From patchwork Fri Nov 23 18:34:55 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 1002506 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=codethink.co.uk Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 431lNW0lNNz9s3q for ; Sat, 24 Nov 2018 05:35:07 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395356AbeKXFUZ (ORCPT ); Sat, 24 Nov 2018 00:20:25 -0500 Received: from imap1.codethink.co.uk ([176.9.8.82]:60741 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730102AbeKXFUZ (ORCPT ); Sat, 24 Nov 2018 00:20:25 -0500 Received: from cpc118554-reig6-2-0-cust775.6-3.cable.virginm.net ([86.18.95.8] helo=xylophone.i.decadent.org.uk) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1gQGI5-0001K6-0V; Fri, 23 Nov 2018 18:34:57 +0000 Date: Fri, 23 Nov 2018 18:34:55 +0000 From: Ben Hutchings To: Alexei Starovoitov , Daniel Borkmann Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] bpf/verifier: Log instruction patching when verbose logging is enabled Message-ID: <20181123183455.qjokyt6zpa2yck6s@xylophone.i.decadent.org.uk> References: <20181123183356.5q4bu47zpj5wdufb@xylophone.i.decadent.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181123183356.5q4bu47zpj5wdufb@xylophone.i.decadent.org.uk> User-Agent: NeoMutt/20170113 (1.7.2) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org User-space does not have access to the patched eBPF code, but we need to be able to test that patches are being applied. Therefore log distinct messages for each case that requires patching. Signed-off-by: Ben Hutchings --- kernel/bpf/verifier.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4ce049cd30a3..ea4bc796e545 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5844,6 +5844,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) verbose(env, "bpf verifier is misconfigured\n"); return -EINVAL; } else if (cnt) { + verbose(env, "patching in prologue\n"); new_prog = bpf_patch_insn_data(env, 0, insn_buf, cnt); if (!new_prog) return -ENOMEM; @@ -5892,6 +5893,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) }; cnt = ARRAY_SIZE(patch); + verbose(env, + "patching in sanitization against SSB at %d\n", + i + delta); new_prog = bpf_patch_insn_data(env, i + delta, patch, cnt); if (!new_prog) return -ENOMEM; @@ -5973,6 +5977,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) } } + verbose(env, "patching explicit ctx access at %d\n", i + delta); new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); if (!new_prog) return -ENOMEM; @@ -6225,6 +6230,8 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) cnt = ARRAY_SIZE(mask_and_mod) - (is64 ? 1 : 0); } + verbose(env, "patching in divide-by-zero check at %d\n", + i + delta); new_prog = bpf_patch_insn_data(env, i + delta, patchlet, cnt); if (!new_prog) return -ENOMEM; @@ -6244,6 +6251,8 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) return -EINVAL; } + verbose(env, "patching implicit ctx access at %d\n", + i + delta); new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); if (!new_prog) return -ENOMEM; @@ -6307,6 +6316,8 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) map)->index_mask); insn_buf[2] = *insn; cnt = 3; + verbose(env, "patching in tail-call bounds check at %d", + i + delta); new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); if (!new_prog) return -ENOMEM; @@ -6342,6 +6353,8 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) return -EINVAL; } + verbose(env, "patching in map lookup at %d", + i + delta); new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); if (!new_prog)