From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB555373 for ; Fri, 5 Jan 2024 00:09:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="H4vmdJNz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 444EDC433C8; Fri, 5 Jan 2024 00:09:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1704413361; bh=w0oVyUN/TDhRIPiUcWir17QHZrWVndHP47wjQtrAnsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H4vmdJNzNfF15k/cESrQJ/7kpq8WLtgYbUzQ0puYj5DTfXa4iMSymLY0ChEr+ki1I xd5HQ6i+Wx8m0gFl5YO9gga65LyW/AfLQ+KpyQrwsvQ3WIIYVtwWsAs0D3FgUm1K0h lv5VF2cVIqZc4w+0R/6oWbmSUowMa/ijWPpbm3UZe+DuKqoBjqTLn/FKh61RM+cMxS yybSNlHBqk+ycCFuIZrfIvAqygGQXmrN30Cz06/e/sg/zlyX10tzMC0LUdKwCzVMbo hauG5bTF/ZS7PbXNQDktHrYwtXfze1vFNbYmcHduGT164Y042ySX3zasXq1vrvGjp4 m+mM5lsjoPMNA== From: Andrii Nakryiko To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org Cc: andrii@kernel.org, kernel-team@meta.com, Dave Marchevsky Subject: [PATCH bpf-next 3/8] bpf: prepare btf_prepare_func_args() for multiple tags per argument Date: Thu, 4 Jan 2024 16:09:04 -0800 Message-Id: <20240105000909.2818934-4-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240105000909.2818934-1-andrii@kernel.org> References: <20240105000909.2818934-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add btf_arg_tag flags enum to be able to record multiple tags per argument. Also streamline pointer argument processing some more. Signed-off-by: Andrii Nakryiko --- kernel/bpf/btf.c | 53 ++++++++++++++++++++++++++++++------------- kernel/bpf/verifier.c | 1 - 2 files changed, 37 insertions(+), 17 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 47163cb28b83..ccaf57e755fc 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6784,6 +6784,11 @@ static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t) return false; } +enum btf_arg_tag { + ARG_TAG_CTX = 0x1, + ARG_TAG_NONNULL = 0x2, +}; + /* Process BTF of a function to produce high-level expectation of function * arguments (like ARG_PTR_TO_CTX, or ARG_PTR_TO_MEM, etc). This information * is cached in subprog info for reuse. @@ -6865,10 +6870,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) * Only PTR_TO_CTX and SCALAR are supported atm. */ for (i = 0; i < nargs; i++) { - bool is_nonnull = false; const char *tag; - - t = btf_type_by_id(btf, args[i].type); + u32 tags = 0; tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:"); if (IS_ERR(tag) && PTR_ERR(tag) == -ENOENT) { @@ -6886,43 +6889,61 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) bpf_log(log, "arg#%d type tag is not supported in static functions\n", i); return -EOPNOTSUPP; } + if (strcmp(tag, "ctx") == 0) { - sub->args[i].arg_type = ARG_PTR_TO_CTX; - continue; + tags |= ARG_TAG_CTX; + } else if (strcmp(tag, "nonnull") == 0) { + tags |= ARG_TAG_NONNULL; + } else { + bpf_log(log, "arg#%d has unsupported set of tags\n", i); + return -EOPNOTSUPP; } - if (strcmp(tag, "nonnull") == 0) - is_nonnull = true; } + t = btf_type_by_id(btf, args[i].type); while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); - if (btf_type_is_ptr(t) && btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { + if (!btf_type_is_ptr(t)) + goto skip_pointer; + + if ((tags & ARG_TAG_CTX) || btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { + if (tags & ~ARG_TAG_CTX) { + bpf_log(log, "arg#%d has invalid combination of tags\n", i); + return -EINVAL; + } sub->args[i].arg_type = ARG_PTR_TO_CTX; continue; } - if (btf_type_is_ptr(t) && btf_is_dynptr_ptr(btf, t)) { + if (btf_is_dynptr_ptr(btf, t)) { + if (tags) { + bpf_log(log, "arg#%d has invalid combination of tags\n", i); + return -EINVAL; + } sub->args[i].arg_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY; continue; } - if (is_global && btf_type_is_ptr(t)) { + if (is_global) { /* generic user data pointer */ u32 mem_size; t = btf_type_skip_modifiers(btf, t->type, NULL); ref_t = btf_resolve_size(btf, t, &mem_size); if (IS_ERR(ref_t)) { - bpf_log(log, - "arg#%d reference type('%s %s') size cannot be determined: %ld\n", - i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), + bpf_log(log, "arg#%d reference type('%s %s') size cannot be determined: %ld\n", + i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), PTR_ERR(ref_t)); return -EINVAL; } - sub->args[i].arg_type = is_nonnull ? ARG_PTR_TO_MEM : ARG_PTR_TO_MEM_OR_NULL; + sub->args[i].arg_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL; + if (tags & ARG_TAG_NONNULL) + sub->args[i].arg_type &= ~PTR_MAYBE_NULL; sub->args[i].mem_size = mem_size; continue; } - if (is_nonnull) { - bpf_log(log, "arg#%d marked as non-null, but is not a pointer type\n", i); + +skip_pointer: + if (tags) { + bpf_log(log, "arg#%d has pointer tag, but is not a pointer type\n", i); return -EINVAL; } if (btf_type_is_int(t) || btf_is_any_enum(t)) { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d5f4ff1eb235..271c82bf9697 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -20037,7 +20037,6 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) state->first_insn_idx = env->subprog_info[subprog].start; state->last_insn_idx = -1; - regs = state->frame[state->curframe]->regs; if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) { const char *sub_name = subprog_name(env, subprog); -- 2.34.1