slab poisons objects with 0x5a both when they are constructed and when
they are freed.  So it is not possible to tell whether a deref of
0x5a5a5a5a was a use-before-initialisation bug or a use-after-free bug.

The patch changes it so that

1) A deref of 0x5a5a5a5a means use-of-uninitialised-memory

2) A deref of 0x6b6b6b6b means use-of-freed-memory.

move_vma() calls do_munmap() and then uses the memory at *new_vma.

But when starting X11 it just happens that the memory which do_munmap
unmapped had the same start address and the range at *new_vma.  So new_vma
is freed by do_munmap().

This was never noticed before because (vm_flags & VM_LOCKED) evaluates
false when vm_flags is 0x5a5a5a5a.  But I just changed that to 0x6b6b6b6b
and boom - we call make_pages_present() with start == end == 0x6b6b6b6b and
it goes BUG.

So I think the right fix here is for move_vma() to not inspect the values
of any vma's after it has called do_munmap().

The patch does that, for `new_vma'.

The local variable `vma' is also being used after the call do do_munmap(),
and this may also be a bug.  Proving that this is not so, and adding a
comment to explain why is hereby added to Hugh's todo list ;)

There's a small window in which another CPU could dirty the page after
we've cleaned it, and before we've moved it to mapping->dirty_pages().
The end result is a dirty page on mapping->locked_pages, which is
wrong.

So take mapping->page_lock before clearing the dirty bit.

Running a `mount -o remount' against ext3 deadlocks if there is heavy
write activity.  It's a sort of AB/BA deadlock caused by calling
log_wait_commit() under lock_super().  The caller holds lock_super()
and is waiting for a commit, but the commit cannot complete because
lock_super() is also used in the block allocator.

The way we fixed this in tha past is to drop the superblock lock inside
ext3.  The way this patch fixes it is to arrange for lock_super() to
not be held around the ->sync_fs() call.

Also: sync_filesystems is on the sys_sync() path and is racy wrt
unmount.  Check sb->s_root after taking sb->s_umount.

 - set up kernel stack pointer for sysenter at each context switch.
 - disable sysenter while in vm86 mode.
 - clean up mtrr number defines and SEP feature testing

Don't disable PCI devices before changing the BARs, as discussed
recently.  Disabling PCI_COMMAND_MASTER bit is an obvious bug.

Further, pdev_enable_device() is a leftover from very old (2.0, I guess)
alpha PCI code.  It's used in pci_assign_unassigned_resources() to
enable *every* PCI device in the system.  So, if we have two graphic
cards on the same bus, both with legacy VGA IO...  oops.

Actually, only alpha relied on that due to the lack of
pcibios_enable_device (which has been already fixed).

This replaces the dynamically allocated two-level array in sys_poll with
a dynamically allocated linked list.  The current implementation causes
at least two alloc/free calls, even if only one or two descriptors are
polled.  This reduces that to one alloc/free, and the .text segment is
around 220 bytes shorter.  The microbenchmark that polls one pipe fd is
around 30% faster.  [1140 cycles instead of 1604 cycles, Celeron mobile
1.13 GHz]

into home.transmeta.com:/home/torvalds/v2.5/linux

into tetrachloride.(none):/mnt/stuff/kernel/2.5/agpgart

into home.transmeta.com:/home/torvalds/v2.5/linux

into home.transmeta.com:/home/torvalds/v2.5/linux

Description:
  everywhere the NFS client uses the req_offset() function today, it adds
  req->wb_offset to the result.  this patch simply makes "+req->wb_offset"
  a part of the req_offset() function.

Test status:
  Passes all Connectathon '02 tests with v2, v3, UDP and TCP.  Passes
  NFS torture tests on an x86 UP highmem system.

Description:
  The default set_page_dirty address space op is too heavyweight for NFS,
  which doesn't use buffers.

Description:
  andrew morton suggested there are places in the NFS client that could
  make use of kmap_atomic instead of vanilla kmap in order to improve
  scalability on 8-way and higher SMP systems.

Test status:
  Passes all Connectathon '02 tests with v2 and v3, UDP and TCP; passes
  NFS torture tests on a UP HIGHMEM x86 system.

This moves most of the duplicated text in the various v850 platform-
specific linker scripts (each of which was previously completely
standalone) into cpp macros in vmlinux.lds.S, which are then used by the
platform linker scripts as appropriate.  This should make the scripts a
lot easier to maintain.

Also, a number of linker-script bugs are fixed.

The old code seems completely wrong; I guess it was just left over from
whichever architecture this code was copied from.

These are used for the new in-kernel module loader (actually not all the
relocation types are used right now, but are included for completeness).

Only the EM_CYGNUS_V850 macro, which is in a global namespace, is added
to <linux/elf.h>; the relocation types, which are private to the v850,
are added to <asm-v850/elf.h>.  [Perhaps some other archs can do a
similar split, to reduce the bloat in <linux/elf.h>]

A few symbols are only defined when CONFIG_MMU=y, but are exported
(by kernel/ksyms.c) unconditionally.  This patch makes them conditional.

Adds extra includes needed because sched.h doesn't include them anymore,
and removes includes of sched.h where they're not really necessary.

Fix task->cpus_allowed bitmask truncations on 64.bit architectures.

Originally by Bjorn Helgaas for 2.4.x.

into home.transmeta.com:/home/torvalds/v2.5/linux

major changes to actually fit.

SGI Modid: 2.5.x-xfs:slinx:132210a

SGI Modid: 2.5.x-xfs:slinx:135454a

SGI Modid: 2.5.x-xfs:slinx:135453a

very first read on mount.  Make some of the surrounding code dealing
with buffers consistent.

SGI Modid: 2.5.x-xfs:slinx:135452a

SGI Modid: 2.5.x-xfs:slinx:135307a

SGI Modid: 2.5.x-xfs:slinx:135308a

SGI Modid: 2.5.x-xfs:slinx:135207a

SGI Modid: 2.5.x-xfs:slinx:135199a

SGI Modid: 2.5.x-xfs:slinx:135153a

SGI Modid: 2.5.x-xfs:slinx:135137a