Unlike other filesystem objects, symbolic links do not have an owner,
group, access mode, times, etc. Instead, these attributes are taken from
the directory that contains the link. The only attributes returned from
an lstat() that refer to the symbolic link itself are the file type
(S_IFLNK), size, blocks, and link count (always 1).
This is bogus, and disagrees with the implementation and symlink(7).
Removed it.
PR: docs/10269
Submitted by: Tolik <tolik@sibptus.tomsk.ru>
Include <machine/ansi.h> so that this file is self-sufficient again.
Rev.1.6 doesn't do this as claimed unless <nlist.h> has nonstandard
pollution.
Cleaned up includes.
changes have made this too expensive. This gains about 1.25% on
worldstone on my SMP machine.
Swap-less machines, for instance PicoBSDs, and machines which experience
page-out trafic, check with top(1), will probably want to reenable this
with:
ln -s H /etc/malloc.conf
Suggested by: alc (&dyson ?)
that counted the number of elements in argv. The counter is incremented
in the next-iteration section of the loop, not the body, so at termination
it's already "counted" the element that failed the continuation test - in
this case the NULL argv terminator.
Noted by: bde
call them. All the execX() libc functions should be vfork() safe now.
Specifically:
- execlp() does the argument count-and-build into a vector from alloca
(like the others) - buildargv() is no longer used (and gone).
- execvp() uses alloca/strcpy rather than strdup().
- the ENOEXEC handler uses alloca rather than malloc.
- a couple of free() calls removed - alloca works on the local stack and
the allocations are freed on function exit (which is why buildargv
wasn't useful - it's alloca() context would disappear on return).
Along the way:
- If alloca() fails (can it?), set errno = ENOMEM explicitly.
- The ENOEXEC recovery routine that trys again with /bin/sh appeared to
not be terminating the new argv[] array for /bin/sh, allowing it to
walk off the end of the list.
I dithered a bit about using alloca() even more as it's most commonly
associated with gcc. However, standalone portable (using malloc) and
machine-specific assembler alloca implementations appear to be available
on just about all the architectures we're likely to want to port to.
alloca will be the least of our problems if ever going to another compiler.
kern.chroot_allow_open_directories = 0
chroot(2) fails if there are open directories.
kern.chroot_allow_open_directories = 1 (default)
chroot(2) fails if there are open directories and the process
is subject of a previous chroot(2).
kern.chroot_allow_open_directories = anything else
filedescriptors are not checked. (old behaviour).
I'm very interested in reports about software which breaks when
running with the default setting.
o Runnable threads are now maintained in priority queues. The
implementation requires two things:
1.) The priority queues must be protected during insertion
and removal of threads. Since the kernel scheduler
must modify the priority queues, a spinlock for
protection cannot be used. The functions
_thread_kern_sched_defer() and _thread_kern_sched_undefer()
were added to {un}defer kernel scheduler activation.
2.) A thread (active) priority change can be performed only
when the thread is removed from the priority queue. The
implementation uses a threads active priority when
inserting it into the queue.
A by-product is that thread switches are much faster. A
separate queue is used for waiting and/or blocked threads,
and it is searched at most 2 times in the kernel scheduler
when there are active threads. It should be possible to
reduce this to once by combining polling of threads waiting
on I/O with the loop that looks for timed out threads and
the minimum timeout value.
o Functions to defer kernel scheduler activation were added. These
are _thread_kern_sched_defer() and _thread_kern_sched_undefer()
and may be called recursively. These routines do not block the
scheduling signal, but latch its occurrence. The signal handler
will not call the kernel scheduler when the running thread has
deferred scheduling, but it will be called when running thread
undefers scheduling.
o Added support for _POSIX_THREAD_PRIORITY_SCHEDULING. All the
POSIX routines required by this should now be implemented.
One note, SCHED_OTHER, SCHED_FIFO, and SCHED_RR are required
to be defined by including pthread.h. These defines are currently
in sched.h. I modified pthread.h to include sched.h but don't
know if this is the proper thing to do.
o Added support for priority protection and inheritence mutexes.
This allows definition of _POSIX_THREAD_PRIO_PROTECT and
_POSIX_THREAD_PRIO_INHERIT.
o Added additional error checks required by POSIX for mutexes and
condition variables.
o Provided a wrapper for sigpending which is marked as a hidden
syscall.
o Added a non-portable function as a debugging aid to allow an
application to monitor thread context switches. An application
can install a routine that gets called everytime a thread
(explicitly created by the application) gets context switched.
The routine gets passed the pthread IDs of the threads that are
being switched in and out.
Submitted by: Dan Eischen <eischen@vigrid.com>
Changes by me:
o Added a PS_SPINBLOCK state to deal with the priority inversion
problem most often (I think) seen by threads calling malloc/free/realloc.
o Dispatch signals to the running thread directly rather than at a
context switch to avoid the situation where the switch never occurs.
ifdefs are too ugly for this to be much of a simplification. The
existence tests are even uglier now. Note that the previous commit
was not submitted by me. It missed the point and just added a second
layer of unused removals.
Fixed hard-coded "libcrypt"s. The LCRYPTBASE macro mainly makes
things hard to read, but use it while we have it.
which ones cause us to fail. Now all open errors on the databse file
will cause the next file in the list to be tried.
Submitted by: Arne Henrik Juul <arnej@math.ntnu.no>
PR: 4585
levels (-O3 and above) won't remove essential code. Many thanks
to Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru> for pointing out
that it was the optimizer's removal of this code that caused make
world with -O3 to break. With this change, make buildworld now
completes.
