From patchwork Thu Jul 14 19:14:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12918446 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1BF6CCA47B for ; Thu, 14 Jul 2022 19:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229458AbiGNTVi (ORCPT ); Thu, 14 Jul 2022 15:21:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232159AbiGNTVi (ORCPT ); Thu, 14 Jul 2022 15:21:38 -0400 X-Greylist: delayed 356 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 14 Jul 2022 12:21:37 PDT Received: from sinsgout.his.huawei.com (sinsgout.his.huawei.com [119.8.179.247]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55FEB43332 for ; Thu, 14 Jul 2022 12:21:37 -0700 (PDT) Received: from sinmsgout01.his.huawei.com (unknown [172.28.115.139]) by sinsgout.his.huawei.com (SkyGuard) with ESMTP id 4LkPN16dzjz3h03s for ; Fri, 15 Jul 2022 03:15:45 +0800 (CST) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.156.147]) by sinmsgout01.his.huawei.com (SkyGuard) with ESMTP id 4LkPGD2NQwz9xFB2; Fri, 15 Jul 2022 03:10:44 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 14 Jul 2022 21:15:32 +0200 From: Roberto Sassu To: , , , , , , , CC: , Benjamin Tissoires Subject: [RFC][PATCH v8 01/12] btf: Add a new kfunc set which allows to mark a function to be sleepable Date: Thu, 14 Jul 2022 21:14:44 +0200 Message-ID: <20220714191455.2101834-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220714191455.2101834-1-roberto.sassu@huawei.com> References: <20220714191455.2101834-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml754-chm.china.huawei.com (10.201.108.204) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC From: Benjamin Tissoires This allows to declare a kfunc as sleepable and prevents its use in a non sleepable program. Acked-by: KP Singh Signed-off-by: Benjamin Tissoires Signed-off-by: KP Singh --- include/linux/btf.h | 2 ++ kernel/bpf/btf.c | 12 ++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index 1bfed7fa0428..6e7517573d9e 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -18,6 +18,7 @@ enum btf_kfunc_type { BTF_KFUNC_TYPE_RELEASE, BTF_KFUNC_TYPE_RET_NULL, BTF_KFUNC_TYPE_KPTR_ACQUIRE, + BTF_KFUNC_TYPE_SLEEPABLE, BTF_KFUNC_TYPE_MAX, }; @@ -37,6 +38,7 @@ struct btf_kfunc_id_set { struct btf_id_set *release_set; struct btf_id_set *ret_null_set; struct btf_id_set *kptr_acquire_set; + struct btf_id_set *sleepable_set; }; struct btf_id_set *sets[BTF_KFUNC_TYPE_MAX]; }; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4423045b8ff3..2a28ead92841 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6177,7 +6177,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, struct bpf_verifier_log *log = &env->log; u32 i, nargs, ref_id, ref_obj_id = 0; bool is_kfunc = btf_is_kernel(btf); - bool rel = false, kptr_get = false; + bool rel = false, kptr_get = false, sleepable = false; const char *func_name, *ref_tname; const struct btf_type *t, *ref_t; const struct btf_param *args; @@ -6208,9 +6208,10 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, } if (is_kfunc) { - /* Only kfunc can be release func */ rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_RELEASE, func_id); + sleepable = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_SLEEPABLE, func_id); kptr_get = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_KPTR_ACQUIRE, func_id); } @@ -6410,6 +6411,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, func_name); return -EINVAL; } + + if (sleepable && !env->prog->aux->sleepable) { + bpf_log(log, "kernel function %s is sleepable but the program is not\n", + func_name); + return -EINVAL; + } + /* returns argument register number > 0 in case of reference release kfunc */ return rel ? ref_regno : 0; }