functions to be used by the dynamic linker. This can be called by
threads packages at start-up time. I will add the call to libc_r
soon.
Also add a default locking method that is used up until dllockinit()
is called. The default method works by blocking SIGVTALRM, SIGPROF,
and SIGALRM in critical sections. It is based on the observation
that most user-space threads packages implement thread preemption
with one of these signals (usually SIGVTALRM).
The dynamic linker has never been reentrant, but it became less
reentrant in revision 1.34 of "src/libexec/rtld-elf/rtld.c".
Starting with that revision, multiple threads each doing lazy
binding could interfere with each other. The usual symptom was
that a symbol was falsely reported as undefined at start-up time.
It was rare but not unseen. This commit fixes it.
Fixed some style bugs (always use precisely 1 space after `:' in
dependency specifications).
Removed bogus dependency of ${FULLKERNEL} on ${BEFORE_DEPEND}.
is not configured. Including <isa/isavar.h> when it is not used is
harmful as well as bogus, since it includes "isa_if.h" which is not
generated when isa is not configured.
Fixed some style bugs for cam (superflous umask and missing newline).
Fixed bogons for apm. The pattern "apm*" matched too many things; apm
and apmctl were both made twice by `MAKEDEV all'. Hopefully no one
depends on `MAKEDEV apm0' making apm or on `MAKEDEV apm' making apmctl.
fixee incoherency of pipe timestamps relative to file timestamps in
the usual case where getnanotime() is not used for the latter. (File
and pipe timestamps are still incoherent relative to real time unless
the vfs_timestamp_precision sysctl is set to 2 or 3).
Some interface botches went away, leaving the macros unused outside of
the implementation of interrupt masking, and it was silly for the
implementation to use the macros in only one place each.
Use SYMLINKS instead of an ad hoc rule for installing words -> web2.
Don't override the install target; doing so just breaks things like
SYMLINKS.
Don't override the correct defaults for the all, clean, depend, lint
and tags targets. Don't add a null rule to the cleandepend target.
the docs on a couple other keys. While I'm here, document another ~3 bugs
that have been around for all eternity in the hope that I'll someday bother
to fix them.
apm_default_resume() to sometimes set a very wrong time.
(1) Accesses to the RTC index and data registers were not atomic enough.
Interrupts were not masked. This was only good enough until an
interrupt handler (rtcintr()) started accessing the RTC in FreeBSD-2.0.
(2) Access to the block of time registers in inittodr() was not atomic
enough. inittodr() has 244us to read the time registers. Interrupts
were not masked. This was only good enough until something (apm)
started calling inittodr() after boot time in FreeBSD-2.0.
The fix for (2) also makes the timecounter update more atomic, although
this is currently unimportant due to the low resolution of the RTC.
Problem reported by: mckay
