From patchwork Wed May 22 18:55:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiong Wang X-Patchwork-Id: 1103531 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=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=netronome.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="axaxDQWn"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 458MKV6rMKz9s7h for ; Thu, 23 May 2019 04:55:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729700AbfEVSz5 (ORCPT ); Wed, 22 May 2019 14:55:57 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:54628 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729685AbfEVSz5 (ORCPT ); Wed, 22 May 2019 14:55:57 -0400 Received: by mail-wm1-f68.google.com with SMTP id i3so3264106wml.4 for ; Wed, 22 May 2019 11:55:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Ncqbrt/07UxSSRx11KfiCqsSMYm+iMTRE09QQPITNZE=; b=axaxDQWnKToE0QyxZlKW0MKYmtmzujKfebY3ogIT21rp2pn1EYtxgq6GG8Isy6lsPI 3KaPwNZTMff1gGNcnxxGf/Hc+pXA29/drDgBqHTJulJ0EIJmBQ5PJkZOqql4J0gCEdNv EjxRw67zA1/vmweqPPlQ37cPgrcDzaRyS6fIntSD1C59juReHCUBzmzF08CpNwG8GwxR FTF1BizH3J0/xW+1rp2tJyzFh8mH71cAR6daPCCiHjihWNXMyIz3cedNGgUAAeJFx1f6 0QbepybanwGy1UpCwbZ1k5S8r0mmn73QBujWX7Fo1wWiEoNavtn96e9QbjwMkzKQASYe Cb0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Ncqbrt/07UxSSRx11KfiCqsSMYm+iMTRE09QQPITNZE=; b=CHw4fUYcjDwQbirfmGHmje/ffAywxr2XOLdkO5RRZ75MkH0LxorqJf4guot+af1EdR W9qZ1qyoZDjgZZKUA870hy8Zl66GZN1XBrigFg7r/deMOPIByLGVsNMQfb3ZzKNh9GJy Nvy+PjY+dN+vMTxaKngL9YNPlrPj56YOPmSe2ZTda3KiRaCyCaEDhEUxfR/okLFK2tgY F0ia2nxxY5g5OgesMU0bXC6d4hDYSXUArzu0fm4uvv3dk9gfckdyKZ2Cfsb6cE41VCAK 0MaivTPD/uiCiP08TKYDfUbOa24R0cfuBBGKx7uQXgFdCmxcROcQuf7omiX8wL36CWSl C1YA== X-Gm-Message-State: APjAAAVLxMS/efpxgS8MS47WAMWvjq9kPNXbeL9vMVvlzJsR6a3Ym2bq 9r0o+DPXwRRkfuQidw7sYZ/50A== X-Google-Smtp-Source: APXvYqyiPS8Ia/Qph5I07WpwV9NCzJovkoSkcusTXVfbRIAVxPEMXjI1FzHsqeDlP0y5U0L5aH5BhA== X-Received: by 2002:a1c:200a:: with SMTP id g10mr8841759wmg.121.1558551355598; Wed, 22 May 2019 11:55:55 -0700 (PDT) Received: from cbtest28.netronome.com ([217.38.71.146]) by smtp.gmail.com with ESMTPSA id t12sm16328801wro.2.2019.05.22.11.55.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 22 May 2019 11:55:54 -0700 (PDT) From: Jiong Wang To: alexei.starovoitov@gmail.com, daniel@iogearbox.net Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, oss-drivers@netronome.com, davem@davemloft.net, paul.burton@mips.com, udknight@gmail.com, zlim.lnx@gmail.com, illusionist.neo@gmail.com, naveen.n.rao@linux.ibm.com, sandipan@linux.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, jakub.kicinski@netronome.com, Jiong Wang Subject: [PATCH v7 bpf-next 06/16] bpf: verifier: randomize high 32-bit when BPF_F_TEST_RND_HI32 is set Date: Wed, 22 May 2019 19:55:02 +0100 Message-Id: <1558551312-17081-7-git-send-email-jiong.wang@netronome.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558551312-17081-1-git-send-email-jiong.wang@netronome.com> References: <1558551312-17081-1-git-send-email-jiong.wang@netronome.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This patch randomizes high 32-bit of a definition when BPF_F_TEST_RND_HI32 is set. Suggested-by: Alexei Starovoitov Signed-off-by: Jiong Wang --- kernel/bpf/verifier.c | 68 ++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 57 insertions(+), 11 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 560e17d..0a8cab8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7621,33 +7621,79 @@ static int opt_remove_nops(struct bpf_verifier_env *env) return 0; } -static int opt_subreg_zext_lo32(struct bpf_verifier_env *env) +static int opt_subreg_zext_lo32_rnd_hi32(struct bpf_verifier_env *env, + const union bpf_attr *attr) { + struct bpf_insn *patch, zext_patch[2], rnd_hi32_patch[4]; struct bpf_insn_aux_data *aux = env->insn_aux_data; + int i, patch_len, delta = 0, len = env->prog->len; struct bpf_insn *insns = env->prog->insnsi; - int i, delta = 0, len = env->prog->len; - struct bpf_insn zext_patch[2]; struct bpf_prog *new_prog; + bool rnd_hi32; + rnd_hi32 = attr->prog_flags & BPF_F_TEST_RND_HI32; zext_patch[1] = BPF_ZEXT_REG(0); + rnd_hi32_patch[1] = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, 0); + rnd_hi32_patch[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); + rnd_hi32_patch[3] = BPF_ALU64_REG(BPF_OR, 0, BPF_REG_AX); for (i = 0; i < len; i++) { int adj_idx = i + delta; struct bpf_insn insn; - if (!aux[adj_idx].zext_dst) + insn = insns[adj_idx]; + if (!aux[adj_idx].zext_dst) { + u8 code, class; + u32 imm_rnd; + + if (!rnd_hi32) + continue; + + code = insn.code; + class = BPF_CLASS(code); + if (insn_no_def(&insn)) + continue; + + /* NOTE: arg "reg" (the fourth one) is only used for + * BPF_STX which has been ruled out in above + * check, it is safe to pass NULL here. + */ + if (is_reg64(env, &insn, insn.dst_reg, NULL, DST_OP)) { + if (class == BPF_LD && + BPF_MODE(code) == BPF_IMM) + i++; + continue; + } + + /* ctx load could be transformed into wider load. */ + if (class == BPF_LDX && + aux[adj_idx].ptr_type == PTR_TO_CTX) + continue; + + imm_rnd = get_random_int(); + rnd_hi32_patch[0] = insn; + rnd_hi32_patch[1].imm = imm_rnd; + rnd_hi32_patch[3].dst_reg = insn.dst_reg; + patch = rnd_hi32_patch; + patch_len = 4; + goto apply_patch_buffer; + } + + if (!bpf_jit_needs_zext()) continue; - insn = insns[adj_idx]; zext_patch[0] = insn; zext_patch[1].dst_reg = insn.dst_reg; zext_patch[1].src_reg = insn.dst_reg; - new_prog = bpf_patch_insn_data(env, adj_idx, zext_patch, 2); + patch = zext_patch; + patch_len = 2; +apply_patch_buffer: + new_prog = bpf_patch_insn_data(env, adj_idx, patch, patch_len); if (!new_prog) return -ENOMEM; env->prog = new_prog; insns = new_prog->insnsi; aux = env->insn_aux_data; - delta += 2; + delta += patch_len - 1; } return 0; @@ -8507,10 +8553,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, /* do 32-bit optimization after insn patching has done so those patched * insns could be handled correctly. */ - if (ret == 0 && bpf_jit_needs_zext() && - !bpf_prog_is_dev_bound(env->prog->aux)) { - ret = opt_subreg_zext_lo32(env); - env->prog->aux->verifier_zext = !ret; + if (ret == 0 && !bpf_prog_is_dev_bound(env->prog->aux)) { + ret = opt_subreg_zext_lo32_rnd_hi32(env, attr); + env->prog->aux->verifier_zext = bpf_jit_needs_zext() ? !ret + : false; } if (ret == 0)