From patchwork Thu Apr 21 14:07:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 12821679 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 EF2C6C4332F for ; Thu, 21 Apr 2022 14:08:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388937AbiDUOK6 (ORCPT ); Thu, 21 Apr 2022 10:10:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388939AbiDUOK4 (ORCPT ); Thu, 21 Apr 2022 10:10:56 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DBFA326AEC for ; Thu, 21 Apr 2022 07:07:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1650550078; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rS2oog3eO5CDVH6MLeAPYqGuTIVoniasbiUdyIVQinI=; b=ZuHTZhSKLtFNYiYRFDE5K+PP6O+Mf0Jtx2aMSGkOGuYAVVlCtKM/WvDoWnY1/5Nk3qRkne /20CQg7IAxjh1q1arDySva19OXfnUGxNvWaHxRL2/gyNfKRy0LRBJf5jgh6Gr0vkVgK34k Y3GcJDdpg/b0kDi+LUzi8uLUixC5Yv8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-661-MWsIkoWSN2CW2BDWJmDDwg-1; Thu, 21 Apr 2022 10:07:55 -0400 X-MC-Unique: MWsIkoWSN2CW2BDWJmDDwg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 04CAC38107A6; Thu, 21 Apr 2022 14:07:55 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.194.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5D5E40EC002; Thu, 21 Apr 2022 14:07:52 +0000 (UTC) From: Benjamin Tissoires To: Greg KH , Jiri Kosina , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, bpf@vger.kernel.org, Benjamin Tissoires Subject: [RFC bpf-next v4 4/7] btf: Add a new kfunc set which allows to mark a function to be sleepable Date: Thu, 21 Apr 2022 16:07:37 +0200 Message-Id: <20220421140740.459558-5-benjamin.tissoires@redhat.com> In-Reply-To: <20220421140740.459558-1-benjamin.tissoires@redhat.com> References: <20220421140740.459558-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC This allows to declare a kfunc as sleepable and prevents its use in a non sleepable program. Signed-off-by: Benjamin Tissoires --- new in v4 --- include/linux/btf.h | 2 ++ kernel/bpf/btf.c | 16 +++++++++++++--- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index 76a3ff48ae2a..b8b83dcf86bf 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -17,6 +17,7 @@ enum btf_kfunc_type { BTF_KFUNC_TYPE_ACQUIRE, BTF_KFUNC_TYPE_RELEASE, BTF_KFUNC_TYPE_RET_NULL, + BTF_KFUNC_TYPE_SLEEPABLE, BTF_KFUNC_TYPE_MAX, }; @@ -35,6 +36,7 @@ struct btf_kfunc_id_set { struct btf_id_set *acquire_set; struct btf_id_set *release_set; struct btf_id_set *ret_null_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 22e6e3cdc7ee..bf6a82461c58 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5889,7 +5889,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, const struct btf_type *t, *ref_t; const struct btf_param *args; int ref_regno = 0, ret; - bool rel = false; + bool rel = false, sleepable = false; t = btf_type_by_id(btf, func_id); if (!t || !btf_type_is_func(t)) { @@ -5915,10 +5915,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, return -EINVAL; } - /* Only kfunc can be release func */ - if (is_kfunc) + /* Only kfunc can be release or sleepable func */ + if (is_kfunc) { 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); + } /* check that BTF function arguments match actual types that the * verifier sees. */ @@ -6092,6 +6095,13 @@ 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; }