Pull arm64 fixes from Catalin Marinas:
 "arm64 and perf fixes:

   - build error when accessing MPIDR_HWID_BITMASK from .S

   - fix CTR_EL0 field definitions

   - remove/disable some kernel messages on user faults (unhandled
     signals, unimplemented syscalls)

   - fix kernel page fault in unwind_frame() with function graph tracing

   - fix perf sleeping while atomic errors when booting with ACPI"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: fix unwind_frame() for filtered out fn for function graph tracing
  arm64: Enforce BBM for huge IO/VMAP mappings
  arm64: perf: correct PMUVer probing
  arm_pmu: acpi: request IRQs up-front
  arm_pmu: note IRQs and PMUs per-cpu
  arm_pmu: explicitly enable/disable SPIs at hotplug
  arm_pmu: acpi: check for mismatched PPIs
  arm_pmu: add armpmu_alloc_atomic()
  arm_pmu: fold platform helpers into platform code
  arm_pmu: kill arm_pmu_platdata
  ARM: ux500: remove PMU IRQ bouncer
  arm64: __show_regs: Only resolve kernel symbols when running at EL1
  arm64: Remove unimplemented syscall log message
  arm64: Disable unhandled signal log messages by default
  arm64: cpufeature: Fix CTR_EL0 field definitions
  arm64: uaccess: Formalise types for access_ok()
  arm64: Fix compilation error while accessing MPIDR_HWID_BITMASK from .S files

Pull MIPS fix from James Hogan:
 "A single MIPS fix for mismatching struct compat_flock, resulting in
  bus errors starting Firefox on Debian 8 since 4.13"

* tag 'mips_fixes_4.16_3' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: Drop spurious __unused in struct compat_flock

Pull printk fixlet from Petr Mladek:
 "People expect to see the real pointer value for %px.

  Let's substitute '(null)' only for the other %p? format modifiers that
  need to deference the pointer"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  vsprintf: avoid misleading "(null)" for %px

Pull i2c fixes from Wolfram Sang:
 "Two bugfixes, one v4.16 regression fix, and two documentation fixes"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: designware: Consider SCL GPIO optional
  i2c: busses: i2c-sirf: Fix spelling: "formular" -> "formula".
  i2c: bcm2835: Set up the rising/falling edge delays
  i2c: i801: Add missing documentation entries for Braswell and Kaby Lake
  i2c: designware: must wait for enable

Pull SCSI fixes from James Bottomley:
 "These are mostly fixes for problems with merge window code.

  In addition we have one doc update (alua) and two dead code removals
  (aiclib and octogon) a spurious assignment removal (csiostor) and a
  performance improvement for storvsc involving better interrupt
  spreading and increasing the command per lun handling"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla4xxx: skip error recovery in case of register disconnect.
  scsi: aacraid: fix shutdown crash when init fails
  scsi: qedi: Cleanup local str variable
  scsi: qedi: Fix truncation of CHAP name and secret
  scsi: qla2xxx: Fix incorrect handle for abort IOCB
  scsi: qla2xxx: Fix double free bug after firmware timeout
  scsi: storvsc: Increase cmd_per_lun for higher speed devices
  scsi: qla2xxx: Fix a locking imbalance in qlt_24xx_handle_els()
  scsi: scsi_dh: Document alua_rtpg_queue() arguments
  scsi: Remove Makefile entry for oktagon files
  scsi: aic7xxx: remove aiclib.c
  scsi: qla2xxx: Avoid triggering undefined behavior in qla2x00_mbx_completion()
  scsi: mptfusion: Add bounds check in mptctl_hp_targetinfo()
  scsi: sym53c8xx_2: iterator underflow in sym_getsync()
  scsi: bnx2fc: Fix check in SCSI completion handler for timed out request
  scsi: csiostor: remove redundant assignment to pointer 'ln'
  scsi: ufs: Enable quirk to ignore sending WRITE_SAME command
  scsi: ibmvfc: fix misdefined reserved field in ibmvfc_fcp_rsp_info
  scsi: qla2xxx: Fix memory corruption during hba reset test
  scsi: mpt3sas: fix an out of bound write

Pull drm fixes from Dave Airlie:
 "A bunch of fixes for rc3:

  Exynos:
   - fixes for using monotonic timestamps
   - register definitions
   - removal of unused file

  ipu-v3L
   - minor changes
   - make some register arrays const+static
   - fix some leaks

  meson:
   - fix for vsync

  atomic:
   - fix for memory leak

  EDID parser:
   - add quirks for some more non-desktop devices
   - 6-bit panel fix.

  drm_mm:
   - fix a bug in the core drm mm hole handling

  cirrus:
   - fix lut loading regression

  Lastly there is a deadlock fix around runtime suspend for secondary
  GPUs.

  There was a deadlock between one thread trying to wait for a workqueue
  job to finish in the runtime suspend path, and the workqueue job it
  was waiting for in turn waiting for a runtime_get_sync to return.

  The fixes avoids it by not doing the runtime sync in the workqueue as
  then we always wait for all those tasks to complete before we runtime
  suspend"

* tag 'drm-fixes-for-v4.16-rc3' of git://people.freedesktop.org/~airlied/linux: (25 commits)
  drm/tve200: fix kernel-doc documentation comment include
  drm/edid: quirk Sony PlayStation VR headset as non-desktop
  drm/edid: quirk Windows Mixed Reality headsets as non-desktop
  drm/edid: quirk Oculus Rift headsets as non-desktop
  drm/meson: fix vsync buffer update
  drm: Handle unexpected holes in color-eviction
  drm: exynos: Use proper macro definition for HDMI_I2S_PIN_SEL_1
  drm/exynos: remove exynos_drm_rotator.h
  drm/exynos: g2d: Delete an error message for a failed memory allocation in two functions
  drm/exynos: fix comparison to bitshift when dealing with a mask
  drm/exynos: g2d: use monotonic timestamps
  drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA
  gpu: ipu-csi: add 10/12-bit grayscale support to mbus_code_to_bus_cfg
  gpu: ipu-cpmem: add 16-bit grayscale support to ipu_cpmem_set_image
  gpu: ipu-v3: prg: fix device node leak in ipu_prg_lookup_by_phandle
  gpu: ipu-v3: pre: fix device node leak in ipu_pre_lookup_by_phandle
  drm/amdgpu: Fix deadlock on runtime suspend
  drm/radeon: Fix deadlock on runtime suspend
  drm/nouveau: Fix deadlock on runtime suspend
  drm: Allow determining if current task is output poll worker
  ...

do_task_stat() calls get_wchan(), which further does unwind_frame().
unwind_frame() restores frame->pc to original value in case function
graph tracer has modified a return address (LR) in a stack frame to hook
a function return. However, if function graph tracer has hit a filtered
function, then we can't unwind it as ftrace_push_return_trace() has
biased the index(frame->graph) with a 'huge negative'
offset(-FTRACE_NOTRACE_DEPTH).

Moreover, arm64 stack walker defines index(frame->graph) as unsigned
int, which can not compare a -ve number.

Similar problem we can have with calling of walk_stackframe() from
save_stack_trace_tsk() or dump_backtrace().

This patch fixes unwind_frame() to test the index for -ve value and
restore index accordingly before we can restore frame->pc.

Reproducer:

cd /sys/kernel/debug/tracing/
echo schedule > set_graph_notrace
echo 1 > options/display-graph
echo wakeup > current_tracer
ps -ef | grep -i agent

Above commands result in:
Unable to handle kernel paging request at virtual address ffff801bd3d1e000
pgd = ffff8003cbe97c00
[ffff801bd3d1e000] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000006 [#1] SMP
[...]
CPU: 5 PID: 11696 Comm: ps Not tainted 4.11.0+ #33
[...]
task: ffff8003c21ba000 task.stack: ffff8003cc6c0000
PC is at unwind_frame+0x12c/0x180
LR is at get_wchan+0xd4/0x134
pc : [<ffff00000808892c>] lr : [<ffff0000080860b8>] pstate: 60000145
sp : ffff8003cc6c3ab0
x29: ffff8003cc6c3ab0 x28: 0000000000000001
x27: 0000000000000026 x26: 0000000000000026
x25: 00000000000012d8 x24: 0000000000000000
x23: ffff8003c1c04000 x22: ffff000008c83000
x21: ffff8003c1c00000 x20: 000000000000000f
x19: ffff8003c1bc0000 x18: 0000fffffc593690
x17: 0000000000000000 x16: 0000000000000001
x15: 0000b855670e2b60 x14: 0003e97f22cf1d0f
x13: 0000000000000001 x12: 0000000000000000
x11: 00000000e8f4883e x10: 0000000154f47ec8
x9 : 0000000070f367c0 x8 : 0000000000000000
x7 : 00008003f7290000 x6 : 0000000000000018
x5 : 0000000000000000 x4 : ffff8003c1c03cb0
x3 : ffff8003c1c03ca0 x2 : 00000017ffe80000
x1 : ffff8003cc6c3af8 x0 : ffff8003d3e9e000

Process ps (pid: 11696, stack limit = 0xffff8003cc6c0000)
Stack: (0xffff8003cc6c3ab0 to 0xffff8003cc6c4000)
[...]
[<ffff00000808892c>] unwind_frame+0x12c/0x180
[<ffff000008305008>] do_task_stat+0x864/0x870
[<ffff000008305c44>] proc_tgid_stat+0x3c/0x48
[<ffff0000082fde0c>] proc_single_show+0x5c/0xb8
[<ffff0000082b27e0>] seq_read+0x160/0x414
[<ffff000008289e6c>] __vfs_read+0x58/0x164
[<ffff00000828b164>] vfs_read+0x88/0x144
[<ffff00000828c2e8>] SyS_read+0x60/0xc0
[<ffff0000080834a0>] __sys_trace_return+0x0/0x4

Fixes: 20380bb3 (arm64: ftrace: fix a stack tracer's output under function graph tracer)
Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
[catalin.marinas@arm.com: replace WARN_ON with WARN_ON_ONCE]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

drm/imx: ipu-v3 fixups and grayscale support

- Make const interrupt register arrays static, reduces object size.
- Fix device_node leaks in PRE/PRG phandle lookup functions.
- Add 8-bit and 16-bit grayscale buffer support to ipu_cpmem_set_image,
- add 10-bit and 12-bit grayscale media bus support to ipu-csi,
  to be used by the imx-media driver.

* tag 'imx-drm-next-2018-02-22' of git://git.pengutronix.de/git/pza/linux:
  gpu: ipu-csi: add 10/12-bit grayscale support to mbus_code_to_bus_cfg
  gpu: ipu-cpmem: add 16-bit grayscale support to ipu_cpmem_set_image
  gpu: ipu-v3: prg: fix device node leak in ipu_prg_lookup_by_phandle
  gpu: ipu-v3: pre: fix device node leak in ipu_pre_lookup_by_phandle
  gpu: ipu-cpmem: add 8-bit grayscale support to ipu_cpmem_set_image
  gpu: ipu-v3: make const arrays int_reg static, shrinks object size

The MIPS %.its.S compiler command did not define __ASSEMBLY__, which meant
when compiler_types.h was added to kconfig.h, unexpected things appeared
(e.g. struct declarations) which should not have been present. As done in
the general %.S compiler command, __ASSEMBLY__ is now included here too.

The failure was:

    Error: arch/mips/boot/vmlinux.gz.its:201.1-2 syntax error
    FATAL ERROR: Unable to parse input tree
    /usr/bin/mkimage: Can't read arch/mips/boot/vmlinux.gz.itb.tmp: Invalid argument
    /usr/bin/mkimage Can't add hashes to FIT blob
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 28128c61 ("kconfig.h: Include compiler types to avoid missed struct attributes")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull siginfo fix from Eric Biederman:
 "This fixes a build error that only shows up on blackfin"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  fs/signalfd: fix build error for BUS_MCEERR_AR

Pull crypto fix from Herbert Xu:
 "Fix an oops in the s5p-sss driver when used with ecb(aes)"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s5p-sss - Fix kernel Oops in AES-ECB mode

Fix build error in fs/signalfd.c by using same method that is used in
kernel/signal.c: separate blocks for different signal si_code values.

./fs/signalfd.c: error: 'BUS_MCEERR_AR' undeclared (first use in this function)
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Pull USB fixes from Greg KH:
 "Here are a number of USB fixes for 4.16-rc3

  Nothing major, but a number of different fixes all over the place in
  the USB stack for reported issues. Mostly gadget driver fixes,
  although the typical set of xhci bugfixes are there, along with some
  new quirks additions as well.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (39 commits)
  Revert "usb: musb: host: don't start next rx urb if current one failed"
  usb: musb: fix enumeration after resume
  usb: cdc_acm: prevent race at write to acm while system resumes
  Add delay-init quirk for Corsair K70 RGB keyboards
  usb: ohci: Proper handling of ed_rm_list to handle race condition between usb_kill_urb() and finish_unlinks()
  usb: host: ehci: always enable interrupt for qtd completion at test mode
  usb: ldusb: add PIDs for new CASSY devices supported by this driver
  usb: renesas_usbhs: missed the "running" flag in usb_dmac with rx path
  usb: host: ehci: use correct device pointer for dma ops
  usbip: keep usbip_device sockfd state in sync with tcp_socket
  ohci-hcd: Fix race condition caused by ohci_urb_enqueue() and io_watchdog_func()
  USB: serial: option: Add support for Quectel EP06
  xhci: fix xhci debugfs errors in xhci_stop
  xhci: xhci debugfs device nodes weren't removed after device plugged out
  xhci: Fix xhci debugfs devices node disappearance after hibernation
  xhci: Fix NULL pointer in xhci debugfs
  xhci: Don't print a warning when setting link state for disabled ports
  xhci: workaround for AMD Promontory disabled ports wakeup
  usb: dwc3: core: Fix ULPI PHYs and prevent phy_get/ulpi_init during suspend/resume
  USB: gadget: udc: Add missing platform_device_put() on error in bdc_pci_probe()
  ...

Pull staging/IIO fixes from Greg KH:
 "Here are a small number of staging and iio driver fixes for 4.16-rc2.

  The IIO fixes are all for reported things, and the android driver
  fixes also resolve some reported problems. The remaining fsl-mc
  Kconfig change resolves a build testing error that Arnd reported.

  All of these have been in linux-next with no reported issues"

* tag 'staging-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: buffer: check if a buffer has been set up when poll is called
  iio: adis_lib: Initialize trigger before requesting interrupt
  staging: android: ion: Zero CMA allocated memory
  staging: android: ashmem: Fix a race condition in pin ioctls
  staging: fsl-mc: fix build testing on x86
  iio: srf08: fix link error "devm_iio_triggered_buffer_setup" undefined
  staging: iio: ad5933: switch buffer mode to software
  iio: adc: stm32: fix stm32h7_adc_enable error handling
  staging: iio: adc: ad7192: fix external frequency setting
  iio: adc: aspeed: Fix error handling path

Pull char/misc driver fixes from Greg KH:
 "Here are a handful of char/misc driver fixes for 4.16-rc3.

  There are some binder driver fixes to resolve reported issues in
  stress testing the recent binder changes, some extcon driver fixes,
  and a few mei driver fixes and new device ids.

  All of these, with the exception of the mei driver id additions, have
  been in linux-next for a while. I forgot to push out the mei driver id
  additions to kernel.org until today, but all build tests pass with
  them enabled"

* tag 'char-misc-4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mei: me: add cannon point device ids for 4th device
  mei: me: add cannon point device ids
  mei: set device client to the disconnected state upon suspend.
  ANDROID: binder: synchronize_rcu() when using POLLFREE.
  binder: replace "%p" with "%pK"
  ANDROID: binder: remove WARN() for redundant txn error
  binder: check for binder_thread allocation failure in binder_poll()
  extcon: int3496: process id-pin first so that we start with the right status
  Revert "extcon: axp288: Redo charger type detection a couple of seconds after probe()"
  extcon: axp288: Constify the axp288_pwr_up_down_info array

Pull rdma fixes from Doug Ledford:
 "Nothing in this is overly interesting, it's mostly your garden variety
  fixes.

  There was some work in this merge cycle around the new ioctl kABI, so
  there are fixes in here related to that (probably with more to come).

  We've also recently added new netlink support with a goal of moving
  the primary means of configuring the entire subsystem to netlink
  (eventually, this is a long term project), so there are fixes for
  that.

  Then a few bnxt_re driver fixes, and a few minor WARN_ON removals, and
  that covers this pull request. There are already a few more fixes on
  the list as of this morning, so there will certainly be more to come
  in this rc cycle ;-)

  Summary:

   - Lots of fixes for the new IOCTL interface and general uverbs flow.
     Found through testing and syzkaller

   - Bugfixes for the new resource track netlink reporting

   - Remove some unneeded WARN_ONs that were triggering for some users
     in IPoIB

   - Various fixes for the bnxt_re driver"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (27 commits)
  RDMA/uverbs: Fix kernel panic while using XRC_TGT QP type
  RDMA/bnxt_re: Avoid system hang during device un-reg
  RDMA/bnxt_re: Fix system crash during load/unload
  RDMA/bnxt_re: Synchronize destroy_qp with poll_cq
  RDMA/bnxt_re: Unpin SQ and RQ memory if QP create fails
  RDMA/bnxt_re: Disable atomic capability on bnxt_re adapters
  RDMA/restrack: don't use uaccess_kernel()
  RDMA/verbs: Check existence of function prior to accessing it
  RDMA/vmw_pvrdma: Fix usage of user response structures in ABI file
  RDMA/uverbs: Sanitize user entered port numbers prior to access it
  RDMA/uverbs: Fix circular locking dependency
  RDMA/uverbs: Fix bad unlock balance in ib_uverbs_close_xrcd
  RDMA/restrack: Increment CQ restrack object before committing
  RDMA/uverbs: Protect from command mask overflow
  IB/uverbs: Fix unbalanced unlock on error path for rdma_explicit_destroy
  IB/uverbs: Improve lockdep_check
  RDMA/uverbs: Protect from races between lookup and destroy of uobjects
  IB/uverbs: Hold the uobj write lock after allocate
  IB/uverbs: Fix possible oops with duplicate ioctl attributes
  IB/uverbs: Add ioctl support for 32bit processes
  ...

Merge tag 'riscv-for-linus-4.16-rc3-riscv_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V cleanups from Palmer Dabbelt:
 "This contains a handful of small cleanups.

  The only functional change is that IRQs are now enabled during
  exception handling, which was found when some warnings triggered with
  `CONFIG_DEBUG_ATOMIC_SLEEP=y`.

  The remaining fixes should have no functional change: `sbi_save()` has
  been renamed to `parse_dtb()` reflect what it actually does, and a
  handful of unused Kconfig entries have been removed"

* tag 'riscv-for-linus-4.16-rc3-riscv_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  Rename sbi_save to parse_dtb to improve code readability
  RISC-V: Enable IRQ during exception handling
  riscv: Remove ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select
  riscv: kconfig: Remove RISCV_IRQ_INTC select
  riscv: Remove ARCH_WANT_OPTIONAL_GPIOLIB select

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: don't defer struct page initialization for Xen pv guests
  lib/Kconfig.debug: enable RUNTIME_TESTING_MENU
  vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
  selftests/memfd: add run_fuse_test.sh to TEST_FILES
  bug.h: work around GCC PR82365 in BUG()
  mm/swap.c: make functions and their kernel-doc agree (again)
  mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
  ida: do zeroing in ida_pre_get()
  mm, swap, frontswap: fix THP swap if frontswap enabled
  certs/blacklist_nohashes.c: fix const confusion in certs blacklist
  kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
  mm, mlock, vmscan: no more skipping pagevecs
  mm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats
  Kbuild: always define endianess in kconfig.h
  include/linux/sched/mm.h: re-inline mmdrop()
  tools: fix cross-compile var clobbering

Each read from a file in efivarfs results in two calls to EFI
(one to get the file size, another to get the actual data).

On X86 these EFI calls result in broadcast system management
interrupts (SMI) which affect performance of the whole system.
A malicious user can loop performing reads from efivarfs bringing
the system to its knees.

Linus suggested per-user rate limit to solve this.

So we add a ratelimit structure to "user_struct" and initialize
it for the root user for no limit. When allocating user_struct for
other users we set the limit to 100 per second. This could be used
for other places that want to limit the rate of some detrimental
user action.

In efivarfs if the limit is exceeded when reading, we take an
interruptible nap for 50ms and check the rate limit again.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The header files for some structures could get included in such a way
that struct attributes (specifically __randomize_layout from path.h) would
be parsed as variable names instead of attributes. This could lead to
some instances of a structure being unrandomized, causing nasty GPFs, etc.

This patch makes sure the compiler_types.h header is included in
kconfig.h so that we've always got types and struct attributes defined,
since kconfig.h is included from the compiler command line.
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Root-caused-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Fixes: 3859a271 ("randstruct: Mark various structs for randomization")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On i386, there are 2 types of PLTs, PIC and non-PIC.  PIE and shared
objects must use PIC PLT.  To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first.  There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.

On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches.  Linker can always reduce
PLT32 relocation to PC32 if function is defined locally.   Local
functions should use PC32 relocation.  As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.

R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.

[ hjl is working on having better documentation on this all, but a few
  more notes from him:

   "PLT32 relocation is used as marker for PC-relative branches. Because
    of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
    doesn't have GOT.

    As for symbol resolution, PLT32 and PC32 relocations are almost
    interchangeable. But when linker sees PLT32 relocation against a
    protected symbol, it can resolved locally at link-time since it is
    used on a branch instruction. Linker can't do that for PC32
    relocation"

  but for the kernel use, the two are basically the same, and this
  commit gets things building and working with the current binutils
  master   - Linus ]
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ioremap_page_range doesn't honour break-before-make and attempts to put
down huge mappings (using p*d_set_huge) over the top of pre-existing
table entries. This leads to us leaking page table memory and also gives
rise to TLB conflicts and spurious aborts, which have been seen in
practice on Cortex-A75.

Until this has been resolved, refuse to put block mappings when the
existing entry is found to be present.

Fixes: 324420bf ("arm64: add support for ioremap() block mappings")
Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Reported-by: Lei Li <lious.lilei@hisilicon.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

GPIO library can return -ENOSYS for the failed request.
Instead of failing ->probe() in this case override error code to 0.

Fixes: ca382f5b ("i2c: designware: add i2c gpio recovery option")
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fix spelling.
Signed-off-by: Patryk Kocielnik <patryk.kocielnik@gmail.com>
[wsa: fixed "Initialization", too]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We were leaving them in the power on state (or the state the firmware
had set up for some client, if we were taking over from them).  The
boot state was 30 core clocks, when we actually want to sample some
time after (to make sure that the new input bit has actually arrived).
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Commit f7f99100 ("mm: stop zeroing memory during allocation in
vmemmap") broke Xen pv domains in some configurations, as the "Pinned"
information in struct page of early page tables could get lost.

This will lead to the kernel trying to write directly into the page
tables instead of asking the hypervisor to do so.  The result is a crash
like the following:

  BUG: unable to handle kernel paging request at ffff8801ead19008
  IP: xen_set_pud+0x4e/0xd0
  PGD 1c0a067 P4D 1c0a067 PUD 23a0067 PMD 1e9de0067 PTE 80100001ead19065
  Oops: 0003 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-default+ #271
  Hardware name: Dell Inc. Latitude E6440/0159N7, BIOS A07 06/26/2014
  task: ffffffff81c10480 task.stack: ffffffff81c00000
  RIP: e030:xen_set_pud+0x4e/0xd0
  Call Trace:
   __pmd_alloc+0x128/0x140
   ioremap_page_range+0x3f4/0x410
   __ioremap_caller+0x1c3/0x2e0
   acpi_os_map_iomem+0x175/0x1b0
   acpi_tb_acquire_table+0x39/0x66
   acpi_tb_validate_table+0x44/0x7c
   acpi_tb_verify_temp_table+0x45/0x304
   acpi_reallocate_root_table+0x12d/0x141
   acpi_early_init+0x4d/0x10a
   start_kernel+0x3eb/0x4a1
   xen_start_kernel+0x528/0x532
  Code: 48 01 e8 48 0f 42 15 a2 fd be 00 48 01 d0 48 ba 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 d0 48 8b 00 f6 c4 02 75 5d <4c> 89 65 00 5b 5d 41 5c c3 65 8b 05 52 9f fe 7e 89 c0 48 0f a3
  RIP: xen_set_pud+0x4e/0xd0 RSP: ffffffff81c03cd8
  CR2: ffff8801ead19008
  ---[ end trace 38eca2e56f1b642e ]---

Avoid this problem by not deferring struct page initialization when
running as Xen pv guest.

Pavel said:

: This is unique for Xen, so this particular issue won't effect other
: configurations.  I am going to investigate if there is a way to
: re-enable deferred page initialization on xen guests.

[akpm@linux-foundation.org: explicitly include xen.h]
Link: http://lkml.kernel.org/r/20180216154101.22865-1-jgross@suse.com
Fixes: f7f99100 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: <stable@vger.kernel.org>	[4.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit d3deafaa ("lib/: make RUNTIME_TESTS a menuconfig to ease
disabling it all") causes a regression when using runtime tests due to
it defaults RUNTIME_TESTING_MENU to not set.

Link: http://lkml.kernel.org/r/20180214133015.10090-1-anders.roxell@linaro.org
Fixes: d3deafaa ("lib/: make RUNTIME_TESTS a menuconfig to easedisabling it all")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Cc: Vincent Legoll <vincent.legoll@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Kai Heng Feng has noticed that BUG_ON(PageHighMem(pg)) triggers in
drivers/media/common/saa7146/saa7146_core.c since 19809c2d ("mm,
vmalloc: use __GFP_HIGHMEM implicitly").

saa7146_vmalloc_build_pgtable uses vmalloc_32 and it is reasonable to
expect that the resulting page is not in highmem.  The above commit
aimed to add __GFP_HIGHMEM only for those requests which do not specify
any zone modifier gfp flag.  vmalloc_32 relies on GFP_VMALLOC32 which
should do the right thing.  Except it has been missed that GFP_VMALLOC32
is an alias for GFP_KERNEL on 32b architectures.  Thanks to Matthew to
notice this.

Fix the problem by unconditionally setting GFP_DMA32 in GFP_VMALLOC32
for !64b arches (as a bailout).  This should do the right thing and use
ZONE_NORMAL which should be always below 4G on 32b systems.

Debugged by Matthew Wilcox.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180212095019.GX21609@dhcp22.suse.cz
Fixes: 19809c2d ("mm, vmalloc: use __GFP_HIGHMEM implicitly”)
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Kai Heng Feng <kai.heng.feng@canonical.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While testing memfd tests, there is a missing script, as reported by
kselftest:

  ./run_tests.sh: line 7: ./run_fuse_test.sh: No such file or directory

Link: http://lkml.kernel.org/r/1517955779-11386-1-git-send-email-daniel.diaz@linaro.orgSigned-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Daniel Díaz <daniel.diaz@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.deSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Tested-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There was a conflict between the commit e02a9f04 ("mm/swap.c: make
functions and their kernel-doc agree") and the commit f144c390 ("mm:
docs: fix parameter names mismatch") that both tried to fix mismatch
betweeen pagevec_lookup_entries() parameter names and their description.

Since nr_entries is a better name for the parameter, fix the description
again.

Link: http://lkml.kernel.org/r/1518116946-20947-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[akpm@linux-foundation.org: add colon, per Randy]
Link: http://lkml.kernel.org/r/1518116984-21141-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As far as I can tell, the only place the per-cpu ida_bitmap is populated
is in ida_pre_get.  The pre-allocated element is stolen in two places in
ida_get_new_above, in both cases immediately followed by a memset(0).

Since ida_get_new_above is called with locks held, do the zeroing in
ida_pre_get, or rather let kmalloc() do it.  Also, apparently gcc
generates ~44 bytes of code to do a memset(, 0, 128):

  $ scripts/bloat-o-meter vmlinux.{0,1}
  add/remove: 0/0 grow/shrink: 2/1 up/down: 5/-88 (-83)
  Function                                     old     new   delta
  ida_pre_get                                  115     119      +4
  vermagic                                      27      28      +1
  ida_get_new_above                            715     627     -88

Link: http://lkml.kernel.org/r/20180108225634.15340-1-linux@rasmusvillemoes.dkSigned-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 #1  0x00007fc08889c2f3 malloc (libc.so.6)
 #2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 #3  0x0000560e6005e75c n/a (urxvt)
 #4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 #5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 #6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 #7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 #8  0x0000560e6005cb55 ev_run (urxvt)
 #9  0x0000560e6003b9b9 main (urxvt)
 #10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 #11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c2 ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com
Fixes: bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>	[put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Shaohua Li <shli@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org>	[4.14]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

const must be marked __initconst, not __initdata.

Link: http://lkml.kernel.org/r/20171222001335.1987-1-andi@firstfloor.orgSigned-off-by: Andi Kleen <ak@linux.intel.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>

chan->n_subbufs is set by the user and relay_create_buf() does a kmalloc()
of chan->n_subbufs * sizeof(size_t *).

kmalloc_slab() will generate a warning when this fails if
chan->subbufs * sizeof(size_t *) > KMALLOC_MAX_SIZE.

Limit chan->n_subbufs to the maximum allowed kmalloc() size.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802061216100.122576@chino.kir.corp.google.com
Fixes: f6302f1b ("relay: prevent integer overflow in relay_open()")
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Al 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>

When a thread mlocks an address space backed either by file pages which
are currently not present in memory or swapped out anon pages (not in
swapcache), a new page is allocated and added to the local pagevec
(lru_add_pvec), I/O is triggered and the thread then sleeps on the page.
On I/O completion, the thread can wake on a different CPU, the mlock
syscall will then sets the PageMlocked() bit of the page but will not be
able to put that page in unevictable LRU as the page is on the pagevec
of a different CPU.  Even on drain, that page will go to evictable LRU
because the PageMlocked() bit is not checked on pagevec drain.

The page will eventually go to right LRU on reclaim but the LRU stats
will remain skewed for a long time.

This patch puts all the pages, even unevictable, to the pagevecs and on
the drain, the pages will be added on their LRUs correctly by checking
their evictability.  This resolves the mlocked pages on pagevec of other
CPUs issue because when those pagevecs will be drained, the mlocked file
pages will go to unevictable LRU.  Also this makes the race with munlock
easier to resolve because the pagevec drains happen in LRU lock.

However there is still one place which makes a page evictable and does
PageLRU check on that page without LRU lock and needs special attention.
TestClearPageMlocked() and isolate_lru_page() in clear_page_mlock().

	#0: __pagevec_lru_add_fn	#1: clear_page_mlock

	SetPageLRU()			if (!TestClearPageMlocked())
					  return
	smp_mb() // <--required
					// inside does PageLRU
	if (!PageMlocked())		if (isolate_lru_page())
	  move to evictable LRU		  putback_lru_page()
	else
	  move to unevictable LRU

In '#1', TestClearPageMlocked() provides full memory barrier semantics
and thus the PageLRU check (inside isolate_lru_page) can not be
reordered before it.

In '#0', without explicit memory barrier, the PageMlocked() check can be
reordered before SetPageLRU().  If that happens, '#0' can put a page in
unevictable LRU and '#1' might have just cleared the Mlocked bit of that
page but fails to isolate as PageLRU fails as '#0' still hasn't set
PageLRU bit of that page.  That page will be stranded on the unevictable
LRU.

There is one (good) side effect though.  Without this patch, the pages
allocated for System V shared memory segment are added to evictable LRUs
even after shmctl(SHM_LOCK) on that segment.  This patch will correctly
put such pages to unevictable LRU.

Link: http://lkml.kernel.org/r/20171121211241.18877-1-shakeelb@google.comSigned-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After commit a983b5eb ("mm: memcontrol: fix excessive complexity in
memory.stat reporting"), we observed slowly upward creeping NR_WRITEBACK
counts over the course of several days, both the per-memcg stats as well
as the system counter in e.g.  /proc/meminfo.

The conversion from full per-cpu stat counts to per-cpu cached atomic
stat counts introduced an irq-unsafe RMW operation into the updates.

Most stat updates come from process context, but one notable exception
is the NR_WRITEBACK counter.  While writebacks are issued from process
context, they are retired from (soft)irq context.

When writeback completions interrupt the RMW counter updates of new
writebacks being issued, the decs from the completions are lost.

Since the global updates are routed through the joint lruvec API, both
the memcg counters as well as the system counters are affected.

This patch makes the joint stat and event API irq safe.

Link: http://lkml.kernel.org/r/20180203082353.17284-1-hannes@cmpxchg.org
Fixes: a983b5eb ("mm: memcontrol: fix excessive complexity in memory.stat reporting")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Debugged-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Build testing with LTO found a couple of files that get compiled
differently depending on whether asm/byteorder.h gets included early
enough or not.  In particular, include/asm-generic/qrwlock_types.h is
affected by this, but there are probably others as well.

The symptom is a series of LTO link time warnings, including these:

    net/netlabel/netlabel_unlabeled.h:223: error: type of 'netlbl_unlhsh_add' does not match original declaration [-Werror=lto-type-mismatch]
     int netlbl_unlhsh_add(struct net *net,
    net/netlabel/netlabel_unlabeled.c:377: note: 'netlbl_unlhsh_add' was previously declared here

    include/net/ipv6.h:360: error: type of 'ipv6_renew_options_kern' does not match original declaration [-Werror=lto-type-mismatch]
     ipv6_renew_options_kern(struct sock *sk,
    net/ipv6/exthdrs.c:1162: note: 'ipv6_renew_options_kern' was previously declared here

    net/core/dev.c:761: note: 'dev_get_by_name_rcu' was previously declared here
     struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
    net/core/dev.c:761: note: code may be misoptimized unless -fno-strict-aliasing is used

    drivers/gpu/drm/i915/i915_drv.h:3377: error: type of 'i915_gem_object_set_to_wc_domain' does not match original declaration [-Werror=lto-type-mismatch]
     i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);
    drivers/gpu/drm/i915/i915_gem.c:3639: note: 'i915_gem_object_set_to_wc_domain' was previously declared here

    include/linux/debugfs.h:92:9: error: type of 'debugfs_attr_read' does not match original declaration [-Werror=lto-type-mismatch]
     ssize_t debugfs_attr_read(struct file *file, char __user *buf,
    fs/debugfs/file.c:318: note: 'debugfs_attr_read' was previously declared here

    include/linux/rwlock_api_smp.h:30: error: type of '_raw_read_unlock' does not match original declaration [-Werror=lto-type-mismatch]
     void __lockfunc _raw_read_unlock(rwlock_t *lock) __releases(lock);
    kernel/locking/spinlock.c:246:26: note: '_raw_read_unlock' was previously declared here

    include/linux/fs.h:3308:5: error: type of 'simple_attr_open' does not match original declaration [-Werror=lto-type-mismatch]
     int simple_attr_open(struct inode *inode, struct file *file,
    fs/libfs.c:795: note: 'simple_attr_open' was previously declared here

All of the above are caused by include/asm-generic/qrwlock_types.h
failing to include asm/byteorder.h after commit e0d02285
("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'")
in linux-4.15.

Similar bugs may or may not exist in older kernels as well, but there is
no easy way to test those with link-time optimizations, and kernels
before 4.14 are harder to fix because they don't have Babu's patch
series

We had similar issues with CONFIG_ symbols in the past and ended up
always including the configuration headers though linux/kconfig.h.  This
works around the issue through that same file, defining either
__BIG_ENDIAN or __LITTLE_ENDIAN depending on CONFIG_CPU_BIG_ENDIAN,
which is now always set on all architectures since commit 4c97a0c8
("arch: define CPU_BIG_ENDIAN for all fixed big endian archs").

Link: http://lkml.kernel.org/r/20180202154104.1522809-2-arnd@arndb.deSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As Peter points out, Doing a CALL+RET for just the decrement is a bit silly.

Fixes: d70f2a14 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
Acked-by: Peter Zijlstra (Intel) <peterz@infraded.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>