Commit Graph

633258 Commits

Author SHA1 Message Date
Lina Iyer 598da548ef PM / Domains: Fix compatible for domain idle state
Re-using idle state definition provided by arm,idle-state for domain
idle states creates a lot of confusion and limits further evolution of
the domain idle definition. To keep things clear and simple, define a
idle states for domain using a new compatible "domain-idle-state".

Fix existing PM domains code to look for the newly defined compatible.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-06 22:05:38 +01:00
Geert Uytterhoeven 3499469221 PM / Domains: Do not print PM domain add error message if EPROBE_DEFER
EPROBE_DEFER is not an error, hence printing an error message like

    renesas_irqc e61c0000.interrupt-controller: failed to add to PM domain always-on: -517

may confuse the user.

Suppress the error message in case of EPROBE_DEFER to fix this.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-30 22:39:18 +01:00
Dan Carpenter 44cae7d5a1 PM / Domains: Fix a warning message
The first argument of WARN() is the condition, followed by the message.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-11 01:37:05 +01:00
Colin Ian King a1fee00dc9 PM / Domains: check for negative return from of_count_phandle_with_args()
The return from of_count_phandle_with_args can be negative, so we
should avoid kcalloc of a negative count of genpd_power_stat structs
by sanity checking if count is zero or less.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-27 13:00:32 +02:00
Lina Iyer 411bf2a8db PM / doc: Update device documentation for devices in IRQ-safe PM domains
Update documentation to reflect the changes made to support IRQ safe PM
domains.

Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-24 23:48:22 +02:00
Lina Iyer d716f4798f PM / Domains: Support IRQ safe PM domains
Generic Power Domains currently support turning on/off only in process
context. This prevents the usage of PM domains for domains that could be
powered on/off in a context where IRQs are disabled. Many such domains
exist today and do not get powered off, when the IRQ safe devices in
that domain are powered off, because of this limitation.

However, not all domains can operate in IRQ safe contexts. Genpd
therefore, has to support both cases where the domain may or may not
operate in IRQ safe contexts. Configuring genpd to use an appropriate
lock for that domain, would allow domains that have IRQ safe devices to
runtime suspend and resume, in atomic context.

To achieve domain specific locking, set the domain's ->flag to
GENPD_FLAG_IRQ_SAFE while defining the domain. This indicates that genpd
should use a spinlock instead of a mutex for locking the domain. Locking
is abstracted through genpd_lock() and genpd_unlock() functions that use
the flag to determine the appropriate lock to be used for that domain.

Domains that have lower latency to suspend and resume and can operate
with IRQs disabled may now be able to save power, when the component
devices and sub-domains are idle at runtime.

The restriction this imposes on the domain hierarchy is that non-IRQ
safe domains may not have IRQ-safe subdomains, but IRQ safe domains may
have IRQ safe and non-IRQ safe subdomains and devices.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:56 +02:00
Lina Iyer 35241d12f7 PM / Domains: Abstract genpd locking
Abstract genpd lock/unlock calls, in preparation for domain specific
locks added in the following patches.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:47 +02:00
Lina Iyer 70bb510e42 dt/bindings / PM/Domains: Update binding for PM domain idle states
Update DT bindings to describe idle states of PM domains.

This patch is based on the original patch by Marc Titinger.

Signed-off-by: Marc Titinger <mtitinger+renesas@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:36 +02:00
Lina Iyer 0c9b694a8a PM / Domains: Save the fwnode in genpd_power_state
Save the fwnode for the genpd state in the state node. PM Domain clients
may use the fwnode to read in the platform specific domain state
properties and associate them with the state.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:27 +02:00
Lina Iyer 30f604283e PM / Domains: Allow domain power states to be read from DT
This patch allows domains to define idle states in the DT. SoC's can
define domain idle states in DT using the "domain-idle-states" property
of the domain provider. Add API to read the idle states from DT that can
be set in the genpd object.

This patch is based on the original patch by Marc Titinger.

Signed-off-by: Marc Titinger <mtitinger+renesas@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:15 +02:00
Lina Iyer 405f722601 PM / Domains: Add residency property to genpd states
Residency of a domain's idle state indicates that the minimum idle time
for the domain's idle state to be beneficial for power. Add the
parameter to the state node. Future patches, will use the residency
value in the genpd governor to determine if it is worth while to enter
an idle state.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:20:07 +02:00
Lina Iyer 59d65b73a2 PM / Domains: Make genpd state allocation dynamic
Allow PM Domain states to be defined dynamically by the drivers. This
removes the limitation on the maximum number of states possible for a
domain.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21 22:19:36 +02:00
Linus Torvalds 1001354ca3 Linux 4.9-rc1 2016-10-15 12:17:50 -07:00
Linus Torvalds df34d04a6f Merge tag 'befs-v4.9-rc1' of git://github.com/luisbg/linux-befs
Pull befs fixes from Luis de Bethencourt:
 "I recently took maintainership of the befs file system [0]. This is
  the first time I send you a git pull request, so please let me know if
  all the below is OK.

  Salah Triki and myself have been cleaning the code and fixing a few
  small bugs.

  Sorry I couldn't send this sooner in the merge window, I was waiting
  to have my GPG key signed by kernel members at ELCE in Berlin a few
  days ago."

[0] https://lkml.org/lkml/2016/7/27/502

* tag 'befs-v4.9-rc1' of git://github.com/luisbg/linux-befs: (39 commits)
  befs: befs: fix style issues in datastream.c
  befs: improve documentation in datastream.c
  befs: fix typos in datastream.c
  befs: fix typos in btree.c
  befs: fix style issues in super.c
  befs: fix comment style
  befs: add check for ag_shift in superblock
  befs: dump inode_size superblock information
  befs: remove unnecessary initialization
  befs: fix typo in befs_sb_info
  befs: add flags field to validate superblock state
  befs: fix typo in befs_find_key
  befs: remove unused BEFS_BT_PARMATCH
  fs: befs: remove ret variable
  fs: befs: remove in vain variable assignment
  fs: befs: remove unnecessary *befs_sb variable
  fs: befs: remove useless initialization to zero
  fs: befs: remove in vain variable assignment
  fs: befs: Insert NULL inode to dentry
  fs: befs: Remove useless calls to brelse in befs_find_brun_dblindirect
  ...
2016-10-15 12:09:13 -07:00
Linus Torvalds 9ffc66941d Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
2016-10-15 10:03:15 -07:00
Linus Torvalds 133d970e0d Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main MIPS pull request for 4.9:

  MIPS core arch code:
   - traps: 64bit kernels should read CP0_EBase 64bit
   - traps: Convert ebase to KSEG0
   - c-r4k: Drop bc_wback_inv() from icache flush
   - c-r4k: Split user/kernel flush_icache_range()
   - cacheflush: Use __flush_icache_user_range()
   - uprobes: Flush icache via kernel address
   - KVM: Use __local_flush_icache_user_range()
   - c-r4k: Fix flush_icache_range() for EVA
   - Fix -mabi=64 build of vdso.lds
   - VDSO: Drop duplicated -I*/-E* aflags
   - tracing: move insn_has_delay_slot to a shared header
   - tracing: disable uprobe/kprobe on compact branch instructions
   - ptrace: Fix regs_return_value for kernel context
   - Squash lines for simple wrapper functions
   - Move identification of VP(E) into proc.c from smp-mt.c
   - Add definitions of SYNC barrierstype values
   - traps: Ensure full EBase is written
   - tlb-r4k: If there are wired entries, don't use TLBINVF
   - Sanitise coherentio semantics
   - dma-default: Don't check hw_coherentio if device is non-coherent
   - Support per-device DMA coherence
   - Adjust MIPS64 CAC_BASE to reflect Config.K0
   - Support generating Flattened Image Trees (.itb)
   - generic: Introduce generic DT-based board support
   - generic: Convert SEAD-3 to a generic board
   - Enable hardened usercopy
   - Don't specify STACKPROTECTOR in defconfigs

  Octeon:
   - Delete dead code and files across the platform.
   - Change to use all memory into use by default.
   - Rename upper case variables in setup code to lowercase.
   - Delete legacy hack for broken bootloaders.
   - Leave maintaining the link state to the actual ethernet/PHY drivers.
   - Add DTS for D-Link DSR-500N.
   - Fix PCI interrupt routing on D-Link DSR-500N.

  Pistachio:
   - Remove ANDROID_TIMED_OUTPUT from defconfig

  TX39xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  TX49xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  txx9wdt:
   - Add missing clock (un)prepare calls for CCF

  BMIPS:
   - Add PW, GPIO SDHCI and NAND device node names
   - Support APPENDED_DTB
   - Add missing bcm97435svmb to DT_NONE
   - Rename bcm96358nb4ser to bcm6358-neufbox4-sercom
   - Add DT examples for BCM63268, BCM3368 and BCM6362
   - Add support for BCM3368 and BCM6362

  PCI
   - Reduce stack frame usage
   - Use struct list_head lists
   - Support for CONFIG_PCI_DOMAINS_GENERIC
   - Make pcibios_set_cache_line_size an initcall
   - Inline pcibios_assign_all_busses
   - Split pci.c into pci.c & pci-legacy.c
   - Introduce CONFIG_PCI_DRIVERS_LEGACY
   - Support generic drivers

  CPC
   - Convert bare 'unsigned' to 'unsigned int'
   - Avoid lock when MIPS CM >= 3 is present

  GIC:
   - Delete unused file smp-gic.c

  mt7620:
   - Delete unnecessary assignment for the field "owner" from PCI

  BCM63xx:
   - Let clk_disable() return immediately if clk is NULL

  pm-cps:
   - Change FSB workaround to CPU blacklist
   - Update comments on barrier instructions
   - Use MIPS standard lightweight ordering barrier
   - Use MIPS standard completion barrier
   - Remove selection of sync types
   - Add MIPSr6 CPU support
   - Support CM3 changes to Coherence Enable Register

  SMP:
   - Wrap call to mips_cpc_lock_other in mips_cm_lock_other
   - Introduce mechanism for freeing and allocating IPIs

  cpuidle:
   - cpuidle-cps: Enable use with MIPSr6 CPUs.

  SEAD3:
   - Rewrite to use DT and generic kernel feature.

  USB:
   - host: ehci-sead3: Remove SEAD-3 EHCI code

  FBDEV:
   - cobalt_lcdfb: Drop SEAD3 support

  dt-bindings:
   -  Document a binding for simple ASCII LCDs

  auxdisplay:
   - img-ascii-lcd: driver for simple ASCII LCD displays

  irqchip i8259:
   - i8259: Add domain before mapping parent irq
   - i8259: Allow platforms to override poll function
   - i8259: Remove unused i8259A_irq_pending

  Malta:
   - Rewrite to use DT

  of/platform:
   - Probe "isa" busses by default

  CM:
   - Print CM error reports upon bus errors

  Module:
   - Migrate exception table users off module.h and onto extable.h
   - Make various drivers explicitly non-modular:
   - Audit and remove any unnecessary uses of module.h

  mailmap:
   - Canonicalize to Qais' current email address.

  Documentation:
   - MIPS supports HAVE_REGS_AND_STACK_ACCESS_API

  Loongson1C:
   - Add CPU support for Loongson1C
   - Add board support
   - Add defconfig
   - Add RTC support for Loongson1C board

  All this except one Documentation fix has sat in linux-next and has
  survived Imagination's automated build test system"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits)
  Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API
  MIPS: ptrace: Fix regs_return_value for kernel context
  MIPS: VDSO: Drop duplicated -I*/-E* aflags
  MIPS: Fix -mabi=64 build of vdso.lds
  MIPS: Enable hardened usercopy
  MIPS: generic: Convert SEAD-3 to a generic board
  MIPS: generic: Introduce generic DT-based board support
  MIPS: Support generating Flattened Image Trees (.itb)
  MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0
  MIPS: Print CM error reports upon bus errors
  MIPS: Support per-device DMA coherence
  MIPS: dma-default: Don't check hw_coherentio if device is non-coherent
  MIPS: Sanitise coherentio semantics
  MIPS: PCI: Support generic drivers
  MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY
  MIPS: PCI: Split pci.c into pci.c & pci-legacy.c
  MIPS: PCI: Inline pcibios_assign_all_busses
  MIPS: PCI: Make pcibios_set_cache_line_size an initcall
  MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC
  MIPS: PCI: Use struct list_head lists
  ...
2016-10-15 09:26:12 -07:00
Linus Torvalds 050aaeab99 Merge tag 'sound-fix-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
 "Just a few trivial small fixes"

* tag 'sound-fix-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: line6: fix a crash in line6_hwdep_write()
  ALSA: seq: fix passing wrong pointer in function call of compatibility layer
  ALSA: hda - Fix a failure of micmute led when having multi adcs
  ALSA: line6: Fix POD X3 Live audio input
2016-10-15 09:20:54 -07:00
Linus Torvalds b26b5ef5ec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more misc uaccess and vfs updates from Al Viro:
 "The rest of the stuff from -next (more uaccess work) + assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  score: traps: Add missing include file to fix build error
  fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
  fs/super.c: fix race between freeze_super() and thaw_super()
  overlayfs: Fix setting IOP_XATTR flag
  iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()
  blackfin: no access_ok() for __copy_{to,from}_user()
  arm64: don't zero in __copy_from_user{,_inatomic}
  arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()
  arc: don't leak bits of kernel stack into coredump
  alpha: get rid of tail-zeroing in __copy_user()
2016-10-14 18:19:05 -07:00
Linus Torvalds 87dbe42a16 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
 "Including:

   - nine bug fixes for stable. Some of these we found at the recent two
     weeks of SMB3 test events/plugfests.

   - significant improvements in reconnection (e.g. if server or network
     crashes) especially when mounted with "persistenthandles" or to
     server which advertises Continuous Availability on the share.

   - a new mount option "idsfromsid" which improves POSIX compatibility
     in some cases (when winbind not configured e.g.) by better (and
     faster) fetching uid/gid from acl (when "cifsacl" mount option is
     enabled). NB: we are almost complete work on "cifsacl" (querying
     mode/uid/gid from ACL) for SMB3, but SMB3 support for cifsacl is
     not included in this set.

   - improved handling for SMB3 "credits" (even if server is buggy)

  Still working on two sets of changes:

   - cifsacl enablement for SMB3

   - cleanup of RFC1001 length calculation (so we can handle encryption
     and multichannel and RDMA)

  And a couple of new bugs were reported recently (unrelated to above)
  so will probably have another merge request next week"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (21 commits)
  CIFS: Retrieve uid and gid from special sid if enabled
  CIFS: Add new mount option to set owner uid and gid from special sids in acl
  CIFS: Reset read oplock to NONE if we have mandatory locks after reopen
  CIFS: Fix persistent handles re-opening on reconnect
  SMB2: Separate RawNTLMSSP authentication from SMB2_sess_setup
  SMB2: Separate Kerberos authentication from SMB2_sess_setup
  Expose cifs module parameters in sysfs
  Cleanup missing frees on some ioctls
  Enable previous version support
  Do not send SMB3 SET_INFO request if nothing is changing
  SMB3: Add mount parameter to allow user to override max credits
  fs/cifs: reopen persistent handles on reconnect
  Clarify locking of cifs file and tcon structures and make more granular
  Fix regression which breaks DFS mounting
  fs/cifs: keep guid when assigning fid to fileinfo
  SMB3: GUIDs should be constructed as random but valid uuids
  Set previous session id correctly on SMB3 reconnect
  cifs: Limit the overall credit acquired
  Display number of credits available
  Add way to query creation time of file via cifs xattr
  ...
2016-10-14 17:47:31 -07:00
Linus Torvalds d3304cadb2 Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Some fixes from Omar and Dave Sterba for our new free space tree.

  This isn't heavily used yet, but as we move toward making it the new
  default we wanted to nail down an endian bug"

* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: tests: uninline member definitions in free_space_extent
  btrfs: tests: constify free space extent specs
  Btrfs: expand free space tree sanity tests to catch endianness bug
  Btrfs: fix extent buffer bitmap tests on big-endian systems
  Btrfs: catch invalid free space trees
  Btrfs: fix mount -o clear_cache,space_cache=v2
  Btrfs: fix free space tree bitmaps on big-endian systems
2016-10-14 17:44:56 -07:00
Al Viro 2692a71bbd Merge branch 'work.uaccess' into for-linus 2016-10-14 20:42:44 -04:00
Guenter Roeck 7041c57709 score: traps: Add missing include file to fix build error
score images fail to build as follows.

arch/score/kernel/traps.c: In function 'show_stack':
arch/score/kernel/traps.c:55:3: error:
	implicit declaration of function '__get_user'

__get_user() is declared in asm/uaccess.h, which was previously included
through asm/module.h.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 88dd4a748d ("score: separate extable.h, switch module.h to it")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:42:28 -04:00
Oleg Nesterov f1a9622037 fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
sb_wait_write()->percpu_rwsem_release() fools lockdep to avoid the
false-positives. Now that xfs was fixed by Dave's commit dbad7c9930
("xfs: stop holding ILOCK over filldir callbacks") we can remove it and
change freeze_super() and thaw_super() to run with s_writers.rw_sem locks
held; we add two trivial helpers for that, lockdep_sb_freeze_release()
and lockdep_sb_freeze_acquire().

xfstests-dev/check `grep -il freeze tests/*/???` does not trigger any
warning from lockdep.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:41:59 -04:00
Linus Torvalds 1a892b485f Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
 "This update contains fixes to the "use mounter's permission to access
  underlying layers" area, and miscellaneous other fixes and cleanups.

  No new features this time"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: use vfs_get_link()
  vfs: add vfs_get_link() helper
  ovl: use generic_readlink
  ovl: explain error values when removing acl from workdir
  ovl: Fix info leak in ovl_lookup_temp()
  ovl: during copy up, switch to mounter's creds early
  ovl: lookup: do getxattr with mounter's permission
  ovl: copy_up_xattr(): use strnlen
2016-10-14 17:23:33 -07:00
Oleg Nesterov 89f39af129 fs/super.c: fix race between freeze_super() and thaw_super()
Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than
frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which
drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering.

In this case thaw_super() will wrongly call s_op->unfreeze_fs() before
it was actually frozen, and call sb_freeze_unlock() which leads to the
unbalanced percpu_up_write(). Unfortunately lockdep can't detect this,
so this triggers misc BUG_ON()'s in kernel/rcu/sync.c.

Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:00:34 -04:00