string may be found (from the beginning of the pattern), the point
at which must is found minus that offset may actually point to some
place before the start of the text.
In that case, make start = start.
Alternatively, this could be tested for in the preceding if, but it
did not occur to me. :-)
Caught by: regex(3) test code
Currently, many drivers support more than one bus of ISA, EISA, MCA,
PCI.
Before this commit, we had, for example, some SCSI devices listed more
than once, iirc, some up to three times (ISA/EISA, MCA, PCI).
Since now the "device" line is common for all of them and they only
differ for the hints stuff, I did the following:
First, list Busses: (E)ISA, MCA, PCI and explain, that only ISA
needs the hints stuff.
Move NIC/SCSI stuff, which were the only split sections, behind these
stuff. Describe all drivers only one time and list all supported
chips.
List all device (+ hints for ISA, if possible).
I've also added few additional supported chips to some drivers, xl for
example and some SCSI drivers.
Also, softupdates is no longer disabled by default, so the comment should
not say, it's not enabled by default due to license issues.
Approved by: asmodai
To come: include PAO devices (imp volunteered for help)
used to extract modified boot hints to make loader(8)-time changes
"sticky". It tries to use \ style quoting so that it can be used directly
with foo.conf files. It can also extract specific variables.
ps(1) should not be returning a success code (0), it should return an
error code (1). This was fixed on OpenBSD over 3 years ago.
PR: 19069
Submitted by: Jim Sloan <odinn@atlantabiker.net>
Reviewed by: rwatson
and for all (I hope). Packages such as wine, JDK, and linuxthreads
should no longer have any problems with re-entering the dynamic
linker.
This commit replaces the locking used in the dynamic linker with a
new spinlock-based reader/writer lock implementation. Brian
Fundakowski Feldman <green> argued for this from the very beginning,
but it took me a long time to come around to his point of view.
Spinlocks are the only kinds of locks that work with all thread
packages. But on uniprocessor systems they can be inefficient,
because while a contender for the lock is spinning the holder of the
lock cannot make any progress toward releasing it. To alleviate
this disadvantage I have borrowed a trick from Sleepycat's Berkeley
DB implementation. When spinning for a lock, the requester does a
nanosleep() call for 1 usec. each time around the loop. This will
generally yield the CPU to other threads, allowing the lock holder
to finish its business and release the lock. I chose 1 usec. as the
minimum sleep which would with reasonable certainty not be rounded
down to 0.
The formerly machine-independent file "lockdflt.c" has been moved
into the architecture-specific subdirectories by repository copy.
It now contains the machine-dependent spinlocking code. For the
spinlocks I used the very nifty "simple, non-scalable reader-preference
lock" which I found at
<http://www.cs.rochester.edu/u/scott/synchronization/pseudocode/rw.html>
on all CPUs except the 80386 (the specific CPU model, not the
architecture). The 80386 CPU doesn't support the necessary "cmpxchg"
instruction, so on that CPU a simple exclusive test-and-set lock
is used instead. 80386 CPUs are detected at initialization time by
trying to execute "cmpxchg" and catching the resulting SIGILL
signal.
To reduce contention for the locks, I have revamped a couple of
key data structures, permitting all common operations to be done
under non-exclusive (reader) locking. The only operations that
require exclusive locking now are the rare intrusive operations
such as dlopen() and dlclose().
The dllockinit() interface is now deprecated. It still exists,
but only as a do-nothing stub. I plan to remove it as soon as is
reasonably possible. (From the very beginning it was clearly
labeled as experimental and subject to change.) As far as I know,
only the linuxthreads port uses dllockinit(). This interface turned
out to have several problems. As one example, when the dynamic
linker called a client-supplied locking function, that function
sometimes needed lazy binding, causing re-entry into the dynamic
linker and a big looping mess. And in any case, it turned out to be
too burdensome to require threads packages to register themselves
with the dynamic linker.
"ld-elf.so.1.old". The dynamic linker is a critical component of
the system, and it is difficult to recover if it is damaged and
there isn't a working backup available. For instance, parts of
the toolchain such as the assembler are dynamically linked, making
it impossible to build a new dynamic linker if the installed one
doesn't work.
