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 3A896C433E0 for ; Fri, 19 Mar 2021 10:17:56 +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 BA09164EF6 for ; Fri, 19 Mar 2021 10:17:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA09164EF6 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]:55246 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lNCCY-0005n9-Nb for qemu-devel@archiver.kernel.org; Fri, 19 Mar 2021 06:17:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47760) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lNC8J-00013t-Sw for qemu-devel@nongnu.org; Fri, 19 Mar 2021 06:13:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:24726) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lNC8H-0000AD-Vl for qemu-devel@nongnu.org; Fri, 19 Mar 2021 06:13:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616148809; 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=W2xadBhOlctA+eFTSVDngodlBQX81CnvqOgmN6nNNlI=; b=Z/xVkXq4M2tKtz3N6SAg6LiL/FNuMb9OFQBLoSz6nnVT+efNlQl11JACgUviywMhy4PZ9V NNsEK0jhaSwV+HDIxvXvwQxSHD/vvZvceN+lYL9yNjoKX7+Lwz2lyq0AOtbYMv2JjVEynA Cds7EGnZLLdmKQQp4Gcy4w+ImXEjjFU= 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-172-Fgo1wcwNPMORSNnvKg_FUg-1; Fri, 19 Mar 2021 06:13:27 -0400 X-MC-Unique: Fgo1wcwNPMORSNnvKg_FUg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 426829CC01; Fri, 19 Mar 2021 10:13:26 +0000 (UTC) Received: from t480s.redhat.com (ovpn-112-11.ams2.redhat.com [10.36.112.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9B47B10013C1; Fri, 19 Mar 2021 10:13:10 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v4 04/14] util/mmap-alloc: Factor out calculation of the pagesize for the guard page Date: Fri, 19 Mar 2021 11:12:20 +0100 Message-Id: <20210319101230.21531-5-david@redhat.com> In-Reply-To: <20210319101230.21531-1-david@redhat.com> References: <20210319101230.21531-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.249, 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: Marcel Apfelbaum , Murilo Opsfelder Araujo , Igor Kotrasinski , Eduardo Habkost , "Michael S. Tsirkin" , David Hildenbrand , Richard Henderson , "Dr. David Alan Gilbert" , Peter Xu , Greg Kurz , Stefan Hajnoczi , Igor Mammedov , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Markus Armbruster 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 e6fa8b598b..24854064b4 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, @@ -90,12 +100,12 @@ void *qemu_ram_mmap(int fd, bool is_pmem, off_t map_offset) { + 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; @@ -116,8 +126,7 @@ 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 { @@ -126,7 +135,6 @@ void *qemu_ram_mmap(int fd, } #else guardfd = -1; - pagesize = qemu_real_host_page_size; flags = MAP_PRIVATE | MAP_ANONYMOUS; #endif @@ -138,7 +146,7 @@ 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; @@ -193,8 +201,8 @@ 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; @@ -202,15 +210,8 @@ 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