From owner-svn-src-head@freebsd.org Tue Jun 11 22:41:40 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6D78915C916E; Tue, 11 Jun 2019 22:41:40 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0CBE4838E5; Tue, 11 Jun 2019 22:41:40 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id DCFA58418; Tue, 11 Jun 2019 22:41:39 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5BMfd2w081248; Tue, 11 Jun 2019 22:41:39 GMT (envelope-from dougm@FreeBSD.org) Received: (from dougm@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5BMfdvp081247; Tue, 11 Jun 2019 22:41:39 GMT (envelope-from dougm@FreeBSD.org) Message-Id: <201906112241.x5BMfdvp081247@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: dougm set sender to dougm@FreeBSD.org using -f From: Doug Moore Date: Tue, 11 Jun 2019 22:41:39 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348968 - head/sys/vm X-SVN-Group: head X-SVN-Commit-Author: dougm X-SVN-Commit-Paths: head/sys/vm X-SVN-Commit-Revision: 348968 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 0CBE4838E5 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.98 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.98)[-0.981,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jun 2019 22:41:40 -0000 Author: dougm Date: Tue Jun 11 22:41:39 2019 New Revision: 348968 URL: https://svnweb.freebsd.org/changeset/base/348968 Log: To test to see if a free space is big enough compare the required length to the difference of the two offsets that define the gap, to avoid overflow, rather that adding the length to an offset and comparing that to another offset. This addresses an overflow issue reported by Peter Holm on i386. Reported by: pho Tested by: pho Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20594 Modified: head/sys/vm/vm_map.c Modified: head/sys/vm/vm_map.c ============================================================================== --- head/sys/vm/vm_map.c Tue Jun 11 22:21:29 2019 (r348967) +++ head/sys/vm/vm_map.c Tue Jun 11 22:41:39 2019 (r348968) @@ -1641,13 +1641,14 @@ vm_map_findspace(vm_map_t map, vm_offset_t start, vm_s { vm_map_entry_t llist, rlist, root, y; vm_size_t left_length; + vm_offset_t gap_end; /* * Request must fit within min/max VM address and must avoid * address wrap. */ start = MAX(start, vm_map_min(map)); - if (start + length > vm_map_max(map) || start + length < start) + if (start >= vm_map_max(map) || length > vm_map_max(map) - start) return (vm_map_max(map) - length + 1); /* Empty tree means wide open address space. */ @@ -1655,13 +1656,19 @@ vm_map_findspace(vm_map_t map, vm_offset_t start, vm_s return (start); /* - * After splay, if start comes before root node, then there - * must be a gap from start to the root. + * After splay_split, if start is within an entry, push it to the start + * of the following gap. If rlist is at the end of the gap containing + * start, save the end of that gap in gap_end to see if the gap is big + * enough; otherwise set gap_end to start skip gap-checking and move + * directly to a search of the right subtree. */ root = vm_map_splay_split(map, start, length, &llist, &rlist); - if (root != NULL) + gap_end = rlist->start; + if (root != NULL) { start = root->end; - else if (rlist != &map->header) { + if (root->right != NULL) + gap_end = start; + } else if (rlist != &map->header) { root = rlist; rlist = root->left; root->left = NULL; @@ -1672,18 +1679,9 @@ vm_map_findspace(vm_map_t map, vm_offset_t start, vm_s } vm_map_splay_merge(map, root, llist, rlist); VM_MAP_ASSERT_CONSISTENT(map); - if (start + length <= root->start) + if (length <= gap_end - start) return (start); - /* - * Root is the last node that might begin its gap before - * start, and this is the last comparison where address - * wrap might be a problem. - */ - if (root->right == NULL && - start + length <= vm_map_max(map)) - return (start); - /* With max_free, can immediately tell if no solution. */ if (root->right == NULL || length > root->right->max_free) return (vm_map_max(map) - length + 1); @@ -1800,8 +1798,8 @@ vm_map_alignspace(vm_map_t map, vm_object_t object, vm VM_MAP_ASSERT_LOCKED(map); free_addr = *addr; KASSERT(free_addr == vm_map_findspace(map, free_addr, length), - ("caller failed to provide space %d at address %p", - (int)length, (void*)free_addr)); + ("caller failed to provide space %#jx at address %p", + (uintmax_t)length, (void *)free_addr)); for (;;) { /* * At the start of every iteration, the free space at address