 @@ static void adjust_btf_func(struct bpf_verifier_env *env) 
		return;



	for (i = 0; i < env->subprog_cnt; i++)

		env->prog->aux->func_info[i].insn_offset = env->subprog_info[i].start;

		env->prog->aux->func_info[i].insn_off = env->subprog_info[i].start;

}



/* check %cur's range satisfies %old's */

tools/bpf/bpftool/prog.c

+7 −0
Original line number Diff line number Diff line
@@ -589,6 +589,13 @@ static int do_dump(int argc, char **argv) 
		goto err_free;

	}



	if (func_info && !info.func_info) {

		/* kernel.kptr_restrict is set.  No func_info available. */

		free(func_info);

		func_info = NULL;

		finfo_cnt = 0;

	}



	if ((member_len == &info.jited_prog_len &&

	     info.jited_prog_insns == 0) ||

	    (member_len == &info.xlated_prog_len &&

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