From patchwork Wed May 1 14:43:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiong Wang X-Patchwork-Id: 1093722 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=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="M+FIjdbG"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44vLlT6k3Nz9s9y for ; Thu, 2 May 2019 00:44:53 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726936AbfEAOoR (ORCPT ); Wed, 1 May 2019 10:44:17 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:33114 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726831AbfEAOoP (ORCPT ); Wed, 1 May 2019 10:44:15 -0400 Received: by mail-wr1-f65.google.com with SMTP id e28so1770659wra.0 for ; Wed, 01 May 2019 07:44:13 -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=5gmdeCiumoo/+nRb5YIHgrhrVRpVHEnPYiT7ekQtPGI=; b=M+FIjdbGTZ1NOQyz89Sh4H79MO5GYfgMBj1x9D5597WEGpk/43BjKeLcBOet9CZZkh uyQYEFr3FXKrnItTOjsbV+OohdO9LckTv+XVI2BGgXFSMVi9Wp4zLQfATu62QB+OiZWV 1wywX1Yq/5FHj6JS9OzCEOV5+DlcIGKeGgQS/IxP6FKf0z+OkPRmAtHkwr1JUHV6dutI 1TCAoJlyWsmnIPTDPWwEFVxgMjVPHubRRKUUruFtgiCCkoi6dUNXbHSD72aElmo+76/Q 4jJ2AgPG5QzrNp4aVVur2pwgJDcXYr+BI8RQm5E2UCZuzLLLHb0nVR5rghkkOzOiWkjY tiUg== 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=5gmdeCiumoo/+nRb5YIHgrhrVRpVHEnPYiT7ekQtPGI=; b=ngs311uW5nW6zIB3b3mvsXyvJVF0Ofh3oyQ1YO/MzI2B4TLJc56nVkgRlpnFInptw+ NeCmUGzb6wUe2yIZ9YR+nj78LSMdMjpGeXOgynce2R9qwyeQRhMx8iNV30PPg6fQ+vzT L4FADQgwphcirtqBUr1LUpyBPjoPCW1XQPS7tX7lVySLVs4iOoFFmahm4QZgouj+6jX6 0p1oAvni7l7PwIFFIpGEaCXz9V9vbJ7DQBXI2gFSvR33t51FMbNtch+nLPJyd8gq1Nag gUfqXewDtKjPqCS36Wf8YlBAZb3f6w0T9nTHH8SpS+rYzq0krL1DJ7zehJTn+bbzncMV BOFg== X-Gm-Message-State: APjAAAVXfB1rYKVV2ErFsOknH5hvirjbP5QMT/Rkvdf3OX9J6eHxG7Cj MW2OmpiNh/qZPrYsgv15j2ZXfQ== X-Google-Smtp-Source: APXvYqyB+dZRD1cCmcincSoQ/vVlb5zboKvqC7seyejLkJX0mzXxVCjnptfvaSJ3JtihB0m62QI+0A== X-Received: by 2002:adf:dd12:: with SMTP id a18mr28127132wrm.188.1556721852933; Wed, 01 May 2019 07:44:12 -0700 (PDT) Received: from cbtest28.netronome.com ([217.38.71.146]) by smtp.gmail.com with ESMTPSA id g10sm36164976wrq.2.2019.05.01.07.44.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 01 May 2019 07:44:12 -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 v5 bpf-next 03/17] bpf: verifier: mark patched-insn with sub-register zext flag Date: Wed, 1 May 2019 15:43:48 +0100 Message-Id: <1556721842-29836-4-git-send-email-jiong.wang@netronome.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1556721842-29836-1-git-send-email-jiong.wang@netronome.com> References: <1556721842-29836-1-git-send-email-jiong.wang@netronome.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Patched insns do not go through generic verification, therefore doesn't has zero extension information collected during insn walking. We don't bother analyze them at the moment, for any sub-register def comes from them, just conservatively mark it as needing zero extension. Signed-off-by: Jiong Wang --- kernel/bpf/verifier.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6e62cc8..b75913c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1303,6 +1303,24 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn, return true; } +/* Return TRUE if INSN doesn't have explicit value define. */ +static bool insn_no_def(struct bpf_insn *insn) +{ + u8 class = BPF_CLASS(insn->code); + + return (class == BPF_JMP || class == BPF_JMP32 || + class == BPF_STX || class == BPF_ST); +} + +/* Return TRUE if INSN has defined any 32-bit value explicitly. */ +static bool insn_has_def32(struct bpf_verifier_env *env, struct bpf_insn *insn) +{ + if (insn_no_def(insn)) + return false; + + return !is_reg64(env, insn, insn->dst_reg, NULL, DST_OP); +} + static void mark_insn_zext(struct bpf_verifier_env *env, struct bpf_reg_state *reg) { @@ -7306,14 +7324,23 @@ static void convert_pseudo_ld_imm64(struct bpf_verifier_env *env) * insni[off, off + cnt). Adjust corresponding insn_aux_data by copying * [0, off) and [off, end) to new locations, so the patched range stays zero */ -static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, - u32 off, u32 cnt) +static int adjust_insn_aux_data(struct bpf_verifier_env *env, + struct bpf_prog *new_prog, u32 off, u32 cnt) { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + struct bpf_insn *insn = new_prog->insnsi; + u32 prog_len; int i; + /* aux info at OFF always needs adjustment, no matter fast path + * (cnt == 1) is taken or not. There is no guarantee INSN at OFF is the + * original insn at old prog. + */ + old_data[off].zext_dst = insn_has_def32(env, insn + off + cnt - 1); + if (cnt == 1) return 0; + prog_len = new_prog->len; new_data = vzalloc(array_size(prog_len, sizeof(struct bpf_insn_aux_data))); if (!new_data) @@ -7321,8 +7348,10 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); - for (i = off; i < off + cnt - 1; i++) + for (i = off; i < off + cnt - 1; i++) { new_data[i].seen = true; + new_data[i].zext_dst = insn_has_def32(env, insn + i); + } env->insn_aux_data = new_data; vfree(old_data); return 0; @@ -7355,7 +7384,7 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of env->insn_aux_data[off].orig_idx); return NULL; } - if (adjust_insn_aux_data(env, new_prog->len, off, len)) + if (adjust_insn_aux_data(env, new_prog, off, len)) return NULL; adjust_subprog_starts(env, off, len); return new_prog;