The pasid-num-bits property shouldn't need a dedicated fwspec field,
it's a job for device properties. Add properties for IORT, and access
the number of PASID bits using device_property_read_u32().
Suggested-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NWill Deacon <will@kernel.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: NHanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/20210401154718.307519-3-jean-philippe@linaro.orgSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Commit 986d5ecc ("iommu: Move fwspec->iommu_priv to struct
dev_iommu") removed iommu_priv from fwspec and commit 5702ee24
("ACPI/IORT: Check ATS capability in root complex nodes") added @flags.
Update the struct doc.
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NWill Deacon <will@kernel.org>
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210401154718.307519-2-jean-philippe@linaro.orgSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Function free_iova_fast() is only referenced by dma-iommu.c, which can
only be in-built, so stop exporting it.

This was missed in an earlier tidy-up patch.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/1616675401-151997-5-git-send-email-john.garry@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Function iommu_dma_free_cpu_cached_iovas() no longer has any caller, so
delete it.

With that, function free_cpu_cached_iovas() may be made static.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/1616675401-151997-4-git-send-email-john.garry@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Now that the core code handles flushing per-IOVA domain CPU rcaches,
remove the handling here.
Reviewed-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1616675401-151997-3-git-send-email-john.garry@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Like the Intel IOMMU driver already does, flush the per-IOVA domain
CPU rcache when a CPU goes offline - there's no point in keeping it.
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1616675401-151997-2-git-send-email-john.garry@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

When restarting after searching below the cached node fails, resetting
the start point to the anchor node is often overly pessimistic. If
allocations are made with mixed limits - particularly in the case of the
opportunistic 32-bit allocation for PCI devices - this could mean
significant time wasted walking through the whole populated upper range
just to reach the initial limit. We can improve on that by implementing
a proper tree traversal to find the first node above the relevant limit,
and set the exact start point.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/076b3484d1e5057b95d8c387c894bd6ad2514043.1614962123.git.robin.murphy@arm.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Repeating the rb_entry() boilerplate all over the place gets old fast.
Before adding yet more instances, add a little hepler to tidy it up.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/03931d86c0ad71f44b29394e3a8d38bfc32349cd.1614962123.git.robin.murphy@arm.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

In converting intel-iommu over to the common IOMMU DMA ops, it quietly
lost the functionality of its "forcedac" option. Since this is a handy
thing both for testing and for performance optimisation on certain
platforms, reimplement it under the common IOMMU parameter namespace.

For the sake of fixing the inadvertent breakage of the Intel-specific
parameter, remove the dmar_forcedac remnants and hook it up as an alias
while documenting the transition to the new common parameter.

Fixes: c588072b ("iommu/vt-d: Convert intel iommu driver to the iommu ops")
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/7eece8e0ea7bfbe2cd0e30789e0d46df573af9b0.1614961776.git.robin.murphy@arm.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

The device iommu probe/attach might have failed leaving dev->iommu
to NULL and device drivers may still invoke these functions resulting
in a crash in iommu vendor driver code.

Hence make sure we check that.

Fixes: a3a19592 ("iommu: Add APIs for multiple domains per device")
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210303173611.520-1-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Doing a

	prctl(PR_SET_MM, PR_SET_MM_AUXV, addr, 1);

will copy 1 byte from userspace to (quite big) on-stack array
and then stash everything to mm->saved_auxv.
AT_NULL terminator will be inserted at the very end.

/proc/*/auxv handler will find that AT_NULL terminator
and copy original stack contents to userspace.

This devious scheme requires CAP_SYS_RESOURCE.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull irq fixes from Thomas Gleixner:
 "A set of irqchip updates:

   - Make the GENERIC_IRQ_MULTI_HANDLER configuration correct

   - Add a missing DT compatible string for the Ingenic driver

   - Remove the pointless debugfs_file pointer from struct irqdomain"

* tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ingenic: Add support for the JZ4760
  dt-bindings/irq: Add compatible string for the JZ4760B
  irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly
  irqdomain: Remove debugfs_file from struct irq_domain

Pull timer fix from Thomas Gleixner:
 "A single fix in for hrtimers to prevent an interrupt storm caused by
  the lack of reevaluation of the timers which expire in softirq context
  under certain circumstances, e.g. when the clock was set"

* tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler updates:

   - Prevent a NULL pointer dereference in the migration_stop_cpu()
     mechanims

   - Prevent self concurrency of affine_move_task()

   - Small fixes and cleanups related to task migration/affinity setting

   - Ensure that sync_runqueues_membarrier_state() is invoked on the
     current CPU when it is in the cpu mask"

* tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/membarrier: fix missing local execution of ipi_sync_rq_state()
  sched: Simplify set_affinity_pending refcounts
  sched: Fix affine_move_task() self-concurrency
  sched: Optimize migration_cpu_stop()
  sched: Collate affine_move_task() stoppers
  sched: Simplify migration_cpu_stop()
  sched: Fix migration_cpu_stop() requeueing

Pull objtool fix from Thomas Gleixner:
 "A single objtool fix to handle the PUSHF/POPF validation correctly for
  the paravirt changes which modified arch_local_irq_restore not to use
  popf"

* tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool,x86: Fix uaccess PUSHF/POPF validation

Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - A fix for the static_call mechanism so it handles unaligned
     addresses correctly.

   - Make u64_stats_init() a macro so every instance gets a seperate
     lockdep key.

   - Make seqcount_latch_init() a macro as well to preserve the static
     variable which is used for the lockdep key"

* tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  seqlock,lockdep: Fix seqcount_latch_init()
  u64_stats,lockdep: Fix u64_stats_init() vs lockdep
  static_call: Fix the module key fixup

Pull perf fixes from Borislav Petkov:

 - Make sure PMU internal buffers are flushed for per-CPU events too and
   properly handle PID/TID for large PEBS.

 - Handle the case properly when there's no PMU and therefore return an
   empty list of perf MSRs for VMX to switch instead of reading random
   garbage from the stack.

* tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case
  perf/x86/intel: Set PERF_ATTACH_SCHED_CB for large PEBS and LBR
  perf/core: Flush PMU internal buffers for per-CPU events

Pull EFI fix from Ard Biesheuvel via Borislav Petkov:
 "Fix an oversight in the handling of EFI_RT_PROPERTIES_TABLE, which was
  added v5.10, but failed to take the SetVirtualAddressMap() RT service
  into account"

* tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table

Pull x86 fixes from Borislav Petkov:

 - A couple of SEV-ES fixes and robustifications: verify usermode stack
   pointer in NMI is not coming from the syscall gap, correctly track
   IRQ states in the #VC handler and access user insn bytes atomically
   in same handler as latter cannot sleep.

 - Balance 32-bit fast syscall exit path to do the proper work on exit
   and thus not confuse audit and ptrace frameworks.

 - Two fixes for the ORC unwinder going "off the rails" into KASAN
   redzones and when ORC data is missing.

* tag 'x86_urgent_for_v5.12_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev-es: Use __copy_from_user_inatomic()
  x86/sev-es: Correctly track IRQ states in runtime #VC handler
  x86/sev-es: Check regs->sp is trusted before adjusting #VC IST stack
  x86/sev-es: Introduce ip_within_syscall_gap() helper
  x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls
  x86/unwind/orc: Silence warnings caused by missing ORC data
  x86/unwind/orc: Disable KASAN checking in the ORC unwinder, part 2

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.12:

   - Fix wrong instruction encoding for lis in ppc_function_entry(),
     which could potentially lead to missed kprobes.

   - Fix SET_FULL_REGS on 32-bit and 64e, which prevented ptrace of
     non-volatile GPRs immediately after exec.

   - Clean up a missed SRR specifier in the recent interrupt rework.

   - Don't treat unrecoverable_exception() as an interrupt handler, it's
     called from other handlers so shouldn't do the interrupt entry/exit
     accounting itself.

   - Fix build errors caused by missing declarations for
     [en/dis]able_kernel_vsx().

  Thanks to Christophe Leroy, Daniel Axtens, Geert Uytterhoeven, Jiri
  Olsa, Naveen N. Rao, and Nicholas Piggin"

* tag 'powerpc-5.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/traps: unrecoverable_exception() is not an interrupt handler
  powerpc: Fix missing declaration of [en/dis]able_kernel_vsx()
  powerpc/64s/exception: Clean up a missed SRR specifier
  powerpc: Fix inverted SET_FULL_REGS bitop
  powerpc/64s: Use symbolic macros for function entry encoding
  powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()

Pull KVM fixes from Paolo Bonzini:
 "More fixes for ARM and x86"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: LAPIC: Advancing the timer expiration on guest initiated write
  KVM: x86/mmu: Skip !MMU-present SPTEs when removing SP in exclusive mode
  KVM: kvmclock: Fix vCPUs > 64 can't be online/hotpluged
  kvm: x86: annotate RCU pointers
  KVM: arm64: Fix exclusive limit for IPA size
  KVM: arm64: Reject VM creation when the default IPA size is unsupported
  KVM: arm64: Ensure I-cache isolation between vcpus of a same VM
  KVM: arm64: Don't use cbz/adr with external symbols
  KVM: arm64: Fix range alignment when walking page tables
  KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
  KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config()
  KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available
  KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
  KVM: arm64: Fix nVHE hyp panic host context restore
  KVM: arm64: Avoid corrupting vCPU context register in guest exit
  KVM: arm64: nvhe: Save the SPE context early
  kvm: x86: use NULL instead of using plain integer as pointer
  KVM: SVM: Connect 'npt' module param to KVM's internal 'npt_enabled'
  KVM: x86: Ensure deadline timer has truly expired before posting its IRQ

Merge misc fixes from Andrew Morton:
 "28 patches.

  Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
  highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
  zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
  ia64"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
  zram: fix broken page writeback
  zram: fix return value on writeback_store
  mm/memcg: set memcg when splitting page
  mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
  ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
  ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
  mm/userfaultfd: fix memory corruption due to writeprotect
  kasan: fix KASAN_STACK dependency for HW_TAGS
  kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
  mm/madvise: replace ptrace attach requirement for process_madvise
  include/linux/sched/mm.h: use rcu_dereference in in_vfork()
  kfence: fix reports if constant function prefixes exist
  kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
  kfence: fix printk format for ptrdiff_t
  linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
  MAINTAINERS: exclude uapi directories in API/ABI section
  binfmt_misc: fix possible deadlock in bm_register_write
  mm/highmem.c: fix zero_user_segments() with start > end
  hugetlb: do early cow when page pinned on src mm
  mm: use is_cow_mapping() across tree where proper
  ...

Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

  - More compatible strings for the Ingenic irqchip (introducing the
    JZ4760B SoC)
  - Select GENERIC_IRQ_MULTI_HANDLER on the ARM ep93xx platform
  - Drop all GENERIC_IRQ_MULTI_HANDLER selections from the irqchip
    Kconfig, now relying on the architecture to get it right
  - Drop the debugfs_file field from struct irq_domain, now that
    debugfs can track things on its own

Pull char/misc driver fixes from Greg KH:
 "Here are some small misc/char driver fixes to resolve some reported
  problems:

   - habanalabs driver fixes

   - Acrn build fixes (reported many times)

   - pvpanic module table export fix

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

* tag 'char-misc-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc/pvpanic: Export module FDT device table
  misc: fastrpc: restrict user apps from sending kernel RPC messages
  virt: acrn: Correct type casting of argument of copy_from_user()
  virt: acrn: Use EPOLLIN instead of POLLIN
  virt: acrn: Use vfs_poll() instead of f_op->poll()
  virt: acrn: Make remove_cpu sysfs invisible with !CONFIG_HOTPLUG_CPU
  cpu/hotplug: Fix build error of using {add,remove}_cpu() with !CONFIG_SMP
  habanalabs: fix debugfs address translation
  habanalabs: Disable file operations after device is removed
  habanalabs: Call put_pid() when releasing control device
  drivers: habanalabs: remove unused dentry pointer for debugfs files
  habanalabs: mark hl_eq_inc_ptr() as static

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for reported problems. They
  include:

   - wfx header file cleanup patch reverted as it could cause problems

   - comedi driver endian fixes

   - buffer overflow problems for staging wifi drivers

   - build dependency issue for rtl8192e driver

  All have been in linux-next for a while with no reported problems"

* tag 'staging-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (23 commits)
  Revert "staging: wfx: remove unused included header files"
  staging: rtl8188eu: prevent ->ssid overflow in rtw_wx_set_scan()
  staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data()
  staging: rtl8192u: fix ->ssid overflow in r8192_wx_set_scan()
  staging: comedi: pcl726: Use 16-bit 0 for interrupt data
  staging: comedi: ni_65xx: Use 16-bit 0 for interrupt data
  staging: comedi: ni_6527: Use 16-bit 0 for interrupt data
  staging: comedi: comedi_parport: Use 16-bit 0 for interrupt data
  staging: comedi: amplc_pc236_common: Use 16-bit 0 for interrupt data
  staging: comedi: pcl818: Fix endian problem for AI command data
  staging: comedi: pcl711: Fix endian problem for AI command data
  staging: comedi: me4000: Fix endian problem for AI command data
  staging: comedi: dmm32at: Fix endian problem for AI command data
  staging: comedi: das800: Fix endian problem for AI command data
  staging: comedi: das6402: Fix endian problem for AI command data
  staging: comedi: adv_pci1710: Fix endian problem for AI command data
  staging: comedi: addi_apci_1500: Fix endian problem for command sample
  staging: comedi: addi_apci_1032: Fix endian problem for COS sample
  staging: ks7010: prevent buffer overflow in ks_wlan_set_scan()
  staging: rtl8712: Fix possible buffer overflow in r8712_sitesurvey_cmd
  ...

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes to resolve some
  reported problems:

   - led tty trigger fixes based on review and were acked by the led
     maintainer

   - revert a max310x serial driver patch as it was causing problems

   - revert a pty change as it was also causing problems

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

* tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "drivers:tty:pty: Fix a race causing data loss on close"
  Revert "serial: max310x: rework RX interrupt handling"
  leds: trigger/tty: Use led_set_brightness_sync() from workqueue
  leds: trigger: Fix error path to not unlock the unlocked mutex

Pull USB fixes from Greg KH:
 "Here are a small number of USB fixes for 5.12-rc3 to resolve a bunch
  of reported issues:

   - usbip fixups for issues found by syzbot

   - xhci driver fixes and quirk additions

   - gadget driver fixes

   - dwc3 QCOM driver fix

   - usb-serial new ids and fixes

   - usblp fix for a long-time issue

   - cdc-acm quirk addition

   - other tiny fixes for reported problems

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

* tag 'usb-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
  xhci: Fix repeated xhci wake after suspend due to uncleared internal wake state
  usb: xhci: Fix ASMedia ASM1042A and ASM3242 DMA addressing
  xhci: Improve detection of device initiated wake signal.
  usb: xhci: do not perform Soft Retry for some xHCI hosts
  usbip: fix vudc usbip_sockfd_store races leading to gpf
  usbip: fix vhci_hcd attach_store() races leading to gpf
  usbip: fix stub_dev usbip_sockfd_store() races leading to gpf
  usbip: fix vudc to check for stream socket
  usbip: fix vhci_hcd to check for stream socket
  usbip: fix stub_dev to check for stream socket
  usb: dwc3: qcom: Add missing DWC3 OF node refcount decrement
  USB: usblp: fix a hang in poll() if disconnected
  USB: gadget: udc: s3c2410_udc: fix return value check in s3c2410_udc_probe()
  usb: renesas_usbhs: Clear PIPECFG for re-enabling pipe with other EPNUM
  usb: dwc3: qcom: Honor wakeup enabled/disabled state
  usb: gadget: f_uac1: stop playback on function disable
  usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot
  USB: gadget: u_ether: Fix a configfs return code
  usb: dwc3: qcom: add ACPI device id for sc8180x
  Goodix Fingerprint device is not a modem
  ...

Pull erofs fix from Gao Xiang:
 "Fix an urgent regression introduced by commit baa2c7c9 ("block:
  set .bi_max_vecs as actual allocated vector number"), which could
  cause unexpected hung since linux 5.12-rc1.

  Resolve it by avoiding using bio->bi_max_vecs completely"

* tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix bio->bi_max_vecs behavior change

Merge tag 'kbuild-fixes-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - avoid 'make image_name' invoking syncconfig

 - fix a couple of bugs in scripts/dummy-tools

 - fix LLD_VENDOR and locale issues in scripts/ld-version.sh

 - rebuild GCC plugins when the compiler is upgraded

 - allow LTO to be enabled with KASAN_HW_TAGS

 - allow LTO to be enabled without LLVM=1

* tag 'kbuild-fixes-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: fix ld-version.sh to not be affected by locale
  kbuild: remove meaningless parameter to $(call if_changed_rule,dtc)
  kbuild: remove LLVM=1 test from HAS_LTO_CLANG
  kbuild: remove unneeded -O option to dtc
  kbuild: dummy-tools: adjust to scripts/cc-version.sh
  kbuild: Allow LTO to be selected with KASAN_HW_TAGS
  kbuild: dummy-tools: support MPROFILE_KERNEL checks for ppc
  kbuild: rebuild GCC plugins when the compiler is upgraded
  kbuild: Fix ld-version.sh script if LLD was built with LLD_VENDOR
  kbuild: dummy-tools: fix inverted tests for gcc
  kbuild: add image_name to no-sync-config-targets

commit 0d835962 ("zram: support page writeback") introduced two
problems.  It overwrites writeback_store's return value as kstrtol's
return value, which makes return value zero so user could see zero as
return value of write syscall even though it wrote data successfully.

It also breaks index value in the loop in that it doesn't increase the
index any longer.  It means it can write only first starting block index
so user couldn't write all idle pages in the zram so lose memory saving
chance.

This patch fixes those issues.

Link: https://lkml.kernel.org/r/20210312173949.2197662-2-minchan@kernel.org
Fixes: 0d835962("zram: support page writeback")
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: NAmos Bianchi <amosbianchi@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: John Dias <joaodias@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

writeback_store's return value is overwritten by submit_bio_wait's return
value.  Thus, writeback_store will return zero since there was no IO
error.  In the end, write syscall from userspace will see the zero as
return value, which could make the process stall to keep trying the write
until it will succeed.

Link: https://lkml.kernel.org/r/20210312173949.2197662-1-minchan@kernel.org
Fixes: 3b82a051("drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store")
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: John Dias <joaodias@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As described in the split_page() comment, for the non-compound high order
page, the sub-pages must be freed individually.  If the memcg of the first
page is valid, the tail pages cannot be uncharged when be freed.

For example, when alloc_pages_exact is used to allocate 1MB continuous
physical memory, 2MB is charged(kmemcg is enabled and __GFP_ACCOUNT is
set).  When make_alloc_exact free the unused 1MB and free_pages_exact free
the applied 1MB, actually, only 4KB(one page) is uncharged.

Therefore, the memcg of the tail page needs to be set when splitting a
page.

Michel:

There are at least two explicit users of __GFP_ACCOUNT with
alloc_exact_pages added recently.  See 7efe8ef2 ("KVM: arm64:
Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT") and c4196218
("KVM: s390: Add memcg accounting to KVM allocations"), so this is not
just a theoretical issue.

Link: https://lkml.kernel.org/r/20210304074053.65527-3-zhouguanghui1@huawei.comSigned-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Weilong Chen <chenweilong@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename mem_cgroup_split_huge_fixup to split_page_memcg and explicitly pass
in page number argument.

In this way, the interface name is more common and can be used by
potential users.  In addition, the complete info(memcg and flag) of the
memcg needs to be set to the tail pages.

Link: https://lkml.kernel.org/r/20210304074053.65527-2-zhouguanghui1@huawei.comSigned-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Weilong Chen <chenweilong@huawei.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not return error sign properly.

The bug is in mismatch between get/set errors:

static inline long syscall_get_error(struct task_struct *task,
                                     struct pt_regs *regs)
{
        return regs->r10 == -1 ? regs->r8:0;
}

static inline long syscall_get_return_value(struct task_struct *task,
                                            struct pt_regs *regs)
{
        return regs->r8;
}

static inline void syscall_set_return_value(struct task_struct *task,
                                            struct pt_regs *regs,
                                            int error, long val)
{
        if (error) {
                /* error < 0, but ia64 uses > 0 return value */
                regs->r8 = -error;
                regs->r10 = -1;
        } else {
                regs->r8 = val;
                regs->r10 = 0;
        }
}

Tested on v5.10 on rx3600 machine (ia64 9040 CPU).

Link: https://lkml.kernel.org/r/20210221002554.333076-2-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
Reported-by: NDmitry V. Levin <ldv@altlinux.org>
Reviewed-by: NDmitry V. Levin <ldv@altlinux.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not work for syscalls called via
glibc's syscall() wrapper.

ia64 has two ways to call syscalls from userspace: via `break` and via
`eps` instructions.

The difference is in stack layout:

1. `eps` creates simple stack frame: no locals, in{0..7} == out{0..8}
2. `break` uses userspace stack frame: may be locals (glibc provides
   one), in{0..7} == out{0..8}.

Both work fine in syscall handling cde itself.

But `ptrace(PTRACE_GET_SYSCALL_INFO)` uses unwind mechanism to
re-extract syscall arguments but it does not account for locals.

The change always skips locals registers. It should not change `eps`
path as kernel's handler already enforces locals=0 and fixes `break`.

Tested on v5.10 on rx3600 machine (ia64 9040 CPU).

Link: https://lkml.kernel.org/r/20210221002554.333076-1-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
Reported-by: NDmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Userfaultfd self-test fails occasionally, indicating a memory corruption.

Analyzing this problem indicates that there is a real bug since mmap_lock
is only taken for read in mwriteprotect_range() and defers flushes, and
since there is insufficient consideration of concurrent deferred TLB
flushes in wp_page_copy().  Although the PTE is flushed from the TLBs in
wp_page_copy(), this flush takes place after the copy has already been
performed, and therefore changes of the page are possible between the time
of the copy and the time in which the PTE is flushed.

To make matters worse, memory-unprotection using userfaultfd also poses a
problem.  Although memory unprotection is logically a promotion of PTE
permissions, and therefore should not require a TLB flush, the current
userrfaultfd code might actually cause a demotion of the architectural PTE
permission: when userfaultfd_writeprotect() unprotects memory region, it
unintentionally *clears* the RW-bit if it was already set.  Note that this
unprotecting a PTE that is not write-protected is a valid use-case: the
userfaultfd monitor might ask to unprotect a region that holds both
write-protected and write-unprotected PTEs.

The scenario that happens in selftests/vm/userfaultfd is as follows:

cpu0				cpu1			cpu2
----				----			----
							[ Writable PTE
							  cached in TLB ]
userfaultfd_writeprotect()
[ write-*unprotect* ]
mwriteprotect_range()
mmap_read_lock()
change_protection()

change_protection_range()
...
change_pte_range()
[ *clear* “write”-bit ]
[ defer TLB flushes ]
				[ page-fault ]
				...
				wp_page_copy()
				 cow_user_page()
				  [ copy page ]
							[ write to old
							  page ]
				...
				 set_pte_at_notify()

A similar scenario can happen:

cpu0		cpu1		cpu2		cpu3
----		----		----		----
						[ Writable PTE
				  		  cached in TLB ]
userfaultfd_writeprotect()
[ write-protect ]
[ deferred TLB flush ]
		userfaultfd_writeprotect()
		[ write-unprotect ]
		[ deferred TLB flush]
				[ page-fault ]
				wp_page_copy()
				 cow_user_page()
				 [ copy page ]
				 ...		[ write to page ]
				set_pte_at_notify()

This race exists since commit 292924b2 ("userfaultfd: wp: apply
_PAGE_UFFD_WP bit").  Yet, as Yu Zhao pointed, these races became apparent
since commit 09854ba9 ("mm: do_wp_page() simplification") which made
wp_page_copy() more likely to take place, specifically if page_count(page)
> 1.

To resolve the aforementioned races, check whether there are pending
flushes on uffd-write-protected VMAs, and if there are, perform a flush
before doing the COW.

Further optimizations will follow to avoid during uffd-write-unprotect
unnecassary PTE write-protection and TLB flushes.

Link: https://lkml.kernel.org/r/20210304095423.3825684-1-namit@vmware.com
Fixes: 09854ba9 ("mm: do_wp_page() simplification")
Signed-off-by: NNadav Amit <namit@vmware.com>
Suggested-by: NYu Zhao <yuzhao@google.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Tested-by: NPeter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>	[5.9+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's a runtime failure when running HW_TAGS-enabled kernel built with
GCC on hardware that doesn't support MTE.  GCC-built kernels always have
CONFIG_KASAN_STACK enabled, even though stack instrumentation isn't
supported by HW_TAGS.  Having that config enabled causes KASAN to issue
MTE-only instructions to unpoison kernel stacks, which causes the failure.

Fix the issue by disallowing CONFIG_KASAN_STACK when HW_TAGS is used.

(The commit that introduced CONFIG_KASAN_HW_TAGS specified proper
 dependency for CONFIG_KASAN_STACK_ENABLE but not for CONFIG_KASAN_STACK.)

Link: https://lkml.kernel.org/r/59e75426241dbb5611277758c8d4d6f5f9298dac.1615215441.git.andreyknvl@google.com
Fixes: 6a63a63f ("kasan: introduce CONFIG_KASAN_HW_TAGS")
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reported-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called
after debug_pagealloc_unmap_pages(). This causes a crash when
debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an
unmapped page.

This patch puts kasan_free_nondeferred_pages() before
debug_pagealloc_unmap_pages() and arch_free_page(), which can also make
the page unavailable.

Link: https://lkml.kernel.org/r/24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com
Fixes: 94ab5b61 ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS")
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

process_madvise currently requires ptrace attach capability.
PTRACE_MODE_ATTACH gives one process complete control over another
process.  It effectively removes the security boundary between the two
processes (in one direction).  Granting ptrace attach capability even to a
system process is considered dangerous since it creates an attack surface.
This severely limits the usage of this API.

The operations process_madvise can perform do not affect the correctness
of the operation of the target process; they only affect where the data is
physically located (and therefore, how fast it can be accessed).  What we
want is the ability for one process to influence another process in order
to optimize performance across the entire system while leaving the
security boundary intact.

Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ and
CAP_SYS_NICE.  PTRACE_MODE_READ to prevent leaking ASLR metadata and
CAP_SYS_NICE for influencing process performance.

Link: https://lkml.kernel.org/r/20210303185807.2160264-1-surenb@google.comSigned-off-by: NSuren Baghdasaryan <surenb@google.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <stable@vger.kernel.org>	[5.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>