fixes problem reported by Ken Nakata <kenn@synap.ne.jp> on the mac68k
where the stack amap chunking caused entry->end to wrap around to zero,
thus corrupting the map entry list and causing kmem_map to fill.
write protection. this stops data corruption where it was possible
to change the in-memory copy of an append-only file (but not the on-disk
copy). this is documented in NetBSD security advisory 1998-003. thanks
to darrenr, lukem, cgd, mycroft and mrg for this.
later incremented correctedly, causing the wrong data to be paged out, which
then caused general lossage later when the data was paged in and the process
tried to use it. found by pk.
the new proc structure when performing a fork. This makes it much
easier to abort a fork operation and return an error if we run out
of KVA space.
The U-area pages are still wired down in {,u}vm_fork(), as before.
- release the correct page (ppsp[lcv], not pg)
- don't access the page's fields after we have released it
- in the uvm_objct case: move on to the next page if we've released
[should have been merged in on 1998/02/12, but we somehow missed it]
the very rare case of shared mappings that have amap's attached in a
reasonable way -- this is not currently causing any problems, but i
fixed it anyway. update the comment in this section of code and also
be smarter about avoiding needless calls to pmap_protect().
that we don't try and sync them later. should get rid of the
"uvm_vnp_sync: dying vnode on sync list" related warnings that were
occuring during a "make install."
the SPARC.
Remove the #ifdef COMPAT_13 for automatically adding a sharing type, since the
interface is *supposed* to support this.
Also modify the DIAGNOSTIC messages here a bit.
- Protect option headers from inclusion if ! _KERNEL or if _LKM.
- Make sure struct uvm_history is always the same size (not dependent
on NCPU).
- Add fmtlen and fnlen members to struct uvm_history_ent, which specify
the lengths fo the fmt and fn strings.
- Add name, namelen, and a list entry to struct uvm_history.
- When a history is initialized, place it on the global list of all histories.
the history buffers are "struct uvm_history_ent" to ensure proper
alignment (eg, alpha). this fixes a boottime panic when the pdhist was
used before it had been initialised.
for the pagedaemon allocating from kmem_object. this should
prevent from the pagedaemon running out of memory and deadlocking.
fix counting of wired pages.
add some debugging code to detect attempts to reference free vm_pages.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the UVM kernel code portion.
this will be KNF'd shortly. :-)
thorpej