Only used internally in the FPU core code.

While at it, convert to the percpu accessors which verify preemption is
disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.686806639@linutronix.de

No point in being in global headers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.628516182@linutronix.de

Nothing outside the core code requires them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.572439164@linutronix.de

Nothing outside the core code needs these.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.513368075@linutronix.de

It's only required in the xstate init code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.455836597@linutronix.de

Further disintegration of internal.h:

Move the CPU feature tests to a core header and remove the unused one.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.401510559@linutronix.de

internal.h is a kitchen sink which needs to get out of the way to prepare
for the upcoming changes.

Move the context switch and exit to user inlines into a separate header,
which is all that code needs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.349132461@linutronix.de

No need to keep it around.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.296435736@linutronix.de

Prepare for replacing the KVM copy xstate to user function by extending
copy_xstate_to_uabi_buf() with a pkru argument which allows the caller to
hand in the pkru value, which is required for KVM because the guest PKRU is
not accessible via current. Fixup all callsites accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.191902137@linutronix.de

Copying a user space buffer to the memory buffer is already available in
the FPU core. The copy mechanism in KVM lacks sanity checks and needs to
use cpuid() to lookup the offset of each component, while the FPU core has
this information cached.

Make the FPU core variant accessible for KVM and replace the home brewed
mechanism.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.134065207@linutronix.de

Swapping the host/guest FPU is directly fiddling with FPU internals which
requires 5 exports. The upcoming support of dynamically enabled states
would even need more.

Implement a swap function in the FPU core code and export that instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.076072399@linutronix.de

No point to keep them around after boot.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.017919252@linutronix.de

These loops evaluating xfeature bits are really hard to read. Create an
iterator and use for_each_set_bit_from() inside which already does the right
thing.

No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.958107505@linutronix.de

No point in having this duplicated all over the place with needlessly
different defines.

Provide a proper initialization function which initializes user buffers
properly and make KVM use it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.897664678@linutronix.de

There is no reason why kernel and IO worker threads need a full clone of
the parent's FPU state. Both are kernel threads which are not supposed to
use FPU. So copying a large state or doing XSAVE() is pointless. Just clean
out the minimally required state for those tasks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.839822981@linutronix.de

There is no reason to clone FPU in arch_dup_task_struct(). Quite the
contrary - it prevents optimizations. Move it to copy_thread().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.780714235@linutronix.de

Zeroing the forked task's FPU registers buffer to avoid leaking init
optimized stale data into the clone is a pointless exercise for the case
where the current task has TIF_NEED_FPU_LOAD set. In that case, the FPU
registers state is copied from current's FPU register buffer which can
contain stale init optimized data as well.

The alledged information leak is non-existant because this stale init
optimized data is used nowhere and cannot leak anywhere.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.722854569@linutronix.de

Defensive programming is useful, but this on_boot_cpu debug is really
silly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.665080855@linutronix.de

These interfaces are really only valid for features which are independently
managed and not part of the task context state for various reasons.

Tighten the checks and adjust the misleading comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.608492174@linutronix.de

PKRU code does not need anything from FPU headers. Include cpufeature.h
instead and fixup the resulting fallout in perf.

This is a preparation for FPU changes in order to prevent recursive include
hell.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.551522694@linutronix.de

copy_fpstate_to_sigframe() does not have a slow path anymore. Neither does
the !ia32 restore in __fpu_restore_sig().

Update the comments accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.493570236@linutronix.de

Unused since the FPU switching rework.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.433135710@linutronix.de

Resolve the conflict between these commits:

   x86/fpu:      1193f408 ("x86/fpu/signal: Change return type of __fpu_restore_sig() to boolean")

   x86/urgent:   d298b035 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
                 b2381acd ("x86/fpu: Mask out the invalid MXCSR bits properly")

 Conflicts:
        arch/x86/kernel/fpu/signal.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This is a fix for the fix (yeah, /facepalm).

The correct mask to use is not the negation of the MXCSR_MASK but the
actual mask which contains the supported bits in the MXCSR register.

Reported and debugged by Ville Syrjälä <ville.syrjala@linux.intel.com>

Fixes: d298b035 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ser Olmy <ser.olmy@protonmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/YWgYIYXLriayyezv@intel.com

This Kconfig option was added initially so that memory encryption is
enabled by default on machines which support it.

However, devices which have DMA masks that are less than the bit
position of the encryption bit, aka C-bit, require the use of an IOMMU
or the use of SWIOTLB.

If the IOMMU is disabled or in passthrough mode, the kernel would switch
to SWIOTLB bounce-buffering for those transfers.

In order to avoid that,

  2cc13bb4 ("iommu: Disable passthrough mode when SME is active")

disables the default IOMMU passthrough mode so that devices for which the
default 256K DMA is insufficient, can use the IOMMU instead.

However 2, there are cases where the IOMMU is disabled in the BIOS, etc.
(think the usual hardware folk "oops, I dropped the ball there" cases) or a
driver doesn't properly use the DMA APIs or a device has a firmware or
hardware bug, e.g.:

  ea68573d ("drm/amdgpu: Fail to load on RAVEN if SME is active")

However 3, in the above GPU use case, there are APIs like Vulkan and
some OpenGL/OpenCL extensions which are under the assumption that
user-allocated memory can be passed in to the kernel driver and both the
GPU and CPU can do coherent and concurrent access to the same memory.
That cannot work with SWIOTLB bounce buffers, of course.

So, in order for those devices to function, drop the "default y" for the
SME by default active option so that users who want to have SME enabled,
will need to either enable it in their config or use "mem_encrypt=on" on
the kernel command line.

 [ tlendacky: Generalize commit message. ]

Fixes: 7744ccdb ("x86/mm: Add Secure Memory Encryption (SME) support")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/8bbacd0e-4580-3194-19d2-a0ecad7df09c@molgen.mpg.de

Pull powerpc fixes from Michael Ellerman:
 "A bit of a big batch, partly because I didn't send any last week, and
  also just because the BPF fixes happened to land this week.

  Summary:

   - Fix a regression hit by the IPR SCSI driver, introduced by the
     recent addition of MSI domains on pseries.

   - A big series including 8 BPF fixes, some with potential security
     impact and the rest various code generation issues.

   - Fix our program check assembler entry path, which was accidentally
     jumping into a gas macro and generating strange stack frames, which
     could confuse find_bug().

   - A couple of fixes, and related changes, to fix corner cases in our
     machine check handling.

   - Fix our DMA IOMMU ops, which were not always returning the optimal
     DMA mask, leading to at least one device falling back to 32-bit DMA
     when it shouldn't.

   - A fix for KUAP handling on 32-bit Book3S.

   - Fix crashes seen when kdumping on some pseries systems.

  Thanks to Naveen N. Rao, Nicholas Piggin, Alexey Kardashevskiy, Cédric
  Le Goater, Christophe Leroy, Mahesh Salgaonkar, Abdul Haleem,
  Christoph Hellwig, Johan Almbladh, Stan Johnson"

* tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init
  powerpc/32s: Fix kuap_kernel_restore()
  powerpc/pseries/msi: Add an empty irq_write_msi_msg() handler
  powerpc/64s: Fix unrecoverable MCE calling async handler from NMI
  powerpc/64/interrupt: Reconcile soft-mask state in NMI and fix false BUG
  powerpc/64: warn if local irqs are enabled in NMI or hardirq context
  powerpc/traps: do not enable irqs in _exception
  powerpc/64s: fix program check interrupt emergency stack path
  powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000
  powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END
  powerpc/bpf ppc32: Fix JMP32_JSET_K
  powerpc/bpf ppc32: Fix ALU32 BPF_ARSH operation
  powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC
  powerpc/security: Add a helper to query stf_barrier type
  powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
  powerpc/bpf: Fix BPF_MOD when imm == 1
  powerpc/bpf: Validate branch ranges
  powerpc/lib: Add helper to check if offset is within conditional branch range
  powerpc/iommu: Report the correct most efficient DMA mask for PCI devices

Pull objtool fixes from Borislav Petkov:

 - Remove an extra section.len member in favour of section.sh_size

 - Align .altinstructions section creation with the kernel's by creating
   them with entry size of 0

 - Fix objtool to convert a reloc symbol to a section offset and not to
   not warn about not knowing how

* tag 'objtool_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Remove redundant 'len' field from struct section
  objtool: Make .altinstructions section entry size consistent
  objtool: Remove reloc symbol type checks in get_alt_entry()

Pull x86 fixes from Borislav Petkov:

 - A FPU fix to properly handle invalid MXCSR values: 32-bit masks them
   out due to historical reasons and 64-bit kernels reject them

 - A fix to clear X86_FEATURE_SMAP when support for is not
   config-enabled

 - Three fixes correcting misspelled Kconfig symbols used in code

 - Two resctrl object cleanup fixes

 - Yet another attempt at fixing the neverending saga of botched x86
   timers, this time because some incredibly smart hardware decides to
   turn off the HPET timer in a low power state - who cares if the OS is
   relying on it...

 - Check the full return value range of an SEV VMGEXIT call to determine
   whether it returned an error

* tag 'x86_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Restore the masking out of reserved MXCSR bits
  x86/Kconfig: Correct reference to MWINCHIP3D
  x86/platform/olpc: Correct ifdef symbol to intended CONFIG_OLPC_XO15_SCI
  x86/entry: Clear X86_FEATURE_SMAP when CONFIG_X86_SMAP=n
  x86/entry: Correct reference to intended CONFIG_64_BIT
  x86/resctrl: Fix kfree() of the wrong type in domain_add_cpu()
  x86/resctrl: Free the ctrlval arrays when domain_setup_mon_state() fails
  x86/hpet: Use another crystalball to evaluate HPET usability
  x86/sev: Return an error on a returned non-zero SW_EXITINFO1[31:0]

Pull i2c fixes from Wolfram Sang:
 "Three driver bugfixes and one leak fix for the core"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mlxcpld: Modify register setting for 400KHz frequency
  i2c: mlxcpld: Fix criteria for frequency setting
  i2c: mediatek: Add OFFSET_EXT_CONF setting back
  i2c: acpi: fix resource leak in reconfiguration device addition

Pull SCSI fixes from James Bottomley:
 "Five fixes, all in drivers.

  The big change is the UFS task management rework, with lpfc next and
  the rest being fairly minor and obvious fixes"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: iscsi: Fix iscsi_task use after free
  scsi: lpfc: Fix memory overwrite during FC-GS I/O abort handling
  scsi: elx: efct: Delete stray unlock statement
  scsi: ufs: core: Fix task management completion
  scsi: acornscsi: Remove scsi_cmd_to_tag() reference

Pull block fixes from Jens Axboe:
 "Two small fixes for this release:

   - Add missing QUEUE_FLAG_HCTX_ACTIVE in the debugfs handling
     (Johannes)

   - Fix double free / UAF issue in __alloc_disk_node (Tetsuo)"

* tag 'block-5.15-2021-10-09' of git://git.kernel.dk/linux-block:
  block: decode QUEUE_FLAG_HCTX_ACTIVE in debugfs output
  block: genhd: fix double kfree() in __alloc_disk_node()

Pull ksmbd fixes from Steve French:
 "Six fixes for the ksmbd kernel server, including two additional
  overflow checks, a fix for oops, and some cleanup (e.g. remove dead
  code for less secure dialects that has been removed)"

* tag '5.15-rc4-ksmbd-fixes' of git://git.samba.org/ksmbd:
  ksmbd: fix oops from fuse driver
  ksmbd: fix version mismatch with out of tree
  ksmbd: use buf_data_size instead of recalculation in smb3_decrypt_req()
  ksmbd: remove the leftover of smb2.0 dialect support
  ksmbd: check strictly data area in ksmbd_smb2_check_message()
  ksmbd: add the check to vaildate if stream protocol length exceeds maximum value

Pull RISC-V fixes from Palmer Dabbelt:

 - A pair of fixes (along with the necessory cleanup) to our VDSO, to
   avoid a locking during OOM and to prevent the text from overflowing
   into the data page

 - A fix to checksyscalls to teach it about our rv32 UABI

 - A fix to add clone3() to the rv32 UABI, which was pointed out by
   checksyscalls

 - A fix to properly flush the icache on the local CPU in addition to
   the remote CPUs

* tag 'riscv-for-linus-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  checksyscalls: Unconditionally ignore fstat{,at}64
  riscv: Flush current cpu icache before other cpus
  RISC-V: Include clone3() on rv32
  riscv/vdso: make arch_setup_additional_pages wait for mmap_sem for write killable
  riscv/vdso: Move vdso data page up front
  riscv/vdso: Refactor asm/vdso.h

Pull s390 fixes from Vasily Gorbik:

 - Fix potential memory leak on a error path in eBPF

 - Fix handling of zpci device on reserve

* tag 's390-5.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: fix zpci_zdev_put() on reserve
  bpf, s390: Fix potential memory leak about jit_data

Pull xtensa fixes from Max Filippov:

 - fix build/boot issues caused by CONFIG_OF vs CONFIC_USE_OF usage

 - fix reset handler for xtfpga boards

* tag 'xtensa-20211008' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: xtfpga: Try software restart before simulating CPU reset
  xtensa: xtfpga: use CONFIG_USE_OF instead of CONFIG_OF
  xtensa: call irqchip_init only when CONFIG_USE_OF is selected
  xtensa: use CONFIG_USE_OF instead of CONFIG_OF

Pull xen fixes from Juergen Gross:

 - fix two minor issues in the Xen privcmd driver plus a cleanup patch
   for that driver

 - fix multiple issues related to running as PVH guest and some related
   earlyprintk fixes for other Xen guest types

 - fix an issue introduced in 5.15 the Xen balloon driver

* tag 'for-linus-5.15b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: fix cancelled balloon action
  xen/x86: adjust data placement
  x86/PVH: adjust function/data placement
  xen/x86: hook up xen_banner() also for PVH
  xen/x86: generalize preferred console model from PV to PVH Dom0
  xen/x86: make "earlyprintk=xen" work for HVM/PVH DomU
  xen/x86: allow "earlyprintk=xen" to work for PV Dom0
  xen/x86: make "earlyprintk=xen" work better for PVH Dom0
  xen/x86: allow PVH Dom0 without XEN_PV=y
  xen/x86: prevent PVH type from getting clobbered
  xen/privcmd: drop "pages" parameter from xen_remap_pfn()
  xen/privcmd: fix error handling in mmap-resource processing
  xen/privcmd: replace kcalloc() by kvcalloc() when allocating empty pages

Merge tag 'asm-generic-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic fixes from Arnd Bergmann:
 "There is one build fix for Arm platforms that ended up impacting most
  architectures because of the way the drivers/firmware Kconfig file is
  wired up:

  The CONFIG_QCOM_SCM dependency have caused a number of randconfig
  regressions over time, and some still remain in v5.15-rc4. The fix we
  agreed on in the end is to make this symbol selected by any driver
  using it, and then building it even for non-Arm platforms with
  CONFIG_COMPILE_TEST.

  To make this work on all architectures, the drivers/firmware/Kconfig
  file needs to be included for all architectures to make the symbol
  itself visible.

  In a separate discussion, we found that a sound driver patch that is
  pending for v5.16 needs the same change to include this Kconfig file,
  so the easiest solution seems to have my Kconfig rework included in
  v5.15.

  Finally, the branch also includes a small unrelated build fix for
  NOMMU architectures"

Link: https://lore.kernel.org/all/20210928153508.101208f8@canb.auug.org.au/
Link: https://lore.kernel.org/all/20210928075216.4193128-1-arnd@kernel.org/
Link: https://lore.kernel.org/all/20211007151010.333516-1-arnd@kernel.org/

* tag 'asm-generic-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic/io.h: give stub iounmap() on !MMU same prototype as elsewhere
  qcom_scm: hide Kconfig symbol
  firmware: include drivers/firmware/Kconfig unconditionally

Pull ACPI fix from Rafael Wysocki:
 "Fix a recent ACPI-related regression in the PCI subsystem that
  introduced a NULL pointer dereference possible to trigger from
  user space via sysfs on some systems"

* tag 'acpi-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI: ACPI: Check parent pointer in acpi_pci_find_companion()

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.15-rc5 that resolve a number of
  reported issues:

   - gadget driver fixes

   - xhci build warning fixes

   - build configuration fix

   - cdc-acm tty handling fixes

   - cdc-wdm fix

   - typec fixes

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

* tag 'usb-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix break reporting
  USB: cdc-acm: fix racy tty buffer accesses
  usb: gadget: f_uac2: fixed EP-IN wMaxPacketSize
  usb: cdc-wdm: Fix check for WWAN
  usb: chipidea: ci_hdrc_imx: Also search for 'phys' phandle
  usb: typec: tcpm: handle SRC_STARTUP state if cc changes
  usb: typec: tcpci: don't handle vSafe0V event if it's not enabled
  usb: typec: tipd: Remove dependency on "connector" child fwnode
  Partially revert "usb: Kconfig: using select for USB_COMMON dependency"
  usb: dwc3: gadget: Revert "set gadgets parent to the right controller"
  usb: xhci: tegra: mark PM functions as __maybe_unused