Extract the string test code into its own source file, to allow
compiling it either to a loadable module, or built into the kernel.

Fixes: 03270c13 ("lib/string.c: add testcases for memset16/32/64")
Link: http://lkml.kernel.org/r/1505397744-3387-1-git-send-email-geert@linux-m68k.orgSigned-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This include was added by commit 187f1882 ("BUG: headers with
BUG/BUG_ON etc. need linux/bug.h") because BUG_ON() was used in this
header at that time.

Some time later, commit 6d75f366 ("lib: radix-tree: check accounting
of existing slot replacement users") removed the use of BUG_ON() from
this header.

Since then, there is no reason to include <linux/bug.h>.

Link: http://lkml.kernel.org/r/1505660151-4383-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chris Mi <chrism@mellanox.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit bc6245e5 ("bug: split BUILD_BUG stuff out into
<linux/build_bug.h>"), #include <linux/build_bug.h> is better to pull
minimal headers needed for BUILG_BUG() family.

Link: http://lkml.kernel.org/r/1505700775-19826-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Cc: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tests for duplicate section headers, missing section content, link and
scm reachability.

Miscellanea:

o Add --self-test=<foo> options
  (a comma separated list of any of sections, patterns, links or scm)
  where the default without options is all tests
o Rename check_maintainers_patterns to self_test
o Rename self_test_pattern_info to self_test_info

[tom.saeger@oracle.com: improvements]
Link: http://lkml.kernel.org/r/13e3986c374902fcf08ae947e36c5c608bbe3b79.1510075301.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NTom Saeger <tom.saeger@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add "--self-test" option to get_maintainer.pl to show potential
issues in MAINTAINERS file(s) content.

Pattern check warnings are shown for "F" and "X" patterns found in
MAINTAINERS file(s) which do not match any files known by git.

Link: http://lkml.kernel.org/r/64994f911b3510d0f4c8ac2e113501dfcec1f3c9.1509559540.git.tom.saeger@oracle.comSigned-off-by: NTom Saeger <tom.saeger@oracle.com>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix minor typo.

Fix missing words in explaining parsing of last line number.

Link: http://lkml.kernel.org/r/ebb7ff42-4945-103f-d5b4-f07a6f3343a7@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

line-range is supposed to treat "1-" as "1-endoffile", so
handle the special case by setting last_lineno to UINT_MAX.

Fixes this error:

  dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1
  dynamic_debug:ddebug_exec_query: query parse failed

Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NJason Baron <jbaron@akamai.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If 'write' is 0, we can avoid a call to spin_lock/spin_unlock.

Link: http://lkml.kernel.org/r/20171020193331.7233-1-christophe.jaillet@wanadoo.frSigned-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: NLuis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The GCC randomize layout plugin can randomize the member offsets of
sensitive kernel data structures.  To use this feature, certain
annotations and members are added to the structures which affect the
member offsets even if this plugin is not used.

All of these structures are completely randomized, except for task_struct
which leaves out some of its members.  All the other members are wrapped
within an anonymous struct with the __randomize_layout attribute.  This is
done using the randomized_struct_fields_start and
randomized_struct_fields_end defines.

When the plugin is disabled, the behaviour of this attribute can vary
based on the GCC version.  For GCC 5.1+, this attribute maps to
__designated_init otherwise it is just an empty define but the anonymous
structure is still present.  For other compilers, both
randomized_struct_fields_start and randomized_struct_fields_end default
to empty defines meaning the anonymous structure is not introduced at
all.

So, if a module compiled with Clang, such as a BPF program, needs to
access task_struct fields such as pid and comm, the offsets of these
members as recognized by Clang are different from those recognized by
modules compiled with GCC.  If GCC 4.6+ is used to build the kernel,
this can be solved by introducing appropriate defines for Clang so that
the anonymous structure is seen when determining the offsets for the
members.

Link: http://lkml.kernel.org/r/20171109064645.25581-1-sandipan@linux.vnet.ibm.comSigned-off-by: NSandipan Das <sandipan@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prior to v4.11, x86 used warn_slowpath_fmt() for handling WARN()s.
After WARN() was moved to using UD0 on x86, the warning text started
appearing _before_ the "cut here" line.  This appears to have been a
long-standing bug on architectures that used __WARN_TAINT, but it didn't
get fixed.

v4.11 and earlier on x86:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 2956 at drivers/misc/lkdtm_bugs.c:65 lkdtm_WARNING+0x21/0x30
  This is a warning message
  Modules linked in:

v4.12 and later on x86:

  This is a warning message
  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 2982 at drivers/misc/lkdtm_bugs.c:68 lkdtm_WARNING+0x15/0x20
  Modules linked in:

With this fix:

  ------------[ cut here ]------------
  This is a warning message
  WARNING: CPU: 3 PID: 3009 at drivers/misc/lkdtm_bugs.c:67 lkdtm_WARNING+0x15/0x20

Since the __FILE__ reporting happens as part of the UD0 handler, it
isn't trivial to move the message to after the WARNING line, but at
least we can fix the position of the "cut here" line so all the various
logging tools will start including the actual runtime warning message
again, when they follow the instruction and "cut here".

Link: http://lkml.kernel.org/r/1510100869-73751-4-git-send-email-keescook@chromium.org
Fixes: 9a93848f ("x86/debug: Implement __WARN() using UD0")
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "cut here" string is used in a few paths.  Define it in a single
place.

Link: http://lkml.kernel.org/r/1510100869-73751-3-git-send-email-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In order to test the ordering of WARN format strings, actually include
one in LKDTM.

Link: http://lkml.kernel.org/r/1510100869-73751-2-git-send-email-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When we pass the result of a multiplication as the timeout or the delay,
we can get a warning from gcc-7:

  drivers/mmc/host/bcm2835.c:596:149: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
  drivers/mfd/arizona-core.c:247:195: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
  drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c:49:27: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]

The warning is a bit questionable inside of a macro, but this is
intentional on the side of the gcc developers.  It is also an indication
of another problem: we evaluate the timeout and sleep arguments multiple
times, which can have undesired side-effects when those are complex
expressions.

This changes the two iopoll variants to use local variables for storing
copies of the timeouts.  This adds some more type safety, and avoids
both the double-evaluation and the gcc warning.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81484
Link: http://lkml.kernel.org/r/20170726133756.2161367-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20171102114048.1526955-1-arnd@arndb.deSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parse-maintainers.pl is convenient, but currently hard-codes the
filenames that are used.

Allow user-specified filenames to simplify the use of the script.

Link: http://lkml.kernel.org/r/48703c068b3235223ffa3b2eb268fa0a125b25e0.1502251549.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some architectures store the WARN_ONCE state in the flags field of the
bug_entry.  Clear that one too when resetting once state through
/sys/kernel/debug/clear_warn_once

Pointed out by Michael Ellerman

Improves the earlier patch that add clear_warn_once.

[ak@linux.intel.com: add a missing ifdef CONFIG_MODULES]
  Link: http://lkml.kernel.org/r/20171020170633.9593-1-andi@firstfloor.org
[akpm@linux-foundation.org: fix unused var warning]
[akpm@linux-foundation.org: Use 0200 for clear_warn_once file, per mpe]
[akpm@linux-foundation.org: clear BUGFLAG_DONE in clear_once_table(), per mpe]
Link: http://lkml.kernel.org/r/20171019204642.7404-1-andi@firstfloor.orgSigned-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I like _ONCE warnings because it's guaranteed that they don't flood the
log.

During testing I find it useful to reset the state of the once warnings,
so that I can rerun tests and see if they trigger again, or can
guarantee that a test run always hits the same warnings.

This patch adds a debugfs interface to reset all the _ONCE warnings so
that they appear again:

  echo 1 > /sys/kernel/debug/clear_warn_once

This is implemented by putting all the warning booleans into a special
section, and clearing it.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20171017221455.6740-1-andi@firstfloor.orgSigned-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The sh decompressor code triggers stack-protector code generation when
using CONFIG_CC_STACKPROTECTOR_STRONG.  As done for arm and mips, add a
simple static stack-protector canary.  As this wasn't protected before,
the risk of using a weak canary is minimized.  Once the kernel is
actually up, a better canary is chosen.

Link: http://lkml.kernel.org/r/1506972007-80614-2-git-send-email-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add unnecessary typos by copying the necessary typos.

Link: http://lkml.kernel.org/r/1505074722.22023.6.camel@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Gcc doesn't know that "len" is guaranteed to be >=1 by dcache and
generates standard while-loop prologue duplicating loop condition.

	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27)
	function                                     old     new   delta
	name_to_int                                  104      77     -27

Link: http://lkml.kernel.org/r/20170912195213.GB17730@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Save ~360 bytes.

	add/remove: 1/0 grow/shrink: 0/4 up/down: 104/-463 (-359)
	function                                     old     new   delta
	name_to_int                                    -     104    +104
	proc_pid_lookup                              217     126     -91
	proc_lookupfd_common                         212     121     -91
	proc_task_lookup                             289     194     -95
	__proc_create                                588     402    -186

Link: http://lkml.kernel.org/r/20170912194850.GA17730@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now there is no convenient way to check if a process is being
coredumped at the moment.

It might be necessary to recognize such state to prevent killing the
process and getting a broken coredump.  Writing a large core might take
significant time, and the process is unresponsive during it, so it might
be killed by timeout, if another process is monitoring and
killing/restarting hanging tasks.

We're getting a significant number of corrupted coredump files on
machines in our fleet, just because processes are being killed by
timeout in the middle of the core writing process.

We do have a process health check, and some agent is responsible for
restarting processes which are not responding for health check requests.
Writing a large coredump to the disk can easily exceed the reasonable
timeout (especially on an overloaded machine).

This flag will allow the agent to distinguish processes which are being
coredumped, extend the timeout for them, and let them produce a full
coredump file.

To provide an ability to detect if a process is in the state of being
coredumped, we can expose a boolean CoreDumping flag in
/proc/pid/status.

Example:
$ cat core.sh
  #!/bin/sh

  echo "|/usr/bin/sleep 10" > /proc/sys/kernel/core_pattern
  sleep 1000 &
  PID=$!

  cat /proc/$PID/status | grep CoreDumping
  kill -ABRT $PID
  sleep 1
  cat /proc/$PID/status | grep CoreDumping

$ ./core.sh
  CoreDumping:	0
  CoreDumping:	1

[guro@fb.com: document CoreDumping flag in /proc/<pid>/status]
  Link: http://lkml.kernel.org/r/20170928135357.GA8470@castle.DHCP.thefacebook.com
Link: http://lkml.kernel.org/r/20170920230634.31572-1-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit f3c931633a59 ("mm, compaction: persistently skip hugetlbfs
pageblocks") has introduced pageblock_skip_persistent() checks into
migration and free scanners, to make sure pageblocks that should be
persistently skipped are marked as such, regardless of the
ignore_skip_hint flag.

Since the previous patch introduced a new no_set_skip_hint flag, the
ignore flag no longer prevents marking pageblocks as skipped.  Therefore
we can remove the special cases.  The relevant pageblocks will be marked
as skipped by the common logic which marks each pageblock where no page
could be isolated.  This makes the code simpler.

Link: http://lkml.kernel.org/r/20171102121706.21504-3-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pageblock skip hints were added as a heuristic for compaction, which
shares core code with CMA.  Since CMA reliability would suffer from the
heuristics, compact_control flag ignore_skip_hint was added for the CMA
use case.  Since 6815bf3f ("mm/compaction: respect ignore_skip_hint
in update_pageblock_skip") the flag also means that CMA won't *update*
the skip hints in addition to ignoring them.

Today, direct compaction can also ignore the skip hints in the last
resort attempt, but there's no reason not to set them when isolation
fails in such case.  Thus, this patch splits off a new no_set_skip_hint
flag to avoid the updating, which only CMA sets.  This should improve
the heuristics a bit, and allow us to simplify the persistent skip bit
handling as the next step.

Link: http://lkml.kernel.org/r/20171102121706.21504-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pageblock_skip_persistent() checks for HugeTLB pages of pageblock order.
When clearing pageblock skip bits for compaction, the bits are not
cleared for such pageblocks, because they cannot contain base pages
suitable for migration, nor free pages to use as migration targets.

This optimization can be simply extended to all compound pages of order
equal or larger than pageblock order, because migrating such pages (if
they support it) cannot help sub-pageblock fragmentation.  This includes
THP's and also gigantic HugeTLB pages, which the current implementation
doesn't persistently skip due to a strict pageblock_order equality check
and not recognizing tail pages.

While THP pages are generally less "persistent" than HugeTLB, we can
still expect that if a THP exists at the point of
__reset_isolation_suitable(), it will exist also during the subsequent
compaction run.  The time difference here could be actually smaller than
between a compaction run that sets a (non-persistent) skip bit on a THP,
and the next compaction run that observes it.

Link: http://lkml.kernel.org/r/20171102121706.21504-1-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is pointless to migrate hugetlb memory as part of memory compaction
if the hugetlb size is equal to the pageblock order.  No defragmentation
is occurring in this condition.

It is also pointless to for the freeing scanner to scan a pageblock
where a hugetlb page is pinned.  Unconditionally skip these pageblocks,
and do so peristently so that they are not rescanned until it is
observed that these hugepages are no longer pinned.

It would also be possible to do this by involving the hugetlb subsystem
in marking pageblocks to no longer be skipped when they hugetlb pages
are freed.  This is a simple solution that doesn't involve any
additional subsystems in pageblock skip manipulation.

[rientjes@google.com: fix build]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708201734390.117182@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151639130.106658@chino.kir.corp.google.comSigned-off-by: NDavid Rientjes <rientjes@google.com>
Tested-by: NMichal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Kcompactd is needlessly ignoring pageblock skip information.  It is
doing MIGRATE_SYNC_LIGHT compaction, which is no more powerful than
MIGRATE_SYNC compaction.

If compaction recently failed to isolate memory from a set of
pageblocks, there is nothing to indicate that kcompactd will be able to
do so, or that it is beneficial from attempting to isolate memory.

Use the pageblock skip hint to avoid rescanning pageblocks needlessly
until that information is reset.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151638550.106658@chino.kir.corp.google.comSigned-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following warning by removing the unused variable:

  mm/shmem.c:3205:27: warning: variable 'info' set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1510774029-30652-1-git-send-email-clabbe@baylibre.comSigned-off-by: NCorentin Labbe <clabbe@baylibre.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dma-debug reports the following warning:

  WARNING: CPU: 3 PID: 298 at kernel-4.4/lib/dma-debug.c:604
  debug _dma_assert_idle+0x1a8/0x230()
  DMA-API: cpu touching an active dma mapped cacheline [cln=0x00000882300]
  CPU: 3 PID: 298 Comm: vold Tainted: G        W  O    4.4.22+ #1
  Hardware name: MT6739 (DT)
  Call trace:
    debug_dma_assert_idle+0x1a8/0x230
    wp_page_copy.isra.96+0x118/0x520
    do_wp_page+0x4fc/0x534
    handle_mm_fault+0xd4c/0x1310
    do_page_fault+0x1c8/0x394
    do_mem_abort+0x50/0xec

I found that debug_dma_alloc_coherent() and debug_dma_free_coherent()
assume that dma_alloc_coherent() always returns a linear address.

However it's possible that dma_alloc_coherent() returns a non-linear
address.  In this case, page_to_pfn(virt_to_page(virt)) will return an
incorrect pfn.  If the pfn is valid and mapped as a COW page, we will
hit the warning when doing wp_page_copy().

Fix this by calculating pfn for linear and non-linear addresses.

[miles.chen@mediatek.com: v4]
  Link: http://lkml.kernel.org/r/1510872972-23919-1-git-send-email-miles.chen@mediatek.com
Link: http://lkml.kernel.org/r/1506484087-1177-1-git-send-email-miles.chen@mediatek.comSigned-off-by: NMiles Chen <miles.chen@mediatek.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a race in the current z3fold implementation between
do_compact() called in a work queue context and the page release
procedure when page's kref goes to 0.

do_compact() may be waiting for page lock, which is released by
release_z3fold_page_locked right before putting the page onto the
"stale" list, and then the page may be freed as do_compact() modifies
its contents.

The mechanism currently implemented to handle that (checking the
PAGE_STALE flag) is not reliable enough.  Instead, we'll use page's kref
counter to guarantee that the page is not released if its compaction is
scheduled.  It then becomes compaction function's responsibility to
decrease the counter and quit immediately if the page was actually
freed.

Link: http://lkml.kernel.org/r/20171117092032.00ea56f42affbed19f4fcc6c@gmail.comSigned-off-by: NVitaly Wool <vitaly.wool@sonymobile.com>
Cc: <Oleksiy.Avramchenko@sony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The cleanup caused build warnings for constant mask pointers:

  mm/mempolicy.c: In function `mpol_to_str':
  ./include/linux/nodemask.h:108:11: warning: the comparison will always evaluate as `true' for the address of `nodes' will never be NULL [-Waddress]

An earlier workaround I suggested was incorporated in the version that
got merged, but that only solved the problem for gcc-7 and higher, while
gcc-4.6 through gcc-6.x still warn.

This changes the printing again to use inline functions that make it
clear to the compiler that the line that does the NULL check has no idea
whether the argument is a constant NULL.

Link: http://lkml.kernel.org/r/20171117101545.119689-1-arnd@arndb.de
Fixes: 0205f755 ("mm: simplify nodemask printing")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Zhangshaokun <zhangshaokun@hisilicon.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull libnvdimm and dax updates from Dan Williams:
 "Save for a few late fixes, all of these commits have shipped in -next
  releases since before the merge window opened, and 0day has given a
  build success notification.

  The ext4 touches came from Jan, and the xfs touches have Darrick's
  reviewed-by. An xfstest for the MAP_SYNC feature has been through
  a few round of reviews and is on track to be merged.

   - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
     'userspace flush' of persistent memory updates via filesystem-dax
     mappings. It arranges for any filesystem metadata updates that may
     be required to satisfy a write fault to also be flushed ("on disk")
     before the kernel returns to userspace from the fault handler.
     Effectively every write-fault that dirties metadata completes an
     fsync() before returning from the fault handler. The new
     MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag
     is validated as supported by the filesystem's ->mmap() file
     operation.

   - Add support for the standard ACPI 6.2 label access methods that
     replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods.
     This enables interoperability with environments that only implement
     the standardized methods.

   - Add support for the ACPI 6.2 NVDIMM media error injection methods.

   - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for
     latch last shutdown status, firmware update, SMART error injection,
     and SMART alarm threshold control.

   - Cleanup physical address information disclosures to be root-only.

   - Fix revalidation of the DIMM "locked label area" status to support
     dynamic unlock of the label area.

   - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
     (system-physical-address) command and error injection commands.

  Acknowledgements that came after the commits were pushed to -next:

   - 957ac8c4 ("dax: fix PMD faults on zero-length files"):
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>

   - a39e596b ("xfs: support for synchronous DAX faults") and
     7b565c9f ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()")
        Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>"

* tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits)
  acpi, nfit: add 'Enable Latch System Shutdown Status' command support
  dax: fix general protection fault in dax_alloc_inode
  dax: fix PMD faults on zero-length files
  dax: stop requiring a live device for dax_flush()
  brd: remove dax support
  dax: quiet bdev_dax_supported()
  fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core
  tools/testing/nvdimm: unit test clear-error commands
  acpi, nfit: validate commands against the device type
  tools/testing/nvdimm: stricter bounds checking for error injection commands
  xfs: support for synchronous DAX faults
  xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
  ext4: Support for synchronous DAX faults
  ext4: Simplify error handling in ext4_dax_huge_fault()
  dax: Implement dax_finish_sync_fault()
  dax, iomap: Add support for synchronous faults
  mm: Define MAP_SYNC and VM_SYNC flags
  dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
  dax: Allow dax_iomap_fault() to return pfn
  dax: Fix comment describing dax_iomap_fault()
  ...

Merge tag 'for-4.15/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull  more device mapper updates from Mike Snitzer:
 "Given your expected travel I figured I'd get these fixes to you sooner
  rather than later.

   - a DM multipath stable@ fix to silence an annoying error message
     that isn't _really_ an error

   - a DM core @stable fix for discard support that was enabled for an
     entire DM device despite only having partial support for discards
     due to a mix of discard capabilities across the underlying devices.

   - a couple other DM core discard fixes.

   - a DM bufio @stable fix that resolves a 32-bit overflow"

* tag 'for-4.15/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: fix integer overflow when limiting maximum cache size
  dm: clear all discard attributes in queue_limits when discards are disabled
  dm: do not set 'discards_supported' in targets that do not need it
  dm: discard support requires all targets in a table support discards
  dm mpath: remove annoying message of 'blk_get_request() returned -11'

Pull rdma maintainership update from Doug Ledford:
 "Add Jason Gunthorpe as co-maintainer of the RDMA stack.

  The change is simply to add Jason Gunthorpe to the MAINTAINERS file
  for the RDMA stack (and update him in the .mailmap). Jason and I have
  talked offline, and Jason will be filing a ticket with the k.o
  helpdesk to get an account on k.o, and then we will likely move the
  rdma tree to an area where we can both access it and use a shared repo
  + individual topic branches + merged up for-next branch as the staging
  basis for each release.

  Timing here is nice because in the US we are headed into a holiday
  period whereas Jason will be around to keep the patch flow progressing
  (I guess Canadians do their equivalent to Thanksgiving in October, so
  he doesn't have an excuse to ignore email for the next week ;-))"

[ .. and Konstantin already got Jason his kernel.org account between the
  pull request and this actual pull    - Linus ]

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  RDMA: Add Jason Gunthorpe as a co-maintainer

Pull ARM SoC driver updates from Arnd Bergmann:
 "This branch contains platform-related driver updates for ARM and
  ARM64, these are the areas that bring the changes:

  New drivers:

   - driver support for Renesas R-Car V3M (R8A77970)

   - power management support for Amlogic GX

   - a new driver for the Tegra BPMP thermal sensor

   - a new bus driver for Technologic Systems NBUS

  Changes for subsystems that prefer to merge through arm-soc:

   - the usual updates for reset controller drivers from Philipp Zabel,
     with five added drivers for SoCs in the arc, meson, socfpa,
     uniphier and mediatek families

   - updates to the ARM SCPI and PSCI frameworks, from Sudeep Holla,
     Heiner Kallweit and Lorenzo Pieralisi

  Changes specific to some ARM-based SoC

   - the Freescale/NXP DPAA QBMan drivers from PowerPC can now work on
     ARM as well

   - several changes for power management on Broadcom SoCs

   - various improvements on Qualcomm, Broadcom, Amlogic, Atmel,
     Mediatek

   - minor Cleanups for Samsung, TI OMAP SoCs"

[ NOTE! This doesn't work without the previous ARM SoC device-tree pull,
  because the R8A77970 driver is missing a header file that came from
  that pull.

  The fact that this got merged afterwards only fixes it at this point,
  and bisection of that driver will fail if/when you walk into the
  history of that driver.           - Linus ]

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (96 commits)
  soc: amlogic: meson-gx-pwrc-vpu: fix power-off when powered by bootloader
  bus: add driver for the Technologic Systems NBUS
  memory: omap-gpmc: Remove deprecated gpmc_update_nand_reg()
  soc: qcom: remove unused label
  soc: amlogic: gx pm domain: add PM and OF dependencies
  drivers/firmware: psci_checker: Add missing destroy_timer_on_stack()
  dt-bindings: power: add amlogic meson power domain bindings
  soc: amlogic: add Meson GX VPU Domains driver
  soc: qcom: Remote filesystem memory driver
  dt-binding: soc: qcom: Add binding for rmtfs memory
  of: reserved_mem: Accessor for acquiring reserved_mem
  of/platform: Generalize /reserved-memory handling
  soc: mediatek: pwrap: fix fatal compiler error
  soc: mediatek: pwrap: fix compiler errors
  arm64: mediatek: cleanup message for platform selection
  soc: Allow test-building of MediaTek drivers
  soc: mediatek: place Kconfig for all SoC drivers under menu
  soc: mediatek: pwrap: add support for MT7622 SoC
  soc: mediatek: pwrap: add common way for setup CS timing extenstion
  soc: mediatek: pwrap: add MediaTek MT6380 as one slave of pwrap
  ..

Pull ARM device-tree updates from Arnd Bergmann:
 "We add device tree files for a couple of additional SoCs in various
  areas:

  Allwinner R40/V40 for entertainment, Broadcom Hurricane 2 for
  networking, Amlogic A113D for audio, and Renesas R-Car V3M for
  automotive.

  As usual, lots of new boards get added based on those and other SoCs:

   - Actions S500 based CubieBoard6 single-board computer

   - Amlogic Meson-AXG A113D based development board
   - Amlogic S912 based Khadas VIM2 single-board computer
   - Amlogic S912 based Tronsmart Vega S96 set-top-box

   - Allwinner H5 based NanoPi NEO Plus2 single-board computer
   - Allwinner R40 based Banana Pi M2 Ultra and Berry single-board computers
   - Allwinner A83T based TBS A711 Tablet

   - Broadcom Hurricane 2 based Ubiquiti UniFi Switch 8
   - Broadcom bcm47xx based Luxul XAP-1440/XAP-810/ABR-4500/XBR-4500
     wireless access points and routers

   - NXP i.MX51 based Zodiac Inflight Innovations RDU1 board
   - NXP i.MX53 based GE Healthcare PPD biometric monitor
   - NXP i.MX6 based Pistachio single-board computer
   - NXP i.MX6 based Vining-2000 automotive diagnostic interface
   - NXP i.MX6 based Ka-Ro TX6 Computer-on-Module in additional variants

   - Qualcomm MSM8974 (Snapdragon 800) based Fairphone 2 phone
   - Qualcomm MSM8974pro (Snapdragon 801) based Sony Xperia Z2 Tablet

   - Realtek RTD1295 based set-top-boxes MeLE V9 and PROBOX2 AVA

   - Renesas R-Car V3M (R8A77970) SoC and "Eagle" reference board
   - Renesas H3ULCB and M3ULCB "Kingfisher" extension infotainment boards
   - Renasas r8a7745 based iWave G22D-SODIMM SoM

   - Rockchip rk3288 based Amarula Vyasa single-board computer

   - Samsung Exynos5800 based Odroid HC1 single-board computer

  For existing SoC support, there was a lot of ongoing work, as usual
  most of that concentrated on the Renesas, Rockchip, OMAP, i.MX,
  Amlogic and Allwinner platforms, but others were also active.

  Rob Herring and many others worked on reducing the number of issues
  that the latest version of 'dtc' now warns about. Unfortunately there
  is still a lot left to do.

  A rework of the ARM foundation model introduced several new files for
  common variations of the model"

* tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (599 commits)
  arm64: dts: uniphier: route on-board device IRQ to GPIO controller for PXs3
  dt-bindings: bus: Add documentation for the Technologic Systems NBUS
  arm64: dts: actions: s900-bubblegum-96: Add fake uart5 clock
  ARM: dts: owl-s500: Add CubieBoard6
  dt-bindings: arm: actions: Add CubieBoard6
  ARM: dts: owl-s500-guitar-bb-rev-b: Add fake uart3 clock
  ARM: dts: owl-s500: Set power domains for CPU2 and CPU3
  arm: dts: mt7623: remove unused compatible string for pio node
  arm: dts: mt7623: update usb related nodes
  arm: dts: mt7623: update crypto node
  ARM: dts: sun8i: a711: Enable USB OTG
  ARM: dts: sun8i: a711: Add regulator support
  ARM: dts: sun8i: a83t: bananapi-m3: Enable AP6212 WiFi on mmc1
  ARM: dts: sun8i: a83t: cubietruck-plus: Enable AP6330 WiFi on mmc1
  ARM: dts: sun8i: a83t: Move mmc1 pinctrl setting to dtsi file
  ARM: dts: sun8i: a83t: allwinner-h8homlet-v2: Add AXP818 regulator nodes
  ARM: dts: sun8i: a83t: bananapi-m3: Add AXP813 regulator nodes
  ARM: dts: sun8i: a83t: cubietruck-plus: Add AXP818 regulator nodes
  ARM: dts: sunxi: Add dtsi for AXP81x PMIC
  arm64: dts: allwinner: H5: Restore EMAC changes
  ...

Pull ARM SoC platform updates from Arnd Bergmann:
 "Most of the commits are for defconfig changes, to enable newly added
  drivers or features that people have started using. For the changed
  lines lines, we have mostly cleanups, the affected platforms are OMAP,
  Versatile, EP93xx, Samsung, Broadcom, i.MX, and Actions.

  The largest single change is the introduction of the TI "sysc" bus
  driver, with the intention of cleaning up more legacy code.

  Two new SoC platforms get added this time:

   - Allwinner R40 is a modernized version of the A20 chip, now with a
     Quad-Core ARM Cortex-A7. According to the manufacturer, it is
     intended for "Smart Hardware"

   - Broadcom Hurricane 2 (Aka Strataconnect BCM5334X) is a family of
     chips meant for managed gigabit ethernet switches, based around a
     Cortex-A9 CPU.

  Finally, we gain SMP support for two platforms: Renesas R-Car E2 and
  Amlogic Meson8/8b, which were previously added but only supported
  uniprocessor operation"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (118 commits)
  ARM: multi_v7_defconfig: Select RPMSG_VIRTIO as module
  ARM: multi_v7_defconfig: enable CONFIG_GPIO_UNIPHIER
  arm64: defconfig: enable CONFIG_GPIO_UNIPHIER
  ARM: meson: enable MESON_IRQ_GPIO in Kconfig for meson8b
  ARM: meson: Add SMP bringup code for Meson8 and Meson8b
  ARM: smp_scu: allow the platform code to read the SCU CPU status
  ARM: smp_scu: add a helper for powering on a specific CPU
  dt-bindings: Amlogic: Add Meson8 and Meson8b SMP related documentation
  ARM: OMAP3: Delete an unnecessary variable initialisation in omap3xxx_hwmod_init()
  ARM: OMAP3: Use common error handling code in omap3xxx_hwmod_init()
  ARM: defconfig: select the right SX150X driver
  arm64: defconfig: Enable QCOM_IOMMU
  arm64: Add ThunderX drivers to defconfig
  arm64: defconfig: Enable Tegra PCI controller
  cpufreq: imx6q: Move speed grading check to cpufreq driver
  arm64: defconfig: re-enable Qualcomm DB410c USB
  ARM: configs: stm32: Add MDMA support in STM32 defconfig
  ARM: imx: Enable cpuidle for i.MX6DL starting at 1.1
  bus: ti-sysc: Fix unbalanced pm_runtime_enable by adding remove
  bus: ti-sysc: mark PM functions as __maybe_unused
  ...

The default max_cache_size_bytes for dm-bufio is meant to be the lesser
of 25% of the size of the vmalloc area and 2% of the size of lowmem.
However, on 32-bit systems the intermediate result in the expression

    (VMALLOC_END - VMALLOC_START) * DM_BUFIO_VMALLOC_PERCENT / 100

overflows, causing the wrong result to be computed.  For example, on a
32-bit system where the vmalloc area is 520093696 bytes, the result is
1174405 rather than the expected 130023424, which makes the maximum
cache size much too small (far less than 2% of lowmem).  This causes
severe performance problems for dm-verity users on affected systems.

Fix this by using mult_frac() to correctly multiply by a percentage.  Do
this for all places in dm-bufio that multiply by a percentage.  Also
replace (VMALLOC_END - VMALLOC_START) with VMALLOC_TOTAL, which contrary
to the comment is now defined in include/linux/vmalloc.h.

Depends-on: 9993bc63 ("sched/x86: Fix overflow in cyc2ns_offset")
Fixes: 95d402f0 ("dm: add bufio")
Cc: <stable@vger.kernel.org> # v3.2+
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Otherwise, it can happen that the QUEUE_FLAG_DISCARD isn't set but the
various discard attributes (which get exposed via sysfs) may be set.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

The DM target's 'discards_supported' flag is intended to act as an
override.  Meaning, even if the underlying storage doesn't support
discards the DM target will.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

A DM device with a mix of discard capabilities (due to some underlying
devices not having discard support) _should_ just return -EOPNOTSUPP for
the region of the device that doesn't support discards (even if only by
way of the underlying driver formally not supporting discards).  BUT,
that does ask the underlying driver to handle something that it never
advertised support for.  In doing so we're exposing users to the
potential for a underlying disk driver hanging if/when a discard is
issued a the device that is incapable and never claimed to support
discards.

Fix this by requiring that each DM target in a DM table provide discard
support as a prereq for a DM device to advertise support for discards.

This may cause some configurations that were happily supporting discards
(even in the face of a mix of discard support) to stop supporting
discards -- but the risk of users hitting driver hangs, and forced
reboots, outweighs supporting those fringe mixed discard
configurations.

Cc: stable@vger.kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>