Fix attribute-creation race with userspace by using the default group
to create also the contingent gpio device attributes.

Fixes: d8f388d8 ("gpio: sysfs interface")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The gpio device attributes were never destroyed when the gpio was
unexported (or on export failures).

Use device_create_with_groups() to create the default device attributes
of the gpio class device. Note that this also fixes the
attribute-creation race with userspace for these attributes.

Remove contingent attributes in export error path and on unexport.

Fixes: d8f388d8 ("gpio: sysfs interface")
Cc: stable <stable@vger.kernel.org>	# v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The gpio-chip device attributes were never destroyed when the device was
removed.

Fix by using device_create_with_groups() to create the device attributes
of the chip class device.

Note that this also fixes the attribute-creation race with userspace.

Fixes: d8f388d8 ("gpio: sysfs interface")
Cc: stable <stable@vger.kernel.org>	# v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Unregister gpiochip device (used to export information through sysfs)
before removing it internally. This way removal will reverse addition.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Move direct and indirect calls to gpiochip_remove_pin_ranges outside of
spin lock as they can end up taking a mutex in pinctrl_remove_gpio_range.

Note that the pin ranges are already added outside of the lock.

Fixes: 9ef0d6f7 ("gpiolib: call pin removal in chip removal function")
Fixes: f23f1516 ("gpiolib: provide provision to register pin ranges")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Fix memory leak and sleep-while-atomic in gpiochip_remove.

The memory leak was introduced by afa82fab ("gpio / ACPI: Move event
handling registration to gpiolib irqchip helpers") that moved the
release of acpi interrupt resources to gpiochip_irqchip_remove, but by
then the resources are no longer accessible as the acpi_gpio_chip has
already been freed by acpi_gpiochip_remove.

Note that this also fixes a few potential sleep-while-atomics, which has
been around since 14250520 ("gpio: add IRQ chip helpers in gpiolib")
when the call to gpiochip_irqchip_remove while holding a spinlock was
added (a couple of irq-domain paths can end up grabbing mutexes).

Fixes: afa82fab ("gpio / ACPI: Move event handling registration to
gpiolib irqchip helpers")
Fixes: 14250520 ("gpio: add IRQ chip helpers in gpiolib")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Clean up gpiochip_add error handling.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Fix potential corruption of gpio-chip list due to failure to remove the
chip from the list before returning in gpiochip_add error path.

The chip could be long gone when the global list is next traversed,
something which could lead to a null-pointer dereference. In the best
case (chip not deallocated) we are just leaking the gpio range.

Fixes: 14e85c0e ("gpio: remove gpio_descs global array")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Memory allocated and references taken by of_gpiochip_add and
acpi_gpiochip_add were never released on errors in gpiochip_add (e.g.
failure to find free gpio range).

Fixes: 391c970c ("of/gpio: add default of_xlate function if device
has a node pointer")
Fixes: 664e3e5a ("gpio / ACPI: register to ACPI events
automatically")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The CrystalCove GPIO chip has can_sleep set so its demultiplexed irqs
will have IRQ_NESTED_THREAD flag set, thus we should use the nested
version handle_nested_irq in CrystalCove's irq handler instead of
handle_generic_irq, or the following warning will be hit and the
functionality is lost:

[ 4089.639554] Hardware name: ASUSTeK COMPUTER INC. T100TA/T100TA, BIOS T100TA.313 08/13/2014
[ 4089.639564]  00000002 00000000 c24fbdf4 c16e0257 c24fbe38 c24fbe28 c105390c c18ec480
[ 4089.639596]  c24fbe54 00000048 c18f8e3b 00000295 c10a60fc 00000295 c10a60fc f4464540
[ 4089.639626]  f446459c c278ad40 c24fbe40 c1053974 00000009 c24fbe38 c18ec480 c24fbe54
[ 4089.639656] Call Trace:
[ 4089.639685]  [<c16e0257>] dump_stack+0x41/0x52
[ 4089.639707]  [<c105390c>] warn_slowpath_common+0x8c/0xc0
[ 4089.639727]  [<c10a60fc>] ? irq_nested_primary_handler+0x2c/0x30
[ 4089.639744]  [<c10a60fc>] ? irq_nested_primary_handler+0x2c/0x30
[ 4089.639763]  [<c1053974>] warn_slowpath_fmt+0x34/0x40
[ 4089.639781]  [<c10a60fc>] irq_nested_primary_handler+0x2c/0x30
[ 4089.639800]  [<c10a5c56>] handle_irq_event_percpu+0x76/0x190
[ 4089.639818]  [<c1461570>] ? regmap_format_10_14_write+0x30/0x30
[ 4089.639836]  [<c1464f4c>] ? _regmap_bus_raw_write+0x4c/0x70
[ 4089.639854]  [<c10a5da1>] handle_irq_event+0x31/0x50
[ 4089.639872]  [<c10a83eb>] handle_simple_irq+0x4b/0x70
[ 4089.639889]  [<c10a5384>] generic_handle_irq+0x24/0x40
[ 4089.639908]  [<c1366d87>] crystalcove_gpio_irq_handler+0xa7/0xc0
[ 4089.639927]  [<c10a85a7>] handle_nested_irq+0x77/0x190
[ 4089.639947]  [<c1469801>] regmap_irq_thread+0x1b1/0x360
[ 4089.639966]  [<c10a6ae8>] irq_thread_fn+0x18/0x30
[ 4089.639983]  [<c10a6906>] irq_thread+0xf6/0x110
[ 4089.640001]  [<c10a6ad0>] ? irq_finalize_oneshot.part.30+0x1b0/0x1b0
[ 4089.640019]  [<c10a6b50>] ? irq_forced_thread_fn+0x50/0x50
[ 4089.640037]  [<c10a6810>] ? irq_thread_check_affinity+0xc0/0xc0
[ 4089.640054]  [<c106f389>] kthread+0xa9/0xc0
[ 4089.640074]  [<c16e6401>] ret_from_kernel_thread+0x21/0x30
[ 4089.640091]  [<c106f2e0>] ? kthread_create_on_node+0x110/0x110
[ 4089.640105] ---[ end trace dca7946ad31eba7d ]---

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=90521Reported-and-tested-by: Brian Loften <bloften80@gmail.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull ARM fixes from Russell King:
 "Three small fixes from over the Christmas period, and wiring up the
  new execveat syscall for ARM"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8275/1: mm: fix PMD_SECT_RDONLY undeclared compile error
  ARM: 8253/1: mm: use phys_addr_t type in map_lowmem() for kernel mem region
  ARM: 8249/1: mm: dump: don't skip regions
  ARM: wire up execveat syscall

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: two vdso fixes, two kbuild fixes and a boot failure fix
  with certain odd memory mappings"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso: Use asm volatile in __getcpu
  x86/build: Clean auto-generated processor feature files
  x86: Fix mkcapflags.sh bash-ism
  x86: Fix step size adjustment during initial memory mapping
  x86_64, vdso: Fix the vdso address randomization algorithm

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: group scheduling corner case fix, two deadline scheduler
  fixes, effective_load() overflow fix, nested sleep fix, 6144 CPUs
  system fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
  sched/deadline: Avoid double-accounting in case of missed deadlines
  sched/deadline: Fix migration of SCHED_DEADLINE tasks
  sched: Fix odd values in effective_load() calculations
  sched, fanotify: Deal with nested sleeps
  sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also some kernel side fixes: uncore PMU
  driver fix, user regs sampling fix and an instruction decoder fix that
  unbreaks PEBS precise sampling"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore/hsw-ep: Handle systems with only two SBOXes
  perf/x86_64: Improve user regs sampling
  perf: Move task_pt_regs sampling into arch code
  x86: Fix off-by-one in instruction decoder
  perf hists browser: Fix segfault when showing callchain
  perf callchain: Free callchains when hist entries are deleted
  perf hists: Fix children sort key behavior
  perf diff: Fix to sort by baseline field by default
  perf list: Fix --raw-dump option
  perf probe: Fix crash in dwarf_getcfi_elf
  perf probe: Fix to fall back to find probe point in symbols
  perf callchain: Append callchains only when requested
  perf ui/tui: Print backtrace symbols when segfault occurs
  perf report: Show progress bar for output resorting

Pull locking fixes from Ingo Molnar:
 "A liblockdep fix and a mutex_unlock() mutex-debugging fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Always clear owner field upon mutex_unlock()
  tools/liblockdep: Fix debug_check thinko in mutex destroy

Fix for BUG_ON(anon_vma->degree) splashes in unlink_anon_vmas() ("kernel
BUG at mm/rmap.c:399!") caused by commit 7a3ef208 ("mm: prevent
endless growth of anon_vma hierarchy")

Anon_vma_clone() is usually called for a copy of source vma in
destination argument.  If source vma has anon_vma it should be already
in dst->anon_vma.  NULL in dst->anon_vma is used as a sign that it's
called from anon_vma_fork().  In this case anon_vma_clone() finds
anon_vma for reusing.

Vma_adjust() calls it differently and this breaks anon_vma reusing
logic: anon_vma_clone() links vma to old anon_vma and updates degree
counters but vma_adjust() overrides vma->anon_vma right after that.  As
a result final unlink_anon_vmas() decrements degree for wrong anon_vma.

This patch assigns ->anon_vma before calling anon_vma_clone().
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com>
Reported-and-tested-by: Oded Gabbay <oded.gabbay@amd.com>
Reported-and-tested-by: Chih-Wei Huang <cwhuang@android-x86.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Daniel Forrest <dan.forrest@ssec.wisc.edu>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org  # to match back-porting of 7a3ef208Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit fee7e49d ("mm: propagate error from stack expansion even for
guard page") made sure that we return the error properly for stack
growth conditions.  It also theorized that counting the guard page
towards the stack limit might break something, but also said "Let's see
if anybody notices".

Somebody did notice.  Apparently android-x86 sets the stack limit very
close to the limit indeed, and including the guard page in the rlimit
check causes the android 'zygote' process problems.

So this adds the (fairly trivial) code to make the stack rlimit check be
against the actual real stack size, rather than the size of the vma that
includes the guard page.
Reported-and-tested-by: Chih-Wei Huang <cwhuang@android-x86.org>
Cc: Jay Foad <jay.foad@gmail.com>
Cc: stable@kernel.org  # to match back-porting of fee7e49dSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull VFIO fix from Alex Williamson:
 "Fix PCI header check in vfio_pci_probe() (Wei Yang)"

* tag 'vfio-v3.19-rc4' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Fix the check on pci device type in vfio_pci_probe()

Pull SCSI fix from James Bottomley:
 "Just one fix: a qlogic busy wait regression"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  qla2xxx: fix busy wait regression

Pull sound fixes from Takashi Iwai:
 "All a few small regression or stable fixes: a Nvidia HDMI ID addition,
  a regression fix for CAIAQ stream count, a typo fix for GPIO setup
  with STAC/IDT HD-audio codecs, and a Fireworks big-endian fix"

* tag 'sound-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: fireworks: fix an endianness bug for transaction length
  ALSA: hda - Add new GPU codec ID 0x10de0072 to snd-hda
  ALSA: hda - Fix wrong gpio_dir & gpio_mask hint setups for IDT/STAC codecs
  ALSA: snd-usb-caiaq: fix stream count check

Pull HID updates from Jiri Kosina:

 - bounds checking fixes in logitech and roccat drivers, from Peter Wu
   and Dan Carpenter

 - double-kfree fix in i2c-hid driver on bus shutdown, from Mika
   Westerberg

 - a couple of various small driver fixes

 - a few device id additions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: roccat: potential out of bounds in pyra_sysfs_write_settings()
  HID: Add a new id 0x501a for Genius MousePen i608X
  HID: logitech-hidpp: prefix the name with "Logitech"
  HID: logitech-hidpp: avoid unintended fall-through
  HID: Allow HID_BATTERY_STRENGTH to be enabled
  HID: i2c-hid: Do not free buffers in i2c_hid_stop()
  HID: add battery quirk for USB_DEVICE_ID_APPLE_ALU_WIRELESS_2011_ISO keyboard
  HID: logitech-hidpp: check WTP report length
  HID: logitech-dj: check report length

Pull drm fixes from Dave Airlie:
 "I'm briefly working between holidays and LCA, so this is close to a
  couple of weeks of fixes,

  Two sets of amdkfd fixes, this is a new feature this kernel, and this
  pull fixes a few issues since it got merged, ordering when built-in to
  kernel and also the iommu vs gpu ordering patch, it also reworks the
  ioctl before the initial release.

  Otherwise:
   - radeon: some misc fixes all over, hdmi, 4k, dpm
   - nouveau: mcp77 init fixes, oops fix, bug on fix, msi fix
   - i915: power fixes, revert VGACNTR patch

  Probably be quiteer next week since I'll be at LCA anyways"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (33 commits)
  drm/amdkfd: rewrite kfd_ioctl() according to drm_ioctl()
  drm/amdkfd: reformat IOCTL definitions to drm-style
  drm/amdkfd: Do copy_to/from_user in general kfd_ioctl()
  drm/radeon: integer underflow in radeon_cp_dispatch_texture()
  drm/radeon: adjust default bapm settings for KV
  drm/radeon: properly filter DP1.2 4k modes on non-DP1.2 hw
  drm/radeon: fix sad_count check for dce3
  drm/radeon: KV has three PPLLs (v2)
  drm/amdkfd: unmap VMID<-->PASID when relesing VMID (non-HWS)
  drm/radeon: Init amdkfd only if it was compiled
  amdkfd: actually allocate longs for the pasid bitmask
  drm/nouveau/nouveau: Do not BUG_ON(!spin_is_locked()) on UP
  drm/nv4c/mc: disable msi
  drm/nouveau/fb/ram/mcp77: enable NISO poller
  drm/nouveau/fb/ram/mcp77: use carveout reg to determine size
  drm/nouveau/fb/ram/mcp77: subclass nouveau_ram
  drm/nouveau: wake up the card if necessary during gem callbacks
  drm/nouveau/device: Add support for GK208B, resolves bug 86935
  drm/nouveau: fix missing return statement in nouveau_ttm_tt_unpopulate
  drm/nouveau/bios: fix oops on pre-nv50 chipsets
  ...

Pull arm64 fixes from Will Deacon:
 "Here is a handful of minor arm64 fixes discovered and fixed over the
  Christmas break.  The main part is adding some missing #includes that
  we seem to be getting transitively but have started causing problems
  in -next.

   - Fix early mapping fixmap corruption by EFI runtime services
   - Fix __NR_compat_syscalls off-by-one
   - Add missing sanity checks for some 32-bit registers
   - Add some missing #includes which we get transitively
   - Remove unused prepare_to_copy() macro"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/efi: add missing call to early_ioremap_reset()
  arm64: fix missing asm/io.h include in kernel/smp_spin_table.c
  arm64: fix missing asm/alternative.h include in kernel/module.c
  arm64: fix missing linux/bug.h include in asm/arch_timer.h
  arm64: fix missing asm/pgtable-hwdef.h include in asm/processor.h
  arm64: sanity checks: add missing AArch32 registers
  arm64: Remove unused prepare_to_copy()
  arm64: Correct __NR_compat_syscalls for bpf

Pull kgdb/kdb fixes from Jason Wessel:
 "These have been around since 3.17 and in kgdb-next for the last 9
  weeks and some will go back to -stable.

  Summary of changes:

  Cleanups
   - kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE

  Fixes
   - kgdb/kdb: Allow access on a single core, if a CPU round up is
     deemed impossible, which will allow inspection of the now "trashed"
     kernel
   - kdb: Add enable mask for the command groups
   - kdb: access controls to restrict sensitive commands"

* tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kernel/debug/debug_core.c: Logging clean-up
  kgdb: timeout if secondary CPUs ignore the roundup
  kdb: Allow access to sensitive commands to be restricted by default
  kdb: Add enable mask for groups of commands
  kdb: Categorize kdb commands (similar to SysRq categorization)
  kdb: Remove KDB_REPEAT_NONE flag
  kdb: Use KDB_REPEAT_* values as flags
  kdb: Rename kdb_register_repeat() to kdb_register_flags()
  kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
  kdb: Remove currently unused kdbtab_t->cmd_flags

Pull two nfsd bugfixes from Bruce Fields.

* 'for-3.19' of git://linux-nfs.org/~bfields/linux:
  rpc: fix xdr_truncate_encode to handle buffer ending on page boundary
  nfsd: fix fi_delegees leak when fi_had_conflict returns true

Pull two Ceph fixes from Sage Weil:
 "These are both pretty trivial: a sparse warning fix and size_t printk
  thing"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: fix sparse endianness warnings
  ceph: use %zu for len in ceph_fill_inline_data()

Pull btrfs fixes from Chris Mason:
 "None of these are huge, but my commit does fix a regression from 3.18
  that could cause lost files during log replay.

  This also adds Dave Sterba to the list of Btrfs maintainers.  It
  doesn't mean we're doing things differently, but Dave has really been
  helping with the maintainer workload for years"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: don't delay inode ref updates during log replay
  Btrfs: correctly get tree level in tree_backref_for_extent
  Btrfs: call inode_dec_link_count() on mkdir error path
  Btrfs: abort transaction if we don't find the block group
  Btrfs, scrub: uninitialized variable in scrub_extent_for_parity()
  Btrfs: add more maintainers

Merge misc fixes from Andrew Morton:
 "12 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process being killed
  memcg: fix destination cgroup leak on task charges migration
  mm: memcontrol: switch soft limit default back to infinity
  mm/debug_pagealloc: remove obsolete Kconfig options
  vfs: renumber FMODE_NONOTIFY and add to uniqueness check
  arch/blackfin/mach-bf533/boards/stamp.c: add linux/delay.h
  ocfs2: fix the wrong directory passed to ocfs2_lookup_ino_from_name() when link file
  MAINTAINERS: update rydberg's addresses
  mm: protect set_page_dirty() from ongoing truncation
  mm: prevent endless growth of anon_vma hierarchy
  exit: fix race between wait_consider_task() and wait_task_zombie()
  ocfs2: remove bogus check in dlm_process_recovery_data

In v3.19-rc3 tree when CONFIG_ARM_LPAE and CONFIG_DEBUG_RODATA are enabled
image failed to compile with the following error:

arch/arm/mm/init.c:661:14: error: ‘PMD_SECT_RDONLY’ undeclared here (not in a function)

It seems that '80d6b0c2 ARM: mm: allow text and rodata sections to be read-only'
and 'ded94779 ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE'
commits crossed. 80d6b0c2 uses PMD_SECT_RDONLY macro but ded94779 renames it
and uses software bits L_PMD_SECT_RDONLY instead.

Fix is to use L_PMD_SECT_RDONLY instead PMD_SECT_RDONLY as ded94779 does in
another places.
Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This is a static checker fix.  We write some binary settings to the
sysfs file.  One of the settings is the "->startup_profile".  There
isn't any checking to make sure it fits into the
pyra->profile_settings[] array in the profile_activated() function.

I added a check to pyra_sysfs_write_settings() in both places because
I wasn't positive that the other callers were correct.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Currently if DEBUG_MUTEXES is enabled, the mutex->owner field is only
cleared iff debug_locks is active. This exposes a race to other users of
the field where the mutex->owner may be still set to a stale value,
potentially upsetting mutex_spin_on_owner() among others.

References: https://bugs.freedesktop.org/show_bug.cgi?id=87955Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1420540175-30204-1-git-send-email-chris@chris-wilson.co.ukSigned-off-by: Ingo Molnar <mingo@kernel.org>

When alloc_fair_sched_group() in sched_create_group() fails,
free_sched_group() is called, and free_fair_sched_group() is called by
free_sched_group(). Since destroy_cfs_bandwidth() is called by
free_fair_sched_group() without calling init_cfs_bandwidth(),
RCU stall occurs at hrtimer_cancel():

  INFO: rcu_sched self-detected stall on CPU { 1}  (t=60000 jiffies g=13074 c=13073 q=0)
  Task dump for CPU 1:
  (fprintd)       R  running task        0  6249      1 0x00000088
  ...
  Call Trace:
   <IRQ>  [<ffffffff81094988>] sched_show_task+0xa8/0x110
   [<ffffffff81097acd>] dump_cpu_task+0x3d/0x50
   [<ffffffff810c3a80>] rcu_dump_cpu_stacks+0x90/0xd0
   [<ffffffff810c7751>] rcu_check_callbacks+0x491/0x700
   [<ffffffff810cbf2b>] update_process_times+0x4b/0x80
   [<ffffffff810db046>] tick_sched_handle.isra.20+0x36/0x50
   [<ffffffff810db0a2>] tick_sched_timer+0x42/0x70
   [<ffffffff810ccb19>] __run_hrtimer+0x69/0x1a0
   [<ffffffff810db060>] ? tick_sched_handle.isra.20+0x50/0x50
   [<ffffffff810ccedf>] hrtimer_interrupt+0xef/0x230
   [<ffffffff810452cb>] local_apic_timer_interrupt+0x3b/0x70
   [<ffffffff8164a465>] smp_apic_timer_interrupt+0x45/0x60
   [<ffffffff816485bd>] apic_timer_interrupt+0x6d/0x80
   <EOI>  [<ffffffff810cc588>] ? lock_hrtimer_base.isra.23+0x18/0x50
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810cc9d2>] hrtimer_try_to_cancel+0x22/0xd0
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810ccaa2>] hrtimer_cancel+0x22/0x30
   [<ffffffff810a3cb5>] free_fair_sched_group+0x25/0xd0
   [<ffffffff8108df46>] free_sched_group+0x16/0x40
   [<ffffffff810971bb>] sched_create_group+0x4b/0x80
   [<ffffffff810aa383>] sched_autogroup_create_attach+0x43/0x1c0
   [<ffffffff8107dc9c>] sys_setsid+0x7c/0x110
   [<ffffffff81647729>] system_call_fastpath+0x12/0x17

Check whether init_cfs_bandwidth() was called before calling
destroy_cfs_bandwidth().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
[ Move the check into destroy_cfs_bandwidth() to aid compilability. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/201412252210.GCC30204.SOMVFFOtQJFLOH@I-love.SAKURA.ne.jpSigned-off-by: Ingo Molnar <mingo@kernel.org>

The dl_runtime_exceeded() function is supposed to ckeck if
a SCHED_DEADLINE task must be throttled, by checking if its
current runtime is <= 0. However, it also checks if the
scheduling deadline has been missed (the current time is
larger than the current scheduling deadline), further
decreasing the runtime if this happens.
This "double accounting" is wrong:

- In case of partitioned scheduling (or single CPU), this
  happens if task_tick_dl() has been called later than expected
  (due to small HZ values). In this case, the current runtime is
  also negative, and replenish_dl_entity() can take care of the
  deadline miss by recharging the current runtime to a value smaller
  than dl_runtime

- In case of global scheduling on multiple CPUs, scheduling
  deadlines can be missed even if the task did not consume more
  runtime than expected, hence penalizing the task is wrong

This patch fix this problem by throttling a SCHED_DEADLINE task
only when its runtime becomes negative, and not modifying the runtime
Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1418813432-20797-3-git-send-email-luca.abeni@unitn.itSigned-off-by: Ingo Molnar <mingo@kernel.org>

According to global EDF, tasks should be migrated between runqueues
without checking if their scheduling deadlines and runtimes are valid.
However, SCHED_DEADLINE currently performs such a check:
a migration happens doing:

	deactivate_task(rq, next_task, 0);
	set_task_cpu(next_task, later_rq->cpu);
	activate_task(later_rq, next_task, 0);

which ends up calling dequeue_task_dl(), setting the new CPU, and then
calling enqueue_task_dl().

enqueue_task_dl() then calls enqueue_dl_entity(), which calls
update_dl_entity(), which can modify scheduling deadline and runtime,
breaking global EDF scheduling.

As a result, some of the properties of global EDF are not respected:
for example, a taskset {(30, 80), (40, 80), (120, 170)} scheduled on
two cores can have unbounded response times for the third task even
if 30/80+40/80+120/170 = 1.5809 < 2

This can be fixed by invoking update_dl_entity() only in case of
wakeup, or if this is a new SCHED_DEADLINE task.
Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1418813432-20797-2-git-send-email-luca.abeni@unitn.itSigned-off-by: Ingo Molnar <mingo@kernel.org>

In effective_load, we have (long w * unsigned long tg->shares) / long W,
when w is negative, it is cast to unsigned long and hence the product is
insanely large. Fix this by casting tg->shares to long.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141219002956.GA25405@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

As per e23738a7 ("sched, inotify: Deal with nested sleeps").

fanotify_read is a wait loop with sleeps in. Wait loops rely on
task_struct::state and sleeps do too, since that's the only means of
actually sleeping. Therefore the nested sleeps destroy the wait loop
state and the wait loop breaks the sleep functions that assume
TASK_RUNNING (mutex_lock).

Fix this by using the new woken_wake_function and wait_woken() stuff,
which registers wakeups in wait and thereby allows shrinking the
task_state::state changes to the actual sleep part.
Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Paris <eparis@redhat.com>
Link: http://lkml.kernel.org/r/20141216152838.GZ3337@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

There was another report of a boot failure with a #GP fault in the
uncore SBOX initialization. The earlier work around was not enough
for this system.

The boot was failing while trying to initialize the third SBOX.

This patch detects parts with only two SBOXes and limits the number
of SBOX units to two there.

Stable material, as it affects boot problems on 3.18.
Tested-by: Andreas Oehler <andreas@oehler-net.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yan, Zheng <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/1420583675-9163-1-git-send-email-andi@firstfloor.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Perf reports user regs for kernel-mode samples so that samples can
be backtraced through user code.  The old code was very broken in
syscall context, resulting in useless backtraces.

The new code, in contrast, is still dangerously racy, but it should
at least work most of the time.
Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: chenggang.qcg@taobao.com
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/243560c26ff0f739978e2459e203f6515367634d.1420396372.git.luto@amacapital.netSigned-off-by: Ingo Molnar <mingo@kernel.org>