From patchwork Wed Oct 26 11:12:49 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cao jin X-Patchwork-Id: 9396581 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 48DF760236 for ; Wed, 26 Oct 2016 11:11:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00E1529973 for ; Wed, 26 Oct 2016 11:11:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E9CDE29A2D; Wed, 26 Oct 2016 11:11:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B62EE29973 for ; Wed, 26 Oct 2016 11:11:25 +0000 (UTC) Received: from localhost ([::1]:33318 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzM7A-0006Ic-DB for patchwork-qemu-devel@patchwork.kernel.org; Wed, 26 Oct 2016 07:11:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzM6n-0006IS-63 for qemu-devel@nongnu.org; Wed, 26 Oct 2016 07:11:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bzM6i-0007dw-HK for qemu-devel@nongnu.org; Wed, 26 Oct 2016 07:11:01 -0400 Received: from [59.151.112.132] (port=49714 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzM6i-0007b8-0m; Wed, 26 Oct 2016 07:10:56 -0400 X-IronPort-AV: E=Sophos;i="5.22,518,1449504000"; d="scan'208";a="12341086" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 26 Oct 2016 19:10:47 +0800 Received: from G08CNEXCHPEKD03.g08.fujitsu.local (unknown [10.167.33.85]) by cn.fujitsu.com (Postfix) with ESMTP id EA690480B678; Wed, 26 Oct 2016 19:10:44 +0800 (CST) Received: from G08FNSTD140223.g08.fujitsu.local (10.167.226.69) by G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.279.2; Wed, 26 Oct 2016 19:10:44 +0800 From: Cao jin To: , Date: Wed, 26 Oct 2016 19:12:49 +0800 Message-ID: <1477480369-6125-1-git-send-email-caoj.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.1.0 MIME-Version: 1.0 X-Originating-IP: [10.167.226.69] X-yoursite-MailScanner-ID: EA690480B678.AB601 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: caoj.fnst@cn.fujitsu.com X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Subject: [Qemu-devel] [PATCH v2] util/mmap-alloc: check parameter before using 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: peter.maydell@linaro.org, thuth@redhat.com, armbru@redhat.com, mst@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Also refactor a little for readability Signed-off-by: Cao jin --- util/mmap-alloc.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 5a85aa3..a32ee53 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -61,7 +61,7 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared) #else void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); #endif - size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr; + size_t offset; void *ptr1; if (ptr == MAP_FAILED) { @@ -73,6 +73,7 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared) /* Always align to host page size */ assert(align >= getpagesize()); + offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr; ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE, MAP_FIXED | (fd == -1 ? MAP_ANONYMOUS : 0) | @@ -83,22 +84,20 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared) return MAP_FAILED; } - ptr += offset; - total -= offset; - if (offset > 0) { - munmap(ptr - offset, offset); + munmap(ptr, offset); } /* * Leave a single PROT_NONE page allocated after the RAM block, to serve as * a guard page guarding against potential buffer overflows. */ + total -= offset; if (total > size + getpagesize()) { - munmap(ptr + size + getpagesize(), total - size - getpagesize()); + munmap(ptr1 + size + getpagesize(), total - size - getpagesize()); } - return ptr; + return ptr1; } void qemu_ram_munmap(void *ptr, size_t size)