This allows associated functions whose `self` argument has
`ArcBorrow<T>` as their type. This, in turn, allows callers to use the
dot syntax to make calls.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This allows us to create references to a ref-counted allocation without
double-indirection and that still allow us to increment the refcount to
a new `Arc<T>`.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

The coercion is only allowed if `U` is a compatible dynamically-sized
type (DST). For example, if we have some type `X` that implements trait
`Y`, then this allows `Arc<X>` to be coerced into `Arc<dyn Y>`.

Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This allows associated functions whose `self` argument has `Arc<T>` or
variants as their type. This, in turn, allows callers to use the dot
syntax to make calls.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This is a basic implementation of `Arc` backed by C's `refcount_t`. It
allows Rust code to idiomatically allocate memory that is ref-counted.

Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Currently we define a number of stubs for compiler-builtin intrinsics
that compiled libcore generates. The defined stubs are weak so they will
not conflict with genuine implementation of these intrinsics, but their
effect is global and will cause non-libcore code that accidently
generate these intrinsics calls compile and bug on runtime.

Instead of defining a stub that can affect all code, this patch uses
objcopy's `--redefine-sym` flag to redirect these calls (from libcore
only) to a prefixed version (e.g. redirect `__multi3` to `__rust_multi3`),
so we can define panciking stubs that are only visible to libcore.

This patch was previously discussed on GitHub [1]. This approach was also
independently proposed by Nick Desaulniers in [2].

Link: https://github.com/Rust-for-Linux/linux/pull/779 [1]
Link: https://lore.kernel.org/lkml/CAKwvOdkc0Qhwu=gfe1+H23TnAa6jnO6A3ZCO687dH6mSrATmDA@mail.gmail.com/


Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked...

The `Cow` type [1] requires that its generic parameter type implements
the `ToOwned` trait [2], which provides a method to create owned data
from borrowed data, usually by cloning.

However, it is infallible, and thus in most cases it is not useful for
the kernel. [3]

Therefore, introduce `cfg(no_borrow)` to remove the `borrow` module
(which contains `ToOwned` and `Cow`) from `alloc`.

Link: https://doc.rust-lang.org/alloc/borrow/enum.Cow.html [1]
Link: https://doc.rust-lang.org/alloc/borrow/trait.ToOwned.html [2]
Link: https://lore.kernel.org/rust-for-linux/20221204103153.117675b1@GaryWorkstation/

 [3]
Cc: Gary Guo <gary@garyguo.net>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Finn Behrens <fin@nyantec.com>

Pull x86 fixes from Borislav Petkov:

 - Make sure the poking PGD is pinned for Xen PV as it requires it this
   way

 - Fixes for two resctrl races when moving a task or creating a new
   monitoring group

 - Fix SEV-SNP guests running under HyperV where MTRRs are disabled to
   not return a UC- type mapping type on memremap() and thus cause a
   serious slowdown

 - Fix insn mnemonics in bioscall.S now that binutils is starting to fix
   confusing insn suffixes

* tag 'x86_urgent_for_v6.2_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: fix poking_init() for Xen PV guests
  x86/resctrl: Fix event counts regression in reused RMIDs
  x86/resctrl: Fix task CLOSID/RMID update race
  x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case
  x86/boot: Avoid using Intel mnemonics in AT&T syntax asm

Pull EDAC fixes from Borislav Petkov:

 - Fix the EDAC device's confusion in the polling setting units

 - Fix a memory leak in highbank's probing function

* tag 'edac_urgent_for_v6.2_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/highbank: Fix memory leak in highbank_mc_probe()
  EDAC/device: Fix period calculation in edac_device_reset_delay_period()

Pull powerpc fixes from Michael Ellerman:

 - Fix a build failure with some versions of ld that have an odd version
   string

 - Fix incorrect use of mutex in the IMC PMU driver

Thanks to Kajol Jain, Michael Petlan, Ojaswin Mujoo, Peter Zijlstra, and
Yang Yingliang.

* tag 'powerpc-6.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/hash: Make stress_hpt_timer_fn() static
  powerpc/imc-pmu: Fix use of mutex in IRQs disabled section
  powerpc/boot: Fix incorrect version calculation issue in ld_version

Pull iommu fixes from Joerg Roedel:

 - Core: Fix an iommu-group refcount leak

 - Fix overflow issue in IOVA alloc path

 - ARM-SMMU fixes from Will:
    - Fix VFIO regression on NXP SoCs by reporting IOMMU_CAP_CACHE_COHERENCY
    - Fix SMMU shutdown paths to avoid device unregistration race

 - Error handling fix for Mediatek IOMMU driver

* tag 'iommu-fixes-v6.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/mediatek-v1: Fix an error handling path in mtk_iommu_v1_probe()
  iommu/iova: Fix alloc iova overflows issue
  iommu: Fix refcount leak in iommu_device_claim_dma_owner
  iommu/arm-smmu-v3: Don't unregister on shutdown
  iommu/arm-smmu: Don't unregister on shutdown
  iommu/arm-smmu: Report IOMMU_CAP_CACHE_COHERENCY even betterer

Pull memblock fix from Mike Rapoport:
 "memblock: always release pages to the buddy allocator in
  memblock_free_late()

  If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
  only releases pages to the buddy allocator if they are not in the
  deferred range. This is correct for free pages (as defined by
  for_each_free_mem_pfn_range_in_zone()) because free pages in the
  deferred range will be initialized and released as part of the
  deferred init process.

  memblock_free_pages() is called by memblock_free_late(), which is used
  to free reserved ranges after memblock_free_all() has run. All pages
  in reserved ranges have been initialized at that point, and
  accordingly, those pages are not touched by the deferred init process.

  This means that currently, if the pages that memblock_free_late()
  intends to release are in the deferred range, they will never be
  released to the buddy allocator. They will forever be reserved.

  In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
  which is also correct for free pages but is not correct for reserved
  pages. KMSAN metadata for reserved pages is initialized by
  kmsan_init_shadow(), which runs shortly before memblock_free_all().

  For both of these reasons, memblock_free_pages() should only be called
  for free pages, and memblock_free_late() should call
  __free_pages_core() directly instead.

  One case where this issue can occur in the wild is EFI boot on x86_64.
  The x86 EFI code reserves all EFI boot services memory ranges via
  memblock_reserve() and frees them later via memblock_free_late()
  (efi_reserve_boot_services() and efi_free_boot_services(),
  respectively).

  If any of those ranges happens to fall within the deferred init range,
  the pages will not be released and that memory will be unavailable.

  For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:

    v6.2-rc2:
    Node 0, zone      DMA
          spanned  4095
          present  3999
          managed  3840
    Node 0, zone    DMA32
          spanned  246652
          present  245868
          managed  178867

    v6.2-rc2 + patch:
    Node 0, zone      DMA
          spanned  4095
          present  3999
          managed  3840
    Node 0, zone    DMA32
          spanned  246652
          present  245868
          managed  222816   # +43,949 pages"

* tag 'fixes-2023-01-14' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  mm: Always release pages to the buddy allocator in memblock_free_late().

Pull kernel hardening fixes from Kees Cook:

 - Fix CFI hash randomization with KASAN (Sami Tolvanen)

 - Check size of coreboot table entry and use flex-array

* tag 'hardening-v6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: Fix CFI hash randomization with KASAN
  firmware: coreboot: Check size of table entry and use flex-array

Pull module fix from Luis Chamberlain:
 "Just one fix for modules by Nick"

* tag 'modules-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  kallsyms: Fix scheduling with interrupts disabled in self-test

Pull cifs fixes from Steve French:

 - memory leak and double free fix

 - two symlink fixes

 - minor cleanup fix

 - two smb1 fixes

* tag '6.2-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix uninitialized memory read for smb311 posix symlink create
  cifs: fix potential memory leaks in session setup
  cifs: do not query ifaces on smb1 mounts
  cifs: fix double free on failed kerberos auth
  cifs: remove redundant assignment to the variable match
  cifs: fix file info setting in cifs_open_file()
  cifs: fix file info setting in cifs_query_path_info()

Pull SCSI fixes from James Bottomley:
 "Two minor fixes in the hisi_sas driver which only impact enterprise
  style multi-expander and shared disk situations and no core changes"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: hisi_sas: Set a port invalid only if there are no devices attached when refreshing port id
  scsi: hisi_sas: Use abort task set to reset SAS disks when discovered

Pull ATA fix from Damien Le Moal:
 "A single fix to prevent building the pata_cs5535 driver with user mode
  linux as it uses msr operations that are not defined with UML"

* tag 'ata-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: pata_cs5535: Don't build on UML

Pull block fixes from Jens Axboe:
 "Nothing major in here, just a collection of NVMe fixes and dropping a
  wrong might_sleep() that static checkers tripped over but which isn't
  valid"

* tag 'block-6.2-2023-01-13' of git://git.kernel.dk/linux:
  MAINTAINERS: stop nvme matching for nvmem files
  nvme: don't allow unprivileged passthrough on partitions
  nvme: replace the "bool vec" arguments with flags in the ioctl path
  nvme: remove __nvme_ioctl
  nvme-pci: fix error handling in nvme_pci_enable()
  nvme-pci: add NVME_QUIRK_IDENTIFY_CNS quirk to Apple T2 controllers
  nvme-apple: add NVME_QUIRK_IDENTIFY_CNS quirk to fix regression
  block: Drop spurious might_sleep() from blk_put_queue()

Pull io_uring fixes from Jens Axboe:
 "A fix for a regression that happened last week, rest is fixes that
  will be headed to stable as well. In detail:

   - Fix for a regression added with the leak fix from last week (me)

   - In writing a test case for that leak, inadvertently discovered a
     case where we a poll request can race. So fix that up and mark it
     for stable, and also ensure that fdinfo covers both the poll tables
     that we have. The latter was an oversight when the split poll table
     were added (me)

   - Fix for a lockdep reported issue with IOPOLL (Pavel)"

* tag 'io_uring-6.2-2023-01-13' of git://git.kernel.dk/linux:
  io_uring: lock overflowing for IOPOLL
  io_uring/poll: attempt request issue after racy poll wakeup
  io_uring/fdinfo: include locked hash table in fdinfo output
  io_uring/poll: add hash if ready poll request can't complete inline
  io_uring/io-wq: only free worker if it was allocated for creation

Pull pci fixes from Bjorn Helgaas:

 - Work around apparent firmware issue that made Linux reject MMCONFIG
   space, which broke PCI extended config space (Bjorn Helgaas)

 - Fix CONFIG_PCIE_BT1 dependency due to mid-air collision between a
   PCI_MSI_IRQ_DOMAIN -> PCI_MSI change and addition of PCIE_BT1 (Lukas
   Bulwahn)

* tag 'pci-v6.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  x86/pci: Treat EfiMemoryMappedIO as reservation of ECAM space
  x86/pci: Simplify is_mmconf_reserved() messages
  PCI: dwc: Adjust to recent removal of PCI_MSI_IRQ_DOMAIN

Clang emits a asan.module_ctor constructor to each object file
when KASAN is enabled, and these functions are indirectly called
in do_ctors. With CONFIG_CFI_CLANG, the compiler also emits a CFI
type hash before each address-taken global function so they can
pass indirect call checks.

However, in commit 0c3e806e ("x86/cfi: Add boot time hash
randomization"), x86 implemented boot time hash randomization,
which relies on the .cfi_sites section generated by objtool. As
objtool is run against vmlinux.o instead of individual object
files with X86_KERNEL_IBT (enabled by default), CFI types in
object files that are not part of vmlinux.o end up not being
included in .cfi_sites, and thus won't get randomized and trip
CFI when called.

Only .vmlinux.export.o and init/version-timestamp.o are linked
into vmlinux separately from vmlinux.o. As these files don't
contain any functions, disable KASAN for both of them to avoid
breaking hash randomization.

Link: https://github.com/ClangBuiltLinux/linux/issues/1742
Fixes: 0c3e806e

 ("x86/cfi: Add boot time hash randomization")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230112224948.1479453-2-samitolvanen@google.com

The memcpy() of the data following a coreboot_table_entry couldn't
be evaluated by the compiler under CONFIG_FORTIFY_SOURCE. To make it
easier to reason about, add an explicit flexible array member to struct
coreboot_device so the entire entry can be copied at once. Additionally,
validate the sizes before copying. Avoids this run-time false positive
warning:

  memcpy: detected field-spanning write (size 168) of single field "&device->entry" at drivers/firmware/google/coreboot_table.c:103 (size 8)

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/all/03ae2704-8c30-f9f0-215b-7cdf4ad35a9a@molgen.mpg.de/


Cc: Jack Rosenthal <jrosenth@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20230107031406.gonna.761-kees@kernel.org


Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Link: https://lore.kernel.org/r/20230112230312.give.446-kees@kernel.org

kallsyms_on_each* may schedule so must not be called with interrupts
disabled. The iteration function could disable interrupts, but this
also changes lookup_symbol() to match the change to the other timing
code.

Reported-by: Erhard F. <erhard_f@mailbox.org>
Link: https://lore.kernel.org/all/bug-216902-206035@https.bugzilla.kernel.org%2F/


Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202212251728.8d0872ff-oliver.sang@intel.com
Fixes: 30f3bb09

 ("kallsyms: Add self-test facility")
Tested-by: "Erhard F." <erhard_f@mailbox.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

This driver uses MSR functions that aren't implemented under UML.
Avoid building it to prevent tripping up allyesconfig.

e.g.
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x3a3): undefined reference to `__tracepoint_read_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x3d2): undefined reference to `__tracepoint_write_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x457): undefined reference to `__tracepoint_write_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x481): undefined reference to `do_trace_write_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x4d5): undefined reference to `do_trace_write_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x4f5): undefined reference to `do_trace_read_msr'
/usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x51c): undefined reference to `do_trace_write_msr'

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Fix the PMCR_EL0 reset value after the PMU rework

   - Correctly handle S2 fault triggered by a S1 page table walk by not
     always classifying it as a write, as this breaks on R/O memslots

   - Document why we cannot exit with KVM_EXIT_MMIO when taking a write
     fault from a S1 PTW on a R/O memslot

   - Put the Apple M2 on the naughty list for not being able to
     correctly implement the vgic SEIS feature, just like the M1 before
     it

   - Reviewer updates: Alex is stepping down, replaced by Zenghui

  x86:

   - Fix various rare locking issues in Xen emulation and teach lockdep
     to detect them

   - Documentation improvements

   - Do not return host topology information from KVM_GET_SUPPORTED_CPUID"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86/xen: Avoid deadlock by adding kvm->arch.xen.xen_lock leaf node lock
  KVM: Ensure lockdep knows about kvm->lock vs. vcpu->mutex ordering rule
  KVM: x86/xen: Fix potential deadlock in kvm_xen_update_runstate_guest()
  KVM: x86/xen: Fix lockdep warning on "recursive" gpc locking
  Documentation: kvm: fix SRCU locking order docs
  KVM: x86: Do not return host topology information from KVM_GET_SUPPORTED_CPUID
  KVM: nSVM: clarify recalc_intercepts() wrt CR8
  MAINTAINERS: Remove myself as a KVM/arm64 reviewer
  MAINTAINERS: Add Zenghui Yu as a KVM/arm64 reviewer
  KVM: arm64: vgic: Add Apple M2 cpus to the list of broken SEIS implementations
  KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_*
  KVM: arm64: Document the behaviour of S1PTW faults on RO memslots
  KVM: arm64: Fix S1PTW handling on RO memslots
  KVM: arm64: PMU: Fix PMCR_EL0 reset value

On the x86-64 architecture even a failing cmpxchg grants exclusive
access to the cacheline, making it preferable to retry the failed op
immediately instead of stalling with the pause instruction.

To illustrate the impact, below are benchmark results obtained by
running various will-it-scale tests on top of the 6.2-rc3 kernel and
Cascade Lake (2 sockets * 24 cores * 2 threads) CPU.

All results in ops/s.  Note there is some variance in re-runs, but the
code is consistently faster when contention is present.

  open3 ("Same file open/close"):
  proc          stock       no-pause
     1         805603         814942       (+%1)
     2        1054980        1054781       (-0%)
     8        1544802        1822858      (+18%)
    24        1191064        2199665      (+84%)
    48         851582        1469860      (+72%)
    96         609481        1427170     (+134%)

  fstat2 ("Same file fstat"):
  proc          stock       no-pause
     1        3013872        3047636       (+1%)
     2        4284687        4400421       (+2%)
     8        3257721        5530156      (+69%)
    24        2239819        5466127     (+144%)
    48        1701072        5256609     (+209%)
    96        1269157        6649326     (+423%)

Additionally, a kernel with a private patch to help access() scalability:
access2 ("Same file access"):

  proc          stock        patched      patched
                                         +nopause
    24        2378041        2005501      5370335  (-15% / +125%)

That is, fixing the problems in access itself *reduces* scalability
after the cacheline ping-pong only happens in lockref with the pause
instruction.

Note that fstat and access benchmarks are not currently integrated into
will-it-scale, but interested parties can find them in pull requests to
said project.

Code at hand has a rather tortured history.  First modification showed
up in commit d472d9d9

 ("lockref: Relax in cmpxchg loop"), written
with Itanium in mind.  Later it got patched up to use an arch-dependent
macro to stop doing it on s390 where it caused a significant regression.
Said macro had undergone revisions and was ultimately eliminated later,
going back to cpu_relax.

While I intended to only remove cpu_relax for x86-64, I got the
following comment from Linus:

    I would actually prefer just removing it entirely and see if
    somebody else hollers. You have the numbers to prove it hurts on
    real hardware, and I don't think we have any numbers to the
    contrary.

    So I think it's better to trust the numbers and remove it as a
    failure, than say "let's just remove it on x86-64 and leave
    everybody else with the potentially broken code"

Additionally, Will Deacon (maintainer of the arm64 port, one of the
architectures previously benchmarked):

    So, from the arm64 side of the fence, I'm perfectly happy just
    removing the cpu_relax() calls from lockref.

As such, come back full circle in history and whack it altogether.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/all/CAGudoHHx0Nqg6DE70zAVA75eV-HXfWyhVMWZ-aSeOofkA_=WdA@mail.gmail.com/


Acked-by: Tony Luck <tony.luck@intel.com> # ia64
Acked-by: Nicholas Piggin <npiggin@gmail.com> # powerpc
Acked-by: Will Deacon <will@kernel.org> # arm64
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Normally we reject ECAM space unless it is reported as reserved in the E820
table or via a PNP0C02 _CRS method (PCI Firmware, r3.3, sec 4.1.2).

07eab090 ("efi/x86: Remove EfiMemoryMappedIO from E820 map"), removes
E820 entries that correspond to EfiMemoryMappedIO regions because some
other firmware uses EfiMemoryMappedIO for PCI host bridge windows, and the
E820 entries prevent Linux from allocating BAR space for hot-added devices.

Some firmware doesn't report ECAM space via PNP0C02 _CRS methods, but does
mention it as an EfiMemoryMappedIO region via EFI GetMemoryMap(), which is
normally converted to an E820 entry by a bootloader or EFI stub.  After
07eab090, that E820 entry is removed, so we reject this ECAM space,
which makes PCI extended config space (offsets 0x100-0xfff) inaccessible.

The lack of extended config space breaks anything that relies on it,
including perf, VSEC telemetry, EDAC, QAT, SR-IOV, etc.

Allow use of ECAM for extended config space when the region is covered by
an EfiMemoryMappedIO region, even if it's not included in E820 or PNP0C02
_CRS.

Link: https://lore.kernel.org/r/ac2693d8-8ba3-72e0-5b66-b3ae008d539d@linux.intel.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216891
Fixes: 07eab090 ("efi/x86: Remove EfiMemoryMappedIO from E820 map")
Link: https://lore.kernel.org/r/20230110180243.1590045-3-helgaas@kernel.org


Reported-by: Kan Liang <kan.liang@linux.intel.com>
Reported-by: Tony Luck <tony.luck@intel.com>
Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reported-by: Yunying Sun <yunying.sun@intel.com>
Reported-by: Baowen Zheng <baowen.zheng@corigine.com>
Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reported-by: Yang Lixiao <lixiao.yang@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Yunying Sun <yunying.sun@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>

Pull EFI fixes from Ard Biesheuvel:

 - avoid a potential crash on the efi_subsys_init() error path

 - use more appropriate error code for runtime services calls issued
   after a crash in the firmware occurred

 - avoid READ_ONCE() for accessing firmware tables that may appear
   misaligned in memory

* tag 'efi-fixes-for-v6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: tpm: Avoid READ_ONCE() for accessing the event log
  efi: rt-wrapper: Add missing include
  efi: fix userspace infinite retry read efivars after EFI runtime services page fault
  efi: fix NULL-deref in init error path

Pull documentation fixes from Jonathan Corbet:
 "Three documentation fixes (or rather two and one warning):

   - Sphinx 6.0 broke our configuration mechanism, so fix it

   - I broke our configuration for non-Alabaster themes; Akira fixed it

   - Deprecate Sphinx < 2.4 with an eye toward future removal"

* tag 'docs-6.2-fixes' of git://git.lwn.net/linux:
  docs/conf.py: Use about.html only in sidebar of alabaster theme
  docs: Deprecate use of Sphinx < 2.4.x
  docs: Fix the docs build with Sphinx 6.0

Nathan reports that recent kernels built with LTO will crash when doing
EFI boot using Fedora's GRUB and SHIM. The culprit turns out to be a
misaligned load from the TPM event log, which is annotated with
READ_ONCE(), and under LTO, this gets translated into a LDAR instruction
which does not tolerate misaligned accesses.

Interestingly, this does not happen when booting the same kernel
straight from the UEFI shell, and so the fact that the event log may
appear misaligned in memory may be caused by a bug in GRUB or SHIM.

However, using READ_ONCE() to access firmware tables is slightly unusual
in any case, and here, we only need to ensure that 'event' is not
dereferenced again after it gets unmapped, but this is already taken
care of by the implicit barrier() semantics of the early_memunmap()
call.

Cc: <stable@vger.kernel.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1782


Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

syzbot reports an issue with overflow filling for IOPOLL:

WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Workqueue: events_unbound io_ring_exit_work
Call trace:
 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773
 io_fill_cqe_req io_uring/io_uring.h:168 [inline]
 io_do_iopoll+0x474/0x62c io_uring/rw.c:1065
 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513
 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056
 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863

There is no real problem for normal IOPOLL as flush is also called with
uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL,
for which __io_cqring_overflow_flush() happens from the CQ waiting path.

Reported-and-tested-by:  <syzbot+6805087452d72929404e@syzkaller.appspotmail.com>
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull sound fixes from Takashi Iwai:
 "This became a slightly big update, but it's more or less expected, as
  the first batch after holidays.

  All changes (but for the last two last-minute fixes) have been stewed
  in linux-next long enough, so it's fairly safe to take:

   - PCM UAF fix in 32bit compat layer

   - ASoC board-specific fixes for Intel, AMD, Medathek, Qualcomm

   - SOF power management fixes

   - ASoC Intel link failure fixes

   - A series of fixes for USB-audio regressions

   - CS35L41 HD-audio codec regression fixes

   - HD-audio device-specific fixes / quirks

  Note that one SPI patch has been taken in ASoC subtree mistakenly, and
  the same fix is found in spi tree, but it should be OK to apply"

* tag 'sound-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (39 commits)
  ALSA: pcm: Move rwsem lock inside snd_ctl_elem_read to prevent UAF
  ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate()
  ALSA: hda/realtek: Enable mute/micmute LEDs on HP Spectre x360 13-aw0xxx
  ASoC: fsl-asoc-card: Fix naming of AC'97 CODEC widgets
  ASoC: fsl_ssi: Rename AC'97 streams to avoid collisions with AC'97 CODEC
  ALSA: hda/hdmi: Add a HP device 0x8715 to force connect list
  ALSA: control-led: use strscpy in set_led_id()
  ALSA: usb-audio: Always initialize fixed_rate in snd_usb_find_implicit_fb_sync_format()
  ASoC: dt-bindings: qcom,lpass-tx-macro: correct clocks on SC7280
  ASoC: dt-bindings: qcom,lpass-wsa-macro: correct clocks on SM8250
  ASoC: qcom: Fix building APQ8016 machine driver without SOUNDWIRE
  ALSA: hda: cs35l41: Check runtime suspend capability at runtime_idle
  ALSA: hda: cs35l41: Don't return -EINVAL from system suspend/resume
  ASoC: fsl_micfil: Correct the number of steps on SX controls
  ALSA: hda/realtek: fix mute/micmute LEDs don't work for a HP platform
  Revert "ALSA: usb-audio: Drop superfluous interface setup at parsing"
  ALSA: usb-audio: More refactoring of hw constraint rules
  ALSA: usb-audio: Relax hw constraints for implicit fb sync
  ALSA: usb-audio: Make sure to stop endpoints before closing EPs
  ALSA: hda - Enable headset mic on another Dell laptop with ALC3254
  ...

Pull power management fixes from Rafael Wysocki:
 "These fix assorted issues in the ARM cpufreq drivers and in the AMD
  P-state driver.

  Specifics:

   - Fix cpufreq policy reference counting in amd-pstate to prevent it
     from crashing on removal (Perry Yuan)

   - Fix double initialization and set suspend-freq for Apple's cpufreq
     driver (Arnd Bergmann, Hector Martin)

   - Fix reading of "reg" property, update cpufreq-dt's blocklist and
     update DT documentation for Qualcomm's cpufreq driver (Konrad
     Dybcio, Krzysztof Kozlowski)

   - Replace 0 with NULL in the Armada cpufreq driver (Miles Chen)

   - Fix potential overflows in the CPPC cpufreq driver (Pierre Gondois)

   - Update blocklist for the Tegra234 Soc cpufreq driver (Sumit Gupta)"

* tag 'pm-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering
  cpufreq: armada-37xx: stop using 0 as NULL pointer
  cpufreq: apple-soc: Switch to the lowest frequency on suspend
  dt-bindings: cpufreq: cpufreq-qcom-hw: document interrupts
  cpufreq: Add SM6375 to cpufreq-dt-platdev blocklist
  cpufreq: Add Tegra234 to cpufreq-dt-platdev blocklist
  cpufreq: qcom-hw: Fix reading "reg" with address/size-cells != 2
  cpufreq: CPPC: Add u64 casts to avoid overflowing
  cpufreq: apple: remove duplicate intializer

Pull ACPI fixes from Rafael Wysocki:
 "These add one more ACPI IRQ override quirk, improve ACPI companion
  lookup for backlight devices and add missing kernel command line
  option values for backlight detection.

  Specifics:

   - Improve ACPI companion lookup for backlight devices in the cases
     when there is more than one candidate ACPI device object (Hans de
     Goede)

   - Add missing support for manual selection of NVidia-WMI-EC or Apple
     GMUX backlight in the kernel command line to the ACPI backlight
     driver (Hans de Goede)

   - Skip ACPI IRQ override on Asus Expertbook B2402CBA (Tamim Khan)"

* tag 'acpi-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Fix selecting wrong ACPI fwnode for the iGPU on some Dell laptops
  ACPI: video: Allow selecting NVidia-WMI-EC or Apple GMUX backlight from the cmdline
  ACPI: resource: Skip IRQ override on Asus Expertbook B2402CBA

Merge tag 'platform-drivers-x86-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Hans de Goede:
 "A set of assorted fixes and hardware-id additions"

* tag 'platform-drivers-x86-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86: thinkpad_acpi: Fix profile mode display in AMT mode
  platform/x86: int3472/discrete: Ensure the clk/power enable pins are in output mode
  platform/x86/amd: Fix refcount leak in amd_pmc_probe
  platform/x86: intel/pmc/core: Add Meteor Lake mobile support
  platform/x86: simatic-ipc: add another model
  platform/x86: simatic-ipc: correct name of a model
  platform/x86: dell-privacy: Only register SW_CAMERA_LENS_COVER if present
  platform/x86: dell-privacy: Fix SW_CAMERA_LENS_COVER reporting
  platform/x86: asus-wmi: Don't load fan curves without fan
  platform/x86: asus-wmi: Ignore fan on E410MA
  platform/x86: asus-wmi: Add quirk wmi_ignore_fan
  platform/x86: asus-nb-wmi: Add alternate mapping for KEY_SCREENLOCK
  platform/x86: asus-nb-wmi: Add alternate mapping for KEY_CAMERA
  platform/surface: aggregator: Add missing call to ssam_request_sync_free()
  platform/surface: aggregator: Ignore command messages not intended for us
  platform/x86: touchscreen_dmi: Add info for the CSL Panther Tab HD
  platform/x86: ideapad-laptop: Add Legion 5 15ARH05 DMI id to set_fn_lock_led_list[]
  platform/x86: sony-laptop: Don't turn off 0x153 keyboard backlight during probe

Pull drm fixes from Dave Airlie:
 "There is a bit of a post-holiday build up here I expect, small fixes
  across the board, amdgpu and msm being the main leaders, with others
  having a few. One code removal patch for nouveau:

  buddy:
   - benchmark regression fix for top-down buddy allocation

  panel:
   - add Lenovo panel orientation quirk

  ttm:
   - fix kernel oops regression

  amdgpu:
   - fix missing fence references
   - fix missing pipeline sync fencing
   - SMU13 fan speed fix
   - SMU13 fix power cap handling
   - SMU13 BACO fix
   - Fix a possible segfault in bo validation error case
   - Delay removal of firmware framebuffer
   - Fix error when unloading

  amdkfd:
   - SVM fix when clearing vram
   - GC11 fix for multi-GPU

  i915:
   - Reserve enough fence slot for i915_vma_unbind_vsync
   - Fix potential use after free
   - Reset engines twice in case of reset failure
   - Use multi-cast registers for SVG Unit registers

  msm:
   - display:
   - doc warning fixes
   - dt attribs cleanups
   - memory leak fix
   - error handing in hdmi probe fix
   - dp_aux_isr incorrect signalling fix
   - shutdown path fix
   - accel:
   - a5xx: fix quirks to be a bitmask
   - a6xx: fix gx halt to avoid 1s hang
   - kexec shutdown fix
   - fix potential double free

  vmwgfx:
   - drop rcu usage to make code more robust

  virtio:
   - fix use-after-free in gem handle code

  nouveau:
   - drop unused nouveau_fbcon.c"

* tag 'drm-fixes-2023-01-13' of git://anongit.freedesktop.org/drm/drm: (35 commits)
  drm: Optimize drm buddy top-down allocation method
  drm/ttm: Fix a regression causing kernel oops'es
  drm/i915/gt: Cover rest of SVG unit MCR registers
  drm/nouveau: Remove file nouveau_fbcon.c
  drm/amdkfd: Fix NULL pointer error for GC 11.0.1 on mGPU
  drm/amd/pm/smu13: BACO is supported when it's in BACO state
  drm/amdkfd: Add sync after creating vram bo
  drm/i915/gt: Reset twice
  drm/amdgpu: fix pipeline sync v2
  drm/vmwgfx: Remove rcu locks from user resources
  drm/virtio: Fix GEM handle creation UAF
  drm/amdgpu: Fixed bug on error when unloading amdgpu
  drm/amd: Delay removal of the firmware framebuffer
  drm/amdgpu: Fix potential NULL dereference
  drm/i915: Fix potential context UAFs
  drm/i915: Reserve enough fence slot for i915_vma_unbind_async
  drm: Add orientation quirk for Lenovo ideapad D330-10IGL
  drm/msm/a6xx: Avoid gx gbit halt during rpm suspend
  drm/msm/adreno: Make adreno quirks not overwrite each other
  drm/msm: another fix for the headless Adreno GPU
  ...

Takes rwsem lock inside snd_ctl_elem_read instead of snd_ctl_elem_read_user
like it was done for write in commit 1fa4445f

 ("ALSA: control - introduce
snd_ctl_notify_one() helper"). Doing this way we are also fixing the following
locking issue happening in the compat path which can be easily triggered and
turned into an use-after-free.

64-bits:
snd_ctl_ioctl
  snd_ctl_elem_read_user
    [takes controls_rwsem]
    snd_ctl_elem_read [lock properly held, all good]
    [drops controls_rwsem]

32-bits:
snd_ctl_ioctl_compat
  snd_ctl_elem_write_read_compat
    ctl_elem_write_read
      snd_ctl_elem_read [missing lock, not good]

CVE-2023-0266 was assigned for this issue.

Cc: stable@kernel.org # 5.13+
Signed-off-by: Clement Lecigne <clecigne@google.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230113120745.25464-1-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>

Pull arm64 fixes from Will Deacon:
 "Here's a sizeable batch of Friday the 13th arm64 fixes for -rc4. What
  could possibly go wrong?

  The obvious reason we have so much here is because of the holiday
  season right after the merge window, but we've also brought back an
  erratum workaround that was previously dropped at the last minute and
  there's an MTE coredumping fix that strays outside of the arch/arm64
  directory.

  Summary:

   - Fix PAGE_TABLE_CHECK failures on hugepage splitting path

   - Fix PSCI encoding of MEM_PROTECT_RANGE function in UAPI header

   - Fix NULL deref when accessing debugfs node if PSCI is not present

   - Fix MTE core dumping when VMA list is being updated concurrently

   - Fix SME signal frame handling when SVE is not implemented by the
     CPU

   - Fix asm constraints for cmpxchg_double() to hazard both words

   - Fix build failure with stack tracer and older versions of Clang

   - Bring back workaround for Cortex-A715 erratum 2645198"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Fix build with CC=clang, CONFIG_FTRACE=y and CONFIG_STACK_TRACER=y
  arm64/mm: Define dummy pud_user_exec() when using 2-level page-table
  arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption
  firmware/psci: Don't register with debugfs if PSCI isn't available
  firmware/psci: Fix MEM_PROTECT_RANGE function numbers
  arm64/signal: Always allocate SVE signal frames on SME only systems
  arm64/signal: Always accept SVE signal frames on SME only systems
  arm64/sme: Fix context switch for SME only systems
  arm64: cmpxchg_double*: hazard against entire exchange variable
  arm64/uprobes: change the uprobe_opcode_t typedef to fix the sparse warning
  arm64: mte: Avoid the racy walk of the vma list during core dump
  elfcore: Add a cprm parameter to elf_core_extra_{phdrs,data_size}
  arm64: mte: Fix double-freeing of the temporary tag storage during coredump
  arm64: ptrace: Use ARM64_SME to guard the SME register enumerations
  arm64/mm: add pud_user_exec() check in pud_user_accessible_page()
  arm64/mm: fix incorrect file_map_count for invalid pmd

A clk, prepared and enabled in mtk_iommu_v1_hw_init(), is not released in
the error handling path of mtk_iommu_v1_probe().

Add the corresponding clk_disable_unprepare(), as already done in the
remove function.

Fixes: b17336c5

 ("iommu/mediatek: add support for mtk iommu generation one HW")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/593e7b7d97c6e064b29716b091a9d4fd122241fb.1671473163.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Joerg Roedel <jroedel@suse.de>