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 ABD2EC433F5 for ; Wed, 24 Nov 2021 12:43:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343832AbhKXMqx (ORCPT ); Wed, 24 Nov 2021 07:46:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:48054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345668AbhKXMoA (ORCPT ); Wed, 24 Nov 2021 07:44:00 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CCD826140D; Wed, 24 Nov 2021 12:25:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637756753; bh=POfwsM4IEN7lbu/X6d9HU1V/T6AITThTyNT19QcwCzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uULXC7lJsntQasEaNRgBmVuMYcMys+Ne66WFMc2BjOTgubzH7R//HtBc6zK7Oik7j umWUUSE/52ZG7rhDGJDMwGNuwhOoshCfrk8hdO8nClNzfri0CRdrSnqxsD2NQ1B6Rs BcE0v6R7aKwAXIpL360DierIL0biDsVX7PvH2VDg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , "Naveen N. Rao" , Christophe Leroy , Michael Ellerman Subject: [PATCH 4.14 193/251] powerpc/bpf: Fix BPF_SUB when imm == 0x80000000 Date: Wed, 24 Nov 2021 12:57:15 +0100 Message-Id: <20211124115716.983053051@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115710.214900256@linuxfoundation.org> References: <20211124115710.214900256@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Naveen N. Rao" upstream commit 5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025 We aren't handling subtraction involving an immediate value of 0x80000000 properly. Fix the same. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy [mpe: Fold in fix from Naveen to use imm <= 32768] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com [adjust macros to account for commits 0654186510a40e and 3a181237916310] Signed-off-by: Naveen N. Rao Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/net/bpf_jit_comp64.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -359,18 +359,25 @@ static int bpf_jit_build_body(struct bpf PPC_SUB(dst_reg, dst_reg, src_reg); goto bpf_alu32_trunc; case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ - case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm >= -32768 && imm < 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ - if (BPF_OP(code) == BPF_SUB) - imm = -imm; - if (imm) { - if (imm >= -32768 && imm < 32768) - PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); - else { - PPC_LI32(b2p[TMP_REG_1], imm); - PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); - } + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm > -32768 && imm <= 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(-imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); } goto bpf_alu32_trunc; case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */