When we put a page on the collection list, we must subtract NPVPPG from the
total free count: one for each pv_entry that's free in that page, and one for
each free pv_entry in other pages that we're going to eat by moving the ones
in the page being collected.
* Map the message buffer with access_type = VM_PROT_READ|VM_PROT_WRITE `just
because'.
* Map the file system buffers with access_type = VM_PROT_READ|VM_PROT_WRITE to
avoid possible problems with pagemove().
* Do not use VM_PROT_EXEC with either of the above.
* Map pages for /dev/mem with access_type = prot. Also, DO NOT use
pmap_kenter() for this, as we DO NOT want to lose modification information.
* Map pages in dumpsys() with VM_PROT_READ.
* Map pages in m68k mappedcopyin()/mappedcopyout() and writeback() with
access_type = prot.
* For now, bus_dma*(), pmap_map(), vmapbuf(), and similar functions still use
access_type = 0. This should probably be revisited.
- returned EOPNOTSUPP rather than -1.
- no check for negative offset.
many of these fix potential security problems in these drivers.
XXX XXX XXX
the d_mmap cdev routine should be changed to have a prototype like:
paddr_t (*d_mmap) __P((dev_t, off_t, int));
by someone!
- cpu_set_kpc() now takes void *arg third argument, passed to the
entry point.
- cpu_fork() allows parent to be non-curproc iff parent is proc0.
When forking non-curproc, assume its state has already been saved.
- Adjust various pieces of machine-dependent code to account of all of this.
which require special handling, e.g. sigreturn on m68k.
This differs from the old sigreturn trap in that we require the syscall
number to be in register d0, just like the regular syscall entry point.
This will allow sigreturn to be versioned in the future without the need
to allocate another trap vector.
u-area in machine-dependent code. Instead, call exit2() to schedule
the reaper to free them for us, once it is safe to do so (i.e. we are
no longer running on the dead proc's vmspace and stack).
as this breaks C++ code that happens to indirectly include this header.
Both Matthias Scheler and I noticed this, independently.
This problem notably does not affect the atari and sun3/sun3x ports,
which have already implemented a similar solution.
was converted to use Mach VM for Net2/4.4BSD. The user segment table
pointer was originally stored in the PCB. When Mach VM came along,
however, it was also stored in the pmap, and loaded into the PCB in
pmap_activate(). pmap_activate() would then note that the PCB's USTP
was now in sync with the pmap's USTP, and the low-level context switch
code would use the value from the PCB.
However, pmap_activate() would also load the hardware MMU context if
the pmap was the current pmap (or, in the case where pmaps can be shared,
such as in NetBSD, if the proc was the current proc). The low-level
context switch code would then reload the hardware _again_ using the
USTP from the PCB.
However, the optimization of not calling pmap_activate() if "stchanged"
was false ended up causing some processes to use stale USTP values from
the PCB when the low-level context switch code reloaded the hardware!
This was noticed by using a real vfork(2) (which worked for some time
before failing, surprisingly!)
Since I'm hard pressed to find any real optimization here (since the
hardware was always reloaded once, sometimes twice!), the code now always
calls pmap_activate(), which uses the correct USTP value (the one in the
pmap). The PCB's USTP is now ignored, and should eventually be g/c'd.
Another optimization can actually be performed, and I have added a comment
describing what it is, but have not yet implemented it.
Also note that most of the loadustp() functions where actually incomplete.
This has been corrected. These functions should probably be split up into
MMU-specific operations, and called indirectly, rather than doing constant
run-time decision making based on values that will never change during the
course of a boot's lifetime.
pseudo-device rnd # /dev/random and in-kernel generator
in config files.
o Add declaration to all architectures.
o Clean up copyright message in rnd.c, rnd.h, and rndpool.c to include
that this code is derived in part from Ted Tyso's linux code.
