commit b24f670b7f5b2058b95370caa9f104b3cefb9f1d upstream.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

commit e4dc601bf99ccd1c95b7e6eef1d3cf3c4b0d4961 upstream.

hwreg_present() and hwreg_write() temporarily change the VBR register to
another vector table. This table contains a valid bus error handler
only, all other entries point to arbitrary addresses.

If an interrupt comes in while the temporary table is active, the
processor will start executing at such an arbitrary address, and the
kernel will crash.

While most callers run early, before interrupts are enabled, or
explicitly disable interrupts, Finn Thain pointed out that macsonic has
one callsite that doesn't, causing intermittent boot crashes.
There's another unsafe callsite in hilkbd.

Fix this for good by disabling and restoring interrupts inside
hwreg_present() and hwreg_write().

Explicitly disabling interrupts can be removed from the callsites later.

Reported-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

commit e571c58f313d35c56e0018470e3375ddd1fd320e upstream.

Skip the futex_atomic_cmpxchg_inatomic() test in futex_init(). It causes a
fatal exception on 68030 (and presumably 68020 also).

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1403061006440.5525@nippy.intranet
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.

Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull m68knommu fixes from Greg Ungerer:
 "Just a small collection of cleanups and fixes this time, no big
  changes.  The most interresting are to make the m68k and m68knommu
  consistently use CONFIG_IOMAP, clean out some unused board config
  options and flush the cache on signal stack creation"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: remove 16 unused boards in Kconfig.machine
  m68k: define 'VM_DATA_DEFAULT_FLAGS' no matter whether has 'NOMMU' or not
  m68knommu: user generic iomap to support ioread*/iowrite*
  m68k/coldfire: flush cache when creating the signal stack frame
  m68knommu: Mark functions only called from setup_arch() __init

Pull PTR_RET() removal patches from Rusty Russell:
 "PTR_RET() is a weird name, and led to some confusing usage.  We ended
  up with PTR_ERR_OR_ZERO(), and replacing or fixing all the usages.

  This has been sitting in linux-next for a whole cycle"

[ There are still some PTR_RET users scattered about, with some of them
  possibly being new, but most of them existing in Rusty's tree too.  We
  have that

      #define PTR_RET(p) PTR_ERR_OR_ZERO(p)

  thing in <linux/err.h>, so they continue to work for now  - Linus ]

* tag 'PTR_RET-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  GFS2: Replace PTR_RET with PTR_ERR_OR_ZERO
  Btrfs: volume: Replace PTR_RET with PTR_ERR_OR_ZERO
  drm/cma: Replace PTR_RET with PTR_ERR_OR_ZERO
  sh_veu: Replace PTR_RET with PTR_ERR_OR_ZERO
  dma-buf: Replace PTR_RET with PTR_ERR_OR_ZERO
  drivers/rtc: Replace PTR_RET with PTR_ERR_OR_ZERO
  mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR().
  staging/zcache: don't use PTR_RET().
  remoteproc: don't use PTR_RET().
  pinctrl: don't use PTR_RET().
  acpi: Replace weird use of PTR_RET.
  s390: Replace weird use of PTR_RET.
  PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
  PTR_RET is now PTR_ERR_OR_ZERO

Pull timers/nohz changes from Ingo Molnar:
 "It mostly contains fixes and full dynticks off-case optimizations, by
  Frederic Weisbecker"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  nohz: Include local CPU in full dynticks global kick
  nohz: Optimize full dynticks's sched hooks with static keys
  nohz: Optimize full dynticks state checks with static keys
  nohz: Rename a few state variables
  vtime: Always debug check snapshot source _before_ updating it
  vtime: Always scale generic vtime accounting results
  vtime: Optimize full dynticks accounting off case with static keys
  vtime: Describe overriden functions in dedicated arch headers
  m68k: hardirq_count() only need preempt_mask.h
  hardirq: Split preempt count mask definitions
  context_tracking: Split low level state headers
  vtime: Fix racy cputime delta update
  vtime: Remove a few unneeded generic vtime state checks
  context_tracking: User/kernel broundary cross trace events
  context_tracking: Optimize context switch off case with static keys
  context_tracking: Optimize guest APIs off case with static key
  context_tracking: Optimize main APIs off case with static key
  context_tracking: Ground setup for static key use
  context_tracking: Remove full dynticks' hacky dependency on wide context tracking
  nohz: Only enable context tracking on full dynticks CPUs
  ...

Pull PCI changes from Bjorn Helgaas:

  PCI device hotplug:
    - Use PCIe native hotplug, not ACPI hotplug, when possible (Neil Horman)
    - Assign resources on per-host bridge basis (Yinghai Lu)

  MPS (Max Payload Size):
    - Allow larger MPS settings below hotplug-capable Root Port (Yijing Wang)
    - Add warnings about unsafe MPS settings (Yijing Wang)
    - Simplify interface and messages (Bjorn Helgaas)

  SR-IOV:
    - Return -ENOSYS on non-SR-IOV devices (Stefan Assmann)
    - Update NumVFs register when disabling SR-IOV (Yijing Wang)

  Virtualization:
    - Add bus and slot reset support (Alex Williamson)
    - Fix ACS (Access Control Services) issues (Alex Williamson)

  Miscellaneous:
    - Simplify PCIe Capability accessors (Bjorn Helgaas)
    - Add pcibios_pm_ops for arch-specific hibernate stuff (Sebastian Ott)
    - Disable decoding during BAR sizing only when necessary (Zoltan Kiss)
    - Delay enabling bridges until they're needed (Yinghai Lu)
    - Split Designware support into Synopsys and Exynos parts (Jingoo Han)
    - Convert class code to use dev_groups (Greg Kroah-Hartman)
    - Cleanup Designware and Exynos I/O access wrappers (Seungwon Jeon)
    - Fix bridge I/O window alignment (Bjorn Helgaas)
    - Add pci_wait_for_pending_transaction() (Casey Leedom)
    - Use devm_ioremap_resource() in Marvell driver (Tushar Behera)

* tag 'pci-v3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (63 commits)
  PCI/ACPI: Fix _OSC ordering to allow PCIe hotplug use when available
  PCI: exynos: Add I/O access wrappers
  PCI: designware: Drop "addr" arg from dw_pcie_readl_rc()/dw_pcie_writel_rc()
  PCI: Remove pcie_cap_has_devctl()
  PCI: Support PCIe Capability Slot registers only for ports with slots
  PCI: Remove PCIe Capability version checks
  PCI: Allow PCIe Capability link-related register access for switches
  PCI: Add offsets of PCIe capability registers
  PCI: Tidy bitmasks and spacing of PCIe capability definitions
  PCI: Remove obsolete comment reference to pci_pcie_cap2()
  PCI: Clarify PCI_EXP_TYPE_PCI_BRIDGE comment
  PCI: Rename PCIe capability definitions to follow convention
  PCI: Warn if unsafe MPS settings detected
  PCI: Fix MPS peer-to-peer DMA comment syntax
  PCI: Disable decoding for BAR sizing only when it was actually enabled
  PCI: Add comment about needing pci_msi_off() even when CONFIG_PCI_MSI=n
  PCI: Add pcibios_pm_ops for optional arch-specific hibernate functionality
  PCI: Don't restrict MPS for slots below Root Ports
  PCI: Simplify MPS test for Downstream Port
  PCI: Remove unnecessary check for pcie_get_mps() failure
  ...