From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5FC27C433E6 for ; Tue, 9 Feb 2021 13:52:45 +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 CEEF664EE6 for ; Tue, 9 Feb 2021 13:52:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CEEF664EE6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57880 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9TRb-0004CY-LD for qemu-devel@archiver.kernel.org; Tue, 09 Feb 2021 08:52:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40538) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9TPW-0002La-P2 for qemu-devel@nongnu.org; Tue, 09 Feb 2021 08:50:34 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30016) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9TPU-00056i-B8 for qemu-devel@nongnu.org; Tue, 09 Feb 2021 08:50:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612878627; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bOu8XmA1JstGIOLwXAHCb6Wx895Ov4AldRwdmbikM0E=; b=bM7eUcwSYdJgFkAKieJzD9gVbiKR2xSwEDDxasXCwjtl27shiENUyiKEqrZwjgYMz2/R/6 zF7hZTjXzeGjQIUHa5l7ul98X6fVn9F9a4oBwrnv+cFD/Pc/OQqCDSgLO6r9z5nGoKasbf mr4K2LfFoq50XTo5XC+MWiu7N8M0iL4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-518-HdBGvKoKM_m2bFx4e0UC_w-1; Tue, 09 Feb 2021 08:50:25 -0500 X-MC-Unique: HdBGvKoKM_m2bFx4e0UC_w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE9E7835E21; Tue, 9 Feb 2021 13:50:23 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-141.ams2.redhat.com [10.36.113.141]) by smtp.corp.redhat.com (Postfix) with ESMTP id C647C60CCF; Tue, 9 Feb 2021 13:50:06 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v1 2/9] util/mmap-alloc: factor out calculation of the pagesize for the guard page Date: Tue, 9 Feb 2021 14:49:32 +0100 Message-Id: <20210209134939.13083-3-david@redhat.com> In-Reply-To: <20210209134939.13083-1-david@redhat.com> References: <20210209134939.13083-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=63.128.21.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Cc: Juan Quintela , Murilo Opsfelder Araujo , Cornelia Huck , Eduardo Habkost , "Michael S. Tsirkin" , Stefan Weil , David Hildenbrand , Richard Henderson , "Dr. David Alan Gilbert" , Peter Xu , Greg Kurz , Halil Pasic , Christian Borntraeger , Stefan Hajnoczi , Igor Mammedov , Thomas Huth , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Igor Kotrasinski Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Let's factor out calculating the size of the guard page and rename the variable to make it clearer that this pagesize only applies to the guard page. Reviewed-by: Peter Xu Acked-by: Murilo Opsfelder Araujo Cc: Igor Kotrasinski Signed-off-by: David Hildenbrand --- util/mmap-alloc.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 890fda6a35..8bdf1f9df8 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -82,6 +82,16 @@ size_t qemu_mempath_getpagesize(const char *mem_path) return qemu_real_host_page_size; } +static inline size_t mmap_guard_pagesize(int fd) +{ +#if defined(__powerpc64__) && defined(__linux__) + /* Mappings in the same segment must share the same page size */ + return qemu_fd_getpagesize(fd); +#else + return qemu_real_host_page_size; +#endif +} + void *qemu_ram_mmap(int fd, size_t size, size_t align, @@ -89,12 +99,12 @@ void *qemu_ram_mmap(int fd, bool shared, bool is_pmem) { + const size_t guard_pagesize = mmap_guard_pagesize(fd); int prot; int flags; int map_sync_flags = 0; int guardfd; size_t offset; - size_t pagesize; size_t total; void *guardptr; void *ptr; @@ -115,8 +125,7 @@ void *qemu_ram_mmap(int fd, * anonymous memory is OK. */ flags = MAP_PRIVATE; - pagesize = qemu_fd_getpagesize(fd); - if (fd == -1 || pagesize == qemu_real_host_page_size) { + if (fd == -1 || guard_pagesize == qemu_real_host_page_size) { guardfd = -1; flags |= MAP_ANONYMOUS; } else { @@ -125,7 +134,6 @@ void *qemu_ram_mmap(int fd, } #else guardfd = -1; - pagesize = qemu_real_host_page_size; flags = MAP_PRIVATE | MAP_ANONYMOUS; #endif @@ -137,7 +145,7 @@ void *qemu_ram_mmap(int fd, assert(is_power_of_2(align)); /* Always align to host page size */ - assert(align >= pagesize); + assert(align >= guard_pagesize); flags = MAP_FIXED; flags |= fd == -1 ? MAP_ANONYMOUS : 0; @@ -191,8 +199,8 @@ void *qemu_ram_mmap(int fd, * a guard page guarding against potential buffer overflows. */ total -= offset; - if (total > size + pagesize) { - munmap(ptr + size + pagesize, total - size - pagesize); + if (total > size + guard_pagesize) { + munmap(ptr + size + guard_pagesize, total - size - guard_pagesize); } return ptr; @@ -200,15 +208,8 @@ void *qemu_ram_mmap(int fd, void qemu_ram_munmap(int fd, void *ptr, size_t size) { - size_t pagesize; - if (ptr) { /* Unmap both the RAM block and the guard page */ -#if defined(__powerpc64__) && defined(__linux__) - pagesize = qemu_fd_getpagesize(fd); -#else - pagesize = qemu_real_host_page_size; -#endif - munmap(ptr, size + pagesize); + munmap(ptr, size + mmap_guard_pagesize(fd)); } } -- 2.29.2