Only allow unprivileged mounts of proc and sysfs if they are already
mounted when the user namespace is created.

proc and sysfs are interesting because they have content that is
per namespace, and so fresh mounts are needed when new namespaces
are created while at the same time proc and sysfs have content that
is shared between every instance.

Respect the policy of who may see the shared content of proc and sysfs
by only allowing new mounts if there was an existing mount at the time
the user namespace was created.

In practice there are only two interesting cases: proc and sysfs are
mounted at their usual places, proc and sysfs are not mounted at all
(some form of mount namespace jail).

Cc: stable@vger.kernel.org
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Only allow mounting the mqueue filesystem if the caller has CAP_SYS_ADMIN
rights over the ipc namespace.   The principle here is if you create
or have capabilities over it you can mount it, otherwise you get to live
with what other people have mounted.

This information is not particularly sensitive and mqueue essentially
only reports which posix messages queues exist.  Still when creating a
restricted environment for an application to live any extra
information may be of use to someone with sufficient creativity.  The
historical if imperfect way this information has been restricted has
been not to allow mounts and restricting this to ipc namespace
creators maintains the spirit of the historical restriction.

Cc: stable@vger.kernel.org
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

As a matter of policy MNT_READONLY should not be changable if the
original mounter had more privileges than creator of the mount
namespace.

Add the flag CL_UNPRIVILEGED to note when we are copying a mount from
a mount namespace that requires more privileges to a mount namespace
that requires fewer privileges.

When the CL_UNPRIVILEGED flag is set cause clone_mnt to set MNT_NO_REMOUNT
if any of the mnt flags that should never be changed are set.

This protects both mount propagation and the initial creation of a less
privileged mount namespace.

Cc: stable@vger.kernel.org
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

When a read-only bind mount is copied from mount namespace in a higher
privileged user namespace to a mount namespace in a lesser privileged
user namespace, it should not be possible to remove the the read-only
restriction.

Add a MNT_LOCK_READONLY mount flag to indicate that a mount must
remain read-only.

CC: stable@vger.kernel.org
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Guarantee that the policy of which files may be access that is
established by setting the root directory will not be violated
by user namespaces by verifying that the root directory points
to the root of the mount namespace at the time of user namespace
creation.

Changing the root is a privileged operation, and as a matter of policy
it serves to limit unprivileged processes to files below the current
root directory.

For reasons of simplicity and comprehensibility the privilege to
change the root directory is gated solely on the CAP_SYS_CHROOT
capability in the user namespace.  Therefore when creating a user
namespace we must ensure that the policy of which files may be access
can not be violated by changing the root directory.

Anyone who runs a processes in a chroot and would like to use user
namespace can setup the same view of filesystems with a mount
namespace instead.  With this result that this is not a practical
limitation for using user namespaces.

Cc: stable@vger.kernel.org
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Change the permission check for yama_ptrace_ptracee to the standard
ptrace permission check, testing if the traceer has CAP_SYS_PTRACE
in the tracees user namespace.
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

When a multi-threaded init exits and the initial thread is not the
last thread to exit the initial thread hangs around as a zombie
until the last thread exits.  In that case zap_pid_ns_processes
needs to wait until there are only 2 hashed pids in the pid
namespace not one.

v2. Replace thread_pid_vnr(me) == 1 with the test thread_group_leader(me)
    as suggested by Oleg.

Cc: stable@vger.kernel.org
Cc: Oleg Nesterov <oleg@redhat.com>
Reported-by: NCaj Larsson <caj@omnicloud.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Don't allow spoofing pids over unix domain sockets in the corner
cases where a user has created a user namespace but has not yet
created a pid namespace.

Cc: stable@vger.kernel.org
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:

	arch/x86/power/built-in.o: In function `restore_processor_state':
	(.text+0x45c): undefined reference to `perf_restore_debug_store'

Fix it by defining the dummy function appropriately.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.

init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update.  Which is not really valid at the
early resume stage, and the warning is quite reasonable.  Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.

This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.
Reported-and-tested-by: NParag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull btrfs fixes from Chris Mason:
 "Eric's rcu barrier patch fixes a long standing problem with our
  unmount code hanging on to devices in workqueue helpers.  Liu Bo
  nailed down a difficult assertion for in-memory extent mappings."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix warning of free_extent_map
  Btrfs: fix warning when creating snapshots
  Btrfs: return as soon as possible when edquot happens
  Btrfs: return EIO if we have extent tree corruption
  btrfs: use rcu_barrier() to wait for bdev puts at unmount
  Btrfs: remove btrfs_try_spin_lock
  Btrfs: get better concurrency for snapshot-aware defrag work

Users report that an extent map's list is still linked when it's actually
going to be freed from cache.

The story is that

a) when we're going to drop an extent map and may split this large one into
smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means
that it's on the list to be logged, then the smaller ems split from it will also
be flagged as EXTENT_FLAG_LOGGING, and this is _not_ expected.

b) we'll keep ems from unlinking the list and freeing when they are flagged with
EXTENT_FLAG_LOGGING, because the log code holds one reference.

The end result is the warning, but the truth is that we set the flag
EXTENT_FLAG_LOGGING only during fsync.

So clear flag EXTENT_FLAG_LOGGING for extent maps split from a large one.
Reported-by: NJohannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reported-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Pull kbuild fix from Michal Marek:
 "One fix for for make headers_install/headers_check to not require make
  3.81.  The requirement has been accidentally introduced in 3.7."

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: fix make headers_check with make 3.80

Pull OpenRISC bug fixes from Jonas Bonn:

 - The GPIO descriptor work has exposed how broken the non-GPIOLIB bits
   for OpenRISC were.  We now require GPIOLIB as this is the preferred
   way forward.

 - The system.h split introduced a bug in llist.h for arches using
   asm-generic/cmpxchg.h directly, which is currently only OpenRISC.
   The patch here moves two defines from asm-generic/atomic.h to
   asm-generic/cmpxchg.h to make things work as they should.

 - The VIRT_TO_BUS selector was added for OpenRISC, but OpenRISC does
   not have the virt_to_bus methods, so there's a patch to remove it
   again.

* tag 'for-3.9-rc3' of git://openrisc.net/jonas/linux:
  openrisc: remove HAVE_VIRT_TO_BUS
  asm-generic: move cmpxchg*_local defs to cmpxchg.h
  openrisc: require gpiolib

Pull char/misc fixes from Greg Kroah-Hartman:
 "Here are some tiny fixes for the w1 drivers and the final removal
  patch for getting rid of CONFIG_EXPERIMENTAL (all users of it are now
  gone from your tree, this just drops the Kconfig item itself.)

  All have been in the linux-next tree for a while"

* tag 'char-misc-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  final removal of CONFIG_EXPERIMENTAL
  w1: fix oops when w1_search is called from netlink connector
  w1-gpio: fix unused variable warning
  w1-gpio: remove erroneous __exit and __exit_p()
  ARM: w1-gpio: fix erroneous gpio requests

Pull sound fixes from Takashi Iwai:
 "A collection of small fixes, as expected for the middle rc:
   - A couple of fixes for potential NULL dereferences and out-of-range
     array accesses revealed by static code parsers
   - A fix for the wrong error handling detected by trinity
   - A regression fix for missing audio on some MacBooks
   - CA0132 DSP loader fixes
   - Fix for EAPD control of IDT codecs on machines w/o speaker
   - Fix a regression in the HD-audio widget list parser code
   - Workaround for the NuForce UDH-100 USB audio"

* tag 'sound-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Fix missing EAPD/GPIO setup for Cirrus codecs
  sound: sequencer: cap array index in seq_chn_common_event()
  ALSA: hda/ca0132 - Remove extra setting of dsp_state.
  ALSA: hda/ca0132 - Check download state of DSP.
  ALSA: hda/ca0132 - Check if dspload_image succeeded.
  ALSA: hda - Disable IDT eapd_switch if there are no internal speakers
  ALSA: hda - Fix snd_hda_get_num_raw_conns() to return a correct value
  ALSA: usb-audio: add a workaround for the NuForce UDH-100
  ALSA: asihpi - fix potential NULL pointer dereference
  ALSA: seq: Fix missing error handling in snd_seq_timer_open()

Pull DMA-mapping fix from Marek Szyprowski:
 "An important fix for all ARM architectures which use ZONE_DMA.
  Without it dma_alloc_* calls with GFP_ATOMIC flag might have allocated
  buffers outsize DMA zone."

* 'fixes-for-3.9' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: DMA-mapping: add missing GFP_DMA flag for atomic buffer allocation

Pull MFD fixes from Samuel Ortiz:
 "This is the first batch of MFD fixes for 3.9.

  With this one we have:

   - An ab8500 build failure fix.
   - An ab8500 device tree parsing fix.
   - A fix for twl4030_madc remove routine to work properly (when
     built-in).
   - A fix for properly registering palmas interrupt handler.
   - A fix for omap-usb init routine to actually write into the
     hostconfig register.
   - A couple of warning fixes for ab8500-gpadc and tps65912"

* tag 'mfd-fixes-3.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-fixes:
  mfd: twl4030-madc: Remove __exit_p annotation
  mfd: ab8500: Kill "reg" property from binding
  mfd: ab8500-gpadc: Complain if we fail to enable vtvout LDO
  mfd: wm831x: Don't forward declare enum wm831x_auxadc
  mfd: twl4030-audio: Fix argument type for twl4030_audio_disable_resource()
  mfd: tps65912: Declare and use tps65912_irq_exit()
  mfd: palmas: Provide irq flags through DT/platform data
  mfd: Make AB8500_CORE select POWER_SUPPLY to fix build error
  mfd: omap-usb-host: Actually update hostconfig

Pull hwmon fixes from Guenter Roeck:
 "Bug fixes for pmbus, ltc2978, and lineage-pem drivers

  Added specific maintainer for some hwmon drivers"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (pmbus/ltc2978) Fix temperature reporting
  hwmon: (pmbus) Fix krealloc() misuse in pmbus_add_attribute()
  hwmon: (lineage-pem) Add missing terminating entry for pem_[input|fan]_attributes
  MAINTAINERS: Add maintainer for MAX6697, INA209, and INA2XX drivers

This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.

The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During the transition to the generic parser, the hook to the codec
specific automute function was forgotten.  This resulted in the silent
output on some MacBooks.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

"chn" here is a number between 0 and 255, but ->chn_info[] only has
16 elements so there is a potential write beyond the end of the
array.

If the seq_mode isn't SEQ_2 then we let the individual drivers
(either opl3.c or midi_synth.c) handle it.  Those functions all
do a bounds check on "chn" so I haven't changed anything here.
The opl3.c driver has up to 18 channels and not 16.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

4740f73f "mfd: remove use of __devexit" removed the __devexit annotation
on the twl4030_madc_remove function, but left an __exit_p() present on the
pointer to this function. Using __exit_p was as wrong with the devexit in
place as it is now, but now we get a gcc warning about an unused function.

In order for the twl4030_madc_remove to work correctly in built-in code, we
have to remove the __exit_p.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

spec->dsp_state is initialized to DSP_DOWNLOAD_INIT, no need to reset
and check it in ca0132_download_dsp().
Signed-off-by: NDylan Reid <dgreid@chromium.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Instead of using the dspload_is_loaded() function, check the dsp_state
that is kept in the spec.  The dspload_is_loaded() function returns
true if the DSP transfer was never started.  This false-positive leads
to multiple second delays when ca0132_setup_efaults() times out on
each write.
Signed-off-by: NDylan Reid <dgreid@chromium.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

If dspload_image() fails, it was ignored and dspload_wait_loaded() was
still called.  dsp_loaded should never be set to true in this case,
skip it.  The check in dspload_wait_loaded() return true if the DSP is
loaded or if it never started.
Signed-off-by: NDylan Reid <dgreid@chromium.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The vm_flags introduced in 6d7825b1 ("mm/fremap.c: fix oops on error
path") is supposed to avoid a compiler warning about unitialized
vm_flags without changing the generated code.

However I am concerned that this is going to be very brittle, and fail
with some compiler versions. The failure could be either of:

- compiler could actually load vma->vm_flags before checking for the
  !vma condition, thus reintroducing the oops

- compiler could optimize out the !vma check, since the pointer just got
  dereferenced shortly before (so the compiler knows it can't be NULL!)

I propose reversing this part of the change and initializing vm_flags to 0
just to avoid the bogus uninitialized use warning.
Signed-off-by: NMichel Lespinasse <walken@google.com>
Cc: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull fix for hlist_entry_safe() regression from Paul McKenney:
 "This contains a single commit that fixes a regression in
  hlist_entry_safe().  This macro references its argument twice, which
  can cause NULL-pointer errors.  This commit applies a gcc statement
  expression, creating a temporary variable to avoid the double
  reference.  This has been posted to LKML at

    https://lkml.org/lkml/2013/3/9/75.

  Kudos to CAI Qian, whose testing uncovered this, to Eric Dumazet, who
  spotted root cause, and to Li Zefan, who tested this commit."

* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  list: Fix double fetch of pointer in hlist_entry_safe()

The current version of hlist_entry_safe() fetches the pointer twice,
once to test for NULL and the other to compute the offset back to the
enclosing structure.  This is OK for normal lock-based use because in
that case, the pointer cannot change.  However, when the pointer is
protected by RCU (as in "rcu_dereference(p)"), then the pointer can
change at any time.  This use case can result in the following sequence
of events:

1.	CPU 0 invokes hlist_entry_safe(), fetches the RCU-protected
	pointer as sees that it is non-NULL.

2.	CPU 1 invokes hlist_del_rcu(), deleting the entry that CPU 0
	just fetched a pointer to.  Because this is the last entry
	in the list, the pointer fetched by CPU 0 is now NULL.

3.	CPU 0 refetches the pointer, obtains NULL, and then gets a
	NULL-pointer crash.

This commit therefore applies gcc's "({ })" statement expression to
create a temporary variable so that the specified pointer is fetched
only once, avoiding the above sequence of events.  Please note that
it is the caller's responsibility to use rcu_dereference() as needed.
This allows RCU-protected uses to work correctly without imposing
any additional overhead on the non-RCU case.

Many thanks to Eric Dumazet for spotting root cause!
Reported-by: NCAI Qian <caiqian@redhat.com>
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NLi Zefan <lizefan@huawei.com>

Pull ext2, ext3, reiserfs, quota fixes from Jan Kara:
 "A fix for regression in ext2, and a format string issue in ext3.  The
  rest isn't too serious."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2: Fix BUG_ON in evict() on inode deletion
  reiserfs: Use kstrdup instead of kmalloc/strcpy
  ext3: Fix format string issues
  quota: add missing use of dq_data_lock in __dquot_initialize

Creating snapshot passes extent_root to commit its transaction,
but it can lead to the warning of checking root for quota in
the __btrfs_end_transaction() when someone else is committing
the current transaction.  Since we've recorded the needed root
in trans_handle, just use it to get rid of the warning.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If one of qgroup fails to reserve firstly, we should return immediately,
it is unnecessary to continue check.
Signed-off-by: NWang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The callers of lookup_inline_extent_info all handle getting an error back
properly, so return an error if we have corruption instead of being a jerk and
panicing.  Still WARN_ON() since this is kind of crucial and I've been seeing it
a bit too much recently for my taste, I think we're doing something wrong
somewhere.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Doing this would reliably fail with -EBUSY for me:

# mount /dev/sdb2 /mnt/scratch; umount /mnt/scratch; mkfs.btrfs -f /dev/sdb2
...
unable to open /dev/sdb2: Device or resource busy

because mkfs.btrfs tries to open the device O_EXCL, and somebody still has it.

Using systemtap to track bdev gets & puts shows a kworker thread doing a
blkdev put after mkfs attempts a get; this is left over from the unmount
path:

btrfs_close_devices
	__btrfs_close_devices
		call_rcu(&device->rcu, free_device);
			free_device
				INIT_WORK(&device->rcu_work, __free_device);
				schedule_work(&device->rcu_work);

so unmount might complete before __free_device fires & does its blkdev_put.

Adding an rcu_barrier() to btrfs_close_devices() causes unmount to wait
until all blkdev_put()s are done, and the device is truly free once
unmount completes.

Cc: stable@vger.kernel.org
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Remove a useless function declaration
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Using spinning case instead of blocking will result in better concurrency
overall.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

On LTC2978, only READ_TEMPERATURE is supported. It reports
the internal junction temperature. This register is unpaged.

On LTC3880, READ_TEMPERATURE and READ_TEMPERATURE2 are supported.
READ_TEMPERATURE is paged and reports external temperatures.
READ_TEMPERATURE2 is unpaged and reports the internal junction
temperature.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # 3.2+
Acked-by: NJean Delvare <khali@linux-fr.org>

If there are no internal speakers, we should not turn the eapd switch
off, because it might be necessary to keep high for Headphone.

BugLink: https://bugs.launchpad.net/bugs/1155016Signed-off-by: NDavid Henningsson <david.henningsson@canonical.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

If krealloc() returns NULL, it *doesn't* free the original. So any code
of the form 'foo = krealloc(foo, …);' is almost certainly a bug.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>