From nobody Tue Feb 10 06:07:32 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520966475055835.9227755185889; Tue, 13 Mar 2018 11:41:15 -0700 (PDT) Received: from localhost ([::1]:41993 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evorG-000874-U9 for importer@patchew.org; Tue, 13 Mar 2018 14:41:10 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55570) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evnog-00006a-Rs for qemu-devel@nongnu.org; Tue, 13 Mar 2018 13:34:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evnoe-0007wT-6e for qemu-devel@nongnu.org; Tue, 13 Mar 2018 13:34:26 -0400 Received: from mout.kundenserver.de ([212.227.126.133]:46463) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1evnod-0007ug-T8 for qemu-devel@nongnu.org; Tue, 13 Mar 2018 13:34:24 -0400 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue005 [212.227.15.167]) with ESMTPSA (Nemesis) id 0MQrwA-1f49Ik2hig-00UNhW; Tue, 13 Mar 2018 18:34:08 +0100 From: Laurent Vivier To: qemu-devel@nongnu.org Date: Tue, 13 Mar 2018 18:33:50 +0100 Message-Id: <20180313173355.4468-14-laurent@vivier.eu> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180313173355.4468-1-laurent@vivier.eu> References: <20180313173355.4468-1-laurent@vivier.eu> X-Provags-ID: V03:K0:aHSO5+u4hNtcp3+AsbPjAhS8Ifuh9OuR+aBgzU+w4XFEnyttG8o 8wf9OhlWxblXLxpEP/VDnGhxJko1+tCJ4mLxABfnwq/pbkxDS9/t/O9rQqSDnqH8ydyrxDh RRf7ZPZ7OOLCTPiVWDcKJe22V/3l465D16Rjhu5oV8Qrw3yJlv6ZizfV5+0Wfw0Wj75psGL rLNtWVS5jt/b2gFZcw4Rw== X-UI-Out-Filterresults: notjunk:1;V01:K0:pdEFI8Esn1Q=:rXd8mPfM3rrbEybsH1ErnI HgKs7YXAYSWTVS86Fvh/Bvf3uqvAvFwXq3DEEOzE3Lsh2U7EvYf8CQc8avxVRtVk5UduVNjAO H5e2brYrw5hAsMOMEJ7INIjQQ5PVUJQMVR0zmZyfts8EL4MiHnh6rgeg7U5PKg+mGsHwcnT2U qK7qPFmvZiKu6OlESliNGYWmdKhld+vSa07zQC7yqfG4jSqmwotmh0qlo+zrXaFDy+7Jpz0YO Vdl5YiVp8ZD6lNRbr96v5UVKXTvX1hxTeNHgk8oM3tBCq2vCPsxydDF91HaireYkLXEdpf2hO UbpPas5MEVwGJ33B1nSkEHoTaAunz/r2+TTeVheVaD2+6Q6TNfqHYcpdx5tZKNV5nMrUpMrLO LivOtFD0u2WZyWp2/Www7cMbC1eVPL+Ezv9h66OKUB2cXnqvFQEUVMl8JfH42Rhusuz2JNPkP T7Tydapbafg6D8u4mYcn9IF84DqW7Ee+ui2gPrQCmqL7gU8IItoxupU3WBkZAHHF40XkacV3Z 1SyLeJZitvwfLpzj2VSpebtwc2psHfcOF8CRKWxENYEE4maOGwvpGNClPFNtMp0+EypvAJ681 s+/jRclHTou5a5Ci0tqoKQ/J4hBzBiJoNllNDBDzEGBzoDK4Ux39Wuqi/rSYXQjS9sU/1gmj8 WpocvbVEY3nf7VqFYBHK9iHrMX/tdZeMtbkybrtiHltw/vN/UhPh4uG5IIroYtVUMe+dt1OVt DUVJ3S8Fff8yTNXLVxYWDg3TuWPXMy86tYVnag== X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 212.227.126.133 Subject: [Qemu-devel] [PULL 13/18] linux-user: init_guest_space: Correctly handle guest_start in commpage initialization X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Luke Shumaker , Riku Voipio , Laurent Vivier Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Luke Shumaker init_guest_commpage needs to check if the mapped space, which ends at real_start+real_size overlaps with where it needs to put the commpage, which is (assuming sane qemu_host_page_size) guest_base + 0xffff000, where guest_base is real_start - guest_start. [guest_base][ 0xffff0000 ][commpage] [guest_base][guest_start][real_size] [commpage] [ real_start ][real_size] [commpage] ^ fail if this gap < 0 Since init_guest_commpage wants to do everything relative to guest_base (rather than real_start), it obviously needs to be comparing 0xffff0000 against guest_start+real_size, not just real_size. This bug has been present since 806d102141b99d4f1e55a97d68b7ea8c8ba3129f in 2012, but guest_start is usually 0, and prior to v2.11 real_size was usually much smaller than 0xffff0000, so it was uncommon for it to have made a difference. Signed-off-by: Luke Shumaker Message-Id: <20171228180814.9749-5-lukeshu@lukeshu.com> Reviewed-by: Peter Maydell Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index dcdd756908..feecbd4163 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1856,7 +1856,7 @@ unsigned long init_guest_space(unsigned long host_sta= rt, #if defined(TARGET_ARM) && !defined(TARGET_AARCH64) /* On 32-bit ARM, we need to also be able to map the commpage.= */ int valid =3D init_guest_commpage(real_start - guest_start, - real_size); + real_size + guest_start); if (valid =3D=3D 1) { break; } else if (valid =3D=3D -1) { --=20 2.14.3