From patchwork Thu Jul 23 17:35:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maciej Fijalkowski X-Patchwork-Id: 1335005 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BCKNn2nkhz9sRR for ; Fri, 24 Jul 2020 03:40:25 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730203AbgGWRkY (ORCPT ); Thu, 23 Jul 2020 13:40:24 -0400 Received: from mga06.intel.com ([134.134.136.31]:56242 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730198AbgGWRkY (ORCPT ); Thu, 23 Jul 2020 13:40:24 -0400 IronPort-SDR: pT14UnaD/gDWX7q675ZyG0AQH/ZaJ8ycV8eyPw87etUIeQNttoyorIFexkjFI4rI8kaUG9Nobz CcBI0yDi/r9A== X-IronPort-AV: E=McAfee;i="6000,8403,9691"; a="212124608" X-IronPort-AV: E=Sophos;i="5.75,387,1589266800"; d="scan'208";a="212124608" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jul 2020 10:40:23 -0700 IronPort-SDR: Qduyl20cZmyPnFWt3HDKVa9lmNaetSz3kGkYlwNPCVfA636ex/SuWOwI/szok6oqiKMV1BexBp v1KdgcYqUQog== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,387,1589266800"; d="scan'208";a="462940330" Received: from ranger.igk.intel.com ([10.102.21.164]) by orsmga005.jf.intel.com with ESMTP; 23 Jul 2020 10:40:21 -0700 From: Maciej Fijalkowski To: ast@kernel.org, daniel@iogearbox.net Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, bjorn.topel@intel.com, magnus.karlsson@intel.com, Maciej Fijalkowski Subject: [PATCH v3 bpf-next 5/6] bpf: allow for tailcalls in BPF subprograms for x64 JIT Date: Thu, 23 Jul 2020 19:35:07 +0200 Message-Id: <20200723173508.62285-6-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200723173508.62285-1-maciej.fijalkowski@intel.com> References: <20200723173508.62285-1-maciej.fijalkowski@intel.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Relax verifier's restriction that was meant to forbid tailcall usage when subprog count was higher than 1. Also, do not max out the stack depth of program that utilizes tailcalls. Signed-off-by: Maciej Fijalkowski --- kernel/bpf/verifier.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0cf5e4e4af95..2e8f20875c90 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4176,10 +4176,12 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_FUNC_tail_call: if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) goto error; +#if !defined(CONFIG_X86_64) || !defined(CONFIG_BPF_JIT_ALWAYS_ON) if (env->subprog_cnt > 1) { verbose(env, "tail_calls are not allowed in programs with bpf-to-bpf calls\n"); return -EINVAL; } +#endif break; case BPF_FUNC_perf_event_read: case BPF_FUNC_perf_event_output: @@ -10290,7 +10292,9 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) * the program array. */ prog->cb_access = 1; +#if !defined(CONFIG_X86_64) || !defined(CONFIG_BPF_JIT_ALWAYS_ON) env->prog->aux->stack_depth = MAX_BPF_STACK; +#endif env->prog->aux->max_pkt_offset = MAX_PACKET_OFF; /* mark bpf_tail_call as different opcode to avoid