[ Upstream commit d8ed1d43e17898761c7221014a15a4c7501d2ff3 ]

When page alloc debugging is not enabled, we essentially accept any
virtual address for linear kernel TLB misses.  But with kgdb, kernel
address probing, and other facilities we can try to access arbitrary
crap.

So, make sure the address we miss on will translate to physical memory
that actually exists.

In order to make this work we have to embed the valid address bitmap
into the kernel image.  And in order to make that less expensive we
make an adjustment, in that the max physical memory address is
decreased to "1 << 41", even on the chips that support a 42-bit
physical address space.  We can do this because bit 41 indicates
"I/O space" and thus covers non-memory ranges.

The result of this is that:

1) kpte_linear_bitmap shrinks from 2K to 1K in size

2) we need 64K more for the valid address bitmap

We can't let the valid address bitmap be dynamically allocated
once we start using it to validate TLB misses, otherwise we have
crazy issues to deal with wrt. recursive TLB misses and such.

If we're in a TLB miss it could be the deepest trap level that's legal
inside of the cpu.  So if we TLB miss referencing the bitmap, the cpu
will be out of trap levels and enter RED state.

To guard against out-of-range accesses to the bitmap, we have to check
to make sure no bits in the physical address above bit 40 are set.  We
could export and use last_valid_pfn for this check, but that's just an
unnecessary extra memory reference.

On the plus side of all this, since we load all of these translations
into the special 4MB mapping TSB, and we check the TSB first for TLB
misses, there should be absolutely no real cost for these new checks
in the TLB miss path.

Reported-by: heyongli@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

These got overlooked first time around.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: David S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
  cpumask: remove cpumask allocation from idle_balance, fix
  numa, cpumask: move numa_node_id default implementation to topology.h, fix
  cpumask: remove cpumask allocation from idle_balance
  x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
  x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
  x86: microcode: cleanup
  x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
  cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
  numa, cpumask: move numa_node_id default implementation to topology.h
  cpumask: convert node_to_cpumask_map[] to cpumask_var_t
  cpumask: remove x86 cpumask_t uses.
  cpumask: use cpumask_var_t in uv_flush_tlb_others.
  cpumask: remove cpumask_t assignment from vector_allocation_domain()
  cpumask: make Xen use the new operators.
  cpumask: clean up summit's send_IPI functions
  cpumask: use new cpumask functions throughout x86
  x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
  cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
  cpumask: convert node_to_cpumask_map[] to cpumask_var_t
  x86: unify 32 and 64-bit node_to_cpumask_map
  ...

Pass the original flags to rwlock arch-code, so that it can re-enable
interrupts if implemented for that architecture.

Initially, make __raw_read_lock_flags and __raw_write_lock_flags stubs
which just do the same thing as non-flags variants.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:

	arch/x86/include/asm/topology.h
	drivers/oprofile/buffer_sync.c
(Both cases: changed in Linus' tree, removed in Ingo's).

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Fix reset hangs on Niagara systems.
  cpumask: use mm_cpumask() wrapper: sparc
  cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL.: sparc
  cpumask: remove the now-obsoleted pcibus_to_cpumask(): sparc
  cpumask: remove cpu_coregroup_map: sparc
  cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.: sparc
  cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.: sparc64
  cpumask: Use accessors code.: sparc64
  cpumask: Use accessors code: sparc
  cpumask: arch_send_call_function_ipi_mask: sparc
  cpumask: Use smp_call_function_many(): sparc64

Conflicts:
	arch/x86/kernel/cpu/common.c