between creation of a file descriptor and close(2) when using kernel
assisted threads. What we do is stick descriptors in the table, but
mark them as "larval". This causes essentially everything to treat
it as a non-existent descriptor, except for fdalloc(), which sees a
filled slot so that it won't (incorrectly) allocate it again. When
a descriptor is fully constructed, the code that has constructed it
marks it as "mature" (which actually clears the "larval" flag), and
things continue to work as normal.
While here, gather all the code that gets a descriptor from the table
into a fd_getfile() function, and call it, rather than having the
same (sometimes incorrect) code copied all over the place.
doesn't have the exec bit set, we need to have PROT_EXEC set
in order for some expected mmap/mprotect behavior to work, so
do the last bit slightly differently: if udv_attach() fails, and
the protection (NOT maxprot) doens't include PROT_EXEC, then clear
PROT_EXEC from maxprot and try udv_attach() again.
Sigh, mmap really needs to be rototilled.
in the mmap() call. maxprot is used to create device mappings,
and always including PROT_EXEC causes the mapping to fail on the Alpha
when mapping a non-RAM offset of /dev/mem (which may be sparse, so
instruction fetch from there is disallowed).
routine. Works similarly fto pmap_prefer(), but allows callers
to specify a minimum power-of-two alignment of the region.
How we ever got along without this for so long is beyond me.
<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>
also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.
uvm_map_pageable(map, ...) implies unlocking passed map, just before the
function call.
- If we bail out before calling the uvm_map_pageable, unlock the map
by ourself to prevent a panic ``locking against myself''. The panic is,
for example, caused when cdrecord is invoked with too large fifo size.
Add a new type voff_t (defined as a synonym for off_t) to describe offsets
into uvm objects, and update the appropriate interfaces to use it, the
most visible effect being the ability to mmap() file offsets beyond
the range of a vaddr_t.
Originally by Chuck Silvers; blame me for problems caused by merging this
into non-UBC.
value (KERN_SUCCESS or KERN_RESOURCE_SHORTAGE) indicating if it succeeded
or failed. Change the `wired' and `access_type' arguments to a single
`flags' argument, which includes the access type, and flags:
PMAP_WIRED the old `wired' boolean
PMAP_CANFAIL pmap_enter() is allowed to fail
If PMAP_CANFAIL is not specified, the pmap should behave as it always
has in the face of a drastic resource shortage: fall over dead.
Change the fault handler to deal with failure (which indicates resource
shortage) by unlocking everything, waiting for the pagedaemon to free
more memory, then retrying the fault.
of some functions. Use these flags in uvm_map_pageable() to determine
if the map is locked on entry (replaces an already present boolean_t
argument `islocked'), and if the function should return with the map
still locked.
* Implement MADV_DONTNEED: deactivate pages in the specified range,
semantics similar to Solaris's MADV_DONTNEED.
* Add MADV_FREE: free pages and swap resources associated with the
specified range, causing the range to be reloaded from backing
store (vnodes) or zero-fill (anonymous), semantics like FreeBSD's
MADV_FREE and like Digital UNIX's MADV_DONTNEED (isn't it SO GREAT
that madvise(2) isn't standardized!?)
As part of this, move the non-map-modifying advice handling out of
uvm_map_advise(), and into sys_madvise().
As another part, implement general amap cleaning in uvm_map_clean(), and
change uvm_map_clean() to only push dirty pages to disk if PGO_CLEANIT
is set in its flags (and update sys___msync13() accordingly). XXX Add
a patchable global "amap_clean_works", defaulting to 1, which can disable
the amap cleaning code, just in case problems are unearthed; this gives
a developer/user a quick way to recover and send a bug report (e.g. boot
into DDB and change the value).
XXX Still need to implement a real uao_flush().
XXX Need to update the manual page.
With these changes, rebuilding libc will automatically cause the new
malloc(3) to use MADV_FREE to actually release pages and swap resources
when it decides that can be done.
> XXX (in)sanity check. We don't do proper datasize checking
> XXX for anonymous (or private writable) mmap(). However,
> XXX know that if we're trying to allocate more than the amount
> XXX remaining under our current data size limit, _that_ should
> XXX be disallowed.
This is one link on the chain of lossage known as PR#7897. It's
definitely not the right fix, but it's better than nothing.
- rather than treating MAP_COPY like MAP_PRIVATE by sheer virtue of it not
being MAP_SHARED, actually convert the MAP_COPY flag into MAP_PRIVATE.
- return EINVAL if MAP_SHARED and MAP_PRIVATE are both included in flags.
* Provide POSIX 1003.1b mlockall(2) and munlockall(2) system calls.
MCL_CURRENT is presently implemented. MCL_FUTURE is not fully
implemented. Also, the same one-unlock-for-every-lock caveat
currently applies here as it does to mlock(2). This will be
addressed in a future commit.
* Provide the mincore(2) system call, with the same semantics as
Solaris.
* Clean up the error recovery in uvm_map_pageable().
* Fix a bug where a process would hang if attempting to mlock a
zero-fill region where none of the pages in that region are resident.
[ This fix has been submitted for inclusion in 1.4.1 ]
offset and size of the requested region to be mapped, so that the
udv_attach() can use the device d_mmap() entry to check mappability
of the requested region.
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.
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.
thorpej