This adds the remaining two hypercalls defined by PAPR for manipulating
the XICS interrupt controller, H_IPOLL and H_XIRR_X.  H_IPOLL returns
information about the priority and pending interrupts for a virtual
cpu, without changing any state.  H_XIRR_X is like H_XIRR in that it
reads and acknowledges the highest-priority pending interrupt, but it
also returns the timestamp (timebase register value) from when the
interrupt was first received by the hypervisor.  Currently we just
return the current time, since we don't do any software queueing of
virtual interrupts inside the XICS emulation code.

These hcalls are not currently used by Linux guests, but may be in
future.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Commit a9c4e541


"powerpc/kprobe: Complete kprobe and migrate exception frame"
introduced a regression:

While returning from exception handling in case of PREEMPT enabled,
_TIF_NEED_RESCHED bit is checked in TI_FLAGS (thread_info flag) of current
task. Only if this bit is set, it should continue with the process of
calling preempt_schedule_irq() to schedule highest priority task if
available.

Current code assumes that r8 contains TI_FLAGS and check this for
_TIF_NEED_RESCHED, but as r8 is modified in the code which executes before
this check, r8 no longer contains the expected TI_FLAGS information.

As a result check for comparison with _TIF_NEED_RESCHED was failing even if
NEED_RESCHED bit is set in the current thread_info flag. Due to this,
preempt_schedule_irq() and in turn scheduler was not getting called even if
highest priority task is ready for execution.

So, store temporary results in r0 instead of r8 to prevent r8 from getting
modified as subsequent code is dependent on its value.

Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
CC: <stable@vger.kernel.org> [v3.7+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

If a hash bucket gets full, we "evict" a more/less random entry from it.
When we do that we don't invalidate the TLB (hpte_remove) because we assume
the old translation is still technically "valid". This implies that when
we are invalidating or updating pte, even if HPTE entry is not valid
we should do a tlb invalidate.

This was a regression introduced by b1022fbd



Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

No code changes, just documenting what's happening a little better.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

On context switch, we should have no prefetch streams leak from one
userspace process to another.  This frees up prefetch resources for the
next process.

Based on patch from Milton Miller.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Maynard informed me that neither the oprofile kernel module nor oprofile
userspace has been updated to support that "legacy" oprofile module
interface for power8, which is indicated by "ppc64/power8." This results
in no samples. The solution is to default to the "timer" type, instead.
The raw entry also should be updated, as "ppc64/ibm-compat-v1" indicates
to oprofile userspace to use "compatibility events" which are obsolete
in ISA 2.07.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

For the mpic with a flag MPIC_SINGLE_DEST_CPU, only one bit should be
set in interrupt destination registers.

The code is applicable to 64-bit platforms as well as 32-bit.

Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

When in an active transaction that takes a signal, we need to be careful with
the stack.  It's possible that the stack has moved back up after the tbegin.
The obvious case here is when the tbegin is called inside a function that
returns before a tend.  In this case, the stack is part of the checkpointed
transactional memory state.  If we write over this non transactionally or in
suspend, we are in trouble because if we get a tm abort, the program counter
and stack pointer will be back at the tbegin but our in memory stack won't be
valid anymore.

To avoid this, when taking a signal in an active transaction, we need to use
the stack pointer from the checkpointed state, rather than the speculated
state.  This ensures that the signal context (written tm suspended) will be
written below the stack required for the rollback.  The transaction is aborted
becuase of the treclaim, so any memory written between the tbegin and the
signal will be rolled back anyway.

For signals taken in non-TM or suspended mode, we use the
normal/non-checkpointed stack pointer.

Tested with 64 and 32 bit signals

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

These cause codes are usable by userspace, so let's export to uapi.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

If we are emulating an instruction inside an active user transaction that
touches memory, the kernel can't emulate it as it operates in transactional
suspend context.  We need to abort these transactions and send them back to
userspace for the hardware to rollback.

We can service these if the user transaction is in suspend mode, since the
kernel will operate in the same suspend context.

This adds a check to all alignment faults and to specific instruction
emulations (only string instructions for now).  If the user process is in an
active (non-suspended) transaction, we abort the transaction go back to
userspace allowing the HW to roll back the transaction and tell the user of the
failure.  This also adds new tm abort cause codes to report the reason of the
persistent error to the user.

Crappy test case here http://neuling.org/devel/junkcode/aligntm.c



Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # 3.9 only
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

PAPR carves out 0xff-0xe0 for hypervisor use of transactional memory software
abort cause codes.  Unfortunately we don't respect this currently.

Below fixes this to move our cause codes to below this region.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # 3.9 only
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Pull drm fixes from Dave Airlie:
 "This is mostly exynos and intel fixes, along with some vblank patches
  I lost from Rob a few months ago that make wayland work better on lots
  of GPUs, also a qxl kconfig fix."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (22 commits)
  qxl: fix Kconfig deps - select FB_DEFERRED_IO
  drm/exynos: replace request_threaded_irq with devm function
  drm/exynos: remove unnecessary devm_kfree
  drm/exynos: fix build warnings from ipp fimc
  drm/exynos: cleanup device pointer usages
  drm/exynos: wait for the completion of pending page flip
  drm/exynos: use drm_send_vblank_event() helper
  drm/i915: avoid premature DP AUX timeouts
  drm/i915: avoid premature timeouts in __wait_seqno()
  drm/i915: use msecs_to_jiffies_timeout instead of open coding the same
  drm/i915: add msecs_to_jiffies_timeout to guarantee minimum duration
  drm/i915: force full modeset if the connector is in DPMS OFF mode
  drm/exynos: page flip fixes
  drm/exynos: exynos_hdmi: Pass correct pointer to free_irq()
  drm/exynos: exynos_drm_ipp: Fix incorrect usage of IS_ERR_OR_NULL
  drm/exynos: exynos_drm_fbdev: Fix incorrect usage of IS_ERR_OR_NULL
  drm/imx: use drm_send_vblank_event() helper
  drm/shmob: use drm_send_vblank_event() helper
  drm/radeon: use drm_send_vblank_event() helper
  drm/nouveau: use drm_send_vblank_event() helper
  ...

Pull crypto fixes from Herbert Xu:
 "This push fixes a crash in the new sha256_ssse3 driver as well as a
  DMA setup/teardown bug in caam"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: sha256_ssse3 - fix stack corruption with SSSE3 and AVX implementations
  crypto: caam - fix inconsistent assoc dma mapping direction

Pull CIFS fixes from Steve French:
 "Fixes for a couple of DFS problems, a problem with extended security
  negotiation and two other small cifs fixes"

* 'for-3.10' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix composing of mount options for DFS referrals
  cifs: stop printing the unc= option in /proc/mounts
  cifs: fix error handling when calling cifs_parse_devname
  cifs: allow sec=none mounts to work against servers that don't support extended security
  cifs: fix potential buffer overrun when composing a new options string
  cifs: only set ops for inodes in I_NEW state

Merge tag 'trace-fixes-v3.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two more fixes:

  The first one was reported by Mauro Carvalho Chehab, where if a poll()
  is done against a trace buffer for a CPU that has never been online,
  it will crash the kernel, as buffers are only created when a CPU comes
  on line, but the trace files are for all possible CPUs.

  This fix is to check if the buffer was allocated and if not return
  -EINVAL.

  That was the simple fix, the real fix is a bit more complex and not
  for a -rc release.  We could have the files created when the CPUs come
  online.  That would require some design changes.

  The second one was reported by Peter Zijlstra.  If the kernel command
  line has ftrace=nop, it will lock up the system on boot up.  This is
  because the new design for 3.10 has the nop tracer bootstrap the
  tracing subsystem.  When ftrace=<trace> is defined, when a that tracer
  is registered, it starts the tracing, but uses the nop tracer to clear
  things out.  What happened here was that ftrace=nop caused the
  registering of nop to start it and use nop before it was initialized.

  The only thing nop needs to have done to initialize it is to have the
  tracer point its current_tracer structure member to the nop tracer.
  Doing that before registering the nop tracer makes everything work."

* tag 'trace-fixes-v3.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Do not poll non allocated cpu buffers
  tracing: Fix crash when ftrace=nop on the kernel command line

Pull m68k fixes from Geert Uytterhoeven:
 - futex support that I had missed before,
 - A long-overdue update of the m68k defconfigs.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Update defconfigs for v3.9
  m68k: implement futex.h to support userspace robust futexes and PI mutexes

Pull microblaze fixes from Michal Simek:
 "One patch fix futex support and my patches fix warnings which were
  reported by Geert's regression testing"

* 'next' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Reversed logic in futex cmpxchg
  microblaze: Use proper casting for inb/inw/inl in io.h
  microblaze: Initialize temp variable to remove compilation warning

The tracing infrastructure sets up for possible CPUs, but it uses
the ring buffer polling, it is possible to call the ring buffer
polling code with a CPU that hasn't been allocated. This will cause
a kernel oops when it access a ring buffer cpu buffer that is part
of the possible cpus but hasn't been allocated yet as the CPU has never
been online.

Reported-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

The _XFER stack element size was set too small, 8 bytes, when it needs to be
16 bytes. As _XFER is the last stack element used by these implementations,
the 16 byte stores with 'movdqa' corrupt the stack where the value of register
%r12 is temporarily stored. As these implementations align the stack pointer
to 16 bytes, this corruption did not happen every time.

Patch corrects this issue.

Reported-by: Julian Wollrath <jwollrath@web.de>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Tested-by: Julian Wollrath <jwollrath@web.de>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

futex_atomic_cmpxchg_inatomic exchanged if the values were
unequal rather than equal. This caused incorrect behavior
of robust futexes.

Signed-off-by: Kirk Meyer <kirk.meyer@sencore.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

do_smart_update_queue() is called when an operation (semop,
semctl(SETVAL), semctl(SETALL), ...) modified the array.  It must check
which of the sleeping tasks can proceed.

do_smart_update_queue() missed a few wakeups:
 - if a sleeping complex op was completed, then all per-semaphore queues
   must be scanned - not only those that were modified by *sops
 - if a sleeping simple op proceeded, then the global queue must be
   scanned again

And:
 - the test for "|sops == NULL) before scanning the global queue is not
   required: If the global queue is empty, then it doesn't need to be
   scanned - regardless of the reason for calling do_smart_update_queue()

The patch is not optimized, i.e.  even completing a wait-for-zero
operation causes a rescan.  This is done to keep the patch as simple as
possible.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NFS client bugfixes from Trond Myklebust:

 - Stable fix to prevent an rpc_task wakeup race
 - Fix a NFSv4.1 session drain deadlock
 - Fix a NFSv4/v4.1 mount regression when not running rpc.gssd
 - Ensure auth_gss pipe detection works in namespaces
 - Fix SETCLIENTID fallback if rpcsec_gss is not available

* tag 'nfs-for-3.10-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix SETCLIENTID fallback if GSS is not available
  SUNRPC: Prevent an rpc_task wakeup race
  NFSv4.1 Fix a pNFS session draining deadlock
  SUNRPC: Convert auth_gss pipe detection to work in namespaces
  SUNRPC: Faster detection if gssd is actually running
  SUNRPC: Fix a bug in gss_create_upcall

Pull amd64 edac fix from Borislav Petkov:
 "A sysfs file permissions correction"

* tag 'edac_fixes_for_3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  amd64_edac: Fix bogus sysfs file permissions

Pull parisc fixes from Helge Deller:
 "This time we made the kernel- and interruption stack allocation
  reentrant which fixed some strange kernel crashes (specifically
  protection ID traps).

  Furthemore this patchset fixes the interrupt stack in UP and SMP
  configurations by using native locking instructions.  And finally
  usage of floating point calculations on parisc were disabled in the
  MPILIB."

* 'parisc-for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix irq stack on UP and SMP
  parisc/superio: Use module_pci_driver to register driver
  parisc: make interrupt and interruption stack allocation reentrant
  parisc: show number of FPE and unaligned access handler calls in /proc/interrupts
  parisc: add additional parisc git tree to MAINTAINERS file
  parisc: use PAGE_SHIFT instead of hardcoded value 12 in pacache.S
  parisc: add rp5470 entry to machine database
  MPILIB: disable usage of floating point registers on parisc

Pull xfs fixes from Ben Myers:
 "Here are fixes for corruption on 512 byte filesystems, a rounding
  error, a use-after-free, some flags to fix lockdep reports, and
  several fixes related to CRCs.  We have a somewhat larger post -rc1
  queue than usual due to fixes related to the CRC feature we merged for
  3.10:

   - Fix for corruption with FSX on 512 byte blocksize filesystems
   - Fix rounding error in xfs_free_file_space
   - Fix use-after-free with extent free intents
   - Add several missing KM_NOFS flags to fix lockdep reports
   - Several fixes for CRC related code"

* tag 'for-linus-v3.10-rc3' of git://oss.sgi.com/xfs/xfs:
  xfs: remote attribute lookups require the value length
  xfs: xfs_attr_shortform_allfit() does not handle attr3 format.
  xfs: xfs_da3_node_read_verify() doesn't handle XFS_ATTR3_LEAF_MAGIC
  xfs: fix missing KM_NOFS tags to keep lockdep happy
  xfs: Don't reference the EFI after it is freed
  xfs: fix rounding in xfs_free_file_space
  xfs: fix sub-page blocksize data integrity writes

Pull bettery fixes from Anton Vorontsov:
 "Last minute one-liners: wrong kfree usage fix, module alias fixup and
  kconfig adjustments"

* tag 'for-v3.10-fixes' of git://git.infradead.org/battery-2.6:
  pm2301_charger: Fix module alias prefix
  wm831x_backup: Fix wrong kfree call for devdata->backup.name
  bq27x00: Fix I2C dependency in KConfig
  lp8788-charger: Fix kconfig dependency

Pull power management and ACPI fixes from Rafael Wysocki:

 - Additional CPU ID for the intel_pstate driver from Dirk Brandewie.

 - More cpufreq fixes related to ARM big.LITTLE support and locking from
   Viresh Kumar.

 - VIA C7 cpufreq build fix from Rafał Bilski.

 - ACPI power management fix making it possible to use device power
   states regardless of the CONFIG_PM setting from Rafael J Wysocki.

 - New ACPI video blacklist item from Bastian Triller.

* tag 'pm+acpi-3.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: Add "Asus UL30A" to ACPI video detect blacklist
  cpufreq: arm_big_little_dt: Instantiate as platform_driver
  cpufreq: arm_big_little_dt: Register driver only if DT has valid data
  cpufreq / e_powersaver: Fix linker error when ACPI processor is a module
  cpufreq / intel_pstate: Add additional supported CPU ID
  cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT
  ACPI / PM: Allow device power states to be used for CONFIG_PM unset

Pull slave-dma fixes from Vinod Koul:
 "We have two patches from Andy & Rafael fixing the Lynxpoint dma"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  ACPI / LPSS: register clock device for Lynxpoint DMA properly
  dma: acpi-dma: parse CSRT to extract additional resources

kcore_vmalloc is in fs/proc/kcore.c and kcore_mem is unused across
the tree. Noticed while grepping the tree for some other kcore stuff.

(score looks pretty unmaintained to me.)

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARC fixes from Vineet Gupta:

 - Fallouts/wreckage of Cache Flush optimizations / aliasing dcache
   support

 - Fix for an interesting bug where piped input to grep was getting
   mysteriously clobbered

* tag 'arc-v3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: lazy dcache flush broke gdb in non-aliasing configs
  ARC: Use enough bits for determining page's cache color
  ARC: Brown paper bag bug in macro for checking cache color
  ARC: copy_(to|from)_user() to honor usermode-access permissions
  ARC: [mm] Prevent stray dcache lines after__sync_icache_dcach()
  ARC: [TB10x] Remove redundant abilis,simple-pinctrl mechanism

Pull ARM fixes from Russell King:
 "Just three this time, all really quite small"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7729/1: vfp: ensure VFP_arch is non-zero when VFP is not supported
  ARM: 7727/1: remove the .vm_mm value from gate_vma
  ARM: 7723/1: crypto: sha1-armv4-large.S: fix SP handling

gdbserver inserting a breakpoint ends up calling copy_user_page() for a
code page. The generic version of which (non-aliasing config) didn't set
the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for
corresponding dynamic loader code page - causing garbade to be executed.

So now aliasing versions of copy_user_highpage()/clear_page() are made
default. There is no significant overhead since all of special alias
handling code is compiled out for non-aliasing build

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Merge fixes from Andrew Morton:
 "A bunch of fixes and one simple fbdev driver which missed the merge
  window because people will still talking about it (to no great
  effect)."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (30 commits)
  aio: fix kioctx not being freed after cancellation at exit time
  mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areas
  drivers/rtc/rtc-max8998.c: check for pdata presence before dereferencing
  ocfs2: goto out_unlock if ocfs2_get_clusters_nocache() failed in ocfs2_fiemap()
  random: fix accounting race condition with lockless irq entropy_count update
  drivers/char/random.c: fix priming of last_data
  mm/memory_hotplug.c: fix printk format warnings
  nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary
  drivers/block/brd.c: fix brd_lookup_page() race
  fbdev: FB_GOLDFISH should depend on HAS_DMA
  drivers/rtc/rtc-pl031.c: pass correct pointer to free_irq()
  auditfilter.c: fix kernel-doc warnings
  aio: fix io_getevents documentation
  revert "selftest: add simple test for soft-dirty bit"
  drivers/leds/leds-ot200.c: fix error caused by shifted mask
  mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer
  linux/kernel.h: fix kernel-doc warning
  mm compaction: fix of improper cache flush in migration code
  rapidio/tsi721: fix bug in MSI interrupt handling
  hfs: avoid crash in hfs_bnode_create
  ...

Pull ARM SoC fixes from Olof Johansson:
 "We didn't have any fixes sent up for -rc2, so this is a slightly
  larger batch.  A bit all over the place platform-wise; OMAP, at91,
  marvell, renesas, sunxi, ux500, etc.

  I tried to summarize highlights but there isn't a whole lot to point
  out.  Lots of little things fixed all over.  A couple of defconfig
  updates due to new/changing options."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (44 commits)
  ARM: at91/sama5: fix incorrect PMC pcr div definition
  ARM: at91/dt: fix macb pinctrl_macb_rmii_mii_alt definition
  ARM: at91: at91sam9n12: move external irq declatation to DT
  ARM: shmobile: marzen: Use error values in usb_power_*
  ARM: tegra: defconfig fixes
  ARM: nomadik: fix IRQ assignment for SMC ethernet
  ARM: vt8500: Add missing NULL terminator in dt_compat
  clk: tegra: add ac97 controller clock
  clk: tegra: remove USB from clk init table
  ARM: dts: mvebu: Fix wrong the address reg value for the L2-cache node
  ARM: plat-orion: Fix num_resources and id for ge10 and ge11
  ARM: OMAP2+: hwmod: Remove sysc slave idle and auto idle apis
  SERIAL: OMAP: Remove the slave idle handling from the driver
  ARM: OMAP2+: serial: Remove the un-used slave idle hooks
  ARM: OMAP2+: hwmod-data: UART IP needs software control to manage sidle modes
  ARM: OMAP2+: hwmod: Add a new flag to handle SIDLE in SWSUP only in active
  ARM: OMAP2+: hwmod: Fix sidle programming in _enable_sysc()/_idle_sysc()
  arm: mvebu: fix the 'ranges' property to handle PCIe
  ARM: mvebu: select ARCH_REQUIRE_GPIOLIB for mvebu platform
  ARM: AM33XX: Add missing .clkdm_name to clkdiv32k_ick clock
  ...

The recent changes overhauling fs/aio.c introduced a bug that results in
the kioctx not being freed when outstanding kiocbs are cancelled at
exit_aio() time.  Specifically, a kiocb that is cancelled has its
completion events discarded by batch_complete_aio(), which then fails to
wake up the process stuck in free_ioctx().  Fix this by modifying the
wait_event() condition in free_ioctx() appropriately.

This patch was tested with the cancel operation in the thread based code
posted yesterday.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Zach Brown <zab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A panic can be caused by simply cat'ing /proc/<pid>/smaps while an
application has a VM_PFNMAP range.  It happened in-house when a
benchmarker was trying to decipher the memory layout of his program.

/proc/<pid>/smaps and similar walks through a user page table should not
be looking at VM_PFNMAP areas.

Certain tests in walk_page_range() (specifically split_huge_page_pmd())
assume that all the mapped PFN's are backed with page structures.  And
this is not usually true for VM_PFNMAP areas.  This can result in panics
on kernel page faults when attempting to address those page structures.

There are a half dozen callers of walk_page_range() that walk through a
task's entire page table (as N.  Horiguchi pointed out).  So rather than
change all of them, this patch changes just walk_page_range() to ignore
VM_PFNMAP areas.

The logic of hugetlb_vma() is moved back into walk_page_range(), as we
want to test any vma in the range.

VM_PFNMAP areas are used by:
- graphics memory manager   gpu/drm/drm_gem.c
- global reference unit     sgi-gru/grufile.c
- sgi special memory        char/mspec.c
- and probably several out-of-tree modules

[akpm@linux-foundation.org: remove now-unused hugetlb_vma() stub]
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>