From patchwork Mon Mar 12 04:27:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Tobin C. Harding" X-Patchwork-Id: 884306 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@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=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tobin.cc Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=tobin.cc header.i=@tobin.cc header.b="WJ1t/ou7"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="fKwuEN/e"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4004hp6Xy1z9sRH for ; Mon, 12 Mar 2018 15:27:38 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750811AbeCLE1h (ORCPT ); Mon, 12 Mar 2018 00:27:37 -0400 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:45207 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764AbeCLE1g (ORCPT ); Mon, 12 Mar 2018 00:27:36 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 1916420E47; Mon, 12 Mar 2018 00:27:36 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute5.internal (MEProxy); Mon, 12 Mar 2018 00:27:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tobin.cc; h=cc :date:from:message-id:subject:to:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=VpjFo8u6KOeUvTmN6GDsZxaVQ85RQKupAr0HUwUmv Xo=; b=WJ1t/ou7sY4K3jAbfQXO5Ho1yQQ6ttdtBZY0FeFIFCnjmbGlt9syo2mAQ hYAHqhCTCxwtQBfRMEQvdFCDzOtqnVByUwudaHnXOaBwNV5eDx7hbag01wEvZGa+ IJv3JEvCRyHEL9SdFF1OV/EHdkbfeDqP26QSKLan+0+FCxpe5w3AbIOzD1qas+Lw mbzpwpluTJ97W3XG2JyEqBoVAVeSOTiR66Vla262ciExLt/GbY+R5ZJzAFn6/mU/ cWgvF9QSfEmQsMnbkNrtM2rNAnNM7tjLWXkbg6qvS1N4aWQJPipOgQg/Wz30/nq/ gENReAdOqOjLw0jazn5Y+9J6+as/Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:message-id:subject:to :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=VpjFo8u6KOeUvTmN6 GDsZxaVQ85RQKupAr0HUwUmvXo=; b=fKwuEN/e/iCby8F630HDVN655nQqB5XO7 fd+2wk90Rwp+8cETKWQvcPJrN7rgd7YpOpFnBMCAGwj0CQ0Na1OvV8+15gq4WBpd UPipcHKzmWDejg/8GGKLoQgmPPIcc8hlJMc24yXHhDmn1JqwGPmHaTTIbxORBaJC RQ55OJxdFv39PSQlCHxGQ2ydpSSjmtoi/MDmWPjJpvxYXFFT9XW4DCVsyEnVi8qT KRCxDChm6N6zO+5rlfRY7QzIc3h9PSEBjGT3FYuuXgeqUeVuNsEIQum//cwxM8WR 0hWzxjLm1Ixo5yM391F9qLmosZ42ZYqO6jKuoaVH+GDTZ5Nagf5RA== X-ME-Sender: Received: from localhost (124-170-217-156.dyn.iinet.net.au [124.170.217.156]) by mail.messagingengine.com (Postfix) with ESMTPA id 5E5CE24108; Mon, 12 Mar 2018 00:27:35 -0400 (EDT) From: "Tobin C. Harding" To: Rob Herring , Frank Rowand Cc: "Tobin C. Harding" , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Tycho Andersen , Kees Cook Subject: [PATCH] of: unittest: Remove VLA stack usage Date: Mon, 12 Mar 2018 15:27:23 +1100 Message-Id: <1520828843-22289-1-git-send-email-me@tobin.cc> X-Mailer: git-send-email 2.7.4 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org The kernel would like to have all stack VLA usage removed[1]. This is a test function so the execution speed is not critical. We can allocate memory for this buffer instead of using a VLA. If kmalloc() fails just return. Allocate buffer with kmalloc(). [1]: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Tobin C. Harding --- Kees is this annoying you, CC'ing you an all my VLA patches? drivers/of/unittest.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index 1991fe4319f5..38cbc343b7da 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -254,12 +254,18 @@ static void __init of_unittest_check_tree_linkage(void) static void __init of_unittest_printf_one(struct device_node *np, const char *fmt, const char *expected) { - unsigned char buf[strlen(expected)+10]; + unsigned char *buf; + int buf_size; int size, i; + buf_size = strlen(expected) + 10; + buf = kmalloc(buf_size, GFP_KERNEL); + if (!buf) + return; + /* Baseline; check conversion with a large size limit */ - memset(buf, 0xff, sizeof(buf)); - size = snprintf(buf, sizeof(buf) - 2, fmt, np); + memset(buf, 0xff, buf_size); + size = snprintf(buf, buf_size - 2, fmt, np); /* use strcmp() instead of strncmp() here to be absolutely sure strings match */ unittest((strcmp(buf, expected) == 0) && (buf[size+1] == 0xff), @@ -270,12 +276,13 @@ static void __init of_unittest_printf_one(struct device_node *np, const char *fm size++; for (i = 0; i < 2; i++, size--) { /* Clear the buffer, and make sure it works correctly still */ - memset(buf, 0xff, sizeof(buf)); + memset(buf, 0xff, buf_size); snprintf(buf, size+1, fmt, np); unittest(strncmp(buf, expected, size) == 0 && (buf[size+1] == 0xff), "snprintf failed; size=%i fmt='%s' expected='%s' rslt='%s'\n", size, fmt, expected, buf); } + kfree(buf); } static void __init of_unittest_printf(void)