From patchwork Mon Sep 14 10:31:44 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 517342 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id EB03E140770 for ; Mon, 14 Sep 2015 20:32:08 +1000 (AEST) Received: from localhost ([::1]:39635 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbR3P-0007OP-2v for incoming@patchwork.ozlabs.org; Mon, 14 Sep 2015 06:32:07 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48200) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbR3A-00077O-34 for qemu-devel@nongnu.org; Mon, 14 Sep 2015 06:31:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZbR36-0003GC-U9 for qemu-devel@nongnu.org; Mon, 14 Sep 2015 06:31:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51954) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbR36-0003G7-Pb for qemu-devel@nongnu.org; Mon, 14 Sep 2015 06:31:48 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 288EAC0B9184; Mon, 14 Sep 2015 10:31:48 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-112-65.ams2.redhat.com [10.36.112.65]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t8EAVkZQ025043; Mon, 14 Sep 2015 06:31:47 -0400 From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 14 Sep 2015 12:31:44 +0200 Message-Id: <1442226704-29349-1-git-send-email-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: riku.voipio@iki.fi Subject: [Qemu-devel] [PATCH] linux-user: assert that target_mprotect cannot fail X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org All error conditions that target_mprotect checks are also checked by target_mmap. EACCESS cannot happen because we are just removing PROT_WRITE. ENOMEM should not happen because we are modifying a whole VMA (and we have bigger problems anyway if it happens). Fixes a Coverity false positive, where Coverity complains about target_mprotect's return value being passed to tb_invalidate_phys_range. Signed-off-by: Paolo Bonzini --- linux-user/mmap.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/linux-user/mmap.c b/linux-user/mmap.c index b2126c7..5606bcd 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -514,10 +514,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, goto fail; if (!(prot & PROT_WRITE)) { ret = target_mprotect(start, len, prot); - if (ret != 0) { - start = ret; - goto the_end; - } + assert(ret == 0); } goto the_end; }