From patchwork Fri May 3 10:42:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiong Wang X-Patchwork-Id: 1094807 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="gCmkMzLq"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44wTK4528gz9s55 for ; Fri, 3 May 2019 20:44:24 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726396AbfECKoY (ORCPT ); Fri, 3 May 2019 06:44:24 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52353 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727491AbfECKnx (ORCPT ); Fri, 3 May 2019 06:43:53 -0400 Received: by mail-wm1-f65.google.com with SMTP id y26so1392892wma.2 for ; Fri, 03 May 2019 03:43:51 -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=URszv7/t7QfVZUhW0Uggw2iCKFbU+bZsnFS6vq2iMu0=; b=gCmkMzLq+4d8OMDZcK3SuIIpZzR7oeVaJw1sj/oswdNSztjGHDJdTDhaLkww9nT4dL 9+WJL2XdIvGLmai/O07m6j8g3hXTwNsZMYRnBXXF1s8MJImuA8YwS1bt831ocV0hlN/U PUmFXJOkD7avuNBCmmhI8yrvjZ42ErTMLpPFSpGG29YmjKwBXtK/tqFkd4dsSP/m6bgN yxDu2mD+SHVPjbp0mZJacf/wRTHoQ7WK1GzLm0FnWppH83zHw6RQvVoGXRZeE1OcqhFW 3DaLc4AvbAy0EVGveDplOuOlcsd2ANlhBjNtz9UOnO6qz9pIZ02IN0eJnemhyd/LzZdH /Zyg== 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=URszv7/t7QfVZUhW0Uggw2iCKFbU+bZsnFS6vq2iMu0=; b=RtAB+lc3SV90Bf5PSaCi8O6/jQGatfT7/KJ//iI3aTQLNkbY3SzRy8CUA/5klwp05n QQ/4Bjn+chvi2uCqS2xsgdBQKxEM0KhjA2D9zYpDE9gLbcggJ6qJX0pLlf3azDCxa1ac nadANQS93i/qfSNCe1hmP1UT/bQA6Eq0B0ajo9/tWnqZFHDaKRcMCNXbG7sVWkWQ5q8N YRc3TTqUDS/C14+tkDkuCBk92kjyaRo+u2Z/37veSczIyuW1cRiBCmLru2LTaWtjYB5v yDy4VSJIrNcd9qYGWqZDDxdsaviHIvkQxAxISzQm9PCoJW2NR71LFN/99AjNGprN1oJT fD8A== X-Gm-Message-State: APjAAAUWpCD0ZTY3fxoTFobBAEfcffwWI0pEGYsv4dYtK9uxpVNZi8Sv Xx0EIEyfQ7EqI+rHI2sADRd8Lg== X-Google-Smtp-Source: APXvYqx5/wFlr9efZAyheV4bxwliZnPxzHL3nwMdWviqU7NPlMuG8DD6eBF70unGFB1L8YoYasXbUg== X-Received: by 2002:a1c:f901:: with SMTP id x1mr5987805wmh.136.1556880230835; Fri, 03 May 2019 03:43:50 -0700 (PDT) Received: from cbtest28.netronome.com ([217.38.71.146]) by smtp.gmail.com with ESMTPSA id r29sm1716999wra.56.2019.05.03.03.43.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 03 May 2019 03:43:49 -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, Jiong Wang Subject: [PATCH v6 bpf-next 07/17] bpf: verifier: randomize high 32-bit when BPF_F_TEST_RND_HI32 is set Date: Fri, 3 May 2019 11:42:34 +0100 Message-Id: <1556880164-10689-8-git-send-email-jiong.wang@netronome.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1556880164-10689-1-git-send-email-jiong.wang@netronome.com> References: <1556880164-10689-1-git-send-email-jiong.wang@netronome.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-Id: netdev.vger.kernel.org This patch randomizes high 32-bit of a definition when BPF_F_TEST_RND_HI32 is set. It does this once the flag set no matter there is hardware zero extension support or not. Because this is a test feature and we want to deliver the most stressful test. Suggested-by: Alexei Starovoitov Signed-off-by: Jiong Wang --- kernel/bpf/verifier.c | 69 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 58 insertions(+), 11 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 999da02..31ffbef 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7648,32 +7648,79 @@ 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_ALU32_IMM(BPF_ZEXT, 0, 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_hardware_zext()) continue; - insn = insns[adj_idx]; zext_patch[0] = insn; zext_patch[1].dst_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; @@ -8533,10 +8580,10 @@ 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_hardware_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_hardware_zext() ? false : !ret; } if (ret == 0)