From patchwork Wed Jul 11 09:32:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 942394 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="UsQr01y1"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41QYkv2QSMz9s0n for ; Wed, 11 Jul 2018 19:32:39 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732472AbeGKJgC (ORCPT ); Wed, 11 Jul 2018 05:36:02 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:36884 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726368AbeGKJgC (ORCPT ); Wed, 11 Jul 2018 05:36:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5cAPcdNZ3Yc2Bpf+XHIdTxn+MKgE+8U3a/ag9W79nME=; b=UsQr01y16CWP9L+7HVu6aqE1Eg lk1WSkRSl5Zdfa9r/u8PZVwhvnuYMpjAPKiOg9lubcmN8gOZF1iMuc5d13wBW1GvYXG9lnCnx/156 IpqpK0T0yGgOgfjqThzL0FwekBtsN0nhb9bXOB8+JMcJibWJJAzcEAyZ6g1Sb/xhpcdM=; Received: from e0022681537dd.dyn.armlinux.org.uk ([2001:4d48:ad52:3201:222:68ff:fe15:37dd]:36374 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1fdBU5-00008i-PQ; Wed, 11 Jul 2018 10:32:29 +0100 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.82_1-5b7a7c0-XX) (envelope-from ) id 1fdBU4-0001Jh-2m; Wed, 11 Jul 2018 10:32:28 +0100 In-Reply-To: <20180711093033.GP17271@n2100.armlinux.org.uk> References: <20180711093033.GP17271@n2100.armlinux.org.uk> From: Russell King To: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Daniel Borkmann Subject: [PATCH net-next v2 12/14] ARM: net: bpf: avoid reloading 'array' MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Wed, 11 Jul 2018 10:32:28 +0100 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Rearranging the order of the initial tail call code a little allows is to avoid reloading the 'array' pointer. Signed-off-by: Russell King --- arch/arm/net/bpf_jit_32.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 0a8b3d0903c4..f0cad9692952 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -1064,16 +1064,16 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) BUILD_BUG_ON(offsetof(struct bpf_array, map.max_entries) > ARM_INST_LDST__IMM12); off = offsetof(struct bpf_array, map.max_entries); - /* array->map.max_entries */ - r_array = arm_bpf_get_reg32(r2[1], tmp2[1], ctx); - emit(ARM_LDR_I(tmp[1], r_array, off), ctx); + r_array = arm_bpf_get_reg32(r2[1], tmp2[0], ctx); /* index is 32-bit for arrays */ r_index = arm_bpf_get_reg32(r3[1], tmp2[1], ctx); + /* array->map.max_entries */ + emit(ARM_LDR_I(tmp[1], r_array, off), ctx); /* index >= array->map.max_entries */ emit(ARM_CMP_R(r_index, tmp[1]), ctx); _emit(ARM_COND_CS, ARM_B(jmp_offset), ctx); - /* tmp2[1] = index */ + /* tmp2[0] = array, tmp2[1] = index */ /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) * goto out; @@ -1095,7 +1095,6 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx) */ BUILD_BUG_ON(imm8m(offsetof(struct bpf_array, ptrs)) < 0); off = imm8m(offsetof(struct bpf_array, ptrs)); - r_array = arm_bpf_get_reg32(r2[1], tmp2[0], ctx); emit(ARM_ADD_I(tmp[1], r_array, off), ctx); emit(ARM_LDR_R_SI(tmp[1], tmp[1], r_index, SRTYPE_ASL, 2), ctx); emit(ARM_CMP_I(tmp[1], 0), ctx);