Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.

To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.

For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:

    # echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
      /sys/kernel/debug/tracing/synthetic_events

Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:

    # cat /sys/kernel/debug/tracing/synthetic_events
    wakeup_latency u64 lat; pid_t pid; int prio

At this point, the synthetic event is ready to use, and a histogram
can be defined using it:

    # echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
    /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger

The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:

    # ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
      enable  filter  format  hist  id  trigger

Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.

How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.

Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a hook for executing extra actions whenever a histogram entry is
added or updated.

The default 'action' when a hist entry is added to a histogram is to
update the set of values associated with it.  Some applications may
want to perform additional actions at that point, such as generate
another event, or compare and save a maximum.

Add a simple framework for doing that; specific actions will be
implemented on top of it in later patches.

Link: http://lkml.kernel.org/r/9482ba6a3eaf5ca6e60954314beacd0e25c05b24.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add the necessary infrastructure to allow the variables defined on one
event to be referenced in another.  This allows variables set by a
previous event to be referenced and used in expressions combining the
variable values saved by that previous event and the event fields of
the current event.  For example, here's how a latency can be
calculated and saved into yet another variable named 'wakeup_lat':

    # echo 'hist:keys=pid,prio:ts0=common_timestamp ...
    # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...

In the first event, the event's timetamp is saved into the variable
ts0.  In the next line, ts0 is subtracted from the second event's
timestamp to produce the latency.

Further users of variable references will be described in subsequent
patches, such as for instance how the 'wakeup_lat' variable above can
be displayed in a latency histogram.

Link: http://lkml.kernel.org/r/b1d3e6975374e34d501ff417c20189c3f9b2c7b8.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Future support for synthetic events requires hist_field 'type'
information, so add a field for that.

Also, make other hist_field attribute usage consistent (size,
is_signed, etc).

Link: http://lkml.kernel.org/r/3fd12a2e86316b05151ba0d7c68268e780af2c9d.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Some accessor functions, such as for variable references, require
access to a corrsponding tracing_map_elt.

Add a tracing_map_elt param to the function signature and update the
accessor functions accordingly.

Link: http://lkml.kernel.org/r/e0f292b068e9e4948da1d5af21b5ae0efa9b5717.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Up until now, hist triggers only needed per-element support for saving
'comm' data, which was saved directly as a private data pointer.

In anticipation of the need to save other data besides 'comm', add a
new hist_elt_data struct for the purpose, and switch the current
'comm'-related code over to that.

Link: http://lkml.kernel.org/r/4502c338c965ddf5fc19fb1ec4764391e001ed4b.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add support for simple addition, subtraction, and unary expressions
(-(expr) and expr, where expr = b-a, a+b, a+b+c) to hist triggers, in
order to support a minimal set of useful inter-event calculations.

These operations are needed for calculating latencies between events
(timestamp1-timestamp0) and for combined latencies (latencies over 3
or more events).

In the process, factor out some common code from key and value
parsing.

Link: http://lkml.kernel.org/r/9a9308ead4fe32a433d9c7e95921fb798394f6b2.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[kbuild test robot fix, add static to parse_atom()]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[ Replaced '//' comments with normal /* */ comments ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Move get_hist_field_flags() to make it more easily accessible for new
code (and keep the move separate from new functionality).

Link: http://lkml.kernel.org/r/32470f0a7047ec7a6e84ba5ec89d6142cc6ede7d.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Named triggers must also have the same set of variables in order to be
considered compatible - update the trigger match test to account for
that.

The reason for this requirement is that named triggers with variables
are meant to allow one or more events to set the same variable.

Link: http://lkml.kernel.org/r/a17eae6328a99917f9d5c66129c9fcd355279ee9.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add support for saving the value of a current event's event field by
assigning it to a variable that can be read by a subsequent event.

The basic syntax for saving a variable is to simply prefix a unique
variable name not corresponding to any keyword along with an '=' sign
to any event field.

Both keys and values can be saved and retrieved in this way:

    # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ...
    # echo 'hist:timer_pid=common_pid:key=$timer_pid ...'

If a variable isn't a key variable or prefixed with 'vals=', the
associated event field will be saved in a variable but won't be summed
as a value:

    # echo 'hist:keys=next_pid:ts1=common_timestamp:...

Multiple variables can be assigned at the same time:

    # echo 'hist:keys=pid:vals=$ts0,$b,field2:ts0=common_timestamp,b=field1 ...

Multiple (or single) variables can also be assigned at the same time
using separate assignments:

    # echo 'hist:keys=pid:vals=$ts0:ts0=common_timestamp:b=field1:c=field2 ...

Variables set as above can be used by being referenced from another
event, as described in a subsequent patch.

Link: http://lkml.kernel.org/r/fc93c4944d9719dbcb1d0067be627d44e98e2adc.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds.  A typical latency histogram using usecs would look like
this:

   # echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ...
   # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ...

This also adds an external trace_clock_in_ns() to trace.c for the
timestamp conversion.

Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Allow hist_data access via hist_field.  Some users of hist_fields
require or will require more access to the associated hist_data.

Link: http://lkml.kernel.org/r/d04cd0768f5228ebb4ac0ba4a847bc4d14d4826f.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map.  This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.

Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var().  tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.

tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.

Link: http://lkml.kernel.org/r/7fa001108252556f0c6dd9d63145eabfe3370d1a.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add support for a timestamp event field.  This is actually a 'pseudo-'
event field in that it behaves like it's part of the event record, but
is really part of the corresponding ring buffer event.

To make use of the timestamp field, users can specify
"common_timestamp" as a field name for any histogram.  Note that this
doesn't make much sense on its own either as either a key or value,
but needs to be supported even so, since follow-on patches will add
support for making use of this field in time deltas.  The
common_timestamp 'field' is not a bona fide event field - so you won't
find it in the event description - but rather it's a synthetic field
that can be used like a real field.

Note that the use of this field requires the ring buffer be put into
'absolute timestamp' mode, which saves the complete timestamp for each
event rather than an offset.  This mode will be enabled if and only if
a histogram makes use of the "common_timestamp" field.

Link: http://lkml.kernel.org/r/97afbd646ed146e26271f3458b4b33e16d7817c2.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
[kasan use-after-free fix]
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

This will make it easier to add variables, and makes the parsing code
cleaner regardless.

Link: http://lkml.kernel.org/r/e574b3291bbe15e35a4dfc87e5395aa715701c98.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Some events such as timestamps require access to a ring_buffer_event
struct; add a param so that hist field functions can access that.

Link: http://lkml.kernel.org/r/2ff4af18e72b6002eb86b26b2a7f39cef7d1dfe4.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The ring_buffer event can provide a timestamp that may be useful to
various triggers - pass it into the handlers for that purpose.

Link: http://lkml.kernel.org/r/6de592683b59fa70ffa5d43d0109896623fc1367.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a new option flag indicating whether or not the ring buffer is in
'absolute timestamp' mode.

Currently this is only set/unset by hist triggers that make use of a
common_timestamp.  As such, there's no reason to make this writeable
for users - its purpose is only to allow users to determine
unequivocally whether or not the ring buffer is in that mode (although
absolute timestamps can coexist with the normal delta timestamps, when
the ring buffer is in absolute mode, timestamps written while absolute
mode is in effect take up more space in the buffer, and are not as
efficient).

Link: http://lkml.kernel.org/r/e8aa7b1cde1cf15014e66545d06ac6ef2ebba456.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

RINGBUF_TYPE_TIME_STAMP is defined but not used, and from what I can
gather was reserved for something like an absolute timestamp feature
for the ring buffer, if not a complete replacement of the current
time_delta scheme.

This code redefines RINGBUF_TYPE_TIME_STAMP to implement absolute time
stamps.  Another way to look at it is that it essentially forces
extended time_deltas for all events.

The motivation for doing this is to enable time_deltas that aren't
dependent on previous events in the ring buffer, making it feasible to
use the ring_buffer_event timetamps in a more random-access way, for
purposes other than serial event printing.

To set/reset this mode, use tracing_set_timestamp_abs() from the
previous interface patch.

Link: http://lkml.kernel.org/r/477b362dba1ce7fab9889a1a8e885a62c472f041.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Define a new function, tracing_set_time_stamp_abs(), which can be used
to enable or disable the use of absolute timestamps rather than time
deltas for a trace array.

Only the interface is added here; a subsequent patch will add the
underlying implementation.

Link: http://lkml.kernel.org/r/ce96119de44c7fe0ee44786d15254e9b493040d3.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

We now have the logic to detect and remove duplicates in the
tracing_map hash table. The code which merges duplicates in the
histogram is redundant now. So, modify this code just to detect
duplicates. The duplication detection code is still kept to ensure
that any rare race condition which might cause duplicates does not go
unnoticed.

Link: http://lkml.kernel.org/r/55215cf59e2674391bdaf772fdafc4c393352b03.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

A duplicate in the tracing_map hash table is when 2 different entries
have the same key and, as a result, the key_hash. This is possible due
to a race condition in the algorithm. This race condition is inherent to
the algorithm and not a bug. This was fine because, until now, we were
only interested in the sum of all the values related to a particular
key (the duplicates are dealt with in tracing_map_sort_entries()). But,
with the inclusion of variables[1], we are interested in individual
values. So, it will not be clear what value to choose when
there are duplicates. So, the duplicates need to be removed.

The duplicates can occur in the code in the following scenarios:

- A thread is in the process of adding a new element. It has
successfully executed cmpxchg() and inserted the key. But, it is still
not done acquiring the trace_map_elt struct, populating it and storing
the pointer to the struct in the value field of tracing_map hash table.
If another thread comes in at this time and wants to add an element with
the same key, it will not see the current element and add a new one.

- There are multiple threads trying to execute cmpxchg at the same time,
one of the threads will succeed and the others will fail. The ones which
fail will go ahead increment 'idx' and add a new element there creating
a duplicate.

This patch detects and avoids the first condition by asking the thread
which detects the duplicate to loop one more time. There is also a
possibility of infinite loop if the thread which is trying to insert
goes to sleep indefinitely and the one which is trying to insert a new
element detects a duplicate. Which is why, the thread loops for
map_size iterations before returning NULL.

The second scenario is avoided by preventing the threads which failed
cmpxchg() from incrementing idx. This way, they will loop
around and check if the thread which succeeded in executing cmpxchg()
had the same key.

[1] http://lkml.kernel.org/r/cover.1498510759.git.tom.zanussi@linux.intel.com

Link: http://lkml.kernel.org/r/e178e89ec399240331d383bd5913d649713110f4.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a line for the log2 modifier, to keep it aligned with
tracing/README.

Link: http://lkml.kernel.org/r/a419028bccab155749a4b8702d5b97af75f1578f.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The hist trigger Documentation takes up a large part of events.txt -
since it will be getting even larger, move it to a separate file.

Link: http://lkml.kernel.org/r/92761155ea4f529e590821b1e02207fe8619f248.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull x86 fixes from Thomas Gleixner:
 "A small set of fixes for x86:

   - Add missing instruction suffixes to assembly code so it can be
     compiled by newer GAS versions without warnings.

   - Switch refcount WARN exceptions to UD2 as we did in general

   - Make the reboot on Intel Edison platforms work

   - A small documentation update so text and sample command match"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation, x86, resctrl: Make text and sample command match
  x86/platform/intel-mid: Handle Intel Edison reboot correctly
  x86/asm: Add instruction suffixes to bitops
  x86/entry/64: Add instruction suffix
  x86/refcounts: Switch to UD2 for exceptions

Pull x86/pti fixes from Thomas Gleixner:
 "Three fixes related to melted spectrum:

   - Sync the cpu_entry_area page table to initial_page_table on 32 bit.

     Otherwise suspend/resume fails because resume uses
     initial_page_table and triggers a triple fault when accessing the
     cpu entry area.

   - Zero the SPEC_CTL MRS on XEN before suspend to address a
     shortcoming in the hypervisor.

   - Fix another switch table detection issue in objtool"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
  objtool: Fix another switch table detection issue
  x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend

Pull timer fixes from Thomas Gleixner:
 "A small set of fixes from the timer departement:

   - Add a missing timer wheel clock forward when migrating timers off a
     unplugged CPU to prevent operating on a stale clock base and
     missing timer deadlines.

   - Use the proper shift count to extract data from a register value to
     prevent evaluating unrelated bits

   - Make the error return check in the FSL timer driver work correctly.
     Checking an unsigned variable for less than zero does not really
     work well.

   - Clarify the confusing comments in the ARC timer code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Forward timer base before migrating timers
  clocksource/drivers/arc_timer: Update some comments
  clocksource/drivers/mips-gic-timer: Use correct shift count to extract data
  clocksource/drivers/fsl_ftm_timer: Fix error return checking

Pull irq fixlet from Thomas Gleixner:
 "Just a documentation update for the missing device tree property of
  the R-Car M3N interrupt controller"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings/irqchip/renesas-irqc: Document R-Car M3-N support

Pull btrfs fixes from David Sterba:

 - when NR_CPUS is large, a SRCU structure can significantly inflate
   size of the main filesystem structure that would not be possible to
   allocate by kmalloc, so the kvalloc fallback is used

 - improved error handling

 - fix endiannes when printing some filesystem attributes via sysfs,
   this is could happen when a filesystem is moved between different
   endianity hosts

 - send fixes: the NO_HOLE mode should not send a write operation for a
   file hole

 - fix log replay for for special files followed by file hardlinks

 - fix log replay failure after unlink and link combination

 - fix max chunk size calculation for DUP allocation

* tag 'for-4.16-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix log replay failure after unlink and link combination
  Btrfs: fix log replay failure after linking special file and fsync
  Btrfs: send, fix issuing write op when processing hole in no data mode
  btrfs: use proper endianness accessors for super_copy
  btrfs: alloc_chunk: fix DUP stripe size handling
  btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_cluster
  btrfs: handle failure of add_pending_csums
  btrfs: use kvzalloc to allocate btrfs_fs_info

Pull i2c fixes from Wolfram Sang:
 "A driver fix and a documentation fix (which makes dependency handling
  for the next cycle easier)"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: octeon: Prevent error message on bus error
  dt-bindings: at24: sort manufacturers alphabetically

Pull libnvdimm fixes from Dan Williams:
 "A 4.16 regression fix, three fixes for -stable, and a cleanup fix:

   - During the merge window support for the new ACPI NVDIMM Platform
     Capabilities structure disabled support for "deep flush", a
     force-unit- access like mechanism for persistent memory. Restore
     that mechanism.

   - VFIO like RDMA is yet one more memory registration / pinning
     interface that is incompatible with Filesystem-DAX. Disable long
     term pins of Filesystem-DAX mappings via VFIO.

   - The Filesystem-DAX detection to prevent long terms pins mistakenly
     also disabled Device-DAX pins which are not subject to the same
     block- map collision concerns.

   - Similar to the setup path, softlockup warnings can trigger in the
     shutdown path for large persistent memory namespaces. Teach
     for_each_device_pfn() to perform cond_resched() in all cases.

   - Boaz noticed that the might_sleep() in dax_direct_access() is stale
     as of the v4.15 kernel.

  These have received a build success notification from the 0day robot,
  and the longterm pin fixes have appeared in -next. However, I recently
  rebased the tree to remove some other fixes that need to be reworked
  after review feedback.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  memremap: fix softlockup reports at teardown
  libnvdimm: re-enable deep flush for pmem devices via fsync()
  vfio: disable filesystem-dax page pinning
  dax: fix vma_is_fsdax() helper
  dax: ->direct_access does not sleep anymore

Merge tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - suppress sparse warnings about unknown attributes

 - fix typos and stale comments

 - fix build error of arch/sh

 - fix wrong use of ld-option vs cc-ldoption

 - remove redundant GCC_PLUGINS_CFLAGS assignment

 - fix another memory leak of Kconfig

 - fix line number in error messages of Kconfig

 - do not write confusing CONFIG_DEFCONFIG_LIST out to .config

 - add xstrdup() to Kconfig to handle memory shortage errors

 - show also a Debian package name if ncurses is missing

* tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  MAINTAINERS: take over Kconfig maintainership
  kconfig: fix line number in recursive inclusion error message
  Coccinelle: memdup: Fix typo in warning messages
  kconfig: Update ncurses package names for menuconfig
  kbuild/kallsyms: trivial typo fix
  kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
  kbuild: drop superfluous GCC_PLUGINS_CFLAGS assignment
  kconfig: Don't leak choice names during parsing
  sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE
  kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
  kconfig: add xstrdup() helper
  kbuild: disable sparse warnings about unknown attributes
  Makefile: Fix lying comment re. silentoldconfig

Pull media fixes from Mauro Carvalho Chehab:

  - some build fixes with randconfigs

  - an m88ds3103 fix to prevent an OOPS if the chip doesn't provide the
    right version during probe (with can happen if the hardware hangs)

  - a potential out of array bounds reference in tvp5150

  - some fixes and improvements in the DVB memory mapped API (added for
    kernel 4.16)

* tag 'media/v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: vb2: Makefile: place vb2-trace together with vb2-core
  media: Don't let tvp5150_get_vbi() go out of vbi_ram_default array
  media: dvb: update buffer mmaped flags and frame counter
  media: dvb: add continuity error indicators for memory mapped buffers
  media: dmxdev: Fix the logic that enables DMA mmap support
  media: dmxdev: fix error code for invalid ioctls
  media: m88ds3103: don't call a non-initalized function
  media: au0828: add VIDEO_V4L2 dependency
  media: dvb: fix DVB_MMAP dependency
  media: dvb: fix DVB_MMAP symbol name
  media: videobuf2: fix build issues with vb2-trace
  media: videobuf2: Add VIDEOBUF2_V4L2 Kconfig option for VB2 V4L2 part

Pull watchdog fixes from Wim Van Sebroeck:

 - rave-sp: add NVMEM dependency

 - build fixes for i6300esb_wdt, xen_wdt and sp5100_tco

* tag 'linux-watchdog-4.16-fixes-1' of git://www.linux-watchdog.org/linux-watchdog:
  watchdog: sp5100_tco.c: fix potential build failure
  watchdog: xen_wdt: fix potential build failure
  watchdog: i6300esb: fix build failure
  watchdog: rave-sp: add NVMEM dependency

Pull KVM fixes from Radim Krčmář:
 "x86:

   - fix NULL dereference when using userspace lapic

   - optimize spectre v1 mitigations by allowing guests to use LFENCE

   - make microcode revision configurable to prevent guests from
     unnecessarily blacklisting spectre v2 mitigation feature"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: fix vcpu initialization with userspace lapic
  KVM: X86: Allow userspace to define the microcode version
  KVM: X86: Introduce kvm_get_msr_feature()
  KVM: SVM: Add MSR-based feature support for serializing LFENCE
  KVM: x86: Add a framework for supporting MSR-based features

The cond_resched() currently in the setup path needs to be duplicated in
the teardown path. Rather than require each instance of
for_each_device_pfn() to open code the same sequence, embed it in the
helper.

Link: https://github.com/intel/ixpdimm_sw/issues/11
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Fixes: 71389703

 ("mm, zone_device: Replace {get, put}_zone_device_page()...")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Re-enable deep flush so that users always have a way to be sure that a
write makes it all the way out to media. Writes from the PMEM driver
always arrive at the NVDIMM since movnt is used to bypass the cache, and
the driver relies on the ADR (Asynchronous DRAM Refresh) mechanism to
flush write buffers on power failure. The Deep Flush mechanism is there
to explicitly write buffers to protect against (rare) ADR failure.  This
change prevents a regression in deep flush behavior so that applications
can continue to depend on fsync() as a mechanism to trigger deep flush
in the filesystem-DAX case.

Fixes: 06e8ccda

 ("acpi: nfit: Add support for detect platform CPU cache...")
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

I have recently picked up Kconfig patches to my tree without any
declaration.  Making it official now.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

Filesystem-DAX is incompatible with 'longterm' page pinning. Without
page cache indirection a DAX mapping maps filesystem blocks directly.
This means that the filesystem must not modify a file's block map while
any page in a mapping is pinned. In order to prevent the situation of
userspace holding of filesystem operations indefinitely, disallow
'longterm' Filesystem-DAX mappings.

RDMA has the same conflict and the plan there is to add a 'with lease'
mechanism to allow the kernel to notify userspace that the mapping is
being torn down for block-map maintenance. Perhaps something similar can
be put in place for vfio.

Note that xfs and ext4 still report:

   "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"

...at mount time, and resolving the dax-dma-vs-truncate problem is one
of the last hurdles to remove that designation.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org>
Reported-by: Haozhong Zhang <haozhong.zhang@intel.com>
Tested-by: Haozhong Zhang <haozhong.zhang@intel.com>
Fixes: d475c634

 ("dax,ext2: replace XIP read and write with DAX I/O")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>