Add PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP support on arm64.
We don't need any special handling for PTRACE_SYSEMU_SINGLESTEP.

It's quite difficult to generalize handling PTRACE_SYSEMU cross
architectures and avoid calls to tracehook_report_syscall_entry twice.
Different architecture have different mechanism to indicate NO_SYSCALL
and trying to generalise adds more code for no gain.

Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

x86 and um use 31 and 32 for PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP
while powerpc uses different value maybe for legacy reasons.

Though handling of PTRACE_SYSEMU can be made architecture independent,
it's hard to make these definations generic. To add to this existing
mess few architectures like arm, c6x and sh use 31 for PTRACE_GETFDPIC
(get the ELF fdpic loadmap address). It's not possible to move the
definations to generic headers.

So we unfortunately have to duplicate the same defination to ARM64 if
we need to support PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP.

Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

While the TIF_SYSCALL_EMU is set in ptrace_resume independent of any
architecture, currently only powerpc and x86 unset the TIF_SYSCALL_EMU
flag in ptrace_disable which gets called from ptrace_detach.

Let's move the clearing of TIF_SYSCALL_EMU flag to __ptrace_unlink
which gets executed from ptrace_detach and also keep it along with
or close to clearing of TIF_SYSCALL_TRACE.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The task_struct argument is not getting used in __do_page_fault(). Hence
just drop it and use current or cuurent->mm instead where ever required.
This does not change any functionality.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

There is an inconsistency between down_read_trylock() success and failure
paths while dealing with kernel access for non exception table areas where
it calls __do_kernel_fault(). In case of failure it just bails out without
holding mmap_sem but when it succeeds it does so while holding mmap_sem.
Fix this inconsistency by just dropping mmap_sem in success path as well.

__do_kernel_fault() calls die_kernel_fault() which then calls show_pte().
show_pte() in this path might become bit more unreliable without holding
mmap_sem. But there are already instances [1] in do_page_fault() where
die_kernel_fault() gets called without holding mmap_sem. show_pte() can
be made more robust independently but in a later patch.

[1] Conditional block for (is_ttbr0_addr && is_el1_permission_fault)
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

We don't currently set the FAULT_FLAG_INSTRUCTION mm flag for EL0
instruction aborts. This has no functional impact, as we don't override
arch_vma_access_permitted(), and the default implementation always returns
true. However, it would be helpful to provide the flag so that it can be
consumed by tracepoints such as dax_pmd_fault.

This patch sets the FAULT_FLAG_INSTRUCTION flag for EL0 instruction aborts.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

There are no callers for the functions which will pass unaligned physical
addresses. Hence just change these BUG_ON() checks into VM_BUG_ON() which
gets compiled out unless CONFIG_VM_DEBUG is enabled.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Should use aff3 instead of aff2 in comment.
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

cpu_enable_ssbs() is called via stop_machine() as part of the cpu_enable
callback. A spin lock is used to ensure the hook is registered before
the rest of the callback is executed.

On -RT spin_lock() may sleep. However, all the callees in stop_machine()
are expected to not sleep. Therefore a raw_spin_lock() is required here.

Given this is already done under stop_machine() and the work done under
the lock is quite small, the latency should not increase too much.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This change makes CONFIG_ZONE_DMA32 defuly y and allows users
to overwrite it only when CONFIG_EXPERT=y.

For the SoCs that do not need CONFIG_ZONE_DMA32, this is the
first step to manage all available memory by a single
zone(normal zone) to reduce the overhead of multiple zones.

The change also fixes a build error when CONFIG_NUMA=y and
CONFIG_ZONE_DMA32=n.

arch/arm64/mm/init.c:195:17: error: use of undeclared identifier 'ZONE_DMA32'
                max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys());

Change since v1:
1. only expose CONFIG_ZONE_DMA32 when CONFIG_EXPERT=y
2. remove redundant IS_ENABLED(CONFIG_ZONE_DMA32)

Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Even though they have got the same value, PMD_TYPE_SECT and PUD_TYPE_SECT
get used for kernel huge mappings. But before that first the table bit gets
cleared using leaf level PTE_TABLE_BIT. Though functionally they are same,
we should use page table level specific macros to be consistent as per the
MMU specifications. Create page table level specific wrappers for kernel
huge mapping entries and just drop mk_sect_prot() which does not have any
other user.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

cache_line_size is derived from CTR_EL0.CWG field and is called mostly
for I/O device drivers. For some platforms like the HiSilicon Kunpeng920
server SoC, cache line sizes are different between L1/2 cache and L3
cache while L1 cache line size is 64-byte and L3 is 128-byte, but
CTR_EL0.CWG is misreporting using L1 cache line size.

We shall correct the right value which is important for I/O performance.
Let's update the cache line size if it is detected from DT or PPTT
information.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Zhenfa Qiu <qiuzhenfa@hisilicon.com>
Reported-by: Zhenfa Qiu <qiuzhenfa@hisilicon.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add coherency_max_size variable to record the maximum cache line size
for different cache levels. If it is available, we will synchronize
it as cache line size, otherwise we will use CTR_EL0.CWG reporting
in cache_line_size() for arm64.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

When the kernel is compiled with CONFIG_KERNEL_MODE_NEON, some part of
the kernel may be able to use FPSIMD/SVE. This is for instance the case
for crypto code.

Any use of FPSIMD/SVE in the kernel are clearly marked by using the
function kernel_neon_{begin, end}. Furthermore, this can only be used
when may_use_simd() returns true.

The current implementation of may_use_simd() allows softirq to use
FPSIMD/SVE unless it is currently in use (i.e kernel_neon_busy is true).
When in use, softirqs usually fall back to a software method.

At the moment, as a softirq may use FPSIMD/SVE, softirqs are disabled
when touching the FPSIMD/SVE context. This has the drawback to disable
all softirqs even if they are not using FPSIMD/SVE.

Since a softirq is supposed to check may_use_simd() anyway before
attempting to use FPSIMD/SVE, there is limited reason to keep softirq
disabled when touching the FPSIMD/SVE context. Instead, we can simply
disable preemption and mark the FPSIMD/SVE context as in use by setting
CPU's fpsimd_context_busy flag.

Two new helpers {get, put}_cpu_fpsimd_context are introduced to mark
the area using FPSIMD/SVE context and they are used to replace
local_bh_{disable, enable}. The functions kernel_neon_{begin, end} are
also re-implemented to use the new helpers.

Additionally, double-underscored versions of the helpers are provided to
called when preemption is already disabled. These are only relevant on
paths where irqs are disabled anyway, so they are not needed for
correctness in the current code. Let's use them anyway though: this
marks critical sections clearly and will help to avoid mistakes during
future maintenance.

The change has been benchmarked on Linux 5.1-rc4 with defconfig.

On Juno2:
    * hackbench 100 process 1000 (10 times)
    * .7% quicker

On ThunderX 2:
    * hackbench 1000 process 1000 (20 times)
    * 3.4% quicker
Reviewed-by: Dave Martin <dave.martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is
the KVM FPSIMD code.

A following patch will introduce a mechanism to acquire owernship of the
FPSIMD/SVE context for performing context management operations. Rather
than having to export the new helpers to get/put the context, we can just
introduce a new function to combine fpsimd_save() and
fpsimd_flush_cpu_state().

This has also the advantage to remove any external call of fpsimd_save()
and fpsimd_flush_cpu_state(), so they can be turned static.

Lastly, the new function can also be used in the PM notifier.
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The function sve_flush_cpu_state() has been removed in commit 21cdd7fd
("KVM: arm64: Remove eager host SVE state saving").

So remove the associated prototype in asm/fpsimd.h.
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

PTE_VALID signifies that the last level page table entry is valid and it is
MMU recognized while walking the page table. This is not a software defined
PTE bit and should not be listed like one. Just move it to appropriate
header file.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Replace all open encoded contiguous huge page size computations with
available macro encodings CONT_PTE_SIZE and CONT_PMD_SIZE. There are other
instances where these macros are used in the file and this change makes it
consistently use the same mnemonic.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull x86 fixes from Ingo Molnar:
 "Two fixes: a quirk for KVM guests running on certain AMD CPUs, and a
  KASAN related build fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Don't force the CPB cap when running under a hypervisor
  x86/boot: Provide KASAN compatible aliases for string routines

Pull perf fixes from Ingo Molnar:
 "On the kernel side there's a bunch of ring-buffer ordering fixes for a
  reproducible bug, plus a PEBS constraints regression fix.

  Plus tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools headers UAPI: Sync kvm.h headers with the kernel sources
  perf record: Fix s390 missing module symbol and warning for non-root users
  perf machine: Read also the end of the kernel
  perf test vmlinux-kallsyms: Ignore aliases to _etext when searching on kallsyms
  perf session: Add missing swap ops for namespace events
  perf namespace: Protect reading thread's namespace
  tools headers UAPI: Sync drm/drm.h with the kernel
  tools headers UAPI: Sync drm/i915_drm.h with the kernel
  tools headers UAPI: Sync linux/fs.h with the kernel
  tools headers UAPI: Sync linux/sched.h with the kernel
  tools arch x86: Sync asm/cpufeatures.h with the with the kernel
  tools include UAPI: Update copy of files related to new fspick, fsmount, fsconfig, fsopen, move_mount and open_tree syscalls
  perf arm64: Fix mksyscalltbl when system kernel headers are ahead of the kernel
  perf data: Fix 'strncat may truncate' build failure with recent gcc
  perf/ring-buffer: Use regular variables for nesting
  perf/ring-buffer: Always use {READ,WRITE}_ONCE() for rb->user_page data
  perf/ring_buffer: Add ordering to rb->nest increment
  perf/ring_buffer: Fix exposing a temporarily decreased data_head
  perf/x86/intel/ds: Fix EVENT vs. UEVENT PEBS constraints

Pull EFI fixes from Ingo Molnar:
 "Two EFI fixes: a quirk for weird systabs, plus add more robust error
  handling in the old 1:1 mapping code"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Allow the number of EFI configuration tables entries to be zero
  efi/x86/Add missing error handling to old_memmap 1:1 mapping code

Pull stacktrace fix from Ingo Molnar:
 "Fix a stack_trace_save_tsk_reliable() regression"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stacktrace: Unbreak stack_trace_save_tsk_reliable()

Pull SPDX fixes from Greg KH:
 "Here are just two small patches, that fix up some found SPDX
  identifier issues.

  The first patch fixes an error in a previous SPDX fixup patch, that
  causes build errors when doing 'make clean' on the tree (the fact that
  almost no one noticed it reflects the fact that kernel developers
  don't like doing that option very often...)

  The second patch fixes up a number of places in the tree where people
  mistyped the string "SPDX-License-Identifier". Given that people can
  not even type their own name all the time without mistakes, this was
  bound to happen, and odds are, we will have to add some type of check
  for this to checkpatch.pl to catch this happening in the future.

  Both of these have passed testing by 0-day"

* tag 'spdx-5.2-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  treewide: fix typos of SPDX-License-Identifier
  crypto: ux500 - fix license comment syntax error

Pull powerpc fixes from Michael Ellerman:
 "A minor fix to our IMC PMU code to print a less confusing error
  message when the driver can't initialise properly.

  A fix for a bug where a user requesting an unsupported branch sampling
  filter can corrupt PMU state, preventing the PMU from counting
  properly.

  And finally a fix for a bug in our support for kexec_file_load(),
  which prevented loading a kernel and initramfs. Most versions of kexec
  don't yet use kexec_file_load().

  Thanks to: Anju T Sudhakar, Dave Young, Madhavan Srinivasan, Ravi
  Bangoria, Thiago Jung Bauermann"

* tag 'powerpc-5.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/kexec: Fix loading of kernel + initramfs with kexec_file_load()
  powerpc/perf: Fix MMCRA corruption by bhrb_filter
  powerpc/powernv: Return for invalid IMC domain

Pull KVM fixes from Paolo Bonzini:
 "Fixes for PPC and s390"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Book3S HV: Restore SPRG3 in kvmhv_p9_guest_entry()
  KVM: PPC: Book3S HV: Fix lockdep warning when entering guest on POWER9
  KVM: PPC: Book3S HV: XIVE: Fix page offset when clearing ESB pages
  KVM: PPC: Book3S HV: XIVE: Take the srcu read lock when accessing memslots
  KVM: PPC: Book3S HV: XIVE: Do not clear IRQ data of passthrough interrupts
  KVM: PPC: Book3S HV: XIVE: Introduce a new mutex for the XIVE device
  KVM: PPC: Book3S HV: XIVE: Fix the enforced limit on the vCPU identifier
  KVM: PPC: Book3S HV: XIVE: Do not test the EQ flag validity when resetting
  KVM: PPC: Book3S HV: XIVE: Clear file mapping when device is released
  KVM: PPC: Book3S HV: Don't take kvm->lock around kvm_for_each_vcpu
  KVM: PPC: Book3S: Use new mutex to synchronize access to rtas token list
  KVM: PPC: Book3S HV: Use new mutex to synchronize MMU setup
  KVM: PPC: Book3S HV: Avoid touching arch.mmu_ready in XIVE release functions
  KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID
  kvm: fix compile on s390 part 2

Pull i2c fixes from Wolfram Sang:
 "A memleak fix for the core, two driver bugfixes, as well as fixing
  missing file patterns to MAINTAINERS"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: add I2C DT bindings to ARM platforms
  MAINTAINERS: add DT bindings to i2c drivers
  i2c: synquacer: fix synquacer_i2c_doxfer() return value
  i2c: mlxcpld: Fix wrong initialization order in probe
  i2c: dev: fix potential memory leak in i2cdev_ioctl_rdwr

Pull thermal SoC fix from Eduardo Valentin:
 "A single revert, detected to cause issues on the tsens driver"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  Revert "drivers: thermal: tsens: Add new operation to check if a sensor is enabled"

Merge tag 'led-fixes-for-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fix from Jacek Anaszewski:
 "Fix for a recent change in LED core, that didn't take into account the
  possibility of calling led_blink_setup() from atomic context"

* tag 'led-fixes-for-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: avoid flush_work in atomic context

Pull block fixes from Jens Axboe:

 - A set of patches fixing code comments / kerneldoc (Bart)

 - Don't allow loop file change for exclusive open (Jan)

 - Fix revalidate of hidden genhd (Jan)

 - Init queue failure memory free fix (Jes)

 - Improve rq limits failure print (John)

 - Fixup for queue removal/addition (Ming)

 - Missed error progagation for io_uring buffer registration (Pavel)

* tag 'for-linus-20190601' of git://git.kernel.dk/linux-block:
  block: print offending values when cloned rq limits are exceeded
  blk-mq: Document the blk_mq_hw_queue_to_node() arguments
  blk-mq: Fix spelling in a source code comment
  block: Fix bsg_setup_queue() kernel-doc header
  block: Fix rq_qos_wait() kernel-doc header
  block: Fix blk_mq_*_map_queues() kernel-doc headers
  block: Fix throtl_pending_timer_fn() kernel-doc header
  block: Convert blk_invalidate_devt() header into a non-kernel-doc header
  block/partitions/ldm: Convert a kernel-doc header into a non-kernel-doc header
  blk-mq: Fix memory leak in error handling
  block: don't protect generic_make_request_checks with blk_queue_enter
  block: move blk_exit_queue into __blk_release_queue
  block: Don't revalidate bdev of hidden gendisk
  loop: Don't change loop device under exclusive opener
  io_uring: Fix __io_uring_register() false success

Pull SCSI fixes from James Bottomley:
 "Six minor fixes to device drivers and one to the multipath alua
  handler.

  The most extensive fix is the zfcp port remove prevention one, but
  it's impact is only s390"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: libsas: delete sas port if expander discover failed
  scsi: libsas: only clear phy->in_shutdown after shutdown event done
  scsi: scsi_dh_alua: Fix possible null-ptr-deref
  scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask
  scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)
  scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_remove
  scsi: libcxgbi: add a check for NULL pointer in cxgbi_check_route()

Merge misc fixes from Andrew Morton:
 "Various fixes and followups"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, compaction: make sure we isolate a valid PFN
  include/linux/generic-radix-tree.h: fix kerneldoc comment
  kernel/signal.c: trace_signal_deliver when signal_group_exit
  drivers/iommu/intel-iommu.c: fix variable 'iommu' set but not used
  spdxcheck.py: fix directory structures
  kasan: initialize tag to 0xff in __kasan_kmalloc
  z3fold: fix sheduling while atomic
  scripts/gdb: fix invocation when CONFIG_COMMON_CLK is not set
  mm/gup: continue VM_FAULT_RETRY processing even for pre-faults
  ocfs2: fix error path kobject memory leak
  memcg: make it work on sparse non-0-node systems
  mm, memcg: consider subtrees in memory.events
  prctl_set_mm: downgrade mmap_sem to read lock
  prctl_set_mm: refactor checks from validate_prctl_map
  kernel/fork.c: make max_threads symbol static
  arch/arm/boot/compressed/decompress.c: fix build error due to lz4 changes
  arch/parisc/configs/c8000_defconfig: remove obsoleted CONFIG_DEBUG_SLAB_LEAK
  mm/vmalloc.c: fix typo in comment
  lib/sort.c: fix kernel-doc notation warnings
  mm: fix Documentation/vm/hmm.rst Sphinx warnings

When we have holes in a normal memory zone, we could endup having
cached_migrate_pfns which may not necessarily be valid, under heavy memory
pressure with swapping enabled ( via __reset_isolation_suitable(),
triggered by kswapd).

Later if we fail to find a page via fast_isolate_freepages(), we may end
up using the migrate_pfn we started the search with, as valid page.  This
could lead to accessing NULL pointer derefernces like below, due to an
invalid mem_section pointer.

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [47/1825]
 Mem abort info:
   ESR = 0x96000004
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000004
   CM = 0, WnR = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp = 0000000082f94ae9
 [0000000000000008] pgd=0000000000000000
 Internal error: Oops: 96000004 [#1] SMP
 ...
 CPU: 10 PID: 6080 Comm: qemu-system-aar Not tainted 510-rc1+ #6
 Hardware name: AmpereComputing(R) OSPREY EV-883832-X3-0001/OSPREY, BIOS 4819 09/25/2018
 pstate: 60000005 (nZCv daif -PAN -UAO)
 pc : set_pfnblock_flags_mask+0x58/0xe8
 lr : compaction_alloc+0x300/0x950
 [...]
 Process qemu-system-aar (pid: 6080, stack limit = 0x0000000095070da5)
 Call trace:
  set_pfnblock_flags_mask+0x58/0xe8
  compaction_alloc+0x300/0x950
  migrate_pages+0x1a4/0xbb0
  compact_zone+0x750/0xde8
  compact_zone_order+0xd8/0x118
  try_to_compact_pages+0xb4/0x290
  __alloc_pages_direct_compact+0x84/0x1e0
  __alloc_pages_nodemask+0x5e0/0xe18
  alloc_pages_vma+0x1cc/0x210
  do_huge_pmd_anonymous_page+0x108/0x7c8
  __handle_mm_fault+0xdd4/0x1190
  handle_mm_fault+0x114/0x1c0
  __get_user_pages+0x198/0x3c0
  get_user_pages_unlocked+0xb4/0x1d8
  __gfn_to_pfn_memslot+0x12c/0x3b8
  gfn_to_pfn_prot+0x4c/0x60
  kvm_handle_guest_abort+0x4b0/0xcd8
  handle_exit+0x140/0x1b8
  kvm_arch_vcpu_ioctl_run+0x260/0x768
  kvm_vcpu_ioctl+0x490/0x898
  do_vfs_ioctl+0xc4/0x898
  ksys_ioctl+0x8c/0xa0
  __arm64_sys_ioctl+0x28/0x38
  el0_svc_common+0x74/0x118
  el0_svc_handler+0x38/0x78
  el0_svc+0x8/0xc
 Code: f8607840 f100001f 8b011401 9a801020 (f9400400)
 ---[ end trace af6a35219325a9b6 ]---

The issue was reported on an arm64 server with 128GB with holes in the
zone (e.g, [32GB@4GB, 96GB@544GB]), with a swap device enabled, while
running 100 KVM guest instances.

This patch fixes the issue by ensuring that the page belongs to a valid
PFN when we fallback to using the lower limit of the scan range upon
failure in fast_isolate_freepages().

Link: http://lkml.kernel.org/r/1558711908-15688-1-git-send-email-suzuki.poulose@arm.com
Fixes: 5a811889 ("mm, compaction: use free lists to quickly locate a migration target")
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Marc Zyngier <marc.zyngier@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>

The DOC comment block section in include/linux/generic-radix-tree.h
contained a spurious colon, causing this warning in the documentation
build:

  include/linux/generic-radix-tree.h:1: warning: no structured comments found

Remove the colon and make the docs build happy.

Link: http://lkml.kernel.org/r/20190524141933.74ae9050@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
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>

In the fixes commit, removing SIGKILL from each thread signal mask and
executing "goto fatal" directly will skip the call to
"trace_signal_deliver".  At this point, the delivery tracking of the
SIGKILL signal will be inaccurate.

Therefore, we need to add trace_signal_deliver before "goto fatal" after
executing sigdelset.

Note: SEND_SIG_NOINFO matches the fact that SIGKILL doesn't have any info.

Link: http://lkml.kernel.org/r/20190425025812.91424-1-weizhenliang@huawei.com
Fixes: cf43a757 ("signal: Restore the stop PTRACE_EVENT_EXIT")
Signed-off-by: Zhenliang Wei <weizhenliang@huawei.com>
Reviewed-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ivan Delalande <colona@arista.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit cf04eee8 ("iommu/vt-d: Include ACPI devices in iommu=pt")
added for_each_active_iommu() in iommu_prepare_static_identity_mapping()
but never used the each element, i.e, "drhd->iommu".

drivers/iommu/intel-iommu.c: In function
'iommu_prepare_static_identity_mapping':
drivers/iommu/intel-iommu.c:3037:22: warning: variable 'iommu' set but
not used [-Wunused-but-set-variable]
 struct intel_iommu *iommu;

Fixed the warning by appending a compiler attribute __maybe_unused for it.

Link: http://lkml.kernel.org/r/20190523013314.2732-1-cai@lca.pwSigned-off-by: Qian Cai <cai@lca.pw>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The LICENSE directory has recently changed structure and this makes
spdxcheck fails as per below:

FAIL: "Blob or Tree named 'other' not found"
Traceback (most recent call last):
  File "scripts/spdxcheck.py", line 240, in <module>
spdx = read_spdxdata(repo)
  File "scripts/spdxcheck.py", line 41, in read_spdxdata
for el in lictree[d].traverse():
[...]
KeyError: "Blob or Tree named 'other' not found"

Fix the script to restore the correctness on checkpatch License checking.

References: 62be257e ("LICENSES: Rename other to deprecated")
References: 8ea8814f ("LICENSES: Clearly mark dual license only licenses")
Link: http://lkml.kernel.org/r/20190523084755.56739-1-vincenzo.frascino@arm.comSigned-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When building with -Wuninitialized and CONFIG_KASAN_SW_TAGS unset, Clang
warns:

mm/kasan/common.c:484:40: warning: variable 'tag' is uninitialized when
used here [-Wuninitialized]
        kasan_unpoison_shadow(set_tag(object, tag), size);
                                              ^~~

set_tag ignores tag in this configuration but clang doesn't realize it at
this point in its pipeline, as it points to arch_kasan_set_tag as being
the point where it is used, which will later be expanded to (void
*)(object) without a use of tag.  Initialize tag to 0xff, as it removes
this warning and doesn't change the meaning of the code.

Link: https://github.com/ClangBuiltLinux/linux/issues/465
Link: http://lkml.kernel.org/r/20190502163057.6603-1-natechancellor@gmail.com
Fixes: 7f94ffbc ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kmem_cache_alloc() may be called from z3fold_alloc() in atomic context, so
we need to pass correct gfp flags to avoid "scheduling while atomic" bug.

Link: http://lkml.kernel.org/r/20190523153245.119dfeed55927e8755250ddd@gmail.com
Fixes: 7c2b8baa ("mm/z3fold.c: add structure for buddy handles")
Signed-off-by: Vitaly Wool <vitaly.vul@sony.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>

CLK_GET_RATE_NOCACHE depends on CONFIG_COMMON_CLK.  Importing constants.py
when CONFIG_COMMON_CLK is not defined causes:

  (gdb) lx-symbols
  (...)
    File "scripts/gdb/linux/proc.py", line 15, in <module>
      from linux import constants
    File "scripts/gdb/linux/constants.py", line 2, in <module>
      LX_CLK_GET_RATE_NOCACHE = gdb.parse_and_eval("CLK_GET_RATE_NOCACHE")
  gdb.error: No symbol "CLK_GET_RATE_NOCACHE" in current context.

Link: http://lkml.kernel.org/r/20190523195313.24701-1-farosas@linux.ibm.com
Fixes: e7e6f462 ("scripts/gdb: print cached rate in lx-clk-summary")
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>