Pull Kconfig updates from Masahiro Yamada:

 - error out if a user specifies a directory instead of a file from
   "Save" menu of GUI interfaces

 - do not overwrite .config if there is no change in the configuration

 - create parent directories as needed when a user specifies a new file
   path from "Save" menu of menuconfig/nconfig

 - fix potential buffer overflow

 - some trivial cleanups

* tag 'kconfig-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: make conf_get_autoconfig_name() static
  kconfig: use snprintf for formatting pathnames
  kconfig: remove useless NULL pointer check in conf_write_dep()
  kconfig: make parent directories for the saved .config as needed
  kconfig: do not write .config if the content is the same
  kconfig: do not accept a directory for configuration output
  kconfig: remove trailing whitespaces
  kconfig: Make nconf-cfg.sh executable

Pull more ACPI updates from Rafael Wysocki:
 "These fix two regressions introduced during the 5.0 cycle, in ACPICA
  and in device PM, cause the values returned by _ADR to be stored in 64
  bits and fix two ACPI documentation issues.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20190509
     including one regression fix:
       * Prevent excessive ACPI debug messages from being printed by
         moving the ACPI_DEBUG_DEFAULT definition to the right place
         (Erik Schmauss).

   - Set the enable_for_wake bits for wakeup GPEs during suspend to idle
     to allow acpi_enable_all_wakeup_gpes() to enable them as
     aproppriate and make wakeup devices sighaling events through ACPI
     GPEs work with suspend-to-idle again (Rajat Jain).

   - Use 64 bits to store the return values of _ADR which are assumed to
     be 64-bit by some bus specs and may contain nonzero bits in the
     upper 32 bits part for some devices (Pierre-Louis Bossart).

   - Fix two minor issues with the ACPI documentation (Sakari Ailus)"

* tag 'acpi-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: PM: Set enable_for_wake for wakeup GPEs during suspend-to-idle
  Documentation: ACPI: Direct references are allowed to devices only
  Documentation: ACPI: Use tabs for graph ASL indentation
  ACPICA: Update version to 20190509
  ACPICA: Linux: move ACPI_DEBUG_DEFAULT flag out of ifndef
  ACPI: bus: change _ADR representation to 64 bits

Pull more power management updates from Rafael Wysocki:
 "These fix a recent regression causing kernels built with CONFIG_PM
  unset to crash on systems that support the Performance and Energy Bias
  Hint (EPB), clean up the cpufreq core and some users of transition
  notifiers and introduce a new power domain flag into the generic power
  domains framework (genpd).

  Specifics:

   - Fix recent regression causing kernels built with CONFIG_PM unset to
     crash on systems that support the Performance and Energy Bias Hint
     (EPB) by avoiding to compile the EPB-related code depending on
     CONFIG_PM when it is unset (Rafael Wysocki).

   - Clean up the transition notifier invocation code in the cpufreq
     core and change some users of cpufreq transition notifiers
     accordingly (Viresh Kumar).

   - Change MAINTAINERS to cover the schedutil governor as part of
     cpufreq (Viresh Kumar).

   - Simplify cpufreq_init_policy() to avoid redundant computations (Yue
     Hu).

   - Add explanatory comment to the cpufreq core (Rafael Wysocki).

   - Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic
     power domains (genpd) framework along with the first user of it
     (Leonard Crestez)"

* tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619
  PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag
  cpufreq: Update MAINTAINERS to include schedutil governor
  cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()
  cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()
  cpufreq: Call transition notifier only once for each policy
  x86: intel_epb: Take CONFIG_PM into account

Pull crypto fixes from Herbert Xu:
 "This fixes a number of issues in the chelsio and caam drivers"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  Revert "crypto: caam/jr - Remove extra memory barrier during job ring dequeue"
  crypto: caam - fix caam_dump_sg that iterates through scatterlist
  crypto: caam - fix DKP detection logic
  MAINTAINERS: Maintainer for Chelsio crypto driver
  crypto: chelsio - count incomplete block in IV
  crypto: chelsio - Fix softlockup with heavy I/O
  crypto: chelsio - Fix NULL pointer dereference

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This patch aims to suppress 3 missing-break-in-switch false positives
on some architectures.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* pm-cpufreq:
  cpufreq: Update MAINTAINERS to include schedutil governor
  cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()
  cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()
  cpufreq: Call transition notifier only once for each policy

* pm-domains:
  soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619
  PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag

* acpi-bus:
  ACPI: bus: change _ADR representation to 64 bits

* acpi-doc:
  Documentation: ACPI: Direct references are allowed to devices only
  Documentation: ACPI: Use tabs for graph ASL indentation

* acpi-pm:
  ACPI: PM: Set enable_for_wake for wakeup GPEs during suspend-to-idle

Pull more rdma updates from Jason Gunthorpe:
 "This is being sent to get a fix for the gcc 9.1 build warnings, and
  I've also pulled in some bug fix patches that were posted in the last
  two weeks.

   - Avoid the gcc 9.1 warning about overflowing a union member

   - Fix the wrong callback type for a single response netlink to doit

   - Bug fixes from more usage of the mlx5 devx interface"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  net/mlx5: Set completion EQs as shared resources
  IB/mlx5: Verify DEVX general object type correctly
  RDMA/core: Change system parameters callback from dumpit to doit
  RDMA: Directly cast the sockaddr union to sockaddr

Merge more updates from Andrew Morton:

 - a couple of hotfixes

 - almost all of the rest of MM

 - lib/ updates

 - binfmt_elf updates

 - autofs updates

 - quite a lot of misc fixes and updates
    - reiserfs, fatfs
    - signals
    - exec
    - cpumask
    - rapidio
    - sysctl
    - pids
    - eventfd
    - gcov
    - panic
    - pps

 - gdb script updates

 - ipc updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (126 commits)
  mm: memcontrol: fix NUMA round-robin reclaim at intermediate level
  mm: memcontrol: fix recursive statistics correctness & scalabilty
  mm: memcontrol: move stat/event counting functions out-of-line
  mm: memcontrol: make cgroup stats and events query API explicitly local
  drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl
  drivers/virt/fsl_hypervisor.c: dereferencing error pointers in ioctl
  mm, memcg: rename ambiguously named memory.stat counters and functions
  arch: remove <asm/sizes.h> and <asm-generic/sizes.h>
  treewide: replace #include <asm/sizes.h> with #include <linux/sizes.h>
  fs/block_dev.c: Remove duplicate header
  fs/cachefiles/namei.c: remove duplicate header
  include/linux/sched/signal.h: replace `tsk' with `task'
  fs/coda/psdev.c: remove duplicate header
  ipc: do cyclic id allocation for the ipc object.
  ipc: conserve sequence numbers in ipcmni_extend mode
  ipc: allow boot time extension of IPCMNI from 32k to 16M
  ipc/mqueue: optimize msg_get()
  ipc/mqueue: remove redundant wq task assignment
  ipc: prevent lockup on alloc_msg and free_msg
  scripts/gdb: print cached rate in lx-clk-summary
  ...

When a cgroup is reclaimed on behalf of a configured limit, reclaim
needs to round-robin through all NUMA nodes that hold pages of the memcg
in question.  However, when assembling the mask of candidate NUMA nodes,
the code only consults the *local* cgroup LRU counters, not the
recursive counters for the entire subtree.  Cgroup limits are frequently
configured against intermediate cgroups that do not have memory on their
own LRUs.  In this case, the node mask will always come up empty and
reclaim falls back to scanning only the current node.

If a cgroup subtree has some memory on one node but the processes are
bound to another node afterwards, the limit reclaim will never age or
reclaim that memory anymore.

To fix this, use the recursive LRU counts for a cgroup subtree to
determine which nodes hold memory of that cgroup.

The code has been broken like this forever, so it doesn't seem to be a
problem in practice.  I just noticed it while reviewing the way the LRU
counters are used in general.

Link: http://lkml.kernel.org/r/20190412151507.2769-5-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NRoman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now, when somebody needs to know the recursive memory statistics
and events of a cgroup subtree, they need to walk the entire subtree and
sum up the counters manually.

There are two issues with this:

1. When a cgroup gets deleted, its stats are lost. The state counters
   should all be 0 at that point, of course, but the events are not.
   When this happens, the event counters, which are supposed to be
   monotonic, can go backwards in the parent cgroups.

2. During regular operation, we always have a certain number of lazily
   freed cgroups sitting around that have been deleted, have no tasks,
   but have a few cache pages remaining. These groups' statistics do not
   change until we eventually hit memory pressure, but somebody
   watching, say, memory.stat on an ancestor has to iterate those every
   time.

This patch addresses both issues by introducing recursive counters at
each level that are propagated from the write side when stats change.

Upward propagation happens when the per-cpu caches spill over into the
local atomic counter.  This is the same thing we do during charge and
uncharge, except that the latter uses atomic RMWs, which are more
expensive; stat changes happen at around the same rate.  In a sparse
file test (page faults and reclaim at maximum CPU speed) with 5 cgroup
nesting levels, perf shows __mod_memcg_page state at ~1%.

Link: http://lkml.kernel.org/r/20190412151507.2769-4-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NRoman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These are getting too big to be inlined in every callsite.  They were
stolen from vmstat.c, which already out-of-lines them, and they have
only been growing since.  The callsites aren't that hot, either.

Move __mod_memcg_state()
     __mod_lruvec_state() and
     __count_memcg_events() out of line and add kerneldoc comments.

Link: http://lkml.kernel.org/r/20190412151507.2769-3-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NRoman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: memcontrol: memory.stat cost & correctness".

The cgroup memory.stat file holds recursive statistics for the entire
subtree.  The current implementation does this tree walk on-demand
whenever the file is read.  This is giving us problems in production.

1. The cost of aggregating the statistics on-demand is high.  A lot of
   system service cgroups are mostly idle and their stats don't change
   between reads, yet we always have to check them.  There are also always
   some lazily-dying cgroups sitting around that are pinned by a handful
   of remaining page cache; the same applies to them.

   In an application that periodically monitors memory.stat in our
   fleet, we have seen the aggregation consume up to 5% CPU time.

2. When cgroups die and disappear from the cgroup tree, so do their
   accumulated vm events.  The result is that the event counters at
   higher-level cgroups can go backwards and confuse some of our
   automation, let alone people looking at the graphs over time.

To address both issues, this patch series changes the stat
implementation to spill counts upwards when the counters change.

The upward spilling is batched using the existing per-cpu cache.  In a
sparse file stress test with 5 level cgroup nesting, the additional cost
of the flushing was negligible (a little under 1% of CPU at 100% CPU
utilization, compared to the 5% of reading memory.stat during regular
operation).

This patch (of 4):

memcg_page_state(), lruvec_page_state(), memcg_sum_events() are
currently returning the state of the local memcg or lruvec, not the
recursive state.

In practice there is a demand for both versions, although the callers
that want the recursive counts currently sum them up by hand.

Per default, cgroups are considered recursive entities and generally we
expect more users of the recursive counters, with the local counts being
special cases.  To reflect that in the name, add a _local suffix to the
current implementations.

The following patch will re-incarnate these functions with recursive
semantics, but with an O(1) implementation.

[hannes@cmpxchg.org: fix bisection hole]
  Link: http://lkml.kernel.org/r/20190417160347.GC23013@cmpxchg.org
Link: http://lkml.kernel.org/r/20190412151507.2769-2-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NRoman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "param.count" value is a u64 thatcomes from the user.  The code
later in the function assumes that param.count is at least one and if
it's not then it leads to an Oops when we dereference the ZERO_SIZE_PTR.

Also the addition can have an integer overflow which would lead us to
allocate a smaller "pages" array than required.  I can't immediately
tell what the possible run times implications are, but it's safest to
prevent the overflow.

Link: http://lkml.kernel.org/r/20181218082129.GE32567@kadam
Fixes: 6db71994 ("drivers/virt: introduce Freescale hypervisor management driver")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

strndup_user() returns error pointers on error, and then in the error
handling we pass the error pointers to kfree().  It will cause an Oops.

Link: http://lkml.kernel.org/r/20181218082003.GD32567@kadam
Fixes: 6db71994 ("drivers/virt: introduce Freescale hypervisor management driver")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I spent literally an hour trying to work out why an earlier version of
my memory.events aggregation code doesn't work properly, only to find
out I was calling memcg->events instead of memcg->memory_events, which
is fairly confusing.

This naming seems in need of reworking, so make it harder to do the
wrong thing by using vmevents instead of events, which makes it more
clear that these are vm counters rather than memcg-specific counters.

There are also a few other inconsistent names in both the percpu and
aggregated structs, so these are all cleaned up to be more coherent and
easy to understand.

This commit contains code cleanup only: there are no logic changes.

[akpm@linux-foundation.org: fix it for preceding changes]
Link: http://lkml.kernel.org/r/20190208224319.GA23801@chrisdown.nameSigned-off-by: NChris Down <chris@chrisdown.name>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Dennis Zhou <dennis@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that all instances of #include <asm/sizes.h> have been replaced with
#include <linux/sizes.h>, we can remove these.

Link: http://lkml.kernel.org/r/1553267665-27228-2-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit dccd2304 ("ARM: 7430/1: sizes.h: move from asm-generic
to <linux/sizes.h>"), <asm/sizes.h> and <asm-generic/sizes.h> are just
wrappers of <linux/sizes.h>.

This commit replaces all <asm/sizes.h> and <asm-generic/sizes.h> to
prepare for the removal.

Link: http://lkml.kernel.org/r/1553267665-27228-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

linux/dax.h is included more than once.

Link: http://lkml.kernel.org/r/5c867e95.1c69fb81.4f15a.e5e4@mx.google.comSigned-off-by: NSabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: NSouptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

linux/xattr.h is included more than once.

Link: http://lkml.kernel.org/r/5c86803d.1c69fb81.1a7c6.2b78@mx.google.comSigned-off-by: NSabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: NSouptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This file uses "task" 85 times and "tsk" 25 times.  It is better to be
consistent.

Link: http://lkml.kernel.org/r/20181129180547.15976-1-avagin@gmail.comSigned-off-by: NAndrei Vagin <avagin@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

linux/poll.h is included more than once.

Link: http://lkml.kernel.org/r/5c86820f.1c69fb81.149f0.0834@mx.google.comSigned-off-by: NSabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For ipcmni_extend mode, the sequence number space is only 7 bits.  So
the chance of id reuse is relatively high compared with the non-extended
mode.

To alleviate this id reuse problem, this patch enables cyclic allocation
for the index to the radix tree (idx).  The disadvantage is that this
can cause a slight slow-down of the fast path, as the radix tree could
be higher than necessary.

To limit the radix tree height, I have chosen the following limits:
 1) The cycling is done over in_use*1.5.
 2) At least, the cycling is done over
   "normal" ipcnmi mode: RADIX_TREE_MAP_SIZE elements
   "ipcmni_extended": 4096 elements

Result:
- for normal mode:
	No change for <= 42 active ipc elements. With more than 42
	active ipc elements, a 2nd level would be added to the radix
	tree.
	Without cyclic allocation, a 2nd level would be added only with
	more than 63 active elements.

- for extended mode:
	Cycling creates always at least a 2-level radix tree.
	With more than 2730 active objects, a 3rd level would be
	added, instead of > 4095 active objects until the 3rd level
	is added without cyclic allocation.

For a 2-level radix tree compared to a 1-level radix tree, I have
observed < 1% performance impact.

Notes:
1) Normal "x=semget();y=semget();" is unaffected: Then the idx
  is e.g. a and a+1, regardless if idr_alloc() or idr_alloc_cyclic()
  is used.

2) The -1% happens in a microbenchmark after this situation:
	x=semget();
	for(i=0;i<4000;i++) {t=semget();semctl(t,0,IPC_RMID);}
	y=semget();
	Now perform semget calls on x and y that do not sleep.

3) The worst-case reuse cycle time is unfortunately unaffected:
   If you have 2^24-1 ipc objects allocated, and get/remove the last
   possible element in a loop, then the id is reused after 128
   get/remove pairs.

Performance check:
A microbenchmark that performes no-op semop() randomly on two IDs,
with only these two IDs allocated.
The IDs were set using /proc/sys/kernel/sem_next_id.
The test was run 5 times, averages are shown.

1 & 2: Base (6.22 seconds for 10.000.000 semops)
1 & 40: -0.2%
1 & 3348: - 0.8%
1 & 27348: - 1.6%
1 & 15777204: - 3.2%

Or: ~12.6 cpu cycles per additional radix tree level.
The cpu is an Intel I3-5010U. ~1300 cpu cycles/syscall is slower
than what I remember (spectre impact?).

V2 of the patch:
- use "min" and "max"
- use RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE instead of
	(2<<12).

[akpm@linux-foundation.org: fix max() warning]
Link: http://lkml.kernel.org/r/20190329204930.21620-3-longman@redhat.comSigned-off-by: NManfred Spraul <manfred@colorfullife.com>
Acked-by: NWaiman Long <longman@redhat.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rewrite, based on the patch from Waiman Long:

The mixing in of a sequence number into the IPC IDs is probably to avoid
ID reuse in userspace as much as possible.  With ipcmni_extend mode, the
number of usable sequence numbers is greatly reduced leading to higher
chance of ID reuse.

To address this issue, we need to conserve the sequence number space as
much as possible.  Right now, the sequence number is incremented for
every new ID created.  In reality, we only need to increment the
sequence number when new allocated ID is not greater than the last one
allocated.  It is in such case that the new ID may collide with an
existing one.  This is being done irrespective of the ipcmni mode.

In order to avoid any races, the index is first allocated and then the
pointer is replaced.

Changes compared to the initial patch:
 - Handle failures from idr_alloc().
 - Avoid that concurrent operations can see the wrong sequence number.
   (This is achieved by using idr_replace()).
 - IPCMNI_SEQ_SHIFT is not a constant, thus renamed to
   ipcmni_seq_shift().
 - IPCMNI_SEQ_MAX is not a constant, thus renamed to ipcmni_seq_max().

Link: http://lkml.kernel.org/r/20190329204930.21620-2-longman@redhat.comSigned-off-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NWaiman Long <longman@redhat.com>
Suggested-by: NMatthew Wilcox <willy@infradead.org>
Acked-by: NWaiman Long <longman@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The maximum number of unique System V IPC identifiers was limited to
32k.  That limit should be big enough for most use cases.

However, there are some users out there requesting for more, especially
those that are migrating from Solaris which uses 24 bits for unique
identifiers.  To satisfy the need of those users, a new boot time kernel
option "ipcmni_extend" is added to extend the IPCMNI value to 16M.  This
is a 512X increase which should be big enough for users out there that
need a large number of unique IPC identifier.

The use of this new option will change the pattern of the IPC
identifiers returned by functions like shmget(2).  An application that
depends on such pattern may not work properly.  So it should only be
used if the users really need more than 32k of unique IPC numbers.

This new option does have the side effect of reducing the maximum number
of unique sequence numbers from 64k down to 128.  So it is a trade-off.

The computation of a new IPC id is not done in the performance critical
path.  So a little bit of additional overhead shouldn't have any real
performance impact.

Link: http://lkml.kernel.org/r/20190329204930.21620-1-longman@redhat.comSigned-off-by: NWaiman Long <longman@redhat.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Our msg priorities became an rbtree as of d6629859 ("ipc/mqueue:
improve performance of send/recv").  However, consuming a msg in
msg_get() remains logarithmic (still being better than the case before
of course).  By applying well known techniques to cache pointers we can
have the node with the highest priority in O(1), which is specially nice
for the rt cases.  Furthermore, some callers can call msg_get() in a
loop.

A new msg_tree_erase() helper is also added to encapsulate the tree
removal and node_cache game.  Passes ltp mq testcases.

Link: http://lkml.kernel.org/r/20190321190216.1719-2-dave@stgolabs.netSigned-off-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We already store the current task fo the new waiter before calling
wq_sleep() in both send and recv paths.  Trivially remove the redundant
assignment.

Link: http://lkml.kernel.org/r/20190321190216.1719-1-dave@stgolabs.netSigned-off-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

msgctl10 of ltp triggers the following lockup When CONFIG_KASAN is
enabled on large memory SMP systems, the pages initialization can take a
long time, if msgctl10 requests a huge block memory, and it will block
rcu scheduler, so release cpu actively.

After adding schedule() in free_msg, free_msg can not be called when
holding spinlock, so adding msg to a tmp list, and free it out of
spinlock

  rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
  rcu:     Tasks blocked on level-1 rcu_node (CPUs 16-31): P32505
  rcu:     Tasks blocked on level-1 rcu_node (CPUs 48-63): P34978
  rcu:     (detected by 11, t=35024 jiffies, g=44237529, q=16542267)
  msgctl10        R  running task    21608 32505   2794 0x00000082
  Call Trace:
   preempt_schedule_irq+0x4c/0xb0
   retint_kernel+0x1b/0x2d
  RIP: 0010:__is_insn_slot_addr+0xfb/0x250
  Code: 82 1d 00 48 8b 9b 90 00 00 00 4c 89 f7 49 c1 ee 03 e8 59 83 1d 00 48 b8 00 00 00 00 00 fc ff df 4c 39 eb 48 89 9d 58 ff ff ff <41> c6 04 06 f8 74 66 4c 8d 75 98 4c 89 f1 48 c1 e9 03 48 01 c8 48
  RSP: 0018:ffff88bce041f758 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
  RAX: dffffc0000000000 RBX: ffffffff8471bc50 RCX: ffffffff828a2a57
  RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: ffff88bce041f780
  RBP: ffff88bce041f828 R08: ffffed15f3f4c5b3 R09: ffffed15f3f4c5b3
  R10: 0000000000000001 R11: ffffed15f3f4c5b2 R12: 000000318aee9b73
  R13: ffffffff8471bc50 R14: 1ffff1179c083ef0 R15: 1ffff1179c083eec
   kernel_text_address+0xc1/0x100
   __kernel_text_address+0xe/0x30
   unwind_get_return_address+0x2f/0x50
   __save_stack_trace+0x92/0x100
   create_object+0x380/0x650
   __kmalloc+0x14c/0x2b0
   load_msg+0x38/0x1a0
   do_msgsnd+0x19e/0xcf0
   do_syscall_64+0x117/0x400
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

  rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
  rcu:     Tasks blocked on level-1 rcu_node (CPUs 0-15): P32170
  rcu:     (detected by 14, t=35016 jiffies, g=44237525, q=12423063)
  msgctl10        R  running task    21608 32170  32155 0x00000082
  Call Trace:
   preempt_schedule_irq+0x4c/0xb0
   retint_kernel+0x1b/0x2d
  RIP: 0010:lock_acquire+0x4d/0x340
  Code: 48 81 ec c0 00 00 00 45 89 c6 4d 89 cf 48 8d 6c 24 20 48 89 3c 24 48 8d bb e4 0c 00 00 89 74 24 0c 48 c7 44 24 20 b3 8a b5 41 <48> c1 ed 03 48 c7 44 24 28 b4 25 18 84 48 c7 44 24 30 d0 54 7a 82
  RSP: 0018:ffff88af83417738 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
  RAX: dffffc0000000000 RBX: ffff88bd335f3080 RCX: 0000000000000002
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88bd335f3d64
  RBP: ffff88af83417758 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000001 R11: ffffed13f3f745b2 R12: 0000000000000000
  R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
   is_bpf_text_address+0x32/0xe0
   kernel_text_address+0xec/0x100
   __kernel_text_address+0xe/0x30
   unwind_get_return_address+0x2f/0x50
   __save_stack_trace+0x92/0x100
   save_stack+0x32/0xb0
   __kasan_slab_free+0x130/0x180
   kfree+0xfa/0x2d0
   free_msg+0x24/0x50
   do_msgrcv+0x508/0xe60
   do_syscall_64+0x117/0x400
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Davidlohr said:
 "So after releasing the lock, the msg rbtree/list is empty and new
  calls will not see those in the newly populated tmp_msg list, and
  therefore they cannot access the delayed msg freeing pointers, which
  is good. Also the fact that the node_cache is now freed before the
  actual messages seems to be harmless as this is wanted for
  msg_insert() avoiding GFP_ATOMIC allocations, and after releasing the
  info->lock the thing is freed anyway so it should not change things"

Link: http://lkml.kernel.org/r/1552029161-4957-1-git-send-email-lirongqing@baidu.comSigned-off-by: NLi RongQing <lirongqing@baidu.com>
Signed-off-by: NZhang Yu <zhangyu31@baidu.com>
Reviewed-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The clk rate is always stored in clk_core but might be out of date and
require calls to update from hardware.

Deal with that case by printing a (c) suffix.

Link: http://lkml.kernel.org/r/1a474318982a5f0125f2360c4161029b17f56bd1.1556881728.git.leonard.crestez@nxp.comSigned-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

An incorrect argument to list_for_each is an internal error in gdb
scripts so a TypeError should be raised.  The gdb.GdbError exception
type is intended for user errors such as incorrect invocation.

Drop the type assertion in list_for_each_entry because list_for_each
isn't going to suddenly yield something else.

Applies to both list and hlist

Link: http://lkml.kernel.org/r/c1d3fd4db13d999a3ba57f5bbc1924862d824f61.1556881728.git.leonard.crestez@nxp.comSigned-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NStephen Boyd <sboyd@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Finding an individual clk_core requires walking the tree which can be
quite complicated so add a helper for easy access.

(gdb) print *(struct clk_scu*)$lx_clk_core_lookup("uart0_clk")->hw

Link: http://lkml.kernel.org/r/Message-ID:
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an lx-clk-summary command which prints a subset of
/sys/kernel/debug/clk/clk_summary.

This can be used to examine hangs caused by clk not being enabled.

Link: http://lkml.kernel.org/r/Message-ID:
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows easily examining kernel hlists in python.

Link: http://lkml.kernel.org/r/Message-ID:
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NStephen Boyd <sboyd@kernel.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These scripts have some pep8 style warnings.  Fix them up so that this
directory is all pep8 clean.

Link: http://lkml.kernel.org/r/20190329220844.38234-6-swboyd@chromium.orgSigned-off-by: NStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement a command to print the timer list, much like how
/proc/timer_list is implemented.  This can be used to look at the
pending timers on a crashed system.

[swboyd@chromium.org: v2]
  Link: http://lkml.kernel.org/r/20190329220844.38234-5-swboyd@chromium.org
Link: http://lkml.kernel.org/r/20190325184522.260535-5-swboyd@chromium.orgSigned-off-by: NStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement gdb functions for rb_first(), rb_last(), rb_next(), and
rb_prev().  These can be useful to iterate through the kernel's
red-black trees.

[swboyd@chromium.org: v2]
  Link: http://lkml.kernel.org/r/20190329220844.38234-4-swboyd@chromium.org
Link: http://lkml.kernel.org/r/20190325184522.260535-4-swboyd@chromium.orgSigned-off-by: NStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lx-configdump <file> dumps the contents of the gzipped .config to a text
file when the config is included in the kernel with CONFIG_IKCONFIG.  By
default, the file written is called config.txt, but it can be any user
supplied filename as well.  If the kernel config is in a module
(configs.ko), then it can be loaded along with symbols for the module
loaded with 'lx-symbols' and then this command will still work.

Obviously if you have the whole vmlinux then this can also be achieved
with scripts/extract-ikconfig, but this gdb script can be useful to
confirm that the memory contents of the config in memory and the vmlinux
contents on disk match what is expected.

[swboyd@chromium.org: v2]
  Link: http://lkml.kernel.org/r/20190329220844.38234-3-swboyd@chromium.org
Link: http://lkml.kernel.org/r/20190325184522.260535-3-swboyd@chromium.orgSigned-off-by: NStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "gdb script for kconfig and timer list".

This is a handful of changes to the kernel's gdb scripts to do some more
debugging with kgdb.  The first patch allows the vmlinux to be reloaded
from where it was specified on the command line so that this set of
scripts can be used from anywhere.  The second patch adds a script to
dump the config.gz to a file on the host debugging machine.  The third
patch adds some rb tree utilities and the last patch uses those rb tree
walking utilities to dump out the contents of /proc/timer_list from a
system under debug.

This patch (of 5):

If I run 'gdb <path/to/vmlinux>' and there's the vmlinux-gdb.py file
there I can properly see symbols and use the lx commands provided by the
GDB scripts.  But once I run 'lx-symbols' at the command prompt, gdb
reloads the vmlinux symbols assuming that this script was run from the
directory that has vmlinux at the root.  That isn't always true, but we
could just look and see what symbols were already loaded and use that
instead.  Let's do that so this can work by being invoked anywhere.

Link: http://lkml.kernel.org/r/20190325184522.260535-2-swboyd@chromium.orgSigned-off-by: NStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements the PPS ECHO functionality for pps-gpio, that
sysfs claims is available already.

Configuration is done via device tree bindings.

No changes are made to userspace interfaces.

This patch was originally written by Lukas Senger as part of a masters
thesis project and modified for inclusion into the linux kernel by Tom
Burkart.

Link: http://lkml.kernel.org/r/20190324043305.6627-4-tom@aussec.comSigned-off-by: NTom Burkart <tom@aussec.com>
Acked-by: NRodolfo Giometti <giometti@enneenne.com>
Signed-off-by: NLukas Senger <lukas@fridolin.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements the device tree binding changes required for the
PPS ECHO functionality for pps-gpio, that sysfs claims is available
already.

It adds two DT properties for configuring the PPS ECHO functionality.

This patch is provided separated from the rest of the patch per
Documentation/devicetree/bindings/submitting-patches.txt.

This patch was originally written by Lukas Senger as part of a masters
thesis project and modified for inclusion into the linux kernel by Tom
Burkart.

Link: http://lkml.kernel.org/r/20190324043305.6627-3-tom@aussec.comSigned-off-by: NTom Burkart <tom@aussec.com>
Signed-off-by: NLukas Senger <lukas@fridolin.com>
Acked-by: NRodolfo Giometti <giometti@enneenne.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>