UBIFS: introduce categorized lprops counter

commit 98a1eebda3cb2a84ecf1f219bb3a95769033d1bf upstream.

This commit is a preparation for a subsequent bugfix. We introduce a
counter for categorized lprops.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
UBIFS: fix mounting problems after power cuts

commit a28ad42a4a0c6f302f488f26488b8b37c9b30024 upstream.

This is a bugfix for a problem with the following symptoms:

1. A power cut happens
2. After reboot, we try to mount UBIFS
3. Mount fails with "No space left on device" error message

UBIFS complains like this:

UBIFS error (pid 28225): grab_empty_leb: could not find an empty LEB

The root cause of this problem is that when we mount, not all LEBs are
categorized. Only those which were read are. However, the
'ubifs_find_free_leb_for_idx()' function assumes that all LEBs were
categorized and 'c->freeable_cnt' is valid, which is a false assumption.

This patch fixes the problem by teaching 'ubifs_find_free_leb_for_idx()'
to always fall back to LPT scanning if no freeable LEBs were found.

This problem was reported by few people in the past, but Brent Taylor
was able to reproduce it and send me a flash image which cannot be mounted,
which made it easy to hunt the bug. Kudos to Brent.

Reported-by: Brent Taylor <motobud@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
futex: Handle futex_pi OWNER_DIED take over correctly

commit 59fa6245192159ab5e1e17b8e31f15afa9cff4bf upstream.

Siddhesh analyzed a failure in the take over of pi futexes in case the
owner died and provided a workaround.
See: http://sourceware.org/bugzilla/show_bug.cgi?id=14076

The detailed problem analysis shows:

Futex F is initialized with PTHREAD_PRIO_INHERIT and
PTHREAD_MUTEX_ROBUST_NP attributes.

T1 lock_futex_pi(F);

T2 lock_futex_pi(F);
   --> T2 blocks on the futex and creates pi_state which is associated
       to T1.

T1 exits
   --> exit_robust_list() runs
       --> Futex F userspace value TID field is set to 0 and
           FUTEX_OWNER_DIED bit is set.

T3 lock_futex_pi(F);
   --> Succeeds due to the check for F's userspace TID field == 0
   --> Claims ownership of the futex and sets its own TID into the
       userspace TID field of futex F
   --> returns to user space

T1 --> exit_pi_state_list()
       --> Transfers pi_state to waiter T2 and wakes T2 via
       	   rt_mutex_unlock(&pi_state->mutex)

T2 --> acquires pi_state->mutex and gains real ownership of the
       pi_state
   --> Claims ownership of the futex and sets its own TID into the
       userspace TID field of futex F
   --> returns to user space

T3 --> observes inconsistent state

This problem is independent of UP/SMP, preemptible/non preemptible
kernels, or process shared vs. private. The only difference is that
certain configurations are more likely to expose it.

So as Siddhesh correctly analyzed the following check in
futex_lock_pi_atomic() is the culprit:

	if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {

We check the userspace value for a TID value of 0 and take over the
futex unconditionally if that's true.

AFAICT this check is there as it is correct for a different corner
case of futexes: the WAITERS bit became stale.

Now the proposed change

-	if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
+       if (unlikely(ownerdied ||
+                       !(curval & (FUTEX_TID_MASK | FUTEX_WAITERS)))) {

solves the problem, but it's not obvious why and it wreckages the
"stale WAITERS bit" case.

What happens is, that due to the WAITERS bit being set (T2 is blocked
on that futex) it enforces T3 to go through lookup_pi_state(), which
in the above case returns an existing pi_state and therefor forces T3
to legitimately fight with T2 over the ownership of the pi_state (via
pi_state->mutex). Probelm solved!

Though that does not work for the "WAITERS bit is stale" problem
because if lookup_pi_state() does not find existing pi_state it
returns -ERSCH (due to TID == 0) which causes futex_lock_pi() to
return -ESRCH to user space because the OWNER_DIED bit is not set.

Now there is a different solution to that problem. Do not look at the
user space value at all and enforce a lookup of possibly available
pi_state. If pi_state can be found, then the new incoming locker T3
blocks on that pi_state and legitimately races with T2 to acquire the
rt_mutex and the pi_state and therefor the proper ownership of the
user space futex.

lookup_pi_state() has the correct order of checks. It first tries to
find a pi_state associated with the user space futex and only if that
fails it checks for futex TID value = 0. If no pi_state is available
nothing can create new state at that point because this happens with
the hash bucket lock held.

So the above scenario changes to:

T1 lock_futex_pi(F);

T2 lock_futex_pi(F);
   --> T2 blocks on the futex and creates pi_state which is associated
       to T1.

T1 exits
   --> exit_robust_list() runs
       --> Futex F userspace value TID field is set to 0 and
           FUTEX_OWNER_DIED bit is set.

T3 lock_futex_pi(F);
   --> Finds pi_state and blocks on pi_state->rt_mutex

T1 --> exit_pi_state_list()
       --> Transfers pi_state to waiter T2 and wakes it via
       	   rt_mutex_unlock(&pi_state->mutex)

T2 --> acquires pi_state->mutex and gains ownership of the pi_state
   --> Claims ownership of the futex and sets its own TID into the
       userspace TID field of futex F
   --> returns to user space

This covers all gazillion points on which T3 might come in between
T1's exit_robust_list() clearing the TID field and T2 fixing it up. It
also solves the "WAITERS bit stale" problem by forcing the take over.

Another benefit of changing the code this way is that it makes it less
dependent on untrusted user space values and therefor minimizes the
possible wreckage which might be inflicted.

As usual after staring for too long at the futex code my brain hurts
so much that I really want to ditch that whole optimization of
avoiding the syscall for the non contended case for PI futexes and rip
out the maze of corner case handling code. Unfortunately we can't as
user space relies on that existing behaviour, but at least thinking
about it helps me to preserve my mental sanity. Maybe we should
nevertheless :)

Reported-and-tested-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1210232138540.2756@ionos
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mac80211: sync acccess to tx_filtered/ps_tx_buf queues

commit 987c285c2ae2e4e32aca3a9b3252d28171c75711 upstream.

These are accessed without a lock when ending STA PSM. If the
sta_cleanup timer accesses these lists at the same time, we might crash.

This may fix some mysterious crashes we had during
ieee80211_sta_ps_deliver_wakeup.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ASoC: wm8978: pll incorrectly configured when codec is master

commit 55c6f4cb6ef49afbb86222c6a3ff85329199c729 upstream.

When MCLK is supplied externally and BCLK and LRC are configured as outputs
(codec is master), the PLL values are only calculated correctly on the first
transmission.  On subsequent transmissions, at differenct sample rates, the
wrong PLL values are used.  Test for f_opclk instead of f_pllout to determine
if the PLL values are needed.

Signed-off-by: Eric Millbrandt <emillbrandt@dekaresearch.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
device_cgroup: fix RCU usage

commit 201e72acb2d3821e2de9ce6091e98859c316b29a upstream.

dev_cgroup->exceptions is protected with devcgroup_mutex for writes
and RCU for reads; however, RCU usage isn't correct.

* dev_exception_clean() doesn't use RCU variant of list_del() and
  kfree().  The function can race with may_access() and may_access()
  may end up dereferencing already freed memory.  Use list_del_rcu()
  and kfree_rcu() instead.

* may_access() may be called only with RCU read locked but doesn't use
  RCU safe traversal over ->exceptions.  Use list_for_each_entry_rcu().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
[bwh: Backported to 3.2:
 - Adjust context
 - Exception list is called whitelist]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ASoC: dapm: Use card_list during DAPM shutdown

commit 445632ad6dda42f4d3f9df2569a852ca0d4ea608 upstream.

DAPM shutdown incorrectly uses "list" field of codec struct while
iterating over probed components (codec_dev_list). "list" field
refers to codecs registered in the system, "card_list" field is
used for probed components.

Signed-off-by: Misael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
s390/signal: set correct address space control

commit fa968ee215c0ca91e4a9c3a69ac2405aae6e5d2f upstream.

If user space is running in primary mode it can switch to secondary
or access register mode, this is used e.g. in the clock_gettime code
of the vdso. If a signal is delivered to the user space process while
it has been running in access register mode the signal handler is
executed in access register mode as well which will result in a crash
most of the time.

Set the address space control bits in the PSW to the default for the
execution of the signal handler and make sure that the previous
address space control is restored on signal return. Take care
that user space can not switch to the kernel address space by
modifying the registers in the signal frame.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[bwh: Backported to 3.2:
 - Adjust filename
 - The RI bit is not included in PSW_MASK_USER]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
wireless: allow 40 MHz on world roaming channels 12/13

commit 43c771a1963ab461a2f194e3c97fded1d5fe262f upstream.

When in world roaming mode, allow 40 MHz to be used
on channels 12 and 13 so that an AP that is, e.g.,
using HT40+ on channel 9 (in the UK) can be used.

Reported-by: Eddie Chapman <eddie@ehuk.net>
Tested-by: Eddie Chapman <eddie@ehuk.net>
Acked-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drm/i915/sdvo: clean up connectors on intel_sdvo_init() failures

commit d0ddfbd3d1346c1f481ec2289eef350cdba64b42 upstream.

Any failures in intel_sdvo_init() after the intel_sdvo_setup_output() call
left behind ghost connectors, attached (with a dangling pointer) to the
sdvo that has been cleaned up and freed. Properly destroy any connectors
attached to the encoder.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=46381
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: bjo@nord-west.org
[danvet: added a comment to explain why we need to clean up connectors
even when sdvo_output_setup fails.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
s390/gup: add missing TASK_SIZE check to get_user_pages_fast()

commit d55c4c613fc4d4ad2ba0fc6fa2b57176d420f7e4 upstream.

When walking page tables we need to make sure that everything
is within bounds of the ASCE limit of the task's address space.
Otherwise we might calculate e.g. a pud pointer which is not
within a pud and dereference it.
So check against TASK_SIZE (which is the ASCE limit) before
walking page tables.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
USB: option: add Novatel E362 and Dell Wireless 5800 USB IDs

commit fcb21645f1bd86d2be29baf48aa1b298de52ccc7 upstream.

The Dell 5800 appears to be a simple rebrand of the Novatel E362.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
USB: option: add Alcatel X220/X500D USB IDs

commit c0bc3098871dd9b964f6b45ec1e4d70d87811744 upstream.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drm/radeon: fix logic error in atombios_encoders.c

commit b9196395c905edec512dfd6690428084228c16ec upstream.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=50431

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ttm: Clear the ttm page allocated from high memory zone correctly

commit ac207ed2471150e06af0afc76e4becc701fa2733 upstream.

The TTM page can be allocated from high memory. In such case it is
wrong to use the page_address(page) as the virtual address for the high memory
page.

bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=50241

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
memcg: oom: fix totalpages calculation for memory.swappiness==0

commit 9a5a8f19b43430752067ecaee62fc59e11e88fa6 upstream.

oom_badness() takes a totalpages argument which says how many pages are
available and it uses it as a base for the score calculation.  The value
is calculated by mem_cgroup_get_limit which considers both limit and
total_swap_pages (resp.  memsw portion of it).

This is usually correct but since fe35004fbf9e ("mm: avoid swapping out
with swappiness==0") we do not swap when swappiness is 0 which means
that we cannot really use up all the totalpages pages.  This in turn
confuses oom score calculation if the memcg limit is much smaller than
the available swap because the used memory (capped by the limit) is
negligible comparing to totalpages so the resulting score is too small
if adj!=0 (typically task with CAP_SYS_ADMIN or non zero oom_score_adj).
A wrong process might be selected as result.

The problem can be worked around by checking mem_cgroup_swappiness==0
and not considering swap at all in such a case.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tmpfs: change final i_blocks BUG to WARNING

commit 0f3c42f522dc1ad7e27affc0a4aa8c790bce0a66 upstream.

Under a particular load on one machine, I have hit shmem_evict_inode()'s
BUG_ON(inode->i_blocks), enough times to narrow it down to a particular
race between swapout and eviction.

It comes from the "if (freed > 0)" asymmetry in shmem_recalc_inode(),
and the lack of coherent locking between mapping's nrpages and shmem's
swapped count.  There's a window in shmem_writepage(), between lowering
nrpages in shmem_delete_from_page_cache() and then raising swapped
count, when the freed count appears to be +1 when it should be 0, and
then the asymmetry stops it from being corrected with -1 before hitting
the BUG.

One answer is coherent locking: using tree_lock throughout, without
info->lock; reasonable, but the raw_spin_lock in percpu_counter_add() on
used_blocks makes that messier than expected.  Another answer may be a
further effort to eliminate the weird shmem_recalc_inode() altogether,
but previous attempts at that failed.

So far undecided, but for now change the BUG_ON to WARN_ON: in usual
circumstances it remains a useful consistency check.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.

commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.

On systems with very large memory (1 TB in our case), BIOS may report a
reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
these from the direct mapping.

[ hpa: this should be done not just for > 4 GB but for everything above the legacy
  region (1 MB), at the very least.  That, however, turns out to require significant
  restructuring.  That work is well underway, but is not suitable for rc/stable. ]

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86, mm: Find_early_table_space based on ranges that are actually being mapped

commit 844ab6f993b1d32eb40512503d35ff6ad0c57030 upstream.

Current logic finds enough space for direct mapping page tables from 0
to end. Instead, we only need to find enough space to cover mr[0].start
to mr[nr_range].end -- the range that is actually being mapped by
init_memory_mapping()

This is needed after 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a, to address
the panic reported here:

  https://lkml.org/lkml/2012/10/20/160
  https://lkml.org/lkml/2012/10/21/157

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-Toonie
Tested-by: Tom Rini <trini@ti.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
[bwh: Backported to 3.2:
 - Adjust context
 - The log message format is a bit different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86, mm: Undo incorrect revert in arch/x86/mm/init.c

commit f82f64dd9f485e13f29f369772d4a0e868e5633a upstream.

Commit

    844ab6f9 x86, mm: Find_early_table_space based on ranges that are actually being mapped

added back some lines back wrongly that has been removed in commit

    7b16bbf97 Revert "x86/mm: Fix the size calculation of mapping tables"

remove them again.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQW_vuaYQbmagVnxT2DGsYc=9tNeAbdBq53sYkitPOwxSQ@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>