Merge tag 'for-5.4/io_uring-2019-09-27' of git://git.kernel.dk/linux-block

Pull more io_uring updates from Jens Axboe:
 "Just two things in here:

   - Improvement to the io_uring CQ ring wakeup for batched IO (me)

   - Fix wrong comparison in poll handling (yangerkun)

  I realize the first one is a little late in the game, but it felt
  pointless to hold it off until the next release. Went through various
  testing and reviews with Pavel and peterz"

* tag 'for-5.4/io_uring-2019-09-27' of git://git.kernel.dk/linux-block:
  io_uring: make CQ ring wakeups be more efficient
  io_uring: compare cached_cq_tail with cq.head in_io_uring_poll

Merge tag 'for-linus-2019-09-27' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few fixes/changes to round off this merge window. This contains:

   - Small series making some functional tweaks to blk-iocost (Tejun)

   - Elevator switch locking fix (Ming)

   - Kill redundant call in blk-wbt (Yufen)

   - Fix flush timeout handling (Yufen)"

* tag 'for-linus-2019-09-27' of git://git.kernel.dk/linux-block:
  block: fix null pointer dereference in blk_mq_rq_timed_out()
  rq-qos: get rid of redundant wbt_update_limits()
  iocost: bump up default latency targets for hard disks
  iocost: improve nr_lagging handling
  iocost: better trace vrate changes
  block: don't release queue's sysfs lock during switching elevator
  blk-mq: move lockdep_assert_held() into elevator_exit

Merge branch 'for-5.4' of git://git./linux/kernel/git/rzhang/linux

Pull thermal management updates from Zhang Rui:

 - Add Amit Kucheria as thermal subsystem Reviewer (Amit Kucheria)

 - Fix a use after free bug when unregistering thermal zone devices (Ido
   Schimmel)

 - Fix thermal core framework to use put_device() when device_register()
   fails (Yue Hu)

 - Enable intel_pch_thermal and MMIO RAPL support for Intel Icelake
   platform (Srinivas Pandruvada)

 - Add clock operations in qorip thermal driver, for some platforms with
   clock control like i.MX8MQ (Anson Huang)

 - A couple of trivial fixes and cleanups for thermal core and different
   soc thermal drivers (Amit Kucheria, Christophe JAILLET, Chuhong Yuan,
   Fuqian Huang, Kelsey Skunberg, Nathan Huckleberry, Rishi Gupta,
   Srinivas Kandagatla)

* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  MAINTAINERS: Add Amit Kucheria as reviewer for thermal
  thermal: Add some error messages
  thermal: Fix use-after-free when unregistering thermal zone device
  thermal/drivers/core: Use put_device() if device_register() fails
  thermal_hwmon: Sanitize thermal_zone type
  thermal: intel: Use dev_get_drvdata
  thermal: intel: int3403: replace printk(KERN_WARN...) with pr_warn(...)
  thermal: intel: int340x_thermal: Remove unnecessary acpi_has_method() uses
  thermal: int340x: processor_thermal: Add Ice Lake support
  drivers: thermal: qcom: tsens: Fix memory leak from qfprom read
  thermal: tegra: Fix a typo
  thermal: rcar_gen3_thermal: Replace devm_add_action() followed by failure action with devm_add_action_or_reset()
  thermal: armada: Fix -Wshift-negative-value
  dt-bindings: thermal: qoriq: Add optional clocks property
  thermal: qoriq: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  thermal: qoriq: Use devm_platform_ioremap_resource() instead of of_iomap()
  thermal: qoriq: Fix error path of calling qoriq_tmu_register_tmu_zone fail
  thermal: qoriq: Add clock operations
  drivers: thermal: processor_thermal_device: Export sysfs interface for TCC offset

Merge tag 'linux-watchdog-5.4-rc1' of git://linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - addition of AST2600, i.MX7ULP and F81803 watchdog support

 - removal of the w90x900 and ks8695 drivers

 - ziirave_wdt improvements

 - small fixes and improvements

* tag 'linux-watchdog-5.4-rc1' of git://www.linux-watchdog.org/linux-watchdog: (51 commits)
  watchdog: f71808e_wdt: Add F81803 support
  watchdog: qcom: remove unnecessary variable from private storage
  watchdog: qcom: support pre-timeout when the bark irq is available
  watchdog: imx_sc: this patch just fixes whitespaces
  watchdog: apseed: Add access_cs0 option for alt-boot
  watchdog: aspeed: add support for dual boot
  watchdog: orion_wdt: use timer1 as a pretimeout
  watchdog: Add i.MX7ULP watchdog support
  dt-bindings: watchdog: Add i.MX7ULP bindings
  dt-bindings: watchdog: sun4i: Add the watchdog clock
  dt-bindings: watchdog: sun4i: Add the watchdog interrupts
  dt-bindings: watchdog: Convert Allwinner watchdog to a schema
  dt-bindings: watchdog: Add YAML schemas for the generic watchdog bindings
  watchdog: aspeed: Add support for AST2600
  dt-bindings: watchdog: Add ast2600 compatible
  watchdog: ziirave_wdt: Update checked I2C functionality mask
  watchdog: ziirave_wdt: Drop ziirave_firm_write_block_data()
  watchdog: ziirave_wdt: Fix DOWNLOAD_START payload
  watchdog: ziirave_wdt: Drop status polling code
  watchdog: ziirave_wdt: Fix RESET_PROCESSOR payload
  ...

Merge tag 'drm-next-2019-09-27' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
 "Fixes built up over the past 1.5 weeks or so, it's two weeks of
  amdgpu, some core cleanups and some panfrost fixes. I also finally
  figured out why my desktop was slow to do a bunch of stuff (someone
  gave it an IPv6 address which can't reach anything!).

  core:
   - Some cleanups and fixes in the self-refresh helpers
   - Some cleanups and fixes in the atomic helpers

  amdgpu:
   - Fix a 64 bit divide
   - Prevent a memory leak in a failure case in dc
   - Load proper gfx firmware on navi14 variants
   - Add more navi12 and navi14 PCI ids
   - Misc fixes for renoir
   - Fix bandwidth issues with multiple displays on vega20
   - Support for Dali
   - Fix a possible oops with KFD on hawaii
   - Fix for backlight level after resume on some APUs
   - Other misc fixes

  panfrost:
   - Multiple panfrost fixes for regulator support and page fault
     handling"

* tag 'drm-next-2019-09-27' of git://anongit.freedesktop.org/drm/drm: (34 commits)
  drm/amd/display: prevent memory leak
  drm/amdgpu/gfx10: add support for wks firmware loading
  drm/amdgpu/display: include slab.h in dcn21_resource.c
  drm/amdgpu/display: fix 64 bit divide
  drm/panfrost: Prevent race when handling page fault
  drm/panfrost: Remove NULL checks for regulator
  drm/panfrost: Fix regulator_get_optional() misuse
  drm: Measure Self Refresh Entry/Exit times to avoid thrashing
  drm: Fix kerneldoc and remove unused struct member in self_refresh helper
  drm/atomic: Rename crtc_state->pageflip_flags to async_flip
  drm/atomic: Reject FLIP_ASYNC unconditionally
  drm/atomic: Take the atomic toys away from X
  drm/amdgpu: flag navi12 and 14 as experimental for 5.4
  drm/kms: Duct-tape for mode object lifetime checks
  drm/amdgpu: add navi12 pci id
  drm/amdgpu: add navi14 PCI ID for work station SKU
  drm/amdkfd: Swap trap temporary registers in gfx10 trap handler
  drm/amd/powerplay: implement sysfs for getting dpm clock
  drm/amd/display: Restore backlight brightness after system resume
  drm/amd/display: Implement voltage limitation for dali
  ...

Merge tag 'ntb-5.4' of git://github.com/jonmason/ntb

Pull NTB updates from Jon Mason:
 "A few bugfixes and support for new AMD NTB hardware"

* tag 'ntb-5.4' of git://github.com/jonmason/ntb:
  NTB: fix IDT Kconfig typos/spellos
  ntb_hw_amd: Add memory window support for new AMD hardware
  ntb_hw_amd: Add a new NTB PCI device ID
  NTB: ntb_transport: remove redundant assignment to rc
  ntb_hw_switchtec: make ntb_mw_set_trans() work when addr == 0
  ntb: point to right memory window index

keys: Add Jarkko Sakkinen as co-maintainer

To address a major procedural concern on Linus's part the keyrings needs
a co-maintainer.

Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block: fix null pointer dereference in blk_mq_rq_timed_out()

We got a null pointer deference BUG_ON in blk_mq_rq_timed_out()
as following:

[  108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040
[  108.827059] PGD 0 P4D 0
[  108.827313] Oops: 0000 [#1] SMP PTI
[  108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431
[  108.829503] Workqueue: kblockd blk_mq_timeout_work
[  108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330
[  108.838191] Call Trace:
[  108.838406]  bt_iter+0x74/0x80
[  108.838665]  blk_mq_queue_tag_busy_iter+0x204/0x450
[  108.839074]  ? __switch_to_asm+0x34/0x70
[  108.839405]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.839823]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.840273]  ? syscall_return_via_sysret+0xf/0x7f
[  108.840732]  blk_mq_timeout_work+0x74/0x200
[  108.841151]  process_one_work+0x297/0x680
[  108.841550]  worker_thread+0x29c/0x6f0
[  108.841926]  ? rescuer_thread+0x580/0x580
[  108.842344]  kthread+0x16a/0x1a0
[  108.842666]  ? kthread_flush_work+0x170/0x170
[  108.843100]  ret_from_fork+0x35/0x40

The bug is caused by the race between timeout handle and completion for
flush request.

When timeout handle function blk_mq_rq_timed_out() try to read
'req->q->mq_ops', the 'req' have completed and reinitiated by next
flush request, which would call blk_rq_init() to clear 'req' as 0.

After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"),
normal requests lifetime are protected by refcount. Until 'rq->ref'
drop to zero, the request can really be free. Thus, these requests
cannot been reused before timeout handle finish.

However, flush request has defined .end_io and rq->end_io() is still
called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq'
can be reused by the next flush request handle, resulting in null
pointer deference BUG ON.

We fix this problem by covering flush request with 'rq->ref'.
If the refcount is not zero, flush_end_io() return and wait the
last holder recall it. To record the request status, we add a new
entry 'rq_status', which will be used in flush_end_io().

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org # v4.18+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
-------
v2:
 - move rq_status from struct request to struct blk_flush_queue
v3:
 - remove unnecessary '{}' pair.
v4:
 - let spinlock to protect 'fq->rq_status'
v5:
 - move rq_status after flush_running_idx member of struct blk_flush_queue
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rq-qos: get rid of redundant wbt_update_limits()

We have updated limits after calling wbt_set_min_lat(). No need to
update again.

Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge branch 'timers-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull timer fix from Ingo Molnar:
 "Fix a timer expiry bug that would cause spurious delay of timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Read jiffies once when forwarding base clk

Merge branch 'perf-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull more perf updates from Ingo Molnar:
 "The only kernel change is comment typo fixes.

  The rest is mostly tooling fixes, but also new vendor event additions
  and updates, a bigger libperf/libtraceevent library and a header files
  reorganization that came in a bit late"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
  perf unwind: Fix libunwind build failure on i386 systems
  perf parser: Remove needless include directives
  perf build: Add detection of java-11-openjdk-devel package
  perf jvmti: Include JVMTI support for s390
  perf vendor events: Remove P8 HW events which are not supported
  perf evlist: Fix access of freed id arrays
  perf stat: Fix free memory access / memory leaks in metrics
  perf tools: Replace needless mmap.h with what is needed, event.h
  perf evsel: Move config terms to a separate header
  perf evlist: Remove unused perf_evlist__fprintf() method
  perf evsel: Introduce evsel_fprintf.h
  perf evsel: Remove need for symbol_conf in evsel_fprintf.c
  perf copyfile: Move copyfile routines to separate files
  libperf: Add perf_evlist__poll() function
  libperf: Add perf_evlist__add_pollfd() function
  libperf: Add perf_evlist__alloc_pollfd() function
  libperf: Add libperf_init() call to the tests
  libperf: Merge libperf_set_print() into libperf_init()
  libperf: Add libperf dependency for tests targets
  libperf: Use sys/types.h to get ssize_t, not unistd.h
  ...

Merge tag 'trace-v5.4-2' of git://git./linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Srikar Dronamraju fixed a bug in the newmulti probe code"

* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Fix same probe event argument matching

perf unwind: Fix libunwind build failure on i386 systems

Naresh Kamboju reported, that on the i386 build pr_err()
doesn't get defined properly due to header ordering:

  perf-in.o: In function `libunwind__x86_reg_id':
  tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109:
  undefined reference to `pr_err'

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'usercopy-v5.4-rc1' of git://git./linux/kernel/git/kees/linux

Pull usercopy fix from Kees Cook:
 "Fix hardened usercopy under CONFIG_DEBUG_VIRTUAL"

* tag 'usercopy-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: Avoid HIGHMEM pfn warning

Merge tag 'linux-kselftest-5.4-rc1.1' of git://git./linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:
 "Fixes to existing tests"

* tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tpm2: install python files
  selftests: livepatch: add missing fragments to config
  selftests: watchdog: cleanup whitespace in usage options
  selftest/ftrace: Fix typo in trigger-snapshot.tc
  selftests: watchdog: Add optional file argument
  selftests/seccomp: fix build on older kernels
  selftests: use "$(MAKE)" instead of "make"

Merge tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - Dequeue the request from the receive queue while we're re-encoding
     # v4.20+
   - Fix buffer handling of GSS MIC without slack # 5.1

  Features:
   - Increase xprtrdma maximum transport header and slot table sizes
   - Add support for nfs4_call_sync() calls using a custom
     rpc_task_struct
   - Optimize the default readahead size
   - Enable pNFS filelayout LAYOUTGET on OPEN

  Other bugfixes and cleanups:
   - Fix possible null-pointer dereferences and memory leaks
   - Various NFS over RDMA cleanups
   - Various NFS over RDMA comment updates
   - Don't receive TCP data into a reset request buffer
   - Don't try to parse incomplete RPC messages
   - Fix congestion window race with disconnect
   - Clean up pNFS return-on-close error handling
   - Fixes for NFS4ERR_OLD_STATEID handling"

* tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits)
  pNFS/filelayout: enable LAYOUTGET on OPEN
  NFS: Optimise the default readahead size
  NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU
  NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
  NFSv4: Fix OPEN_DOWNGRADE error handling
  pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid
  NFSv4: Add a helper to increment stateid seqids
  NFSv4: Handle RPC level errors in LAYOUTRETURN
  NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close
  NFSv4: Clean up pNFS return-on-close error handling
  pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors
  NFS: remove unused check for negative dentry
  NFSv3: use nfs_add_or_obtain() to create and reference inodes
  NFS: Refactor nfs_instantiate() for dentry referencing callers
  SUNRPC: Fix congestion window race with disconnect
  SUNRPC: Don't try to parse incomplete RPC messages
  SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic
  SUNRPC: Fix buffer handling of GSS MIC without slack
  SUNRPC: RPC level errors should always set task->tk_rpc_status
  SUNRPC: Don't receive TCP data into a request buffer that has been reset
  ...

binfmt_elf: Do not move brk for INTERP-less ET_EXEC

When brk was moved for binaries without an interpreter, it should have
been limited to ET_DYN only. In other words, the special case was an
ET_DYN that lacks an INTERP, not just an executable that lacks INTERP.
The bug manifested for giant static executables, where the brk would end
up in the middle of the text area on 32-bit architectures.

Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in>
Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'xfs-5.4-merge-8' of git://git./fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "There are a couple of bug fixes and some small code cleanups that came
  in recently:

   - Minor code cleanups

   - Fix a superblock logging error

   - Ensure that collapse range converts the data fork to extents format
     when necessary

   - Revert the ALLOC_USERDATA cleanup because it caused subtle behavior
     regressions"

* tag 'xfs-5.4-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: avoid unused to_mp() function warning
  xfs: log proper length of superblock
  xfs: revert 1baa2800e62d ("xfs: remove the unused XFS_ALLOC_USERDATA flag")
  xfs: removed unneeded variable
  xfs: convert inode to extent format after extent merge due to shift

Merge branch 'work.mount3' of git://git./linux/kernel/git/viro/vfs

Pull jffs2 fix from Al Viro:
 "braino fix for mount API conversion for jffs2"

* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jffs2: Fix mounting under new mount API

Merge tag 's390-5.4-2' of git://git./linux/kernel/git/s390/linux

Pull more s390 updates from Vasily Gorbik:

 - Fix three kasan findings

 - Add PERF_EVENT_IOC_PERIOD ioctl support

 - Add Crypto Express7S support and extend sysfs attributes for pkey

 - Minor common I/O layer documentation corrections

* tag 's390-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/cio: exclude subchannels with no parent from pseudo check
  s390/cio: avoid calling strlen on null pointer
  s390/topology: avoid firing events before kobjs are created
  s390/cpumf: Remove mixed white space
  s390/cpum_sf: Support ioctl PERF_EVENT_IOC_PERIOD
  s390/zcrypt: CEX7S exploitation support
  s390/cio: fix intparm documentation
  s390/pkey: Add sysfs attributes to emit AES CIPHER key blobs

Merge tag 'for-linus-5.4-rc1-tag' of git://git./linux/kernel/git/xen/tip

Pull xen update from Juergen Gross:
 "Only two small patches this time:

   - a small cleanup for swiotlb-xen

   - a fix for PCI initialization for some platforms"

* tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: reserve MCFG areas earlier
  swiotlb-xen: Convert to use macro

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - almost all of the rest of -mm

 - various other subsystems

Subsystems affected by this patch series:
  memcg, misc, core-kernel, lib, checkpatch, reiserfs, fat, fork,
  cpumask, kexec, uaccess, kconfig, kgdb, bug, ipc, lzo, kasan, madvise,
  cleanups, pagemap

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (77 commits)
  arch/sparc/include/asm/pgtable_64.h: fix build
  mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
  ntfs: remove (un)?likely() from IS_ERR() conditions
  IB/hfi1: remove unlikely() from IS_ERR*() condition
  xfs: remove unlikely() from WARN_ON() condition
  wimax/i2400m: remove unlikely() from WARN*() condition
  fs: remove unlikely() from WARN_ON() condition
  xen/events: remove unlikely() from WARN() condition
  checkpatch: check for nested (un)?likely() calls
  hexagon: drop empty and unused free_initrd_mem
  mm: factor out common parts between MADV_COLD and MADV_PAGEOUT
  mm: introduce MADV_PAGEOUT
  mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM
  mm: introduce MADV_COLD
  mm: untag user pointers in mmap/munmap/mremap/brk
  vfio/type1: untag user pointers in vaddr_get_pfn
  tee/shm: untag user pointers in tee_shm_register
  media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get
  drm/radeon: untag user pointers in radeon_gem_userptr_ioctl
  drm/amdgpu: untag user pointers
  ...

arch/sparc/include/asm/pgtable_64.h: fix build

A last-minute fixlet which I'd failed to merge at the appropriate time
had the predictable effect.

Fixes: f672e2c217e2d4b2 ("lib: untag user pointers in strn*_user")
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ntfs: remove (un)?likely() from IS_ERR() conditions

"likely(!IS_ERR(x))" is excessive. IS_ERR() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-11-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/hfi1: remove unlikely() from IS_ERR*() condition

"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-8-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xfs: remove unlikely() from WARN_ON() condition

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-7-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

wimax/i2400m: remove unlikely() from WARN*() condition

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-6-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: remove unlikely() from WARN_ON() condition

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-5-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xen/events: remove unlikely() from WARN() condition

"unlikely(WARN(x))" is excessive. WARN() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-4-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

jffs2: Fix mounting under new mount API

The mounting of jffs2 is broken due to the changes from the new mount API
because it specifies a "source" operation, but then doesn't actually
process it.  But because it specified it, it doesn't return -ENOPARAM and
the caller doesn't process it either and the source gets lost.

Fix this by simply removing the source parameter from jffs2 and letting the
VFS deal with it in the default manner.

To test it, enable CONFIG_MTD_MTDRAM and allow the default size and erase
block size parameters, then try and mount the /dev/mtdblock<N> file that
that creates as jffs2.  No need to initialise it.

Fixes: ec10a24f10c8 ("vfs: Convert jffs2 to use the new mount API")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

io_uring: make CQ ring wakeups be more efficient

For batched IO, it's not uncommon for waiters to ask for more than 1
IO to complete before being woken up. This is a problem with
wait_event() since tasks will get woken for every IO that completes,
re-check condition, then go back to sleep. For batch counts on the
order of what you do for high IOPS, that can result in 10s of extra
wakeups for the waiting task.

Add a private wake function that checks for the wake up count criteria
being met before calling autoremove_wake_function(). Pavel reports that
one test case he has runs 40% faster with proper batching of wakeups.

Reported-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

iocost: bump up default latency targets for hard disks

The default hard disk param sets latency targets at 50ms.  As the
default target percentiles are zero, these don't directly regulate
vrate; however, they're still used to calculate the period length -
100ms in this case.

This is excessively low.  A SATA drive with QD32 saturated with random
IOs can easily reach avg completion latency of several hundred msecs.
A period duration which is substantially lower than avg completion
latency can lead to wildly fluctuating vrate.

Let's bump up the default latency targets to 250ms so that the period
duration is sufficiently long.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

iocost: improve nr_lagging handling

Some IOs may span multiple periods.  As latencies are collected on
completion, the inbetween periods won't register them and may
incorrectly decide to increase vrate.  nr_lagging tracks these IOs to
avoid those situations.  Currently, whenever there are IOs which are
spanning from the previous period, busy_level is reset to 0 if
negative thus suppressing vrate increase.

This has the following two problems.

* When latency target percentiles aren't set, vrate adjustment should
  only be governed by queue depth depletion; however, the current code
  keeps nr_lagging active which pulls in latency results and can keep
  down vrate unexpectedly.

* When lagging condition is detected, it resets the entire negative
  busy_level.  This turned out to be way too aggressive on some
  devices which sometimes experience extended latencies on a small
  subset of commands.  In addition, a lagging IO will be accounted as
  latency target miss on completion anyway and resetting busy_level
  amplifies its impact unnecessarily.

This patch fixes the above two problems by disabling nr_lagging
counting when latency target percentiles aren't set and blocking vrate
increases when there are lagging IOs while leaving busy_level as-is.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

iocost: better trace vrate changes

vrate_adj tracepoint traces vrate changes; however, it does so only
when busy_level is non-zero.  busy_level turning to zero can sometimes
be as interesting an event.  This patch also enables vrate_adj
tracepoint on other vrate related events - busy_level changes and
non-zero nr_lagging.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't release queue's sysfs lock during switching elevator

cecf5d87ff20 ("block: split .sysfs_lock into two locks") starts to
release & acquire sysfs_lock before registering/un-registering elevator
queue during switching elevator for avoiding potential deadlock from
showing & storing 'queue/iosched' attributes and removing elevator's
kobject.

Turns out there isn't such deadlock because 'q->sysfs_lock' isn't
required in .show & .store of queue/iosched's attributes, and just
elevator's sysfs lock is acquired in elv_iosched_store() and
elv_iosched_show(). So it is safe to hold queue's sysfs lock when
registering/un-registering elevator queue.

The biggest issue is that commit cecf5d87ff20 assumes that concurrent
write on 'queue/scheduler' can't happen. However, this assumption isn't
true, because kernfs_fop_write() only guarantees that concurrent write
aren't called on the same open file, but the write could be from
different open on the file. So we can't release & re-acquire queue's
sysfs lock during switching elevator, otherwise use-after-free on
elevator could be triggered.

Fixes the issue by not releasing queue's sysfs lock during switching
elevator.

Fixes: cecf5d87ff20 ("block: split .sysfs_lock into two locks")
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-mq: move lockdep_assert_held() into elevator_exit

Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with
lockdep_assert_held() called in blk_mq_sched_free_requests() which is
run in failure path of elevator_init_mq().

blk_mq_sched_free_requests() is called in the following 3 functions:

elevator_init_mq()
elevator_exit()
blk_cleanup_queue()

In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly
by 'mutex_lock(&q->sysfs_lock)'.

So moving the lockdep_assert_held() from blk_mq_sched_free_requests()
into elevator_exit() for fixing the report by syzbot.

Reported-by: syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com
Fixed: c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'perf-core-for-mingo-5.5-20190925' of git://git./linux/kernel/git/acme/linux into perf/urgent

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

perf record:

  Stephane Eranian:

  - Fix priv level with branch sampling for paranoid=2, i.e. the kernel checks
    if perf_event_attr_attr.exclude_hv is set in addition to .exclude_kernel,
    so reset both to zero.

  Arnaldo Carvalho de Melo:

  - Don't warn about not being able to read kernel maps (kallsyms, etc) when
    kernel samples aren't being collected.

perf list:

  Kim Phillips:

  - Allow plurals for metric, metricgroup., i.e.:

    $ perf list metrics

    was showing nothing, which is very confusing, make it work like:

    $ perf stat metric

perf stat:

  Andi Kleen:

  - Free memory access/leaks detected via valgrind, related to metrics.

Libraries:

libperf:

  Jiri Olsa:

  - Move more stuff from tools/perf, this time a first stab at moving perf_mmap
    methods.

libtracevent:

  Steven Rostedt (VMware):

  - Round up in tep_print_event() time precision.

  Tzvetomir Stoyanov (VMware):

  - Man pages for event print and related and plugins APIs.

  - Move traceevent plugins in its own subdirectory.

Feature detection:

  Thomas Richter:

  - Add detection of java-11-openjdk-devel package, in addition to the older
    versions supported.

Architecture specific:

S/390:

  Thomas Richter (2):

  - Include JVMTI support for s390

Vendor events:

AMD:

  Kim Phillips:

  - Add L3 cache events for Family 17h.

  - Remove redundant '['.

PowerPC:

  Mamatha Inamdar:

  - Remove P8 HW events which are not supported.

Cleanups:

  Arnaldo Carvalho de Melo:

  - Remove needless headers, add needed ones, move things around to reduce the
    headers dependency tree, speeding up builds by not doing needless compiles
    when unrelated stuff gets changed.

  - Ditch unused code that was dragging headers.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'drm-fixes-5.4-2019-09-25' of git://people.freedesktop.org/~agd5f/linux into drm-next

drm-fixes-5.4-2019-09-25:

amdgpu:
- Fix a 64 bit divide
- Prevent a memory leak in a failure case in dc
- Load proper gfx firmware on navi14 variants

drm-fixes-5.4-2019-09-19:

amdgpu:
- Add more navi12 and navi14 PCI ids
- Misc fixes for renoir
- Fix bandwidth issues with multiple displays on vega20
- Support for Dali
- Fix a possible oops with KFD on hawaii
- Fix for backlight level after resume on some APUs
- Other misc fixes

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925213500.3490-1-alexander.deucher@amd.com

checkpatch: check for nested (un)?likely() calls

IS_ERR(), IS_ERR_OR_NULL(), IS_ERR_VALUE() and WARN*() already contain
unlikely() optimization internally.  Thus, there is no point in calling
these functions and defines under likely()/unlikely().

This check is based on the coccinelle rule developed by Enrico Weigelt
https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@metux.net/

Link: http://lkml.kernel.org/r/20190829165025.15750-1-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Joe Perches <joe@perches.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Boris Pismenny <borisp@mellanox.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Denis Efremov <efremov@linux.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Sean Paul <sean@poorly.run>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hexagon: drop empty and unused free_initrd_mem

hexagon never reserves or initializes initrd and the only mention of it is
the empty free_initrd_mem() function.

As we have a generic implementation of free_initrd_mem(), there is no need
to define an empty stub for the hexagon implementation and it can be
dropped.

Link: http://lkml.kernel.org/r/1565858133-25852-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: factor out common parts between MADV_COLD and MADV_PAGEOUT

There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.

Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce MADV_PAGEOUT

When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use.  This could reduce workingset
eviction so it ends up increasing performance.

This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly.  The hint can help kernel in deciding which pages to
evict proactively.

A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size.  If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].

- man-page material

MADV_PAGEOUT (since Linux x.x)

Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.

MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.

[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/

[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM

The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default.  It is for preventing to reclaim dirty pages when CMA try to
migrate pages.  Strictly speaking, we don't need it because CMA didn't
allow to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch.  So
this patch makes references's default value to PAGEREF_RECLAIM and rename
force_reclaim with ignore_references to make it more clear.

This is a preparatory work for next patch.

Link: http://lkml.kernel.org/r/20190726023435.214162-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce MADV_COLD

Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7.

- Background

The Android terminology used for forking a new process and starting an app
from scratch is a cold start, while resuming an existing app is a hot
start.  While we continually try to improve the performance of cold
starts, hot starts will always be significantly less power hungry as well
as faster so we are trying to make hot start more likely than cold start.

To increase hot start, Android userspace manages the order that apps
should be killed in a process called ActivityManagerService.
ActivityManagerService tracks every Android app or service that the user
could be interacting with at any time and translates that into a ranked
list for lmkd(low memory killer daemon).  They are likely to be killed by
lmkd if the system has to reclaim memory.  In that sense they are similar
to entries in any other cache.  Those apps are kept alive for
opportunistic performance improvements but those performance improvements
will vary based on the memory requirements of individual workloads.

- Problem

Naturally, cached apps were dominant consumers of memory on the system.
However, they were not significant consumers of swap even though they are
good candidate for swap.  Under investigation, swapping out only begins
once the low zone watermark is hit and kswapd wakes up, but the overall
allocation rate in the system might trip lmkd thresholds and cause a
cached process to be killed(we measured performance swapping out vs.
zapping the memory by killing a process.  Unsurprisingly, zapping is 10x
times faster even though we use zram which is much faster than real
storage) so kill from lmkd will often satisfy the high zone watermark,
resulting in very few pages actually being moved to swap.

- Approach

The approach we chose was to use a new interface to allow userspace to
proactively reclaim entire processes by leveraging platform information.
This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages
that are known to be cold from userspace and to avoid races with lmkd by
reclaiming apps as soon as they entered the cached state.  Additionally,
it could provide many chances for platform to use much information to
optimize memory efficiency.

To achieve the goal, the patchset introduce two new options for madvise.
One is MADV_COLD which will deactivate activated pages and the other is
MADV_PAGEOUT which will reclaim private pages instantly.  These new
options complement MADV_DONTNEED and MADV_FREE by adding non-destructive
ways to gain some free memory space.  MADV_PAGEOUT is similar to
MADV_DONTNEED in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed immediately; MADV_COLD is similar
to MADV_FREE in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed when memory pressure rises.

This patch (of 5):

When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use.  This could reduce
workingset eviction so it ends up increasing performance.

This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future.  The hint can help kernel in deciding which
pages to evict early during memory pressure.

It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves

active file page -> inactive file LRU
active anon page -> inacdtive anon LRU

Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault.  Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages.  It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied.  Even, it could give a bonus to make
them be reclaimed on swapless system.  However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost.  Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU.  Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device.  Let's start simpler way without adding
complexity at this moment.  However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.

* man-page material

MADV_COLD (since Linux x.x)

Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies.  In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.

MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.

[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: untag user pointers in mmap/munmap/mremap/brk

There isn't a good reason to differentiate between the user address space
layout modification syscalls and the other memory permission/attributes
ones (e.g.  mprotect, madvise) w.r.t.  the tagged address ABI.  Untag the
user addresses on entry to these functions.

Link: http://lkml.kernel.org/r/20190821164730.47450-2-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Dave P Martin <Dave.Martin@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vfio/type1: untag user pointers in vaddr_get_pfn

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

vaddr_get_pfn() uses provided user pointers for vma lookups, which can
only by done with untagged pointers.

Untag user pointers in this function.

Link: http://lkml.kernel.org/r/87422b4d72116a975896f2b19b00f38acbd28f33.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tee/shm: untag user pointers in tee_shm_register

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

tee_shm_register()->optee_shm_unregister()->check_mem_type() uses provided
user pointers for vma lookups (via __check_mem_type()), which can only by
done with untagged pointers.

Untag user pointers in this function.

Link: http://lkml.kernel.org/r/4b993f33196b3566ac81285ff8453219e2079b45.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

videobuf_dma_contig_user_get() uses provided user pointers for vma
lookups, which can only by done with untagged pointers.

Untag the pointers in this function.

Link: http://lkml.kernel.org/r/100436d5f8e4349a78f27b0bbb27e4801fcb946b.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/radeon: untag user pointers in radeon_gem_userptr_ioctl

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

In radeon_gem_userptr_ioctl() an MMU notifier is set up with a (tagged)
userspace pointer.  The untagged address should be used so that MMU
notifiers for the untagged address get correctly matched up with the right
BO.  This funcation also calls radeon_ttm_tt_pin_userptr(), which uses
provided user pointers for vma lookups, which can only by done with
untagged pointers.

This patch untags user pointers in radeon_gem_userptr_ioctl().

Link: http://lkml.kernel.org/r/c856babeb67195b35603b8d5ba386a2819cec5ff.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Suggested-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/amdgpu: untag user pointers

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

In amdgpu_gem_userptr_ioctl() and amdgpu_amdkfd_gpuvm.c/init_user_pages()
an MMU notifier is set up with a (tagged) userspace pointer.  The untagged
address should be used so that MMU notifiers for the untagged address get
correctly matched up with the right BO.  This patch untag user pointers in
amdgpu_gem_userptr_ioctl() for the GEM case and in amdgpu_amdkfd_gpuvm_
alloc_memory_of_gpu() for the KFD case.  This also makes sure that an
untagged pointer is passed to amdgpu_ttm_tt_get_user_pages(), which uses
it for vma lookups.

Link: http://lkml.kernel.org/r/d684e1df08f2ecb6bc292e222b64fa9efbc26e69.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Suggested-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd: untag user pointers

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

userfaultfd code use provided user pointers for vma lookups, which can
only by done with untagged pointers.

Untag user pointers in validate_range().

Link: http://lkml.kernel.org/r/cdc59ddd7011012ca2e689bc88c3b65b1ea7e413.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/namespace: untag user pointers in copy_mount_options

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

In copy_mount_options a user address is being subtracted from TASK_SIZE.
If the address is lower than TASK_SIZE, the size is calculated to not
allow the exact_copy_from_user() call to cross TASK_SIZE boundary.
However if the address is tagged, then the size will be calculated
incorrectly.

Untag the address before subtracting.

Link: http://lkml.kernel.org/r/1de225e4a54204bfd7f25dac2635e31aa4aa1d90.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: untag user pointers in get_vaddr_frames

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

get_vaddr_frames uses provided user pointers for vma lookups, which can
only by done with untagged pointers.  Instead of locating and changing all
callers of this function, perform untagging in it.

Link: http://lkml.kernel.org/r/28f05e49c92b2a69c4703323d6c12208f3d881fe.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: untag user pointers in mm/gup.c

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

mm/gup.c provides a kernel interface that accepts user addresses and
manipulates user pages directly (for example get_user_pages, that is used
by the futex syscall).  Since a user can provided tagged addresses, we
need to handle this case.

Add untagging to gup.c functions that use user addresses for vma lookups.

Link: http://lkml.kernel.org/r/4731bddba3c938658c10ff4ed55cc01c60f4c8f8.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: untag user pointers passed to memory syscalls

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

This patch allows tagged pointers to be passed to the following memory
syscalls: get_mempolicy, madvise, mbind, mincore, mlock, mlock2, mprotect,
mremap, msync, munlock, move_pages.

The mmap and mremap syscalls do not currently accept tagged addresses.
Architectures may interpret the tag as a background colour for the
corresponding vma.

Link: http://lkml.kernel.org/r/aaf0c0969d46b2feb9017f3e1b3ef3970b633d91.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: untag user pointers in strn*_user

Patch series "arm64: untag user pointers passed to the kernel", v19.

=== Overview

arm64 has a feature called Top Byte Ignore, which allows to embed pointer
tags into the top byte of each pointer.  Userspace programs (such as
HWASan, a memory debugging tool [1]) might use this feature and pass
tagged user pointers to the kernel through syscalls or other interfaces.

Right now the kernel is already able to handle user faults with tagged
pointers, due to these patches:

1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a
             tagged pointer")
2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged
      pointers")
3. 276e9327 ("arm64: entry: improve data abort handling of tagged
      pointers")

This patchset extends tagged pointer support to syscall arguments.

As per the proposed ABI change [3], tagged pointers are only allowed to be
passed to syscalls when they point to memory ranges obtained by anonymous
mmap() or sbrk() (see the patchset [3] for more details).

For non-memory syscalls this is done by untaging user pointers when the
kernel performs pointer checking to find out whether the pointer comes
from userspace (most notably in access_ok).  The untagging is done only
when the pointer is being checked, the tag is preserved as the pointer
makes its way through the kernel and stays tagged when the kernel
dereferences the pointer when perfoming user memory accesses.

The mmap and mremap (only new_addr) syscalls do not currently accept
tagged addresses.  Architectures may interpret the tag as a background
colour for the corresponding vma.

Other memory syscalls (mprotect, etc.) don't do user memory accesses but
rather deal with memory ranges, and untagged pointers are better suited to
describe memory ranges internally.  Thus for memory syscalls we untag
pointers completely when they enter the kernel.

=== Other approaches

One of the alternative approaches to untagging that was considered is to
completely strip the pointer tag as the pointer enters the kernel with
some kind of a syscall wrapper, but that won't work with the countless
number of different ioctl calls.  With this approach we would need a
custom wrapper for each ioctl variation, which doesn't seem practical.

An alternative approach to untagging pointers in memory syscalls prologues
is to inspead allow tagged pointers to be passed to find_vma() (and other
vma related functions) and untag them there.  Unfortunately, a lot of
find_vma() callers then compare or subtract the returned vma start and end
fields against the pointer that was being searched.  Thus this approach
would still require changing all find_vma() callers.

=== Testing

The following testing approaches has been taken to find potential issues
with user pointer untagging:

1. Static testing (with sparse [2] and separately with a custom static
   analyzer based on Clang) to track casts of __user pointers to integer
   types to find places where untagging needs to be done.

2. Static testing with grep to find parts of the kernel that call
   find_vma() (and other similar functions) or directly compare against
   vm_start/vm_end fields of vma.

3. Static testing with grep to find parts of the kernel that compare
   user pointers with TASK_SIZE or other similar consts and macros.

4. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running
   a modified syzkaller version that passes tagged pointers to the kernel.

Based on the results of the testing the requried patches have been added
to the patchset.

=== Notes

This patchset is meant to be merged together with "arm64 relaxed ABI" [3].

This patchset is a prerequisite for ARM's memory tagging hardware feature
support [4].

This patchset has been merged into the Pixel 2 & 3 kernel trees and is
now being used to enable testing of Pixel phones with HWASan.

Thanks!

[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html

[2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060e0145f292

[3] https://lkml.org/lkml/2019/6/12/745

[4] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architecture-2018-developments-armv85a

This patch (of 11)

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

strncpy_from_user and strnlen_user accept user addresses as arguments, and
do not go through the same path as copy_from_user and others, so here we
need to handle the case of tagged user addresses separately.

Untag user pointers passed to these functions.

Note, that this patch only temporarily untags the pointers to perform
validity checks, but then uses them as is to perform user memory accesses.

[andreyknvl@google.com: fix sparc4 build]
Link: http://lkml.kernel.org/r/CAAeHK+yx4a-P0sDrXTUxMvO2H0CJZUFPffBrg_cU7oJOZyC7ew@mail.gmail.com
Link: http://lkml.kernel.org/r/c5a78bcad3e94d6cda71fcaa60a423231ae71e4c.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/lzo/lzo1x_compress.c: fix alignment bug in lzo-rle

Fix an unaligned access which breaks on platforms where this is not
permitted (e.g., Sparc).

Link: http://lkml.kernel.org/r/20190912145502.35229-1-dave.rodgman@arm.com
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Cc: Dave Rodgman <dave.rodgman@arm.com>
Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem.c: convert to use built-in RCU list checking

CONFIG_PROVE_RCU_LIST requires list_for_each_entry_rcu() to pass a lockdep
expression if using srcu or locking for protection.  It can only check
regular RCU protection, all other protection needs to be passed as lockdep
expression.

Link: http://lkml.kernel.org/r/20190830231817.76862-2-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Jonathan Derrick <jonathan.derrick@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/mqueue: improve exception handling in do_mq_notify()

Null pointers were assigned to local variables in a few cases as exception
handling.  The jump target “out” was used where no meaningful data
processing actions should eventually be performed by branches of an if
statement then.  Use an additional jump target for calling dev_kfree_skb()
directly.

Return also directly after error conditions were detected when no extra
clean-up is needed by this function implementation.

Link: http://lkml.kernel.org/r/592ef10e-0b69-72d0-9789-fc48f638fdfd@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/mqueue.c: delete an unnecessary check before the macro call dev_kfree_skb()

dev_kfree_skb() input parameter validation, thus the test around the call
is not needed.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/07477187-63e5-cc80-34c1-32dd16b38e12@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: move WARN_ON() "cut here" into exception handler

The original clean up of "cut here" missed the WARN_ON() case (that does
not have a printk message), which was fixed recently by adding an explicit
printk of "cut here".  This had the downside of adding a printk() to every
WARN_ON() caller, which reduces the utility of using an instruction
exception to streamline the resulting code.  By making this a new BUGFLAG,
all of these can be removed and "cut here" can be handled by the exception
handler.

This was very pronounced on PowerPC, but the effect can be seen on x86 as
well.  The resulting text size of a defconfig build shows some small
savings from this patch:

   text    data     bss     dec     hex filename
19691167        5134320 1646664 26472151        193eed7 vmlinux.before
19676362        5134260 1663048 26473670        193f4c6 vmlinux.after

This change also opens the door for creating something like BUG_MSG(),
where a custom printk() before issuing BUG(), without confusing the "cut
here" line.

Link: http://lkml.kernel.org/r/201908200943.601DD59DCE@keescook
Fixes: 6b15f678fb7d ("include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: consolidate __WARN_FLAGS usage

Instead of having separate tests for __WARN_FLAGS, merge the two #ifdef
blocks and replace the synonym WANT_WARN_ON_SLOWPATH macro.

Link: http://lkml.kernel.org/r/20190819234111.9019-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: clean up helper macros to remove __WARN_TAINT()

In preparation for cleaning up "cut here" even more, this removes the
__WARN_*TAINT() helpers, as they limit the ability to add new BUGFLAG_*
flags to call sites.  They are removed by expanding them into full
__WARN_FLAGS() calls.

Link: http://lkml.kernel.org/r/20190819234111.9019-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: lift "cut here" out of __warn()

In preparation for cleaning up "cut here", move the "cut here" logic up
out of __warn() and into callers that pass non-NULL args.  For anyone
looking closely, there are two callers that pass NULL args: one already
explicitly prints "cut here".  The remaining case is covered by how a WARN
is built, which will be cleaned up in the next patch.

Link: http://lkml.kernel.org/r/20190819234111.9019-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: consolidate warn_slowpath_fmt() usage

Instead of having a separate helper for no printk output, just consolidate
the logic into warn_slowpath_fmt().

Link: http://lkml.kernel.org/r/20190819234111.9019-4-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: rename __WARN_printf_taint() to __WARN_printf()

This just renames the helper to improve readability.

Link: http://lkml.kernel.org/r/20190819234111.9019-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: refactor away warn_slowpath_fmt_taint()

Patch series "Clean up WARN() "cut here" handling", v2.

Christophe Leroy noticed that the fix for missing "cut here" in the WARN()
case was adding explicit printk() calls instead of teaching the exception
handler to add it.  This refactors the bug/warn infrastructure to pass
this information as a new BUGFLAG.

Longer details repeated from the last patch in the series:

bug: move WARN_ON() "cut here" into exception handler

The original cleanup of "cut here" missed the WARN_ON() case (that does
not have a printk message), which was fixed recently by adding an explicit
printk of "cut here".  This had the downside of adding a printk() to every
WARN_ON() caller, which reduces the utility of using an instruction
exception to streamline the resulting code.  By making this a new BUGFLAG,
all of these can be removed and "cut here" can be handled by the exception
handler.

This was very pronounced on PowerPC, but the effect can be seen on x86 as
well.  The resulting text size of a defconfig build shows some small
savings from this patch:

   text    data     bss     dec     hex filename
19691167        5134320 1646664 26472151        193eed7 vmlinux.before
19676362        5134260 1663048 26473670        193f4c6 vmlinux.after

This change also opens the door for creating something like BUG_MSG(),
where a custom printk() before issuing BUG(), without confusing the "cut
here" line.

This patch (of 7):

There's no reason to have specialized helpers for passing the warn taint
down to __warn().  Consolidate and refactor helper macros, removing
__WARN_printf() and warn_slowpath_fmt_taint().

Link: http://lkml.kernel.org/r/20190819234111.9019-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb: handle split debug

Some systems (like Chrome OS) may use "split debug" for kernel modules.
That means that the debug symbols are in a different file than the main
elf file.  Let's handle that by also searching for debug symbols that end
in ".ko.debug".

This is a packaging topic.  You can take a normal elf file and split the
debug out of it using objcopy.  Try "man objcopy" and then take a look at
the "--only-keep-debug" option.  It'll give you a whole recipe for doing
splitdebug.  The suffix used for the debug symbols is arbitrary.  If
people have other another suffix besides ".ko.debug" then we could
presumably support that too...

For portage (which is the packaging system used by Chrome OS) split debug
is supported by default (and the suffix is .ko.debug).  ...and so in
Chrome OS we always get the installed elf files stripped and then the
symbols stashed away.

At the moment we don't actually use the normal portage magic to do this
for the kernel though since it affects our ability to get good stack dumps
in the kernel.  We instead pass a script as "strip" [1].

[1] https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/refs/heads/master/eclass/cros-kernel/strip_splitdebug

Link: http://lkml.kernel.org/r/20190730234052.148744-1-dianders@chromium.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kgdb: don't use a notifier to enter kgdb at panic; call directly

Right now kgdb/kdb hooks up to debug panics by registering for the panic
notifier.  This works OK except that it means that kgdb/kdb gets called
_after_ the CPUs in the system are taken offline.  That means that if
anything important was happening on those CPUs (like something that might
have contributed to the panic) you can't debug them.

Specifically I ran into a case where I got a panic because a task was
"blocked for more than 120 seconds" which was detected on CPU 2.  I nicely
got shown stack traces in the kernel log for all CPUs including CPU 0,
which was running 'PID: 111 Comm: kworker/0:1H' and was in the middle of
__mmc_switch().

I then ended up at the kdb prompt where switched over to kgdb to try to
look at local variables of the process on CPU 0.  I found that I couldn't.
Digging more, I found that I had no info on any tasks running on CPUs
other than CPU 2 and that asking kdb for help showed me "Error: no saved
data for this cpu".  This was because all the CPUs were offline.

Let's move the entry of kdb/kgdb to a direct call from panic() and stop
using the generic notifier.  Putting a direct call in allows us to order
things more properly and it also doesn't seem like we're breaking any
abstractions by calling into the debugger from the panic function.

Daniel said:

: This patch changes the way kdump and kgdb interact with each other.
: However it would seem rather odd to have both tools simultaneously armed
: and, even if they were, the user still has the option to use panic_timeout
: to force a kdump to happen.  Thus I think the change of order is
: acceptable.

Link: http://lkml.kernel.org/r/20190703170354.217312-1-dianders@chromium.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

compiler: enable CONFIG_OPTIMIZE_INLINING forcibly

Commit 9012d011660e ("compiler: allow all arches to enable
CONFIG_OPTIMIZE_INLINING") allowed all architectures to enable this
option.  A couple of build errors were reported by randconfig, but all of
them have been ironed out.

Towards the goal of removing CONFIG_OPTIMIZE_INLINING entirely (and it
will simplify the 'inline' macro in compiler_types.h), this commit changes
it to always-on option.  Going forward, the compiler will always be
allowed to not inline functions marked 'inline'.

This is not a problem for x86 since it has been long used by
arch/x86/configs/{x86_64,i386}_defconfig.

I am keeping the config option just in case any problem crops up for other
architectures.

The code clean-up will be done after confirming this is solid.

Link: http://lkml.kernel.org/r/20190830034304.24259-1-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

uaccess: add missing __must_check attributes

The usercopy implementation comments describe that callers of the
copy_*_user() family of functions must always have their return values
checked.  This can be enforced at compile time with __must_check, so add
it where needed.

Link: http://lkml.kernel.org/r/201908251609.ADAD5CAAC1@keescook
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: restore arch_kexec_kernel_image_probe declaration

arch_kexec_kernel_image_probe function declaration has been removed by
commit 9ec4ecef0af7 ("kexec_file,x86,powerpc: factor out kexec_file_ops
functions").  Still this function is overridden by couple of architectures
and proper prototype declaration is therefore important, so bring it back.
This fixes the following sparse warning on s390:
arch/s390/kernel/machine_kexec_file.c:333:5: warning: symbol
'arch_kexec_kernel_image_probe' was not declared.  Should it be static?

Link: http://lkml.kernel.org/r/patch.git-ff1c9045ebdc.your-ad-here.call-01564402297-ext-5690@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: bail out upon SIGKILL when allocating memory.

syzbot found that a thread can stall for minutes inside kexec_load() after
that thread was killed by SIGKILL [1].  It turned out that the reproducer
was trying to allocate 2408MB of memory using kimage_alloc_page() from
kimage_load_normal_segment().  Let's check for SIGKILL before doing memory
allocation.

[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e

Link: http://lkml.kernel.org/r/993c9185-d324-2640-d061-bed2dd18b1f7@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpumask: nicer for_each_cpumask_and() signature

Mask arguments can be swapped without changing anything.  Make arguments
names reflect that:

#define for_each_cpu_and(cpu, mask1, mask2)

Link: http://lkml.kernel.org/r/20190724183350.GA15041@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fork: improve error message for corrupted page tables

When a user process exits, the kernel cleans up the mm_struct of the user
process and during cleanup, check_mm() checks the page tables of the user
process for corruption (E.g: unexpected page flags set/cleared).  For
corrupted page tables, the error message printed by check_mm() isn't very
clear as it prints the loop index instead of page table type (E.g:
Resident file mapping pages vs Resident shared memory pages).  The loop
index in check_mm() is used to index rss_stat[] which represents
individual memory type stats.  Hence, instead of printing index, print
memory type, thereby improving error message.

Without patch:
--------------
[  204.836425] mm/pgtable-generic.c:29: bad p4d 0000000089eb4e92(800000025f941467)
[  204.836544] BUG: Bad rss-counter state mm:00000000f75895ea idx:0 val:2
[  204.836615] BUG: Bad rss-counter state mm:00000000f75895ea idx:1 val:5
[  204.836685] BUG: non-zero pgtables_bytes on freeing mm: 20480

With patch:
-----------
[   69.815453] mm/pgtable-generic.c:29: bad p4d 0000000084653642(800000025ca37467)
[   69.815872] BUG: Bad rss-counter state mm:00000000014a6c03 type:MM_FILEPAGES val:2
[   69.815962] BUG: Bad rss-counter state mm:00000000014a6c03 type:MM_ANONPAGES val:5
[   69.816050] BUG: non-zero pgtables_bytes on freeing mm: 20480

Also, change print function (from printk(KERN_ALERT, ..) to pr_alert()) so
that it matches the other print statement.

Link: http://lkml.kernel.org/r/da75b5153f617f4c5739c08ee6ebeb3d19db0fbc.1565123758.git.sai.praneeth.prakhya@intel.com
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: delete an unnecessary check before brelse()

brelse() tests whether its argument is NULL and then returns immediately.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/cfff3b81-fb5d-af26-7b5e-724266509045@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/do_balan.c: remove set but not used variable

Fix the following gcc warning:

fs/reiserfs/do_balan.c: In function balance_leaf_insert_right:
fs/reiserfs/do_balan.c:629:6: warning: variable ret set but not used
[-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/20190827032932.46622-2-yanaijie@huawei.com
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: zhengbin <zhengbin13@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/journal.c: remove set but not used variable

Fix the following gcc warning:

fs/reiserfs/journal.c: In function flush_used_journal_lists:
fs/reiserfs/journal.c:1791:6: warning: variable ret set but not used
[-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/20190827032932.46622-1-yanaijie@huawei.com
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: zhengbin <zhengbin13@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/do_balan.c: remove set but not used variables

fs/reiserfs/do_balan.c: In function balance_leaf_when_delete:
fs/reiserfs/do_balan.c:245:20: warning: variable ih set but not used [-Wunused-but-set-variable]
fs/reiserfs/do_balan.c: In function balance_leaf_insert_left:
fs/reiserfs/do_balan.c:301:7: warning: variable version set but not used [-Wunused-but-set-variable]
fs/reiserfs/do_balan.c: In function balance_leaf_insert_right:
fs/reiserfs/do_balan.c:649:7: warning: variable version set but not used [-Wunused-but-set-variable]
fs/reiserfs/do_balan.c: In function balance_leaf_new_nodes_insert:
fs/reiserfs/do_balan.c:953:7: warning: variable version set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-8-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/fix_node.c: remove set but not used variables

fs/reiserfs/fix_node.c: In function get_num_ver:
fs/reiserfs/fix_node.c:379:6: warning: variable cur_free set but not used [-Wunused-but-set-variable]
fs/reiserfs/fix_node.c: In function dc_check_balance_internal:
fs/reiserfs/fix_node.c:1737:6: warning: variable maxsize set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-7-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/prints.c: remove set but not used variables

Fixes gcc '-Wunused-but-set-variable' warning:

fs/reiserfs/prints.c: In function check_internal_block_head:
fs/reiserfs/prints.c:749:21: warning: variable blkh set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-6-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/objectid.c: remove set but not used variables

Fixes gcc '-Wunused-but-set-variable' warning:

fs/reiserfs/objectid.c: In function reiserfs_convert_objectid_map_v1:
fs/reiserfs/objectid.c:186:25: warning: variable new_objectid_map set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-5-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/lbalance.c: remove set but not used variables

Fixes gcc '-Wunused-but-set-variable' warning:

fs/reiserfs/lbalance.c: In function leaf_paste_entries:
fs/reiserfs/lbalance.c:1325:9: warning: variable old_entry_num set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-4-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/stree.c: remove set but not used variables

Fixes gcc '-Wunused-but-set-variable' warning:

fs/reiserfs/stree.c: In function search_by_key:
fs/reiserfs/stree.c:596:6: warning: variable right_neighbor_of_leaf_node set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-3-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/journal.c: remove set but not used variables

Fixes gcc '-Wunused-but-set-variable' warning:

fs/reiserfs/journal.c: In function flush_older_commits:
fs/reiserfs/journal.c:894:15: warning: variable first_trans_id set but not used [-Wunused-but-set-variable]
fs/reiserfs/journal.c: In function flush_journal_list:
fs/reiserfs/journal.c:1354:38: warning: variable last set but not used [-Wunused-but-set-variable]
fs/reiserfs/journal.c: In function do_journal_release:
fs/reiserfs/journal.c:1916:6: warning: variable flushed set but not used [-Wunused-but-set-variable]
fs/reiserfs/journal.c: In function do_journal_end:
fs/reiserfs/journal.c:3993:6: warning: variable old_start set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-2-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: reiserfs: remove unnecessary check of bh in remove_from_transaction()

On lines 3430-3434, bh has been assured to be non-null:
    cn = get_journal_hash_dev(sb, journal->j_hash_table, blocknr);
    if (!cn || !cn->bh) {
        return ret;
    }
    bh = cn->bh;

Thus, the check of bh on line 3447 is unnecessary and can be removed.
Thank Andrew Morton for good advice.

Link: http://lkml.kernel.org/r/20190727084019.11307-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Cc: Bharath Vedartham <linux.bhar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: make git output use LANGUAGE=en_US.utf8

git output parsing depends on the language being en_US english.

Make the backtick execution of all `git <foo>` commands set the
LANGUAGE of the process to en_US.utf8 before executing the actual
command using `export LANGUAGE=en_US.utf8; git <foo>`.

Because the command is executed in a child process, the parent
LANGUAGE is unchanged.

Link: http://lkml.kernel.org/r/bb9f29988f3258281956680ff39c3e19e37dc0b8.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: remove obsolete period from "ambiguous SHA1" query

Git dropped the period from its "ambiguous SHA1" error message in commit
0c99171ad2 ("get_short_sha1: mark ambiguity error for translation"), circa
2016.  Drop the period from checkpatch's associated query so as to match
both the old and new error messages.

Link: http://lkml.kernel.org/r/20190830163103.15914-1-sean.j.christopherson@intel.com
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: allow consecutive close braces

checkpatch allows consecutive open braces, so it should also allow
consecutive close braces.

Link: http://lkml.kernel.org/r/bfdb49ae2c3fa7b52fa168769e38b48f959880e2.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: prefer __section over __attribute__((section(...)))

Add another test for __attribute__((section("foo"))) uses that should be
__section(foo)

Link: http://lkml.kernel.org/r/2f374c3c27054b7f978115270d587c624d9962fc.camel@perches.com
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: exclude sizeof sub-expressions from MACRO_ARG_REUSE

The arguments of sizeof are not evaluated so arguments are safe to re-use
in that context.  Excluding sizeof subexpressions means macros like
ARRAY_SIZE can pass checkpatch.

Link: http://lkml.kernel.org/r/20190806070833.24423-1-brendan.jackman@bluwireless.co.uk
Signed-off-by: Brendan Jackman <brendan.jackman@bluwireless.co.uk>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch.pl: warn on invalid commit id

It can happen that a commit message refers to an invalid commit id,
because the referenced hash changed following a rebase, or simply by
mistake.  Add a check in checkpatch.pl which checks that an hash
referenced by a Fixes tag, or just cited in the commit message, is a valid
commit id.

    $ scripts/checkpatch.pl <<'EOF'
    Subject: [PATCH] test commit

    Sample test commit to test checkpatch.pl
    Commit 1da177e4c3f4 ("Linux-2.6.12-rc2") really exists,
    commit 0bba044c4ce7 ("tree") is valid but not a commit,
    while commit b4cc0b1c0cca ("unknown") is invalid.

    Fixes: f0cacc14cade ("unknown")
    Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
    EOF
    WARNING: Unknown commit id '0bba044c4ce7', maybe rebased or not pulled?
    #8:
    commit 0bba044c4ce7 ("tree") is valid but not a commit,

    WARNING: Unknown commit id 'b4cc0b1c0cca', maybe rebased or not pulled?
    #9:
    while commit b4cc0b1c0cca ("unknown") is invalid.

    WARNING: Unknown commit id 'f0cacc14cade', maybe rebased or not pulled?
    #11:
    Fixes: f0cacc14cade ("unknown")

    total: 0 errors, 3 warnings, 4 lines checked

Link: http://lkml.kernel.org/r/20190711001640.13398-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve SPDX license checking

Use perl's m@<match>@ match and not /<match>/ comparisons to avoid
an error using c90's // comment style.

Miscellanea:

o Use normal tab indentation and alignment

Link: http://lkml.kernel.org/r/5e4a8fa7901148fbcd77ab391e6dd0e6bf95777f.camel@perches.com
Link: http://lkml.kernel.org/r/f08eb62458407a145cfedf959d1091af151cd665.1563575364.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: don't interpret stack dumps as commit IDs

Add more types of lines that appear to be stack dumps that also include
hex lines that might otherwise be interpreted as commit IDs.

Link: http://lkml.kernel.org/r/ff00208289224f0ca4eaf4ff7c9c6e087dad0a63.camel@perches.com
Link: http://lkml.kernel.org/r/f7dc9727795db3802809a24162abe0b67e14123b.1563575364.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds

I'm seeing a bunch of debug prints from a user of print_hex_dump_bytes()
in my kernel logs, but I don't have CONFIG_DYNAMIC_DEBUG enabled nor do I
have DEBUG defined in my build.  The problem is that
print_hex_dump_bytes() calls a wrapper function in lib/hexdump.c that
calls print_hex_dump() with KERN_DEBUG level.  There are three cases to
consider here

  1. CONFIG_DYNAMIC_DEBUG=y  --> call dynamic_hex_dum()
  2. CONFIG_DYNAMIC_DEBUG=n && DEBUG --> call print_hex_dump()
  3. CONFIG_DYNAMIC_DEBUG=n && !DEBUG --> stub it out

Right now, that last case isn't detected and we still call
print_hex_dump() from the stub wrapper.

Let's make print_hex_dump_bytes() only call print_hex_dump_debug() so that
it works properly in all cases.

Case #1, print_hex_dump_debug() calls dynamic_hex_dump() and we get same
behavior.  Case #2, print_hex_dump_debug() calls print_hex_dump() with
KERN_DEBUG and we get the same behavior.  Case #3, print_hex_dump_debug()
is a nop, changing behavior to what we want, i.e.  print nothing.

Link: http://lkml.kernel.org/r/20190816235624.115280-1-swboyd@chromium.org
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/extable.c: add missing prototypes

When building with W=1, a number of warnings are issued:

  CC      lib/extable.o
lib/extable.c:63:6: warning: no previous prototype for 'sort_extable' [-Wmissing-prototypes]
   63 | void sort_extable(struct exception_table_entry *start,
      |      ^~~~~~~~~~~~
lib/extable.c:75:6: warning: no previous prototype for 'trim_init_extable' [-Wmissing-prototypes]
   75 | void trim_init_extable(struct module *m)
      |      ^~~~~~~~~~~~~~~~~
lib/extable.c:115:1: warning: no previous prototype for 'search_extable' [-Wmissing-prototypes]
  115 | search_extable(const struct exception_table_entry *base,
      | ^~~~~~~~~~~~~~

Add the missing #include for the prototypes.

Link: http://lkml.kernel.org/r/45574.1565235784@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/generic-radix-tree.c: make 2 functions static inline

When building with W=1, we get some warnings:

l  CC      lib/generic-radix-tree.o
lib/generic-radix-tree.c:39:10: warning: no previous prototype for 'genradix_root_to_depth' [-Wmissing-prototypes]
   39 | unsigned genradix_root_to_depth(struct genradix_root *r)
      |          ^~~~~~~~~~~~~~~~~~~~~~
lib/generic-radix-tree.c:44:23: warning: no previous prototype for 'genradix_root_to_node' [-Wmissing-prototypes]
   44 | struct genradix_node *genradix_root_to_node(struct genradix_root *r)
      |                       ^~~~~~~~~~~~~~~~~~~~~

They're not used anywhere else, so make them static inline.

Link: http://lkml.kernel.org/r/46923.1565236485@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

strscpy: reject buffer sizes larger than INT_MAX

As already done for snprintf(), add a check in strscpy() for giant (i.e.
likely negative and/or miscalculated) copy sizes, WARN, and error out.

Link: http://lkml.kernel.org/r/201907260928.23DE35406@keescook
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/trace/events/writeback.h: fix -Wstringop-truncation warnings

There are many of those warnings.

In file included from ./arch/powerpc/include/asm/paca.h:15,
                 from ./arch/powerpc/include/asm/current.h:13,
                 from ./include/linux/thread_info.h:21,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/powerpc/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from fs/fs-writeback.c:19:
In function 'strncpy',
    inlined from 'perf_trace_writeback_page_template' at
./include/trace/events/writeback.h:56:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified
bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by using the new strscpy_pad() which was introduced in "lib/string:
Add strscpy_pad() function" and will always be NUL-terminated instead of
strncpy().  Also, change strlcpy() to use strscpy_pad() in this file for
consistency.

Link: http://lkml.kernel.org/r/1564075099-27750-1-git-send-email-cai@lca.pw
Fixes: 455b2864686d ("writeback: Initial tracing support")
Fixes: 028c2dd184c0 ("writeback: Add tracing to balance_dirty_pages")
Fixes: e84d0a4f8e39 ("writeback: trace event writeback_queue_io")
Fixes: b48c104d2211 ("writeback: trace event bdi_dirty_ratelimit")
Fixes: cc1676d917f3 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()")
Fixes: 9fb0a7da0c52 ("writeback: add more tracepoints")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nitin Gote <nitin.r.gote@intel.com>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Stephen Kitt <steve@sk2.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>