John Polstra 719077d1be Fix a bug in lseek which caused the loader to fail on some gzipped
kernels.  The error message was "elf_loadexec: cannot seek".

Libstand maintains a read-ahead buffer for each open file, so that
it can read in chunks of 512 bytes for greater efficiency.  When
the loader tries to lseek forward in a file by a small amount, it
sometimes happens that the target file offset is already in the
read-ahead buffer.  But the lseek code simply discarded the contents
of that buffer and performed a seek directly on the underlying
file.  This resulted in an attempt to seek backwards in the file,
since some of the data has already been read into the read-ahead
buffer.  Gzipped data streams cannot seek backwards, so an error
was returned.

This commit adds code which checks to see if the desired file offset
is already in the read-ahead buffer.  If it is, the code simply
adjusts the buffer pointer and length, thereby avoiding a reverse
seek on the gzipped data stream.

I incorporated a suggestion from Matt Dillon which saved a little
bit of code in this fix.

Reviewed by:	dillon, gallatin, jhb
2001-08-29 23:33:22 +00:00
2001-08-29 15:15:59 +00:00
2001-08-29 19:59:30 +00:00
2001-08-27 13:25:43 +00:00
2001-08-29 21:13:26 +00:00
2001-06-11 01:29:40 +00:00
1999-08-28 01:35:59 +00:00
2001-08-24 21:43:35 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The
``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you have to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/i386/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/User commands.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberosIV	Kerberos package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/handbook/synching.html
Description
freebsd with flexible iflib nic queues
Readme 2.6 GiB
Languages
C 60.1%
C++ 26.1%
Roff 4.9%
Shell 3%
Assembly 1.7%
Other 3.7%