From patchwork Mon Oct 5 13:34:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Cave-Ayland X-Patchwork-Id: 303730 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CB8DC4363A for ; Mon, 5 Oct 2020 13:36:12 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B5D0B20756 for ; Mon, 5 Oct 2020 13:36:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B5D0B20756 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50616 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kPQew-000235-Sr for qemu-devel@archiver.kernel.org; Mon, 05 Oct 2020 09:36:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49498) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kPQde-0000wY-PL for qemu-devel@nongnu.org; Mon, 05 Oct 2020 09:34:50 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:35408 helo=mail.default.ilande.uk0.bigv.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kPQdc-00064Y-MA for qemu-devel@nongnu.org; Mon, 05 Oct 2020 09:34:50 -0400 Received: from host86-184-131-21.range86-184.btcentralplus.com ([86.184.131.21] helo=kentang.home) by mail.default.ilande.uk0.bigv.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kPQdV-0001q8-4G; Mon, 05 Oct 2020 14:34:44 +0100 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, pbonzini@redhat.com Date: Mon, 5 Oct 2020 14:34:34 +0100 Message-Id: <20201005133434.12614-1-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 86.184.131.21 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH] configure: don't enable ASLR for --enable-debug Windows builds X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.uk0.bigv.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.uk0.bigv.io X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Unlike other OSs it is not possible for gdb to temporarily disable ASLR when debugging executables on Windows which causes gdb to fail with memory access errors when trying to debug QEMU. Keep ASLR enabled by default on Windows via the --dynamicbase compiler flag except for --enable-debug builds when there is a clear expectation that a functioning gdb is expected at the cost of slightly less security. Signed-off-by: Mark Cave-Ayland Reviewed-by: Richard Henderson --- configure | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/configure b/configure index f46f433649..a3de75b9f8 100755 --- a/configure +++ b/configure @@ -6144,7 +6144,14 @@ fi # Use ASLR, no-SEH and DEP if available if test "$mingw32" = "yes" ; then - for flag in --dynamicbase --no-seh --nxcompat; do + flags="--no-seh --nxcompat" + + # Disable ASLR for debug builds to allow debugging with gdb + if test "$debug" = "no" ; then + flags="--dynamicbase $flags" + fi + + for flag in $flags; do if ld_has $flag ; then QEMU_LDFLAGS="-Wl,$flag $QEMU_LDFLAGS" fi