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: David S. Miller <davem@davemloft.net>

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

Normally, srmmu uses different trap table register values to allow
determination of the cpu we're on.  All of the trap tables have
identical content, they just sit at different offsets from the first
trap table, and the offset shifted down and masked out determines
the cpu we are on.

The code tries to free them up when they aren't actually used
(don't have all 4 cpus, we're on sun4d, etc.) but that causes
problems.

For one thing it triggers false positives in the DMA debugging
code.  And fixing that up while preserving this relative offset
thing isn't trivial.

So just kill the freeing code, it costs us at most 3 pages, big
deal...
Signed-off-by: David S. Miller <davem@davemloft.net>

I think arch/sparc/kernel/sys32.S has an incorrect splice definition:

SIGN2(sys32_splice, sys_splice, %o0, %o1)

The splice() prototype looks like :

       long splice(int fd_in, loff_t *off_in, int fd_out,
                   loff_t *off_out, size_t len, unsigned int flags);

So I think we should have :

SIGN2(sys32_splice, sys_splice, %o0, %o2)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

As noted by Nick Piggin.
Signed-off-by: David S. Miller <davem@davemloft.net>

The first thing sys_truncate() and sys_ftruncate() do is sign extend
the unsigned length arg to a signed type.

Thanks to Benjamin Herrenschmidt for the tip.
Signed-off-by: David S. Miller <davem@davemloft.net>

If kthread_run() fails or never gets to run we'll have NULL
or a pointer encoded error in kenvctrld_task, rather than
a legitimate task pointer.

So this makes bbc_envctrl_cleanup() crash as it passed this
bogus pointer into kthread_stop().
Reported-by: BERTRAND Joël <joel.bertrand@systella.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

The tftpboot build was failing with missing file errors.

It turns out that $(obj)/image wasn't being generated which was causing the a.out conversion to be skipped and hence piggyback to be called with nonexistent files.
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kjetil Oftedal mentioned that piggyback_32 was failing
when building a sparc image.

I tracked this down to the fact that the kernel no longer
provided an absolute symbol named "end".

Commit 86ed40bd ("sparc: unify sections.h")
renamed end to _end but failed to update piggyback_32.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Kjetil Oftedal <oftedal@gmail.com>
Cc: Robert Reif <reif@earthlink.net>
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes the following build warnings:
arch/sparc/boot/piggyback_64.c: In function 'main':
arch/sparc/boot/piggyback_64.c:44: warning: 'end' may be used uninitialized in this function
arch/sparc/boot/piggyback_64.c:44: warning: 'start' may be used uninitialized in this function
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The page allocator and SLAB are available at this point now,
and if we still try to use bootmem allocations here the kernel
spits out warnings.
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 9e9f46c4.

Quoting from the commit message:

 "At this point, it seems to solve more problems than it causes, so let's
  try using it by default.  It's an easy revert if it ends up causing
  trouble."

And guess what? The _CRS code causes trouble.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.infradead.org/battery-2.6:
  da9030_battery: Fix race between event handler and monitor
  Add MAX17040 Fuel Gauge driver
  w1: ds2760_battery: add support for sleep mode feature
  w1: ds2760: add support for EEPROM read and write
  ds2760_battery: cleanups in ds2760_battery_probe()

Merge branches 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/{vfs-2.6,audit-current}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  another race fix in jfs_check_acl()
  Get "no acls for this inode" right, fix shmem breakage
  inline functions left without protection of ifdef (acl)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  audit: inode watches depend on CONFIG_AUDIT not CONFIG_AUDIT_SYSCALL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Even though one cannot make use of the audit watch code without
CONFIG_AUDIT_SYSCALL the spaghetti nature of the audit code means that
the audit rule filtering requires that it at least be compiled.

Thus build the audit_watch code when we build auditfilter like it was
before cfcad62c

Clearly this is a point of potential future cleanup..
Reported-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix the write access fault problem for real

commit 64d1304a (futex: setup writeable mapping for futex ops which
modify user space data) did address only half of the problem of write
access faults.

The patch was made on two wrong assumptions:

1) access_ok(VERIFY_WRITE,...) would actually check write access.

   On x86 it does _NOT_. It's a pure address range check.

2) a RW mapped region can not go away under us.

   That's wrong as well. Nobody can prevent another thread to call
   mprotect(PROT_READ) on that region where the futex resides. If that
   call hits between the get_user_pages_fast() verification and the
   actual write access in the atomic region we are toast again.

The solution is to not rely on access_ok and get_user() for any write
access related fault on private and shared futexes. Instead we need to
fault it in with verification of write access.

There is no generic non destructive write mechanism which would fault
the user page in trough a #PF, but as we already know that we will
fault we can as well call get_user_pages() directly and avoid the #PF
overhead.

If get_user_pages() returns -EFAULT we know that we can not fix it
anymore and need to bail out to user space.

Remove a bunch of confusing comments on this issue as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org

SLUB uses higher order allocations by default but falls back to small
orders under memory pressure. Make sure the GFP mask used in the initial
allocation doesn't include __GFP_NOFAIL.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Traditionally, we never failed small orders (even regardless of any
__GFP_NOFAIL flags), and slab will allocate order-1 allocations even for
small allocations that could fit in a single page (in order to avoid
excessive fragmentation).

Maybe we should remove this warning entirely, but before making that
judgement, at least limit it to bigger allocations.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  Staging: octeon-ethernet: Fix race freeing transmit buffers.
  Staging: octeon-ethernet: Convert to use net_device_ops.
  MIPS: Cavium: Add CPU hotplugging code.
  MIPS: SMP: Allow suspend and hibernation if CPU hotplug is available
  MIPS: Add arch generic CPU hotplug
  DMA: txx9dmac: use dma_unmap_single if DMA_COMPL_{SRC,DEST}_UNMAP_SINGLE set
  MIPS: Sibyte: Fix build error if CONFIG_SERIAL_SB1250_DUART is undefined.
  MIPS: MIPSsim: Fix build error if MSC01E_INT_BASE is undefined.
  MIPS: Hibernation: Remove SMP TLB and cacheflushing code.
  MIPS: Build fix - include <linux/smp.h> into all smp_processor_id() users.
  MIPS: bug.h Build fix - include <linux/compiler.h>.

The existing code had the following race:

Thread-1                       Thread-2

inc/read in_use
                               inc/read in_use
inc tx_free_list[qos].len
                               inc tx_free_list[qos].len

The actual in_use value was incremented twice, but thread-1 is going
to free memory based on its stale value, and will free one too many
times.  The result is that memory is freed back to the kernel while
its packet is still in the transmit buffer.  If the memory is
overwritten before it is transmitted, the hardware will put a valid
checksum on it and send it out (just like it does with good packets).
If by chance the TCP flags are clobbered but not the addresses or
ports, the result can be a broken TCP stream.

The fix is to track the number of freed packets in a single location
(a Fetch-and-Add Unit register).  That way it can never get out of sync
with itself.

We try to free up to MAX_SKB_TO_FREE (currently 10) buffers at a time.
If fewer are available we adjust the free count with the difference.
The action of claiming buffers to free is atomic so two threads cannot
claim the same buffers.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Convert the driver to use net_device_ops as it is now mandatory.

Also compensate for the removal of struct sk_buff's dst field.

The changes are mostly mechanical, the content of ethernet-common.c
was moved to ethernet.c and ethernet-common.{c,h} are removed.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Thanks to Cavium Inc. for the code contribution and help.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The SMP implementation of suspend and hibernate depends on CPU hotplugging.
In the past we didn't have CPU hotplug so suspend and hibernation were not
possible on SMP systems.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Each platform has to add support for CPU hotplugging itself by providing
suitable definitions for the cpu_disable and cpu_die of the smp_ops
methods and setting SYS_SUPPORTS_HOTPLUG_CPU.  A platform should only set
SYS_SUPPORTS_HOTPLUG_CPU once all it's smp_ops definitions have the
necessary changes.  This patch contains the changes to the dummy smp_ops
definition for uni-processor systems.

Parts of the code contributed by Cavium Inc.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This patch does not change actual behaviour since dma_unmap_page is just
an alias of dma_unmap_single on MIPS.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This fixes kernel.org bugzilla 13596, see
http://bugzilla.kernel.org/show_bug.cgi?id=13596

Reported-by: dvice_null@yahoo.com
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This fixes kernel.org bugzilla 13595, see
http://bugzilla.kernel.org/show_bug.cgi?id=13595

Reported-by: dvice_null@yahoo.com
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

We can't perform any flushes on SMP from swsusp_arch_resume because
interrupts are disabled.  A cross-CPU flush is unnecessary anyway
because all but the local CPU have already been disabled.  A local
flush is not needed either because we didn't change any mappings.  So
just delete the code.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Some of the were relying into smp.h being dragged in by another header
which of course is fragile.  <asm/cpu-info.h> uses smp_processor_id()
only in macros and including smp.h there leads to an include loop, so
don't change cpu-info.h.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

In the past this file somehow used to be dragged in.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (48 commits)
  dm mpath: change to be request based
  dm: disable interrupt when taking map_lock
  dm: do not set QUEUE_ORDERED_DRAIN if request based
  dm: enable request based option
  dm: prepare for request based option
  dm raid1: add userspace log
  dm: calculate queue limits during resume not load
  dm log: fix create_log_context to use logical_block_size of log device
  dm target:s introduce iterate devices fn
  dm table: establish queue limits by copying table limits
  dm table: replace struct io_restrictions with struct queue_limits
  dm table: validate device logical_block_size
  dm table: ensure targets are aligned to logical_block_size
  dm ioctl: support cookies for udev
  dm: sysfs add suspended attribute
  dm table: improve warning message when devices not freed before destruction
  dm mpath: add service time load balancer
  dm mpath: add queue length load balancer
  dm mpath: add start_io and nr_bytes to path selectors
  dm snapshot: use barrier when writing exception store
  ...

* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
  uwb: allow WLP to be used with IPv6.
  uwb: event_size should be signed