From patchwork Fri Jul 31 00:03:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maciej Fijalkowski X-Patchwork-Id: 1339179 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 4BHnh03rC2z9sTH for ; Fri, 31 Jul 2020 10:09:04 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730904AbgGaAJC (ORCPT ); Thu, 30 Jul 2020 20:09:02 -0400 Received: from mga12.intel.com ([192.55.52.136]:31495 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730874AbgGaAI7 (ORCPT ); Thu, 30 Jul 2020 20:08:59 -0400 IronPort-SDR: m9KX8/8YqL3FNfILa0d0vw1GxPD9TTocxdyR7NsmBtXEzTBACtDnMFsGOvOGS7qKBstayzb7jW U+WoKuvBMAiw== X-IronPort-AV: E=McAfee;i="6000,8403,9698"; a="131278095" X-IronPort-AV: E=Sophos;i="5.75,416,1589266800"; d="scan'208";a="131278095" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jul 2020 17:08:58 -0700 IronPort-SDR: 6XNMhwAc4uOr1U3z63I0Dh4MveplumSh1W54/SZ05wKpqQMospM4BDt3HrCeM9H3iBP3UjLddD xIK4oJrwxGUw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,416,1589266800"; d="scan'208";a="435237893" Received: from ranger.igk.intel.com ([10.102.21.164]) by orsmga004.jf.intel.com with ESMTP; 30 Jul 2020 17:08:56 -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 v6 bpf-next 5/6] bpf: allow for tailcalls in BPF subprograms for x64 JIT Date: Fri, 31 Jul 2020 02:03:23 +0200 Message-Id: <20200731000324.2253-6-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200731000324.2253-1-maciej.fijalkowski@intel.com> References: <20200731000324.2253-1-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 96a339e24e93..fefc91f350d8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4251,10 +4251,12 @@ 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: @@ -10387,7 +10389,9 @@ 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