FreeBSD The Power to Serve

FreeBSD 7.4-RELEASE Release Notes

The FreeBSD Project

$FreeBSD: stable/7/release/doc/en_US.ISO8859-1/relnotes/article.sgml 219008 2011-02-24 19:22:59Z hrs $

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The release notes for FreeBSD 7.4-RELEASE contain a summary of the changes made to the FreeBSD base system on the 7.4-STABLE development line. This document lists applicable security advisories that were issued since the last release, as well as significant changes to the FreeBSD kernel and userland. Some brief remarks on upgrading are also presented.

1 Introduction

This document contains the release notes for FreeBSD 7.4-RELEASE. It describes recently added, changed, or deleted features of FreeBSD. It also provides some notes on upgrading from previous versions of FreeBSD.

This distribution of FreeBSD 7.4-RELEASE is a release distribution. It can be found at or any of its mirrors. More information on obtaining this (or other) release distributions of FreeBSD can be found in the “Obtaining FreeBSD” appendix to the FreeBSD Handbook.

All users are encouraged to consult the release errata before installing FreeBSD. The errata document is updated with “late-breaking” information discovered late in the release cycle or after the release. Typically, it contains information on known bugs, security advisories, and corrections to documentation. An up-to-date copy of the errata for FreeBSD 7.4-RELEASE can be found on the FreeBSD Web site.

2 What's New

This section describes the most user-visible new or changed features in FreeBSD since 7.3-RELEASE.

Typical release note items document recent security advisories issued after 7.3-RELEASE, new drivers or hardware support, new commands or options, major bug fixes, or contributed software upgrades. They may also list changes to major ports/packages or release engineering practices. Clearly the release notes cannot list every single change made to FreeBSD between releases; this document focuses primarily on security advisories, user-visible changes, and major architectural improvements.

2.1 Security Advisories

Problems described in the following security advisories have been fixed. For more information, consult the individual advisories available from

Advisory Date Topic
SA-10:08.bzip2 20 September 2010

Integer overflow in bzip2 decompression

SA-10:09.pseudofs 10 October 2010

Spurious mutex unlock

SA-10:10.openssl 29 November 2010

OpenSSL multiple vulnerabilities

2.2 Kernel Changes

[sparc64] FreeBSD/sparc64 now supports reservation-based physical memory allocation which provides better performance.

[sparc64] FreeBSD/sparc64 now supports UltraSPARC IV, IV+, and SPARC64 V CPUs.

The alq(9) support has been improved. The alq_writen() and alq_getn() KPIs have been extended to support variable length messages, which is enabled at ALQ creation time depending on the arguments passed to alq_open(). Also, the ALQ_NOACTIVATE and ALQ_ORDERED flags have been added to allow ALQ consumers to have more control over I/O scheduling and resource acquisition respectively. These extensions are fully backward compatible.

The alq(9) support is now provided as a kernel module alq.ko.

The FreeBSD memguard(9) framework has been improved to make it able to detect use-after-free of allocated memories over a longer time. For more details, see memguard(9) manual page.

The following sysctl(8) variables have been added: vm.kmem_map_size for the current kmem map size and vm.kmem_map_free for largest contiguous free range in kmem map.[r213554, r213556, r213560]

2.2.1 Hardware Support

[amd64, i386] The ichwd(4) driver now supports Intel NM10 Express chipset watchdog timer.

[amd64, i386] The qpi(4) pseudo bus driver has been added. This supports extra PCI buses on Intel QPI chipsets where various hardware such as memory controllers for each socket is connected. Multimedia Support

The acpi_video(4) driver has been updated. LCD brightness control notify handler has been implemented.

The acpi_sony(4) helper driver now supports default display brightness, wired LAN power, and bass gain. Network Interface Support

The alc(4) driver now supports Atheros AR8151/AR8152 PCIe Gigabit/Fast Ethernet controllers.

The TX interrupt moderation timer in the alc(4) driver has been reduced from 50ms to 1ms. The 50ms timer resulted in a poor UDP performance.

The bge(4) driver now supports BCM5718 x2 PCI Express dual-port gigabit Ethernet controller family. This family is the successor to the BCM5714/BCM5715 family and supports IPv4/IPv6 checksum offloading, TSO, VLAN hardware tagging, jumbo frames, MSI/MSIX, IOV, RSS and TSS. The current version of the driver supports all hardware features except IOV and RSS/TSS.

The bge(4) driver now supports hardware MAC statistics in controller's internal memory for BCM5705 or newer Broadcom controllers. These counters can be accessed via sysctl(8) variable dev.bge.N.stats.* and provide useful information to diagnose driver issues.

A long-standing bug of ASF heartbeat sending in the bge(4) driver has been fixed.

UDP checksum offloading in the bge(4) driver has been disabled by default. This is because Broadcom controllers have a bug which can generate UDP datagrams with checksum value 0 when TX UDP checksum offloading is enabled. The checksum offloading can be enabled by using the following loader tunable:


A bug in the bge(4) driver which prevented TSO from working in BCM57780 has been fixed.

A bug in the bge(4) driver that could lead to poor performance on a system with more than 4 GB RAM has been fixed. The cause was that all of Broadcom controllers except the BCM5755 and later have a bug in 4 GB-boundary DMA processing and used the bounce buffer in an inefficient way.

The cxgb(4) driver now supports hardware filtering based on inspection of L2/L3/L4 headers. Filtering based on source IP address, destination IP address, source port number, destination port number, 802.1q VLAN frame tag, UDP, TCP, and MAC address is possible. The configuration can be done by the cxgbtool(8) utility. Note that cxgbtool(8) is in src/usr.sbin/cxgbtool but not compiled by default.

The em(4) driver has been updated to version 7.1.9.

The em(4) and igb(4) drivers now provide statistics counters as sysctl(8) MIB objects.

The fxp(4) driver now exports the hardware MAC statistics via sysctl(8) variables.

The fxp(4) driver now supports TSO over VLAN on i82550 and i82551 controllers.

The igb(4) driver has been updated to version 2.0.7.

The miibus(4) has been rewritten for the generic IEEE 802.3 annex 31B full duplex flow control support. The alc(4), bge(4), bce(4), cas(4), fxp(4), gem(4), jme(4), msk(4), nfe(4), re(4), stge(4), and xl(4) drivers along with atphy(4), bmtphy(4), brgphy(4), e1000phy(4), gentbi(4), inphy(4), ip1000phy(4), jmphy(4), nsgphy(4), nsphyter(4), and rgephy(4) have been updated to support flow control via this facility.

The msk(4) driver has been improved:

  • It now supports 88E8059 (Marvell Yukon Optima) devices.

  • A rudimentary interrupt moderation with programmable countdown timer register has been implemented. The default parameter of the holdoff time is 100us and this can be changed via sysctl variable dev.mskc.0.int_holdoff. Note that the interrupt moderation is shared resource on a dual-port controllers and it is impossible to use separate interrupt moderation values for each port.

A bug in the mxge(4) driver that prevented TSO from working has been fixed.

The nfe(4) driver now supports WoL (Wake on LAN).

The re(4) driver now uses 2048 as PCIe Maximum Read Request Size. This improves bulk transfer performance.

The re(4) driver now supports 64-bit DMA addressing for RTL810xE/RTL8168/RTL8111 PCIe controllers.

The re(4) driver now supports hardware interrupt moderation of TX completion interrupts on RTL8169/RTL8168 controllers.

The rl(4) driver now supports WoL (Wake on LAN) on RTL8139B or newer controllers.

The rl(4) driver now supports a device hint to change a way of register access. Although some newer RTL8139 controllers support memory-mapped register access, it is difficult to detect the support automatically. For this reason the driver uses I/O mapping by default and provides the following device hint. If it is set to 0, the driver uses memory mapping for register access.


Note that the default value is 1.

The rl(4) driver has improved interrupt handling. It now has better TX performance under high RX load.

The sk(4) driver now disables TX checksum offloading by default. This is because some revisions of the Yukon controller generate corrupted frames. The checksum offloading can be enabled manually by using txcsum option in the ifconfig(8) utility.

A bug in the sk(4) driver has been fixed. It did not program the station address for Yukon controllers and overriding the station address with ifconfig(8) was not possible.

The sge(4) driver for Silicon Integrated Systems SiS190/191 Fast/Gigabit Ethernet has been added. This supports TSO and TSO over VLAN.

The sis(4) driver now supports WoL (Wake on LAN) on NS DP8315 controller.

A tunable dev.sis.N.manual_pad for the sis(4) driver has been added. This controls whether padding with 0x00 for short frames is done by CPU, rather than the controller. The reason why this tunable has been added is that NS DP83815/DP83816 pads them with 0xff though RFC 1042 specifies it should be 0x00. The tunable is disabled by default, which means padding with 0xff is used because padding with 0x00 by software needs extra CPU cycles. Enabling manual_pad, by setting this sysctl(8) variable to a non-zero value, forces the use of software padding.

The ste(4) driver now supports a device hint to change the device register access mode. The driver uses memory-mapped register access by default, but this caused stability problems with some old IC Plus Corp (formerly Sundace) controllers. The following device hint makes the driver use I/O mapping for register access:


The xl(4) driver now supports WoL (Wake on LAN). Note that not all controllers support this functionality and some need an additional remote wakeup cable.

2.2.2 Network Protocols

An issue in the carp(4) pseudo interface and linkstate changes of the underlying interfaces has been fixed. This happened when a carp(4) interface was created before the underlying interface and its linkstate became UP.

A new loader tunable has been added. It specifies the default value of send interface queue length. The default value for this parameter is 50.

The FreeBSD NFS subsystem now supports a timeout for the negative name cache entries in the client. This avoids a bogus negative name cache entry from persisting forever when another client creates an entry with the same name within the same NFS server time of day clock tick. A system-wide sysctl(8) sysctl variable vfs.nfs.negative_name_timeout can be used to adjust the timeout. Setting this variable to 0 disables negative name caching.

A new netgraph(4) node ng_patch(4) has been added. This performs data modification of packets passing through. Modifications are restricted to a subset of C language operations on unsigned integers of 8, 16, 32 or 64-bit size.

The TCP initial window increase in RFC 3390 which can be controlled by a sysctl(8) variable net.inet.tcp.rfc3390 now reduces the congestion window to the restart window if a TCP connection has been idle for one retransmit timeout or more. For more details, see RFC 5681 Section 4.1.

A bug in FreeBSD TCP Path MTU discovery which could lead to a wrong calculation for an MTU smaller than 256 octets has been fixed. Note that this bug did not affect MTUs equal to or larger than 256 octets.

The siftr(4), Statistical Information For TCP Research (SIFTR) kernel module has been added. This is a facility that logs a range of statistics on active TCP connections to a log file. It provides the ability to make highly granular measurements of TCP connection state, aimed at system administrators, developers and researchers.

The FreeBSD TCP reassembly implementation has been improved. A long-standing accounting bug affecting SMP systems has been fixed and the net.inet.tcp.reass.maxqlen sysctl(8) variable has been retired in favor of a per-connection dynamic limit based on the receive socket buffer size. FreeBSD receivers now handle packet loss (particularly losses caused by queue overflows) significantly better than before which improves connection throughput.

The tun(4) pseudo interface driver now supports explicit UP/DOWN linkstate.

The vlan(4) pseudo interface now supports TSO (TCP Segmentation Offloading). The capability flag is named as IFCAP_VLAN_HWTSO and it is separated from IFCAP_VLAN_HWTAGGING. The age(4), alc(4), ale(4), bce(4), bge(4), cxgb(4), jme(4), re(4), and mxge(4) driver support this feature.

2.2.3 Disks and Storage

The arcmsr(4) driver has been updated to version

The ata(4) driver now supports spindown facility of ATA disks. The atacontrol(8) utility has a new subcommand spindown to support this from userland.

The gconcat(8) GEOM class now supports kernel crash dump. The dumping is performed to the component where a dump partition begins.

The gmultipath(8) utility now supports destroy, rotate, getactive commands.

The ispfw(4), the firmware for isp(4) driver has been added.

The twa(4) driver has been updated. The version number is

2.2.4 File Systems

The inode number handling in ffs(7) file system is now unsigned. Previously some large inode numbers can be treated as negative, and this issue shows up at file systems with the size of more than 16Tb in 16k block case. The newfs(8) utility never create a file system with more than 2^32 inodes by cutting back on the number of inodes per cylinder group if necessary to stay under the limit.

A possible deadlock of zfs receive has been fixed.

2.3 Userland Changes

The arp(8) utility has been improved. It now runs faster even when a single interface has a number of aliases.

A bug in the b64decode(1) utility that prevented an -r option from handling arbitrary breaks in a base64 encoded string has been fixed.

The chgrp(1) and chown(8) now support a -x flag to make it not traverse across multiple mount points for the recursive operation.

The cp(1) now supports a -x flag to make it not traverse across multiple mount points for the recursive operation.

The dhclient(8) utility now reports a reason for exiting and the 10-second period in which the dhclient(8) ignores routing messages has been changed to start just after dhclient-script starts instead of just after it finished. This change fixes a symptom that dhclient(8) silently exits under a certain condition.

A bug in find(1) utility has been fixed. An option -newerXB was interpreted as the same as -newerXm.

The tftp(1) and tftpd(8) utilities have been improved for better interoperability and they now support RFC 1350, 2347, 2348, 2349, and 3617.

An accuracy issue in the jn(3) and jnf(3) functions in libm has been fixed.

The indent(1) utility now supports a -ta flag to treat all _t-suffixed identifiers as types.

The -p option in the mount(8) utility now displays the rw mount option correctly as in the fstab(5) format.

The ncal(1) utility has been updated. The option -b has been replaced with -C and -B number. Options -3 to show previous, current and next month, and -A number to show months after current month have been added. The option -m N YYYY now prints only the month, not the whole year.

An issue in the newfs(8) utility has been fixed. A UFS1 file system created with 64KB blocksize was incorrectly recognized as one with a broken superblock. This is because the FreeBSD kernel checks a partition first for a UFS2 superblock at 64KB offset while it is possible that a UFS1 file systems with 64KB blocksize has an alternative superblock at the same location. For example, a file system created by newfs -U -O 1 -b 65536 -f 8192 could lead to this symptom.

The newsyslog(8) utility does not consider non-existence of a PID file as an error now. A new flag -P reverts it to the old behavior.

The newsyslog(8) utility now supports an -S pidfile option to override the default syslogd(8) PID file.

The pmcstat(8) utility now supports a file and a network socket as a top source. A new option -O filename specifies to send log output to filename, and another new option -R filename specifies to receive events from filename. For a socket, the filename is in a form of ipaddr:port. This allows top monitoring over TCP on a system with no local symbols, for example.

The powerd(8) utility now supports an -m freq and -M freq to control the minimum and maximum frequency, respectively.

The ruptime(1) utility now displays hostnames longer than 12 characters.

The stat(1) utility now supports %Sf output specifier to display the file flags symbolically.

The sysctl(8) utility now supports a -i flag to ignore failures while retrieving individual OIDs. This allows the same list of OIDs to be passed to sysctl(8) across different systems where particular OIDs may not exist, and still get as much information as possible from them.

2.3.1 /etc/rc.d Scripts

The rc.conf(5) now supports a firewall_coscripts variable. This should contain a list of commands which should be executed after firewall starts or stops.

The rc.d/tmp script now uses a unique directory name prefixed with /tmp/.diskless instead of /tmp/.diskless itself. This fixes an issue when /tmp/.diskless exists before the script runs.

2.4 Contributed Software

ISC BIND has been updated to version 9.4-ESV-R4.

The GNU cpio(1) program has been updated to version 2.8.

The less(1) program has been updated to version v436.

The netcat program has been updated to version 4.8.

OpenSSL has been updated to version 0.9.8q.

The tcsh(1) program has been updated to version 6.17.00.

The timezone database has been updated to the tzdata2010o release.

2.5 Release Engineering and Integration

The sysinstall(8) utility now uses the following numbers for default and minimum partition sizes: 1GB for /, 4GB for /var, and 1GB for /tmp.

The supported version of the GNOME desktop environment (x11/gnome2) has been updated to 2.32.1.

The supported version of the KDE desktop environment (x11/kde4) has been updated to 4.5.5.

3 Upgrading from previous releases of FreeBSD

[amd64, i386] Beginning with FreeBSD 6.2-RELEASE, binary upgrades between RELEASE versions (and snapshots of the various security branches) are supported using the freebsd-update(8) utility. The binary upgrade procedure will update unmodified userland utilities, as well as unmodified GENERIC or SMP kernels distributed as a part of an official FreeBSD release. The freebsd-update(8) utility requires that the host being upgraded has Internet connectivity.

An older form of binary upgrade is supported through the Upgrade option from the main sysinstall(8) menu on CDROM distribution media. This type of binary upgrade may be useful on non-i386, non-amd64 machines or on systems with no Internet connectivity.

Source-based upgrades (those based on recompiling the FreeBSD base system from source code) from previous versions are supported, according to the instructions in /usr/src/UPDATING.

Important: Upgrading FreeBSD should, of course, only be attempted after backing up all data and configuration files.

This file, and other release-related documents, can be downloaded from

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For questions about this documentation, e-mail <>.

Last modified on: May 15, 2021 by Allan Jude