From owner-svn-src-head@freebsd.org Wed Sep 5 19:05:30 2018 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 CFB15FFA451; Wed, 5 Sep 2018 19:05:30 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 84BBF8ED1B; Wed, 5 Sep 2018 19:05:30 +0000 (UTC) (envelope-from markj@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 7B96A29D1B; Wed, 5 Sep 2018 19:05:30 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w85J5Uju007401; Wed, 5 Sep 2018 19:05:30 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w85J5UGH007400; Wed, 5 Sep 2018 19:05:30 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201809051905.w85J5UGH007400@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Wed, 5 Sep 2018 19:05:30 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r338472 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 338472 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.27 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: Wed, 05 Sep 2018 19:05:31 -0000 Author: markj Date: Wed Sep 5 19:05:30 2018 New Revision: 338472 URL: https://svnweb.freebsd.org/changeset/base/338472 Log: Correct the condition under which we allocate a terminator node. We will have last_block < blocks if the block count is divisible by BLIST_BMAP_RADIX, but a terminator node is still needed if the tree isn't balanced. In this case we were overruning the blist array by 16 bytes during initialization. While here, add a check for the invalid blocks == 0 case. PR: 231116 Reviewed by: alc, kib (previous version), Doug Moore Approved by: re (gjb) MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17020 Modified: head/sys/kern/subr_blist.c Modified: head/sys/kern/subr_blist.c ============================================================================== --- head/sys/kern/subr_blist.c Wed Sep 5 15:25:23 2018 (r338471) +++ head/sys/kern/subr_blist.c Wed Sep 5 19:05:30 2018 (r338472) @@ -224,17 +224,19 @@ blist_create(daddr_t blocks, int flags) u_daddr_t nodes, radix, skip; int digit; + if (blocks == 0) + panic("invalid block count"); + /* - * Calculate the radix and node count used for scanning. Find the last - * block that is followed by a terminator. + * Calculate the radix and node count used for scanning. */ last_block = blocks - 1; radix = BLIST_BMAP_RADIX; while (radix < blocks) { if (((last_block / radix + 1) & BLIST_META_MASK) != 0) /* - * A terminator will be added. Update last_block to the - * position just before that terminator. + * We must widen the blist to avoid partially + * filled nodes. */ last_block |= radix - 1; radix *= BLIST_META_RADIX; @@ -244,7 +246,9 @@ blist_create(daddr_t blocks, int flags) * Count the meta-nodes in the expanded tree, including the final * terminator, from the bottom level up to the root. */ - nodes = (last_block >= blocks) ? 2 : 1; + nodes = 1; + if (radix - blocks >= BLIST_BMAP_RADIX) + nodes++; last_block /= BLIST_BMAP_RADIX; while (last_block > 0) { nodes += last_block + 1;