Commit Graph

11093 Commits (4cb92fa763823d813d22b45b7f18fcf6e85a72ad)

Author SHA1 Message Date
Benjamin Block 4cb92fa763 s390/pci: Fix cyclic dead-lock in zpci_zdev_put() and zpci_scan_devices()
When triggering PCI device recovery by writing into the SysFS attribute
`recover` of a Physical Function with existing child SR-IOV Virtual
Functions, lockdep is reporting a possible deadlock between three
threads:

         Thread (A)             Thread (B)             Thread (C)
             |                      |                      |
      recover_store()      zpci_scan_devices()    zpci_scan_devices()
lock(pci_rescan_remove_lock)        |                      |
             |                      |                      |
             |                      |            zpci_bus_scan_busses()
             |                      |             lock(zbus_list_lock)
             |              zpci_add_device()              |
             |          lock(zpci_add_remove_lock)         |
             |                      |                      ┴
             |                      |             zpci_bus_scan_bus()
             |                      |         lock(pci_rescan_remove_lock)
             ┴                      |
      zpci_zdev_put()               |
 lock(zpci_add_remove_lock)         |
                                    ┴
                              zpci_bus_get()
                           lock(zbus_list_lock)

In zpci_bus_scan_busses() the `zbus_list_lock` is taken for the whole
duration of the function, which also includes taking
`pci_rescan_remove_lock`, among other things. But `zbus_list_lock` only
really needs to protect the modification of the global registration
`zbus_list`, it can be dropped while the functions within the list
iteration run; this way we break the cycle above.

Break up zpci_bus_scan_busses() into an "iterator" zpci_bus_get_next()
that iterates over `zbus_list` element by element, and acquires and
releases `zbus_list_lock` as necessary, but never keep holding it.
References to `zpci_bus` objects are also acquired and released.

The reference counting on `zpci_bus` objects is also changed so that all
put() and get() operations are done under the protection of
`zbus_list_lock`, and if the operation results in a modification of
`zpci_bus_list`, this modification is done in the same critical section
(apart the very first initialization). This way objects are never seen
on the list that are about to be released and/or half-initialized.

Fixes: 14c87ba812 ("s390/pci: separate zbus registration from scanning")
Suggested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-14 11:03:58 +01:00
Sven Schnelle b1aa01d312 s390/ipl: Clear SBP flag when bootprog is set
With z16 a new flag 'search boot program' was introduced for
list-directed IPL (SCSI, NVMe, ECKD DASD). If this flag is set,
e.g. via selecting the "Automatic" value for the "Boot program
selector" control on an HMC load panel, it is copied to the reipl
structure from the initial ipl structure. When a user now sets a
boot prog via sysfs, the flag is not cleared and the bootloader
will again automatically select the boot program, ignoring user
configuration.

To avoid that, clear the SBP flag when a bootprog sysfs file is
written.

Cc: stable@vger.kernel.org
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-14 11:03:57 +01:00
Heiko Carstens 70075e3d0c s390/bug: Add missing alignment
All objects are supposed to have a minimal alignment of two, since a
couple of instructions only work with even addresses. Add the missing
align statement for the file string.

Fixes: 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-08 15:42:41 +01:00
Heiko Carstens 1a82d430c5 s390/bug: Add missing CONFIG_BUG ifdef again
Fallback to generic BUG implementation in case CONFIG_BUG is disabled.
This restores the old behaviour before 'cond_str' support was added.

It probably doesn't matter, since nobody should disable CONFIG_BUG, but at
least this is consistent to before.

Fixes: 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-08 15:42:36 +01:00
Claudio Imbrenda 2f393c228c KVM: s390: Fix gmap_helper_zap_one_page() again
A few checks were missing in gmap_helper_zap_one_page(), which can lead
to memory corruption in the guest under specific circumstances.

Add the missing checks.

Fixes: 5deafa27d9 ("KVM: s390: Fix to clear PTE when discarding a swapped page")
Cc: stable@vger.kernel.org
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-08 13:06:14 +01:00
Tobias Schumacher f770950a47 s390/pci: Migrate s390 IRQ logic to IRQ domain API
s390 is one of the last architectures using the legacy API for setup and
teardown of PCI MSI IRQs. Migrate the s390 IRQ allocation and teardown
to the MSI parent domain API. For details, see:

https://lore.kernel.org/lkml/20221111120501.026511281@linutronix.de

In detail, create an MSI parent domain for each PCI domain. When a PCI
device sets up MSI or MSI-X IRQs, the library creates a per-device IRQ
domain for this device, which is used by the device for allocating and
freeing IRQs.

The per-device domain delegates this allocation and freeing to the
parent-domain. In the end, the corresponding callbacks of the parent
domain are responsible for allocating and freeing the IRQs.

The allocation is split into two parts:
- zpci_msi_prepare() is called once for each device and allocates the
  required resources. On s390, each PCI function has its own airq
  vector and a summary bit, which must be configured once per function.
  This is done in prepare().
- zpci_msi_alloc() can be called multiple times for allocating one or
  more MSI/MSI-X IRQs. This creates a mapping between the virtual IRQ
  number in the kernel and the hardware IRQ number.

Freeing is split into two counterparts:
- zpci_msi_free() reverts the effects of zpci_msi_alloc() and
- zpci_msi_teardown() reverts the effects of zpci_msi_prepare(). This is
  called once when all IRQs are freed before a device is removed.

Since the parent domain in the end allocates the IRQs, the hwirq
encoding must be unambiguous for all IRQs of all devices. This is
achieved by encoding the hwirq using the devfn and the MSI index.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Tobias Schumacher <ts@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:23 +01:00
Heiko Carstens eb9780a1a3 s390: Select POSIX_CPU_TIMERS_TASK_WORK
After support for VIRT_XFER_TO_GUEST_WORK is available for s390 it is
possible to also select HAVE_POSIX_CPU_TIMERS_TASK_WORK. See [1] for the
reasons why it makes sense, also for architectures which do not support
PREEMPT_RT.

[1] https://lore.kernel.org/all/20200716201923.228696399@linutronix.de

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:19 +01:00
Vasily Gorbik 8543ecc0e0 s390: Unmap early KASAN shadow on memory offlining
Teach the memory hotplug path to tear down KASAN shadow that
was mapped during early boot when a memory block is offlined.

Track for each sclp_mem whether its range was covered by the early
KASAN shadow via an early_shadow_mapped flag. When such a block is
deconfigured and removed via sclp_config_mem_store(), compute the
corresponding shadow range and call vmemmap_free() to unmap the
boot mapped shadow, then clear the flag.

Using vmemmap_free() for the early shadow is safe despite the use
of large mappings in the boot-time KASAN setup. The initial shadow
is mapped with 1M and 2G pages, where possible. The minimum hotplug
memory block size is 128M and always aligned (the identity mapping
is at least 2G aligned), which corresponds to a 16M chunk of at
least 1M aligned shadow. PMD-mapped 1M shadow pages therefore
never need splitting, and PUD-mapped 2G shadow pages can now be
split following the preceding changes.

Relax the modify_pagetable() sanity check in vmem so that, with
KASAN enabled, it may also operate on the KASAN shadow region in
addition to the 1:1 mapping and vmemmap area. This allows the KASAN
shadow unmapping to reuse the common vmem helpers.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:19 +01:00
Vasily Gorbik 6a35d02fec s390/vmem: Support 2G page splitting for KASAN shadow freeing
Export split_pud_page() so it can be used from the vmem code and teach
modify_pud_table() to split PUD-sized mappings when only a subrange
needs to be removed.

If the range to be removed covers a full PUD-sized mapping, keep the
existing behavior: clear the PUD entry and free the backing large page
(for non-direct mappings). Otherwise, split the PUD-mapped page into
PMD mappings and let the walker handle the smaller ranges.

This is needed for KASAN early shadow removal support: memory hotplug
freeing the KASAN early shadow is the only expected caller that will
try to free 2G PUD-mapped regions of non-direct mappings.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:19 +01:00
Vasily Gorbik 1442bb87b8 s390/boot: Use entire page for PTEs
Make boot_pte_alloc() always allocate a full PAGE_SIZE page for
PTE tables, instead of carving two 2K PTE tables out of a single
4K page, similar to commit daa8af80d2 ("s390/mm: Allocate page
table with PAGE_SIZE granularity").

This mirrors the change in the vmem code and ensures that boot page
tables backing the early KASAN shadow can later be fully freed by
the vmem page-table teardown helpers (e.g. when unmapping early
KASAN shadow on memory hotplug).

The leftover-based allocation was originally added to reduce physmem
allocator fragmentation when EDAT was disabled. On current hardware
EDAT1 is available on all production systems, so the complexity is no
longer justified and gets in the way of freeing the shadow mappings.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:19 +01:00
Linus Torvalds 51d90a15fe ARM:
- Support for userspace handling of synchronous external aborts (SEAs),
   allowing the VMM to potentially handle the abort in a non-fatal
   manner.
 
 - Large rework of the VGIC's list register handling with the goal of
   supporting more active/pending IRQs than available list registers in
   hardware. In addition, the VGIC now supports EOImode==1 style
   deactivations for IRQs which may occur on a separate vCPU than the
   one that acked the IRQ.
 
 - Support for FEAT_XNX (user / privileged execute permissions) and
   FEAT_HAF (hardware update to the Access Flag) in the software page
   table walkers and shadow MMU.
 
 - Allow page table destruction to reschedule, fixing long need_resched
   latencies observed when destroying a large VM.
 
 - Minor fixes to KVM and selftests
 
 Loongarch:
 
 - Get VM PMU capability from HW GCFG register.
 
 - Add AVEC basic support.
 
 - Use 64-bit register definition for EIOINTC.
 
 - Add KVM timer test cases for tools/selftests.
 
 RISC/V:
 
 - SBI message passing (MPXY) support for KVM guest
 
 - Give a new, more specific error subcode for the case when in-kernel
   AIA virtualization fails to allocate IMSIC VS-file
 
 - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
   in small chunks
 
 - Fix guest page fault within HLV* instructions
 
 - Flush VS-stage TLB after VCPU migration for Andes cores
 
 s390:
 
 - Always allocate ESCA (Extended System Control Area), instead of
   starting with the basic SCA and converting to ESCA with the
   addition of the 65th vCPU.  The price is increased number of
   exits (and worse performance) on z10 and earlier processor;
   ESCA was introduced by z114/z196 in 2010.
 
 - VIRT_XFER_TO_GUEST_WORK support
 
 - Operation exception forwarding support
 
 - Cleanups
 
 x86:
 
 - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO SPTE
   caching is disabled, as there can't be any relevant SPTEs to zap.
 
 - Relocate a misplaced export.
 
 - Fix an async #PF bug where KVM would clear the completion queue when the
   guest transitioned in and out of paging mode, e.g. when handling an SMI and
   then returning to paged mode via RSM.
 
 - Leave KVM's user-return notifier registered even when disabling
   virtualization, as long as kvm.ko is loaded.  On reboot/shutdown, keeping
   the notifier registered is ok; the kernel does not use the MSRs and the
   callback will run cleanly and restore host MSRs if the CPU manages to
   return to userspace before the system goes down.
 
 - Use the checked version of {get,put}_user().
 
 - Fix a long-lurking bug where KVM's lack of catch-up logic for periodic APIC
   timers can result in a hard lockup in the host.
 
 - Revert the periodic kvmclock sync logic now that KVM doesn't use a
   clocksource that's subject to NTP corrections.
 
 - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the latter
   behind CONFIG_CPU_MITIGATIONS.
 
 - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast path;
   the only reason they were handled in the fast path was to paper of a bug
   in the core #MC code, and that has long since been fixed.
 
 - Add emulator support for AVX MOV instructions, to play nice with emulated
   devices whose guest drivers like to access PCI BARs with large multi-byte
   instructions.
 
 x86 (AMD):
 
 - Fix a few missing "VMCB dirty" bugs.
 
 - Fix the worst of KVM's lack of EFER.LMSLE emulation.
 
 - Add AVIC support for addressing 4k vCPUs in x2AVIC mode.
 
 - Fix incorrect handling of selective CR0 writes when checking intercepts
   during emulation of L2 instructions.
 
 - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32] on
   VMRUN and #VMEXIT.
 
 - Fix a bug where KVM corrupt the guest code stream when re-injecting a soft
   interrupt if the guest patched the underlying code after the VM-Exit, e.g.
   when Linux patches code with a temporary INT3.
 
 - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits to
   userspace, and extend KVM "support" to all policy bits that don't require
   any actual support from KVM.
 
 x86 (Intel):
 
 - Use the root role from kvm_mmu_page to construct EPTPs instead of the
   current vCPU state, partly as worthwhile cleanup, but mostly to pave the
   way for tracking per-root TLB flushes, and elide EPT flushes on pCPU
   migration if the root is clean from a previous flush.
 
 - Add a few missing nested consistency checks.
 
 - Rip out support for doing "early" consistency checks via hardware as the
   functionality hasn't been used in years and is no longer useful in general;
   replace it with an off-by-default module param to WARN if hardware fails
   a check that KVM does not perform.
 
 - Fix a currently-benign bug where KVM would drop the guest's SPEC_CTRL[63:32]
   on VM-Enter.
 
 - Misc cleanups.
 
 - Overhaul the TDX code to address systemic races where KVM (acting on behalf
   of userspace) could inadvertantly trigger lock contention in the TDX-Module;
   KVM was either working around these in weird, ugly ways, or was simply
   oblivious to them (though even Yan's devilish selftests could only break
   individual VMs, not the host kernel)
 
 - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a TDX vCPU,
   if creating said vCPU failed partway through.
 
 - Fix a few sparse warnings (bad annotation, 0 != NULL).
 
 - Use struct_size() to simplify copying TDX capabilities to userspace.
 
 - Fix a bug where TDX would effectively corrupt user-return MSR values if the
   TDX Module rejects VP.ENTER and thus doesn't clobber host MSRs as expected.
 
 Selftests:
 
 - Fix a math goof in mmu_stress_test when running on a single-CPU system/VM.
 
 - Forcefully override ARCH from x86_64 to x86 to play nice with specifying
   ARCH=x86_64 on the command line.
 
 - Extend a bunch of nested VMX to validate nested SVM as well.
 
 - Add support for LA57 in the core VM_MODE_xxx macro, and add a test to
   verify KVM can save/restore nested VMX state when L1 is using 5-level
   paging, but L2 is not.
 
 - Clean up the guest paging code in anticipation of sharing the core logic for
   nested EPT and nested NPT.
 
 guest_memfd:
 
 - Add NUMA mempolicy support for guest_memfd, and clean up a variety of
   rough edges in guest_memfd along the way.
 
 - Define a CLASS to automatically handle get+put when grabbing a guest_memfd
   from a memslot to make it harder to leak references.
 
 - Enhance KVM selftests to make it easer to develop and debug selftests like
   those added for guest_memfd NUMA support, e.g. where test and/or KVM bugs
   often result in hard-to-debug SIGBUS errors.
 
 - Misc cleanups.
 
 Generic:
 
 - Use the recently-added WQ_PERCPU when creating the per-CPU workqueue for
   irqfd cleanup.
 
 - Fix a goof in the dirty ring documentation.
 
 - Fix choice of target for directed yield across different calls to
   kvm_vcpu_on_spin(); the function was always starting from the first
   vCPU instead of continuing the round-robin search.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - Support for userspace handling of synchronous external aborts
     (SEAs), allowing the VMM to potentially handle the abort in a
     non-fatal manner

   - Large rework of the VGIC's list register handling with the goal of
     supporting more active/pending IRQs than available list registers
     in hardware. In addition, the VGIC now supports EOImode==1 style
     deactivations for IRQs which may occur on a separate vCPU than the
     one that acked the IRQ

   - Support for FEAT_XNX (user / privileged execute permissions) and
     FEAT_HAF (hardware update to the Access Flag) in the software page
     table walkers and shadow MMU

   - Allow page table destruction to reschedule, fixing long
     need_resched latencies observed when destroying a large VM

   - Minor fixes to KVM and selftests

  Loongarch:

   - Get VM PMU capability from HW GCFG register

   - Add AVEC basic support

   - Use 64-bit register definition for EIOINTC

   - Add KVM timer test cases for tools/selftests

  RISC/V:

   - SBI message passing (MPXY) support for KVM guest

   - Give a new, more specific error subcode for the case when in-kernel
     AIA virtualization fails to allocate IMSIC VS-file

   - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
     in small chunks

   - Fix guest page fault within HLV* instructions

   - Flush VS-stage TLB after VCPU migration for Andes cores

  s390:

   - Always allocate ESCA (Extended System Control Area), instead of
     starting with the basic SCA and converting to ESCA with the
     addition of the 65th vCPU. The price is increased number of exits
     (and worse performance) on z10 and earlier processor; ESCA was
     introduced by z114/z196 in 2010

   - VIRT_XFER_TO_GUEST_WORK support

   - Operation exception forwarding support

   - Cleanups

  x86:

   - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO
     SPTE caching is disabled, as there can't be any relevant SPTEs to
     zap

   - Relocate a misplaced export

   - Fix an async #PF bug where KVM would clear the completion queue
     when the guest transitioned in and out of paging mode, e.g. when
     handling an SMI and then returning to paged mode via RSM

   - Leave KVM's user-return notifier registered even when disabling
     virtualization, as long as kvm.ko is loaded. On reboot/shutdown,
     keeping the notifier registered is ok; the kernel does not use the
     MSRs and the callback will run cleanly and restore host MSRs if the
     CPU manages to return to userspace before the system goes down

   - Use the checked version of {get,put}_user()

   - Fix a long-lurking bug where KVM's lack of catch-up logic for
     periodic APIC timers can result in a hard lockup in the host

   - Revert the periodic kvmclock sync logic now that KVM doesn't use a
     clocksource that's subject to NTP corrections

   - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the
     latter behind CONFIG_CPU_MITIGATIONS

   - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast
     path; the only reason they were handled in the fast path was to
     paper of a bug in the core #MC code, and that has long since been
     fixed

   - Add emulator support for AVX MOV instructions, to play nice with
     emulated devices whose guest drivers like to access PCI BARs with
     large multi-byte instructions

  x86 (AMD):

   - Fix a few missing "VMCB dirty" bugs

   - Fix the worst of KVM's lack of EFER.LMSLE emulation

   - Add AVIC support for addressing 4k vCPUs in x2AVIC mode

   - Fix incorrect handling of selective CR0 writes when checking
     intercepts during emulation of L2 instructions

   - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32]
     on VMRUN and #VMEXIT

   - Fix a bug where KVM corrupt the guest code stream when re-injecting
     a soft interrupt if the guest patched the underlying code after the
     VM-Exit, e.g. when Linux patches code with a temporary INT3

   - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits
     to userspace, and extend KVM "support" to all policy bits that
     don't require any actual support from KVM

  x86 (Intel):

   - Use the root role from kvm_mmu_page to construct EPTPs instead of
     the current vCPU state, partly as worthwhile cleanup, but mostly to
     pave the way for tracking per-root TLB flushes, and elide EPT
     flushes on pCPU migration if the root is clean from a previous
     flush

   - Add a few missing nested consistency checks

   - Rip out support for doing "early" consistency checks via hardware
     as the functionality hasn't been used in years and is no longer
     useful in general; replace it with an off-by-default module param
     to WARN if hardware fails a check that KVM does not perform

   - Fix a currently-benign bug where KVM would drop the guest's
     SPEC_CTRL[63:32] on VM-Enter

   - Misc cleanups

   - Overhaul the TDX code to address systemic races where KVM (acting
     on behalf of userspace) could inadvertantly trigger lock contention
     in the TDX-Module; KVM was either working around these in weird,
     ugly ways, or was simply oblivious to them (though even Yan's
     devilish selftests could only break individual VMs, not the host
     kernel)

   - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a
     TDX vCPU, if creating said vCPU failed partway through

   - Fix a few sparse warnings (bad annotation, 0 != NULL)

   - Use struct_size() to simplify copying TDX capabilities to userspace

   - Fix a bug where TDX would effectively corrupt user-return MSR
     values if the TDX Module rejects VP.ENTER and thus doesn't clobber
     host MSRs as expected

  Selftests:

   - Fix a math goof in mmu_stress_test when running on a single-CPU
     system/VM

   - Forcefully override ARCH from x86_64 to x86 to play nice with
     specifying ARCH=x86_64 on the command line

   - Extend a bunch of nested VMX to validate nested SVM as well

   - Add support for LA57 in the core VM_MODE_xxx macro, and add a test
     to verify KVM can save/restore nested VMX state when L1 is using
     5-level paging, but L2 is not

   - Clean up the guest paging code in anticipation of sharing the core
     logic for nested EPT and nested NPT

  guest_memfd:

   - Add NUMA mempolicy support for guest_memfd, and clean up a variety
     of rough edges in guest_memfd along the way

   - Define a CLASS to automatically handle get+put when grabbing a
     guest_memfd from a memslot to make it harder to leak references

   - Enhance KVM selftests to make it easer to develop and debug
     selftests like those added for guest_memfd NUMA support, e.g. where
     test and/or KVM bugs often result in hard-to-debug SIGBUS errors

   - Misc cleanups

  Generic:

   - Use the recently-added WQ_PERCPU when creating the per-CPU
     workqueue for irqfd cleanup

   - Fix a goof in the dirty ring documentation

   - Fix choice of target for directed yield across different calls to
     kvm_vcpu_on_spin(); the function was always starting from the first
     vCPU instead of continuing the round-robin search"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits)
  KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
  KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
  KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}
  KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected"
  KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot()
  KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
  KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
  KVM: arm64: selftests: Add test for AT emulation
  KVM: arm64: nv: Expose hardware access flag management to NV guests
  KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW
  KVM: arm64: Implement HW access flag management in stage-1 SW PTW
  KVM: arm64: Propagate PTW errors up to AT emulation
  KVM: arm64: Add helper for swapping guest descriptor
  KVM: arm64: nv: Use pgtable definitions in stage-2 walk
  KVM: arm64: Handle endianness in read helper for emulated PTW
  KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW
  KVM: arm64: Call helper for reading descriptors directly
  KVM: arm64: nv: Advertise support for FEAT_XNX
  KVM: arm64: Teach ptdump about FEAT_XNX permissions
  KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
  ...
2025-12-05 17:01:20 -08:00
Linus Torvalds 7cd122b552 Some filesystems use a kinda-sorta controlled dentry refcount leak to pin
dentries of created objects in dcache (and undo it when removing those).
 Reference is grabbed and not released, but it's not actually _stored_
 anywhere.  That works, but it's hard to follow and verify; among other
 things, we have no way to tell _which_ of the increments is intended
 to be an unpaired one.  Worse, on removal we need to decide whether
 the reference had already been dropped, which can be non-trivial if
 that removal is on umount and we need to figure out if this dentry is
 pinned due to e.g. unlink() not done.  Usually that is handled by using
 kill_litter_super() as ->kill_sb(), but there are open-coded special
 cases of the same (consider e.g. /proc/self).
 
 Things get simpler if we introduce a new dentry flag (DCACHE_PERSISTENT)
 marking those "leaked" dentries.  Having it set claims responsibility
 for +1 in refcount.
 
 The end result this series is aiming for:
 
 * get these unbalanced dget() and dput() replaced with new primitives that
   would, in addition to adjusting refcount, set and clear persistency flag.
 * instead of having kill_litter_super() mess with removing the remaining
   "leaked" references (e.g. for all tmpfs files that hadn't been removed
   prior to umount), have the regular shrink_dcache_for_umount() strip
   DCACHE_PERSISTENT of all dentries, dropping the corresponding
   reference if it had been set.  After that kill_litter_super() becomes
   an equivalent of kill_anon_super().
 
 Doing that in a single step is not feasible - it would affect too many places
 in too many filesystems.  It has to be split into a series.
 
 This work has really started early in 2024; quite a few preliminary pieces
 have already gone into mainline.  This chunk is finally getting to the
 meat of that stuff - infrastructure and most of the conversions to it.
 
 Some pieces are still sitting in the local branches, but the bulk of
 that stuff is here.
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull persistent dentry infrastructure and conversion from Al Viro:
 "Some filesystems use a kinda-sorta controlled dentry refcount leak to
  pin dentries of created objects in dcache (and undo it when removing
  those). A reference is grabbed and not released, but it's not actually
  _stored_ anywhere.

  That works, but it's hard to follow and verify; among other things, we
  have no way to tell _which_ of the increments is intended to be an
  unpaired one. Worse, on removal we need to decide whether the
  reference had already been dropped, which can be non-trivial if that
  removal is on umount and we need to figure out if this dentry is
  pinned due to e.g. unlink() not done. Usually that is handled by using
  kill_litter_super() as ->kill_sb(), but there are open-coded special
  cases of the same (consider e.g. /proc/self).

  Things get simpler if we introduce a new dentry flag
  (DCACHE_PERSISTENT) marking those "leaked" dentries. Having it set
  claims responsibility for +1 in refcount.

  The end result this series is aiming for:

   - get these unbalanced dget() and dput() replaced with new primitives
     that would, in addition to adjusting refcount, set and clear
     persistency flag.

   - instead of having kill_litter_super() mess with removing the
     remaining "leaked" references (e.g. for all tmpfs files that hadn't
     been removed prior to umount), have the regular
     shrink_dcache_for_umount() strip DCACHE_PERSISTENT of all dentries,
     dropping the corresponding reference if it had been set. After that
     kill_litter_super() becomes an equivalent of kill_anon_super().

  Doing that in a single step is not feasible - it would affect too many
  places in too many filesystems. It has to be split into a series.

  This work has really started early in 2024; quite a few preliminary
  pieces have already gone into mainline. This chunk is finally getting
  to the meat of that stuff - infrastructure and most of the conversions
  to it.

  Some pieces are still sitting in the local branches, but the bulk of
  that stuff is here"

* tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  d_make_discardable(): warn if given a non-persistent dentry
  kill securityfs_recursive_remove()
  convert securityfs
  get rid of kill_litter_super()
  convert rust_binderfs
  convert nfsctl
  convert rpc_pipefs
  convert hypfs
  hypfs: swich hypfs_create_u64() to returning int
  hypfs: switch hypfs_create_str() to returning int
  hypfs: don't pin dentries twice
  convert gadgetfs
  gadgetfs: switch to simple_remove_by_name()
  convert functionfs
  functionfs: switch to simple_remove_by_name()
  functionfs: fix the open/removal races
  functionfs: need to cancel ->reset_work in ->kill_sb()
  functionfs: don't bother with ffs->ref in ffs_data_{opened,closed}()
  functionfs: don't abuse ffs_data_closed() on fs shutdown
  convert selinuxfs
  ...
2025-12-05 14:36:21 -08:00
Linus Torvalds 7203ca412f Significant patch series in this merge are as follows:
- The 10 patch series "__vmalloc()/kvmalloc() and no-block support" from
   Uladzislau Rezki reworks the vmalloc() code to support non-blocking
   allocations (GFP_ATOIC, GFP_NOWAIT).
 
 - The 2 patch series "ksm: fix exec/fork inheritance" from xu xin fixes
   a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not inherited
   across fork/exec.
 
 - The 4 patch series "mm/zswap: misc cleanup of code and documentations"
   from SeongJae Park does some light maintenance work on the zswap code.
 
 - The 5 patch series "mm/page_owner: add debugfs files 'show_handles'
   and 'show_stacks_handles'" from Mauricio Faria de Oliveira enhances the
   /sys/kernel/debug/page_owner debug feature.  It adds unique identifiers
   to differentiate the various stack traces so that userspace monitoring
   tools can better match stack traces over time.
 
 - The 2 patch series "mm/page_alloc: pcp->batch cleanups" from Joshua
   Hahn makes some minor alterations to the page allocator's per-cpu-pages
   feature.
 
 - The 2 patch series "Improve UFFDIO_MOVE scalability by removing
   anon_vma lock" from Lokesh Gidra addresses a scalability issue in
   userfaultfd's UFFDIO_MOVE operation.
 
 - The 2 patch series "kasan: cleanups for kasan_enabled() checks" from
   Sabyrzhan Tasbolatov performs some cleanup in the KASAN code.
 
 - The 2 patch series "drivers/base/node: fold node register and
   unregister functions" from Donet Tom cleans up the NUMA node handling
   code a little.
 
 - The 4 patch series "mm: some optimizations for prot numa" from Kefeng
   Wang provides some cleanups and small optimizations to the NUMA
   allocation hinting code.
 
 - The 5 patch series "mm/page_alloc: Batch callers of
   free_pcppages_bulk" from Joshua Hahn addresses long lock hold times at
   boot on large machines.  These were causing (harmless) softlockup
   warnings.
 
 - The 2 patch series "optimize the logic for handling dirty file folios
   during reclaim" from Baolin Wang removes some now-unnecessary work from
   page reclaim.
 
 - The 10 patch series "mm/damon: allow DAMOS auto-tuned for per-memcg
   per-node memory usage" from SeongJae Park enhances the DAMOS auto-tuning
   feature.
 
 - The 2 patch series "mm/damon: fixes for address alignment issues in
   DAMON_LRU_SORT and DAMON_RECLAIM" from Quanmin Yan fixes DAMON_LRU_SORT
   and DAMON_RECLAIM with certain userspace configuration.
 
 - The 15 patch series "expand mmap_prepare functionality, port more
   users" from Lorenzo Stoakes enhances the new(ish)
   file_operations.mmap_prepare() method and ports additional callsites
   from the old ->mmap() over to ->mmap_prepare().
 
 - The 8 patch series "Fix stale IOTLB entries for kernel address space"
   from Lu Baolu fixes a bug (and possible security issue on non-x86) in
   the IOMMU code.  In some situations the IOMMU could be left hanging onto
   a stale kernel pagetable entry.
 
 - The 4 patch series "mm/huge_memory: cleanup __split_unmapped_folio()"
   from Wei Yang cleans up and optimizes the folio splitting code.
 
 - The 5 patch series "mm, swap: misc cleanup and bugfix" from Kairui
   Song implements some cleanups and a minor fix in the swap discard code.
 
 - The 8 patch series "mm/damon: misc documentation fixups" from SeongJae
   Park does as advertised.
 
 - The 9 patch series "mm/damon: support pin-point targets removal" from
   SeongJae Park permits userspace to remove a specific monitoring target
   in the middle of the current targets list.
 
 - The 2 patch series "mm: MISC follow-up patches for linux/pgalloc.h"
   from Harry Yoo implements a couple of cleanups related to mm header file
   inclusion.
 
 - The 2 patch series "mm/swapfile.c: select swap devices of default
   priority round robin" from Baoquan He improves the selection of swap
   devices for NUMA machines.
 
 - The 3 patch series "mm: Convert memory block states (MEM_*) macros to
   enums" from Israel Batista changes the memory block labels from macros
   to enums so they will appear in kernel debug info.
 
 - The 3 patch series "ksm: perform a range-walk to jump over holes in
   break_ksm" from Pedro Demarchi Gomes addresses an inefficiency when KSM
   unmerges an address range.
 
 - The 22 patch series "mm/damon/tests: fix memory bugs in kunit tests"
   from SeongJae Park fixes leaks and unhandled malloc() failures in DAMON
   userspace unit tests.
 
 - The 2 patch series "some cleanups for pageout()" from Baolin Wang
   cleans up a couple of minor things in the page scanner's
   writeback-for-eviction code.
 
 - The 2 patch series "mm/hugetlb: refactor sysfs/sysctl interfaces" from
   Hui Zhu moves hugetlb's sysfs/sysctl handling code into a new file.
 
 - The 9 patch series "introduce VM_MAYBE_GUARD and make it sticky" from
   Lorenzo Stoakes makes the VMA guard regions available in /proc/pid/smaps
   and improves the mergeability of guarded VMAs.
 
 - The 2 patch series "mm: perform guard region install/remove under VMA
   lock" from Lorenzo Stoakes reduces mmap lock contention for callers
   performing VMA guard region operations.
 
 - The 2 patch series "vma_start_write_killable" from Matthew Wilcox
   starts work in permitting applications to be killed when they are
   waiting on a read_lock on the VMA lock.
 
 - The 11 patch series "mm/damon/tests: add more tests for online
   parameters commit" from SeongJae Park adds additional userspace testing
   of DAMON's "commit" feature.
 
 - The 9 patch series "mm/damon: misc cleanups" from SeongJae Park does
   that.
 
 - The 2 patch series "make VM_SOFTDIRTY a sticky VMA flag" from Lorenzo
   Stoakes addresses the possible loss of a VMA's VM_SOFTDIRTY flag when
   that VMA is merged with another.
 
 - The 16 patch series "mm: support device-private THP" from Balbir Singh
   introduces support for Transparent Huge Page (THP) migration in zone
   device-private memory.
 
 - The 3 patch series "Optimize folio split in memory failure" from Zi
   Yan optimizes folio split operations in the memory failure code.
 
 - The 2 patch series "mm/huge_memory: Define split_type and consolidate
   split support checks" from Wei Yang provides some more cleanups in the
   folio splitting code.
 
 - The 16 patch series "mm: remove is_swap_[pte, pmd]() + non-swap
   entries, introduce leaf entries" from Lorenzo Stoakes cleans up our
   handling of pagetable leaf entries by introducing the concept of
   'software leaf entries', of type softleaf_t.
 
 - The 4 patch series "reparent the THP split queue" from Muchun Song
   reparents the THP split queue to its parent memcg.  This is in
   preparation for addressing the long-standing "dying memcg" problem,
   wherein dead memcg's linger for too long, consuming memory resources.
 
 - The 3 patch series "unify PMD scan results and remove redundant
   cleanup" from Wei Yang does a little cleanup in the hugepage collapse
   code.
 
 - The 6 patch series "zram: introduce writeback bio batching" from
   Sergey Senozhatsky improves zram writeback efficiency by introducing
   batched bio writeback support.
 
 - The 4 patch series "memcg: cleanup the memcg stats interfaces" from
   Shakeel Butt cleans up our handling of the interrupt safety of some
   memcg stats.
 
 - The 4 patch series "make vmalloc gfp flags usage more apparent" from
   Vishal Moola cleans up vmalloc's handling of incoming GFP flags.
 
 - The 6 patch series "mm: Add soft-dirty and uffd-wp support for RISC-V"
   from Chunyan Zhang teches soft dirty and userfaultfd write protect
   tracking to use RISC-V's Svrsw60t59b extension.
 
 - The 5 patch series "mm: swap: small fixes and comment cleanups" from
   Youngjun Park fixes a small bug and cleans up some of the swap code.
 
 - The 4 patch series "initial work on making VMA flags a bitmap" from
   Lorenzo Stoakes starts work on converting the vma struct's flags to a
   bitmap, so we stop running out of them, especially on 32-bit.
 
 - The 2 patch series "mm/swapfile: fix and cleanup swap list iterations"
   from Youngjun Park addresses a possible bug in the swap discard code and
   cleans things up a little.
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Merge tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

  "__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki)
     Rework the vmalloc() code to support non-blocking allocations
     (GFP_ATOIC, GFP_NOWAIT)

  "ksm: fix exec/fork inheritance" (xu xin)
     Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not
     inherited across fork/exec

  "mm/zswap: misc cleanup of code and documentations" (SeongJae Park)
     Some light maintenance work on the zswap code

  "mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira)
     Enhance the /sys/kernel/debug/page_owner debug feature by adding
     unique identifiers to differentiate the various stack traces so
     that userspace monitoring tools can better match stack traces over
     time

  "mm/page_alloc: pcp->batch cleanups" (Joshua Hahn)
     Minor alterations to the page allocator's per-cpu-pages feature

  "Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra)
     Address a scalability issue in userfaultfd's UFFDIO_MOVE operation

  "kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov)

  "drivers/base/node: fold node register and unregister functions" (Donet Tom)
     Clean up the NUMA node handling code a little

  "mm: some optimizations for prot numa" (Kefeng Wang)
     Cleanups and small optimizations to the NUMA allocation hinting
     code

  "mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn)
     Address long lock hold times at boot on large machines. These were
     causing (harmless) softlockup warnings

  "optimize the logic for handling dirty file folios during reclaim" (Baolin Wang)
     Remove some now-unnecessary work from page reclaim

  "mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park)
     Enhance the DAMOS auto-tuning feature

  "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan)
     Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace
     configuration

  "expand mmap_prepare functionality, port more users" (Lorenzo Stoakes)
     Enhance the new(ish) file_operations.mmap_prepare() method and port
     additional callsites from the old ->mmap() over to ->mmap_prepare()

  "Fix stale IOTLB entries for kernel address space" (Lu Baolu)
     Fix a bug (and possible security issue on non-x86) in the IOMMU
     code. In some situations the IOMMU could be left hanging onto a
     stale kernel pagetable entry

  "mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang)
     Clean up and optimize the folio splitting code

  "mm, swap: misc cleanup and bugfix" (Kairui Song)
     Some cleanups and a minor fix in the swap discard code

  "mm/damon: misc documentation fixups" (SeongJae Park)

  "mm/damon: support pin-point targets removal" (SeongJae Park)
     Permit userspace to remove a specific monitoring target in the
     middle of the current targets list

  "mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo)
     A couple of cleanups related to mm header file inclusion

  "mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He)
     improve the selection of swap devices for NUMA machines

  "mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista)
     Change the memory block labels from macros to enums so they will
     appear in kernel debug info

  "ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes)
     Address an inefficiency when KSM unmerges an address range

  "mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park)
     Fix leaks and unhandled malloc() failures in DAMON userspace unit
     tests

  "some cleanups for pageout()" (Baolin Wang)
     Clean up a couple of minor things in the page scanner's
     writeback-for-eviction code

  "mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu)
     Move hugetlb's sysfs/sysctl handling code into a new file

  "introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes)
     Make the VMA guard regions available in /proc/pid/smaps and
     improves the mergeability of guarded VMAs

  "mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes)
     Reduce mmap lock contention for callers performing VMA guard region
     operations

  "vma_start_write_killable" (Matthew Wilcox)
     Start work on permitting applications to be killed when they are
     waiting on a read_lock on the VMA lock

  "mm/damon/tests: add more tests for online parameters commit" (SeongJae Park)
     Add additional userspace testing of DAMON's "commit" feature

  "mm/damon: misc cleanups" (SeongJae Park)

  "make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes)
     Address the possible loss of a VMA's VM_SOFTDIRTY flag when that
     VMA is merged with another

  "mm: support device-private THP" (Balbir Singh)
     Introduce support for Transparent Huge Page (THP) migration in zone
     device-private memory

  "Optimize folio split in memory failure" (Zi Yan)

  "mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang)
     Some more cleanups in the folio splitting code

  "mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes)
     Clean up our handling of pagetable leaf entries by introducing the
     concept of 'software leaf entries', of type softleaf_t

  "reparent the THP split queue" (Muchun Song)
     Reparent the THP split queue to its parent memcg. This is in
     preparation for addressing the long-standing "dying memcg" problem,
     wherein dead memcg's linger for too long, consuming memory
     resources

  "unify PMD scan results and remove redundant cleanup" (Wei Yang)
     A little cleanup in the hugepage collapse code

  "zram: introduce writeback bio batching" (Sergey Senozhatsky)
     Improve zram writeback efficiency by introducing batched bio
     writeback support

  "memcg: cleanup the memcg stats interfaces" (Shakeel Butt)
     Clean up our handling of the interrupt safety of some memcg stats

  "make vmalloc gfp flags usage more apparent" (Vishal Moola)
     Clean up vmalloc's handling of incoming GFP flags

  "mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang)
     Teach soft dirty and userfaultfd write protect tracking to use
     RISC-V's Svrsw60t59b extension

  "mm: swap: small fixes and comment cleanups" (Youngjun Park)
     Fix a small bug and clean up some of the swap code

  "initial work on making VMA flags a bitmap" (Lorenzo Stoakes)
     Start work on converting the vma struct's flags to a bitmap, so we
     stop running out of them, especially on 32-bit

  "mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park)
     Address a possible bug in the swap discard code and clean things
     up a little

[ This merge also reverts commit ebb9aeb980 ("vfio/nvgrace-gpu:
  register device memory for poison handling") because it looks
  broken to me, I've asked for clarification   - Linus ]

* tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm: fix vma_start_write_killable() signal handling
  mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate
  mm/swapfile: fix list iteration when next node is removed during discard
  fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling
  mm/kfence: add reboot notifier to disable KFENCE on shutdown
  memcg: remove inc/dec_lruvec_kmem_state helpers
  selftests/mm/uffd: initialize char variable to Null
  mm: fix DEBUG_RODATA_TEST indentation in Kconfig
  mm: introduce VMA flags bitmap type
  tools/testing/vma: eliminate dependency on vma->__vm_flags
  mm: simplify and rename mm flags function for clarity
  mm: declare VMA flags by bit
  zram: fix a spelling mistake
  mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity
  mm/vmscan: skip increasing kswapd_failures when reclaim was boosted
  pagemap: update BUDDY flag documentation
  mm: swap: remove scan_swap_map_slots() references from comments
  mm: swap: change swap_alloc_slow() to void
  mm, swap: remove redundant comment for read_swap_cache_async
  mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational
  ...
2025-12-05 13:52:43 -08:00
Linus Torvalds 015e7b0b0e bpf-next-6.19
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Merge tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to
   test_progs runner (Alexis Lothoré)

 - Convert selftests/bpf/test_xsk to test_progs runner (Bastien
   Curutchet)

 - Replace bpf memory allocator with kmalloc_nolock() in
   bpf_local_storage (Amery Hung), and in bpf streams and range tree
   (Puranjay Mohan)

 - Introduce support for indirect jumps in BPF verifier and x86 JIT
   (Anton Protopopov) and arm64 JIT (Puranjay Mohan)

 - Remove runqslower bpf tool (Hoyeon Lee)

 - Fix corner cases in the verifier to close several syzbot reports
   (Eduard Zingerman, KaFai Wan)

 - Several improvements in deadlock detection in rqspinlock (Kumar
   Kartikeya Dwivedi)

 - Implement "jmp" mode for BPF trampoline and corresponding
   DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance
   from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong)

 - Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul
   Chaignon)

 - Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel
   Borkmann)

 - Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko)

 - Optimize bpf_map_update_elem() for map-in-map types (Ritesh
   Oedayrajsingh Varma)

 - Introduce overwrite mode for BPF ring buffer (Xu Kuohai)

* tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits)
  bpf: optimize bpf_map_update_elem() for map-in-map types
  bpf: make kprobe_multi_link_prog_run always_inline
  selftests/bpf: do not hardcode target rate in test_tc_edt BPF program
  selftests/bpf: remove test_tc_edt.sh
  selftests/bpf: integrate test_tc_edt into test_progs
  selftests/bpf: rename test_tc_edt.bpf.c section to expose program type
  selftests/bpf: Add success stats to rqspinlock stress test
  rqspinlock: Precede non-head waiter queueing with AA check
  rqspinlock: Disable spinning for trylock fallback
  rqspinlock: Use trylock fallback when per-CPU rqnode is busy
  rqspinlock: Perform AA checks immediately
  rqspinlock: Enclose lock/unlock within lock entry acquisitions
  bpf: Remove runqslower tool
  selftests/bpf: Remove usage of lsm/file_alloc_security in selftest
  bpf: Disable file_alloc_security hook
  bpf: check for insn arrays in check_ptr_alignment
  bpf: force BPF_F_RDONLY_PROG on insn array creation
  bpf: Fix exclusive map memory leak
  selftests/bpf: Make CS length configurable for rqspinlock stress test
  selftests/bpf: Add lock wait time stats to rqspinlock stress test
  ...
2025-12-03 16:54:54 -08:00
Linus Torvalds a619fe35ab This update includes the following changes:
API:
 
 - Rewrite memcpy_sglist from scratch.
 - Add on-stack AEAD request allocation.
 - Fix partial block processing in ahash.
 
 Algorithms:
 
 - Remove ansi_cprng.
 - Remove tcrypt tests for poly1305.
 - Fix EINPROGRESS processing in authenc.
 - Fix double-free in zstd.
 
 Drivers:
 
 - Use drbg ctr helper when reseeding xilinx-trng.
 - Add support for PCI device 0x115A to ccp.
 - Add support of paes in caam.
 - Add support for aes-xts in dthev2.
 
 Others:
 
 - Use likely in rhashtable lookup.
 - Fix lockdep false-positive in padata by removing a helper.
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Merge tag 'v6.19-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto updates from Herbert Xu:
 "API:
   - Rewrite memcpy_sglist from scratch
   - Add on-stack AEAD request allocation
   - Fix partial block processing in ahash

  Algorithms:
   - Remove ansi_cprng
   - Remove tcrypt tests for poly1305
   - Fix EINPROGRESS processing in authenc
   - Fix double-free in zstd

  Drivers:
   - Use drbg ctr helper when reseeding xilinx-trng
   - Add support for PCI device 0x115A to ccp
   - Add support of paes in caam
   - Add support for aes-xts in dthev2

  Others:
   - Use likely in rhashtable lookup
   - Fix lockdep false-positive in padata by removing a helper"

* tag 'v6.19-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (71 commits)
  crypto: zstd - fix double-free in per-CPU stream cleanup
  crypto: ahash - Zero positive err value in ahash_update_finish
  crypto: ahash - Fix crypto_ahash_import with partial block data
  crypto: lib/mpi - use min() instead of min_t()
  crypto: ccp - use min() instead of min_t()
  hwrng: core - use min3() instead of nested min_t()
  crypto: aesni - ctr_crypt() use min() instead of min_t()
  crypto: drbg - Delete unused ctx from struct sdesc
  crypto: testmgr - Add missing DES weak and semi-weak key tests
  Revert "crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist"
  crypto: scatterwalk - Fix memcpy_sglist() to always succeed
  crypto: iaa - Request to add Kanchana P Sridhar to Maintainers.
  crypto: tcrypt - Remove unused poly1305 support
  crypto: ansi_cprng - Remove unused ansi_cprng algorithm
  crypto: asymmetric_keys - fix uninitialized pointers with free attribute
  KEYS: Avoid -Wflex-array-member-not-at-end warning
  crypto: ccree - Correctly handle return of sg_nents_for_len
  crypto: starfive - Correctly handle return of sg_nents_for_len
  crypto: iaa - Fix incorrect return value in save_iaa_wq()
  crypto: zstd - Remove unnecessary size_t cast
  ...
2025-12-03 11:28:38 -08:00
Linus Torvalds 5abe8d8efc Crypto library updates for 6.19
This is the main crypto library pull request for 6.19. It includes:
 
 - Add SHA-3 support to lib/crypto/, including support for both the
   hash functions and the extendable-output functions. Reimplement the
   existing SHA-3 crypto_shash support on top of the library.
 
   This is motivated mainly by the upcoming support for the ML-DSA
   signature algorithm, which needs the SHAKE128 and SHAKE256
   functions. But even on its own it's a useful cleanup.
 
   This also fixes the longstanding issue where the
   architecture-optimized SHA-3 code was disabled by default.
 
 - Add BLAKE2b support to lib/crypto/, and reimplement the existing
   BLAKE2b crypto_shash support on top of the library.
 
   This is motivated mainly by btrfs, which supports BLAKE2b checksums.
   With this change, all btrfs checksum algorithms now have library
   APIs. btrfs is planned to start just using the library directly.
 
   This refactor also improves consistency between the BLAKE2b code and
   BLAKE2s code. And as usual, it also fixes the issue where the
   architecture-optimized BLAKE2b code was disabled by default.
 
 - Add POLYVAL support to lib/crypto/, replacing the existing POLYVAL
   support in crypto_shash. Reimplement HCTR2 on top of the library.
 
   This simplifies the code and improves HCTR2 performance. As usual,
   it also makes the architecture-optimized code be enabled by default.
   The generic implementation of POLYVAL is greatly improved as well.
 
 - Clean up the BLAKE2s code.
 
 - Add FIPS self-tests for SHA-1, SHA-2, and SHA-3.
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Merge tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull crypto library updates from Eric Biggers:
 "This is the main crypto library pull request for 6.19. It includes:

   - Add SHA-3 support to lib/crypto/, including support for both the
     hash functions and the extendable-output functions. Reimplement the
     existing SHA-3 crypto_shash support on top of the library.

     This is motivated mainly by the upcoming support for the ML-DSA
     signature algorithm, which needs the SHAKE128 and SHAKE256
     functions. But even on its own it's a useful cleanup.

     This also fixes the longstanding issue where the
     architecture-optimized SHA-3 code was disabled by default.

   - Add BLAKE2b support to lib/crypto/, and reimplement the existing
     BLAKE2b crypto_shash support on top of the library.

     This is motivated mainly by btrfs, which supports BLAKE2b
     checksums. With this change, all btrfs checksum algorithms now have
     library APIs. btrfs is planned to start just using the library
     directly.

     This refactor also improves consistency between the BLAKE2b code
     and BLAKE2s code. And as usual, it also fixes the issue where the
     architecture-optimized BLAKE2b code was disabled by default.

   - Add POLYVAL support to lib/crypto/, replacing the existing POLYVAL
     support in crypto_shash. Reimplement HCTR2 on top of the library.

     This simplifies the code and improves HCTR2 performance. As usual,
     it also makes the architecture-optimized code be enabled by
     default. The generic implementation of POLYVAL is greatly improved
     as well.

   - Clean up the BLAKE2s code

   - Add FIPS self-tests for SHA-1, SHA-2, and SHA-3"

* tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (37 commits)
  fscrypt: Drop obsolete recommendation to enable optimized POLYVAL
  crypto: polyval - Remove the polyval crypto_shash
  crypto: hctr2 - Convert to use POLYVAL library
  lib/crypto: x86/polyval: Migrate optimized code into library
  lib/crypto: arm64/polyval: Migrate optimized code into library
  lib/crypto: polyval: Add POLYVAL library
  crypto: polyval - Rename conflicting functions
  lib/crypto: x86/blake2s: Use vpternlogd for 3-input XORs
  lib/crypto: x86/blake2s: Avoid writing back unchanged 'f' value
  lib/crypto: x86/blake2s: Improve readability
  lib/crypto: x86/blake2s: Use local labels for data
  lib/crypto: x86/blake2s: Drop check for nblocks == 0
  lib/crypto: x86/blake2s: Fix 32-bit arg treated as 64-bit
  lib/crypto: arm, arm64: Drop filenames from file comments
  lib/crypto: arm/blake2s: Fix some comments
  crypto: s390/sha3 - Remove superseded SHA-3 code
  crypto: sha3 - Reimplement using library API
  crypto: jitterentropy - Use default sha3 implementation
  lib/crypto: s390/sha3: Add optimized one-shot SHA-3 digest functions
  lib/crypto: sha3: Support arch overrides of one-shot digest functions
  ...
2025-12-02 18:01:03 -08:00
Linus Torvalds 2547f79b0b s390 updates for 6.19 merge window
- Provide a new interface for dynamic configuration and deconfiguration of
   hotplug memory, allowing with and without memmap_on_memory support. This
   makes the way memory hotplug is handled on s390 much more similar to
   other architectures
 
 - Remove compat support. There shouldn't be any compat user space around
   anymore, therefore get rid of a lot of code which also doesn't need to be
   tested anymore
 
 - Add stackprotector support. GCC 16 will get new compiler options, which
   allow to generate code required for kernel stackprotector support
 
 - Merge pai_crypto and pai_ext PMU drivers into a new driver. This removes
   a lot of duplicated code. The new driver is also extendable and allows
   to support new PMUs
 
 - Add driver override support for AP queues
 
 - Rework and extend zcrypt and AP trace events to allow for tracing of
   crypto requests
 
 - Support block sizes larger than 65535 bytes for CCW tape devices
 
 - Since the rework of the virtual kernel address space the module area and
   the kernel image are within the same 4GB area. This eliminates the need
   of weak per cpu variables. Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
 
 - Various other small improvements and fixes
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Merge tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Provide a new interface for dynamic configuration and deconfiguration
   of hotplug memory, allowing with and without memmap_on_memory
   support. This makes the way memory hotplug is handled on s390 much
   more similar to other architectures

 - Remove compat support. There shouldn't be any compat user space
   around anymore, therefore get rid of a lot of code which also doesn't
   need to be tested anymore

 - Add stackprotector support. GCC 16 will get new compiler options,
   which allow to generate code required for kernel stackprotector
   support

 - Merge pai_crypto and pai_ext PMU drivers into a new driver. This
   removes a lot of duplicated code. The new driver is also extendable
   and allows to support new PMUs

 - Add driver override support for AP queues

 - Rework and extend zcrypt and AP trace events to allow for tracing of
   crypto requests

 - Support block sizes larger than 65535 bytes for CCW tape devices

 - Since the rework of the virtual kernel address space the module area
   and the kernel image are within the same 4GB area. This eliminates
   the need of weak per cpu variables. Get rid of
   ARCH_MODULE_NEEDS_WEAK_PER_CPU

 - Various other small improvements and fixes

* tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (92 commits)
  watchdog: diag288_wdt: Remove KMSG_COMPONENT macro
  s390/entry: Use lay instead of aghik
  s390/vdso: Get rid of -m64 flag handling
  s390/vdso: Rename vdso64 to vdso
  s390: Rename head64.S to head.S
  s390/vdso: Use common STABS_DEBUG and DWARF_DEBUG macros
  s390: Add stackprotector support
  s390/modules: Simplify module_finalize() slightly
  s390: Remove KMSG_COMPONENT macro
  s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
  s390/ap: Restrict driver_override versus apmask and aqmask use
  s390/ap: Rename mutex ap_perms_mutex to ap_attr_mutex
  s390/ap: Support driver_override for AP queue devices
  s390/ap: Use all-bits-one apmask/aqmask for vfio in_use() checks
  s390/debug: Update description of resize operation
  s390/syscalls: Switch to generic system call table generation
  s390/syscalls: Remove system call table pointer from thread_struct
  s390/uapi: Remove 31 bit support from uapi header files
  s390: Remove compat support
  tools: Remove s390 compat support
  ...
2025-12-02 16:37:00 -08:00
Paolo Bonzini e0c26d47de - SCA rework
- VIRT_XFER_TO_GUEST_WORK support
 - Operation exception forwarding support
 - Cleanups
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Merge tag 'kvm-s390-next-6.19-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

- SCA rework
- VIRT_XFER_TO_GUEST_WORK support
- Operation exception forwarding support
- Cleanups
2025-12-02 18:58:47 +01:00
Linus Torvalds 1dce50698a Scoped user mode access and related changes:
- Implement the missing u64 user access function on ARM when
    CONFIG_CPU_SPECTRE=n. This makes it possible to access a 64bit value in
    generic code with [unsafe_]get_user(). All other architectures and ARM
    variants provide the relevant accessors already.
 
  - Ensure that ASM GOTO jump label usage in the user mode access helpers
    always goes through a local C scope label indirection inside the
    helpers. This is required because compilers are not supporting that a
    ASM GOTO target leaves a auto cleanup scope. GCC silently fails to emit
    the cleanup invocation and CLANG fails the build.
 
    This provides generic wrapper macros and the conversion of affected
    architecture code to use them.
 
  - Scoped user mode access with auto cleanup
 
    Access to user mode memory can be required in hot code paths, but if it
    has to be done with user controlled pointers, the access is shielded
    with a speculation barrier, so that the CPU cannot speculate around the
    address range check. Those speculation barriers impact performance quite
    significantly. This can be avoided by "masking" the provided pointer so
    it is guaranteed to be in the valid user memory access range and
    otherwise to point to a guaranteed unpopulated address space. This has
    to be done without branches so it creates an address dependency for the
    access, which the CPU cannot speculate ahead.
 
    This results in repeating and error prone programming patterns:
 
      	    if (can_do_masked_user_access())
                     from = masked_user_read_access_begin((from));
             else if (!user_read_access_begin(from, sizeof(*from)))
                     return -EFAULT;
             unsafe_get_user(val, from, Efault);
             user_read_access_end();
             return 0;
       Efault:
             user_read_access_end();
             return -EFAULT;
 
     which can be replaced with scopes and automatic cleanup:
 
             scoped_user_read_access(from, Efault)
                     unsafe_get_user(val, from, Efault);
             return 0;
        Efault:
             return -EFAULT;
 
  - Convert code which implements the above pattern over to
    scope_user.*.access(). This also corrects a couple of imbalanced
    masked_*_begin() instances which are harmless on most architectures, but
    prevent PowerPC from implementing the masking optimization.
 
  - Add a missing speculation barrier in copy_from_user_iter()
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Merge tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scoped user access updates from Thomas Gleixner:
 "Scoped user mode access and related changes:

   - Implement the missing u64 user access function on ARM when
     CONFIG_CPU_SPECTRE=n.

     This makes it possible to access a 64bit value in generic code with
     [unsafe_]get_user(). All other architectures and ARM variants
     provide the relevant accessors already.

   - Ensure that ASM GOTO jump label usage in the user mode access
     helpers always goes through a local C scope label indirection
     inside the helpers.

     This is required because compilers are not supporting that a ASM
     GOTO target leaves a auto cleanup scope. GCC silently fails to emit
     the cleanup invocation and CLANG fails the build.

     [ Editor's note: gcc-16 will have fixed the code generation issue
       in commit f68fe3ddda4 ("eh: Invoke cleanups/destructors in asm
       goto jumps [PR122835]"). But we obviously have to deal with clang
       and older versions of gcc, so.. - Linus ]

     This provides generic wrapper macros and the conversion of affected
     architecture code to use them.

   - Scoped user mode access with auto cleanup

     Access to user mode memory can be required in hot code paths, but
     if it has to be done with user controlled pointers, the access is
     shielded with a speculation barrier, so that the CPU cannot
     speculate around the address range check. Those speculation
     barriers impact performance quite significantly.

     This cost can be avoided by "masking" the provided pointer so it is
     guaranteed to be in the valid user memory access range and
     otherwise to point to a guaranteed unpopulated address space. This
     has to be done without branches so it creates an address dependency
     for the access, which the CPU cannot speculate ahead.

     This results in repeating and error prone programming patterns:

       	    if (can_do_masked_user_access())
                      from = masked_user_read_access_begin((from));
              else if (!user_read_access_begin(from, sizeof(*from)))
                      return -EFAULT;
              unsafe_get_user(val, from, Efault);
              user_read_access_end();
              return 0;
        Efault:
              user_read_access_end();
              return -EFAULT;

      which can be replaced with scopes and automatic cleanup:

              scoped_user_read_access(from, Efault)
                      unsafe_get_user(val, from, Efault);
              return 0;
         Efault:
              return -EFAULT;

   - Convert code which implements the above pattern over to
     scope_user.*.access(). This also corrects a couple of imbalanced
     masked_*_begin() instances which are harmless on most
     architectures, but prevent PowerPC from implementing the masking
     optimization.

   - Add a missing speculation barrier in copy_from_user_iter()"

* tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/strn*,uaccess: Use masked_user_{read/write}_access_begin when required
  scm: Convert put_cmsg() to scoped user access
  iov_iter: Add missing speculation barrier to copy_from_user_iter()
  iov_iter: Convert copy_from_user_iter() to masked user access
  select: Convert to scoped user access
  x86/futex: Convert to scoped user access
  futex: Convert to get/put_user_inline()
  uaccess: Provide put/get_user_inline()
  uaccess: Provide scoped user access regions
  arm64: uaccess: Use unsafe wrappers for ASM GOTO
  s390/uaccess: Use unsafe wrappers for ASM GOTO
  riscv/uaccess: Use unsafe wrappers for ASM GOTO
  powerpc/uaccess: Use unsafe wrappers for ASM GOTO
  x86/uaccess: Use unsafe wrappers for ASM GOTO
  uaccess: Provide ASM GOTO safe wrappers for unsafe_*_user()
  ARM: uaccess: Implement missing __get_user_asm_dword()
2025-12-02 08:01:39 -08:00
Linus Torvalds 4a26e7032d Core kernel bug handling infrastructure changes for v6.19:
- Improve WARN(), which has vararg printf like arguments,
     to work with the x86 #UD based WARN-optimizing infrastructure
     by hiding the format in the bug_table and replacing this
     first argument with the address of the bug-table entry,
     while making the actual function that's called a UD1 instruction.
     (Peter Zijlstra)
 
   - Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch
     (Ingo Molnar, s390 support by Heiko Carstens)
 
 Fixes and cleanups:
 
   - bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)
 
   - <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
     (Peter Zijlstra)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull bug handling infrastructure updates from Ingo Molnar:
 "Core updates:

   - Improve WARN(), which has vararg printf like arguments, to work
     with the x86 #UD based WARN-optimizing infrastructure by hiding the
     format in the bug_table and replacing this first argument with the
     address of the bug-table entry, while making the actual function
     that's called a UD1 instruction (Peter Zijlstra)

   - Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch (Ingo
     Molnar, s390 support by Heiko Carstens)

  Fixes and cleanups:

   - bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)

   - <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS (Peter
     Zijlstra)"

* tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86/bugs: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
  x86/bug: Fix BUG_FORMAT vs KASLR
  x86_64/bug: Inline the UD1
  x86/bug: Implement WARN_ONCE()
  x86_64/bug: Implement __WARN_printf()
  x86/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED
  x86/bug: Add BUG_FORMAT basics
  bug: Allow architectures to provide __WARN_printf()
  bug: Implement WARN_ON() using __WARN_FLAGS()
  bug: Add report_bug_entry()
  bug: Add BUG_FORMAT_ARGS infrastructure
  bug: Clean up CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  bug: Add BUG_FORMAT infrastructure
  x86: Rework __bug_table helpers
  bugs/s390: Remove private WARN_ON() implementation
  bugs/core: Reorganize fields in the first line of WARNING output, add ->comm[] output
  bugs/sh: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/parisc: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/riscv: Concatenate 'cond_str' with '__FILE__' in __BUG_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/riscv: Pass in 'cond_str' to __BUG_FLAGS()
  ...
2025-12-01 21:33:01 -08:00
Linus Torvalds 6d2c10e889 Scheduler changes for v6.19:
Scalability and load-balancing improvements:
 
   - Enable scheduler feature NEXT_BUDDY (Mel Gorman)
 
   - Reimplement NEXT_BUDDY to align with EEVDF goals (Mel Gorman)
 
   - Skip sched_balance_running cmpxchg when balance is not due (Tim Chen)
 
   - Implement generic code for architecture specific sched domain
     NUMA distances (Tim Chen)
 
   - Optimize the NUMA distances of the sched-domains builds of Intel
     Granite Rapids (GNR) and Clearwater Forest (CWF) platforms
     (Tim Chen)
 
   - Implement proportional newidle balance: a randomized algorithm
     that runs newidle balancing proportional to its success rate.
     (Peter Zijlstra)
 
 Scheduler infrastructure changes:
 
   - Implement the 'sched_change' scoped_guard() pattern for
     the entire scheduler (Peter Zijlstra)
 
   - More broadly utilize the sched_change guard (Peter Zijlstra)
 
   - Add support to pick functions to take runqueue-flags (Joel Fernandes)
 
   - Provide and use set_need_resched_current() (Peter Zijlstra)
 
 Fair scheduling enhancements:
 
   - Forfeit vruntime on yield (Fernand Sieber)
   - Only update stats for allowed CPUs when looking for dst group (Adam Li)
 
 CPU-core scheduling enhancements:
 
   - Optimize core cookie matching check (Fernand Sieber)
 
 Deadline scheduler fixes:
 
   - Only set free_cpus for online runqueues (Doug Berger)
   - Fix dl_server time accounting (Peter Zijlstra)
   - Fix dl_server stop condition (Peter Zijlstra)
 
 Proxy scheduling fixes:
 
   - Yield the donor task (Fernand Sieber)
 
 Fixes and cleanups:
 
   - Fix do_set_cpus_allowed() locking (Peter Zijlstra)
   - Fix migrate_disable_switch() locking (Peter Zijlstra)
   - Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked() (Hao Jia)
   - Increase sched_tick_remote timeout (Phil Auld)
   - sched/deadline: Use cpumask_weight_and() in dl_bw_cpus() (Shrikanth Hegde)
   - sched/deadline: Clean up select_task_rq_dl() (Shrikanth Hegde)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Scalability and load-balancing improvements:

   - Enable scheduler feature NEXT_BUDDY (Mel Gorman)

   - Reimplement NEXT_BUDDY to align with EEVDF goals (Mel Gorman)

   - Skip sched_balance_running cmpxchg when balance is not due (Tim
     Chen)

   - Implement generic code for architecture specific sched domain NUMA
     distances (Tim Chen)

   - Optimize the NUMA distances of the sched-domains builds of Intel
     Granite Rapids (GNR) and Clearwater Forest (CWF) platforms (Tim
     Chen)

   - Implement proportional newidle balance: a randomized algorithm that
     runs newidle balancing proportional to its success rate. (Peter
     Zijlstra)

  Scheduler infrastructure changes:

   - Implement the 'sched_change' scoped_guard() pattern for the entire
     scheduler (Peter Zijlstra)

   - More broadly utilize the sched_change guard (Peter Zijlstra)

   - Add support to pick functions to take runqueue-flags (Joel
     Fernandes)

   - Provide and use set_need_resched_current() (Peter Zijlstra)

  Fair scheduling enhancements:

   - Forfeit vruntime on yield (Fernand Sieber)

   - Only update stats for allowed CPUs when looking for dst group (Adam
     Li)

  CPU-core scheduling enhancements:

   - Optimize core cookie matching check (Fernand Sieber)

  Deadline scheduler fixes:

   - Only set free_cpus for online runqueues (Doug Berger)

   - Fix dl_server time accounting (Peter Zijlstra)

   - Fix dl_server stop condition (Peter Zijlstra)

  Proxy scheduling fixes:

   - Yield the donor task (Fernand Sieber)

  Fixes and cleanups:

   - Fix do_set_cpus_allowed() locking (Peter Zijlstra)

   - Fix migrate_disable_switch() locking (Peter Zijlstra)

   - Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked()
     (Hao Jia)

   - Increase sched_tick_remote timeout (Phil Auld)

   - sched/deadline: Use cpumask_weight_and() in dl_bw_cpus() (Shrikanth
     Hegde)

   - sched/deadline: Clean up select_task_rq_dl() (Shrikanth Hegde)"

* tag 'sched-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  sched: Provide and use set_need_resched_current()
  sched/fair: Proportional newidle balance
  sched/fair: Small cleanup to update_newidle_cost()
  sched/fair: Small cleanup to sched_balance_newidle()
  sched/fair: Revert max_newidle_lb_cost bump
  sched/fair: Reimplement NEXT_BUDDY to align with EEVDF goals
  sched/fair: Enable scheduler feature NEXT_BUDDY
  sched: Increase sched_tick_remote timeout
  sched/fair: Have SD_SERIALIZE affect newidle balancing
  sched/fair: Skip sched_balance_running cmpxchg when balance is not due
  sched/deadline: Minor cleanup in select_task_rq_dl()
  sched/deadline: Use cpumask_weight_and() in dl_bw_cpus
  sched/deadline: Document dl_server
  sched/deadline: Fix dl_server stop condition
  sched/deadline: Fix dl_server time accounting
  sched/core: Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked()
  sched/eevdf: Fix min_vruntime vs avg_vruntime
  sched/core: Add comment explaining force-idle vruntime snapshots
  sched/core: Optimize core cookie matching check
  sched/proxy: Yield the donor task
  ...
2025-12-01 21:04:45 -08:00
Linus Torvalds 63e6995005 objtool updates for v6.19:
- klp-build livepatch module generation (Josh Poimboeuf)
 
    Introduce new objtool features and a klp-build
    script to generate livepatch modules using a
    source .patch as input.
 
    This builds on concepts from the longstanding out-of-tree
    kpatch project which began in 2012 and has been used for
    many years to generate livepatch modules for production kernels.
    However, this is a complete rewrite which incorporates
    hard-earned lessons from 12+ years of maintaining kpatch.
 
    Key improvements compared to kpatch-build:
 
     - Integrated with objtool: Leverages objtool's existing control-flow
       graph analysis to help detect changed functions.
 
     - Works on vmlinux.o: Supports late-linked objects, making it
       compatible with LTO, IBT, and similar.
 
     - Simplified code base: ~3k fewer lines of code.
 
     - Upstream: No more out-of-tree #ifdef hacks, far less cruft.
 
     - Cleaner internals: Vastly simplified logic for symbol/section/reloc
       inclusion and special section extraction.
 
     - Robust __LINE__ macro handling: Avoids false positive binary diffs
       caused by the __LINE__ macro by introducing a fix-patch-lines script
       which injects #line directives into the source .patch to preserve
       the original line numbers at compile time.
 
  - Disassemble code with libopcodes instead of running objdump
    (Alexandre Chartre)
 
  - Disassemble support (-d option to objtool) by Alexandre Chartre,
    which supports the decoding of various Linux kernel code generation
    specials such as alternatives:
 
       17ef:  sched_balance_find_dst_group+0x62f                 mov    0x34(%r9),%edx
       17f3:  sched_balance_find_dst_group+0x633               | <alternative.17f3>             | X86_FEATURE_POPCNT
       17f3:  sched_balance_find_dst_group+0x633               | call   0x17f8 <__sw_hweight64> | popcnt %rdi,%rax
       17f8:  sched_balance_find_dst_group+0x638                 cmp    %eax,%edx
 
    ... jump table alternatives:
 
       1895:  sched_use_asym_prio+0x5                            test   $0x8,%ch
       1898:  sched_use_asym_prio+0x8                            je     0x18a9 <sched_use_asym_prio+0x19>
       189a:  sched_use_asym_prio+0xa                          | <jump_table.189a>                        | JUMP
       189a:  sched_use_asym_prio+0xa                          | jmp    0x18ae <sched_use_asym_prio+0x1e> | nop2
       189c:  sched_use_asym_prio+0xc                            mov    $0x1,%eax
       18a1:  sched_use_asym_prio+0x11                           and    $0x80,%ecx
 
    ... exception table alternatives:
 
     native_read_msr:
       5b80:  native_read_msr+0x0                                                     mov    %edi,%ecx
       5b82:  native_read_msr+0x2                                                   | <ex_table.5b82> | EXCEPTION
       5b82:  native_read_msr+0x2                                                   | rdmsr           | resume at 0x5b84 <native_read_msr+0x4>
       5b84:  native_read_msr+0x4                                                     shl    $0x20,%rdx
 
    .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT
         example in sched_balance_find_dst_group() above):
 
       2faaf:  start_thread_common.constprop.0+0x1f                                    jne    0x2fba4 <start_thread_common.constprop.0+0x114>
       2fab5:  start_thread_common.constprop.0+0x25                                  | <alternative.2fab5>                  | X86_FEATURE_ALWAYS                                  | X86_BUG_NULL_SEG
       2fab5:  start_thread_common.constprop.0+0x25                                  | jmp    0x2faba <.altinstr_aux+0x2f4> | jmp    0x4b0 <start_thread_common.constprop.0+0x3f> | nop5
       2faba:  start_thread_common.constprop.0+0x2a                                    mov    $0x2b,%eax
 
    ... NOP sequence shortening:
 
       1048e2:  snapshot_write_finalize+0xc2                                            je     0x104917 <snapshot_write_finalize+0xf7>
       1048e4:  snapshot_write_finalize+0xc4                                            nop6
       1048ea:  snapshot_write_finalize+0xca                                            nop11
       1048f5:  snapshot_write_finalize+0xd5                                            nop11
       104900:  snapshot_write_finalize+0xe0                                            mov    %rax,%rcx
       104903:  snapshot_write_finalize+0xe3                                            mov    0x10(%rdx),%rax
 
    ... and much more.
 
  - Function validation tracing support (Alexandre Chartre)
 
  - Various -ffunction-sections fixes (Josh Poimboeuf)
 
  - Clang AutoFDO (Automated Feedback-Directed Optimizations) support (Josh Poimboeuf)
 
  - Misc fixes and cleanups (Borislav Petkov, Chen Ni,
    Dylan Hatch, Ingo Molnar, John Wang, Josh Poimboeuf,
    Pankaj Raghav, Peter Zijlstra, Thorsten Blum)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - klp-build livepatch module generation (Josh Poimboeuf)

   Introduce new objtool features and a klp-build script to generate
   livepatch modules using a source .patch as input.

   This builds on concepts from the longstanding out-of-tree kpatch
   project which began in 2012 and has been used for many years to
   generate livepatch modules for production kernels. However, this is a
   complete rewrite which incorporates hard-earned lessons from 12+
   years of maintaining kpatch.

   Key improvements compared to kpatch-build:

    - Integrated with objtool: Leverages objtool's existing control-flow
      graph analysis to help detect changed functions.

    - Works on vmlinux.o: Supports late-linked objects, making it
      compatible with LTO, IBT, and similar.

    - Simplified code base: ~3k fewer lines of code.

    - Upstream: No more out-of-tree #ifdef hacks, far less cruft.

    - Cleaner internals: Vastly simplified logic for
      symbol/section/reloc inclusion and special section extraction.

    - Robust __LINE__ macro handling: Avoids false positive binary diffs
      caused by the __LINE__ macro by introducing a fix-patch-lines
      script which injects #line directives into the source .patch to
      preserve the original line numbers at compile time.

 - Disassemble code with libopcodes instead of running objdump
   (Alexandre Chartre)

 - Disassemble support (-d option to objtool) by Alexandre Chartre,
   which supports the decoding of various Linux kernel code generation
   specials such as alternatives:

      17ef:  sched_balance_find_dst_group+0x62f                 mov    0x34(%r9),%edx
      17f3:  sched_balance_find_dst_group+0x633               | <alternative.17f3>             | X86_FEATURE_POPCNT
      17f3:  sched_balance_find_dst_group+0x633               | call   0x17f8 <__sw_hweight64> | popcnt %rdi,%rax
      17f8:  sched_balance_find_dst_group+0x638                 cmp    %eax,%edx

   ... jump table alternatives:

      1895:  sched_use_asym_prio+0x5                            test   $0x8,%ch
      1898:  sched_use_asym_prio+0x8                            je     0x18a9 <sched_use_asym_prio+0x19>
      189a:  sched_use_asym_prio+0xa                          | <jump_table.189a>                        | JUMP
      189a:  sched_use_asym_prio+0xa                          | jmp    0x18ae <sched_use_asym_prio+0x1e> | nop2
      189c:  sched_use_asym_prio+0xc                            mov    $0x1,%eax
      18a1:  sched_use_asym_prio+0x11                           and    $0x80,%ecx

   ... exception table alternatives:

    native_read_msr:
      5b80:  native_read_msr+0x0                                                     mov    %edi,%ecx
      5b82:  native_read_msr+0x2                                                   | <ex_table.5b82> | EXCEPTION
      5b82:  native_read_msr+0x2                                                   | rdmsr           | resume at 0x5b84 <native_read_msr+0x4>
      5b84:  native_read_msr+0x4                                                     shl    $0x20,%rdx

   .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT
        example in sched_balance_find_dst_group() above):

      2faaf:  start_thread_common.constprop.0+0x1f                                    jne    0x2fba4 <start_thread_common.constprop.0+0x114>
      2fab5:  start_thread_common.constprop.0+0x25                                  | <alternative.2fab5>                  | X86_FEATURE_ALWAYS                                  | X86_BUG_NULL_SEG
      2fab5:  start_thread_common.constprop.0+0x25                                  | jmp    0x2faba <.altinstr_aux+0x2f4> | jmp    0x4b0 <start_thread_common.constprop.0+0x3f> | nop5
      2faba:  start_thread_common.constprop.0+0x2a                                    mov    $0x2b,%eax

   ... NOP sequence shortening:

      1048e2:  snapshot_write_finalize+0xc2                                            je     0x104917 <snapshot_write_finalize+0xf7>
      1048e4:  snapshot_write_finalize+0xc4                                            nop6
      1048ea:  snapshot_write_finalize+0xca                                            nop11
      1048f5:  snapshot_write_finalize+0xd5                                            nop11
      104900:  snapshot_write_finalize+0xe0                                            mov    %rax,%rcx
      104903:  snapshot_write_finalize+0xe3                                            mov    0x10(%rdx),%rax

   ... and much more.

 - Function validation tracing support (Alexandre Chartre)

 - Various -ffunction-sections fixes (Josh Poimboeuf)

 - Clang AutoFDO (Automated Feedback-Directed Optimizations) support
   (Josh Poimboeuf)

 - Misc fixes and cleanups (Borislav Petkov, Chen Ni, Dylan Hatch, Ingo
   Molnar, John Wang, Josh Poimboeuf, Pankaj Raghav, Peter Zijlstra,
   Thorsten Blum)

* tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  objtool: Fix segfault on unknown alternatives
  objtool: Build with disassembly can fail when including bdf.h
  objtool: Trim trailing NOPs in alternative
  objtool: Add wide output for disassembly
  objtool: Compact output for alternatives with one instruction
  objtool: Improve naming of group alternatives
  objtool: Add Function to get the name of a CPU feature
  objtool: Provide access to feature and flags of group alternatives
  objtool: Fix address references in alternatives
  objtool: Disassemble jump table alternatives
  objtool: Disassemble exception table alternatives
  objtool: Print addresses with alternative instructions
  objtool: Disassemble group alternatives
  objtool: Print headers for alternatives
  objtool: Preserve alternatives order
  objtool: Add the --disas=<function-pattern> action
  objtool: Do not validate IBT for .return_sites and .call_sites
  objtool: Improve tracing of alternative instructions
  objtool: Add functions to better name alternatives
  objtool: Identify the different types of alternatives
  ...
2025-12-01 20:18:59 -08:00
Linus Torvalds 415d34b92c namespace-6.19-rc1
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Merge tag 'namespace-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull namespace updates from Christian Brauner:
 "This contains substantial namespace infrastructure changes including a new
  system call, active reference counting, and extensive header cleanups.
  The branch depends on the shared kbuild branch for -fms-extensions support.

  Features:

   - listns() system call

     Add a new listns() system call that allows userspace to iterate
     through namespaces in the system. This provides a programmatic
     interface to discover and inspect namespaces, addressing
     longstanding limitations:

     Currently, there is no direct way for userspace to enumerate
     namespaces. Applications must resort to scanning /proc/*/ns/ across
     all processes, which is:
      - Inefficient - requires iterating over all processes
      - Incomplete - misses namespaces not attached to any running
        process but kept alive by file descriptors, bind mounts, or
        parent references
      - Permission-heavy - requires access to /proc for many processes
      - No ordering or ownership information
      - No filtering per namespace type

     The listns() system call solves these problems:

       ssize_t listns(const struct ns_id_req *req, u64 *ns_ids,
                      size_t nr_ns_ids, unsigned int flags);

       struct ns_id_req {
             __u32 size;
             __u32 spare;
             __u64 ns_id;
             struct /* listns */ {
                     __u32 ns_type;
                     __u32 spare2;
                     __u64 user_ns_id;
             };
       };

     Features include:
      - Pagination support for large namespace sets
      - Filtering by namespace type (MNT_NS, NET_NS, USER_NS, etc.)
      - Filtering by owning user namespace
      - Permission checks respecting namespace isolation

   - Active Reference Counting

     Introduce an active reference count that tracks namespace
     visibility to userspace. A namespace is visible in the following
     cases:
      - The namespace is in use by a task
      - The namespace is persisted through a VFS object (namespace file
        descriptor or bind-mount)
      - The namespace is a hierarchical type and is the parent of child
        namespaces

     The active reference count does not regulate lifetime (that's still
     done by the normal reference count) - it only regulates visibility
     to namespace file handles and listns().

     This prevents resurrection of namespaces that are pinned only for
     internal kernel reasons (e.g., user namespaces held by
     file->f_cred, lazy TLB references on idle CPUs, etc.) which should
     not be accessible via (1)-(3).

   - Unified Namespace Tree

     Introduce a unified tree structure for all namespaces with:
      - Fixed IDs assigned to initial namespaces
      - Lookup based solely on inode number
      - Maintained list of owned namespaces per user namespace
      - Simplified rbtree comparison helpers

   Cleanups

    - Header Reorganization:
      - Move namespace types into separate header (ns_common_types.h)
      - Decouple nstree from ns_common header
      - Move nstree types into separate header
      - Switch to new ns_tree_{node,root} structures with helper functions
      - Use guards for ns_tree_lock

   - Initial Namespace Reference Count Optimization
      - Make all reference counts on initial namespaces a nop to avoid
        pointless cacheline ping-pong for namespaces that can never go
        away
      - Drop custom reference count initialization for initial namespaces
      - Add NS_COMMON_INIT() macro and use it for all namespaces
      - pid: rely on common reference count behavior

   - Miscellaneous Cleanups
      - Rename exit_task_namespaces() to exit_nsproxy_namespaces()
      - Rename is_initial_namespace() and make argument const
      - Use boolean to indicate anonymous mount namespace
      - Simplify owner list iteration in nstree
      - nsfs: raise SB_I_NODEV, SB_I_NOEXEC, and DCACHE_DONTCACHE explicitly
      - nsfs: use inode_just_drop()
      - pidfs: raise DCACHE_DONTCACHE explicitly
      - pidfs: simplify PIDFD_GET__NAMESPACE ioctls
      - libfs: allow to specify s_d_flags
      - cgroup: add cgroup namespace to tree after owner is set
      - nsproxy: fix free_nsproxy() and simplify create_new_namespaces()

  Fixes:

   - setns(pidfd, ...) race condition

     Fix a subtle race when using pidfds with setns(). When the target
     task exits after prepare_nsset() but before commit_nsset(), the
     namespace's active reference count might have been dropped. If
     setns() then installs the namespaces, it would bump the active
     reference count from zero without taking the required reference on
     the owner namespace, leading to underflow when later decremented.

     The fix resurrects the ownership chain if necessary - if the caller
     succeeded in grabbing passive references, the setns() should
     succeed even if the target task exits or gets reaped.

   - Return EFAULT on put_user() error instead of success

   - Make sure references are dropped outside of RCU lock (some
     namespaces like mount namespace sleep when putting the last
     reference)

   - Don't skip active reference count initialization for network
     namespace

   - Add asserts for active refcount underflow

   - Add asserts for initial namespace reference counts (both passive
     and active)

   - ipc: enable is_ns_init_id() assertions

   - Fix kernel-doc comments for internal nstree functions

   - Selftests
      - 15 active reference count tests
      - 9 listns() functionality tests
      - 7 listns() permission tests
      - 12 inactive namespace resurrection tests
      - 3 threaded active reference count tests
      - commit_creds() active reference tests
      - Pagination and stress tests
      - EFAULT handling test
      - nsid tests fixes"

* tag 'namespace-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (103 commits)
  pidfs: simplify PIDFD_GET_<type>_NAMESPACE ioctls
  nstree: fix kernel-doc comments for internal functions
  nsproxy: fix free_nsproxy() and simplify create_new_namespaces()
  selftests/namespaces: fix nsid tests
  ns: drop custom reference count initialization for initial namespaces
  pid: rely on common reference count behavior
  ns: add asserts for initial namespace active reference counts
  ns: add asserts for initial namespace reference counts
  ns: make all reference counts on initial namespace a nop
  ipc: enable is_ns_init_id() assertions
  fs: use boolean to indicate anonymous mount namespace
  ns: rename is_initial_namespace()
  ns: make is_initial_namespace() argument const
  nstree: use guards for ns_tree_lock
  nstree: simplify owner list iteration
  nstree: switch to new structures
  nstree: add helper to operate on struct ns_tree_{node,root}
  nstree: move nstree types into separate header
  nstree: decouple from ns_common header
  ns: move namespace types into separate header
  ...
2025-12-01 09:47:41 -08:00
Linus Torvalds b04b2e7a61 vfs-6.19-rc1.misc
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Merge tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE
     permission checks during path lookup and adds the
     IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid
     expensive permission work.

   - Hide dentry_cache behind runtime const machinery.

   - Add German Maglione as virtiofs co-maintainer.

  Cleanups:

   - Tidy up and inline step_into() and walk_component() for improved
     code generation.

   - Re-enable IOCB_NOWAIT writes to files. This refactors file
     timestamp update logic, fixing a layering bypass in btrfs when
     updating timestamps on device files and improving FMODE_NOCMTIME
     handling in VFS now that nfsd started using it.

   - Path lookup optimizations extracting slowpaths into dedicated
     routines and adding branch prediction hints for mntput_no_expire(),
     fd_install(), lookup_slow(), and various other hot paths.

   - Enable clang's -fms-extensions flag, requiring a JFS rename to
     avoid conflicts.

   - Remove spurious exports in fs/file_attr.c.

   - Stop duplicating union pipe_index declaration. This depends on the
     shared kbuild branch that brings in -fms-extensions support which
     is merged into this branch.

   - Use MD5 library instead of crypto_shash in ecryptfs.

   - Use largest_zero_folio() in iomap_dio_zero().

   - Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and
     initrd code.

   - Various typo fixes.

  Fixes:

   - Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs()
     call with wait == 1 to commit super blocks. The emergency sync path
     never passed this, leaving btrfs data uncommitted during emergency
     sync.

   - Use local kmap in watch_queue's post_one_notification().

   - Add hint prints in sb_set_blocksize() for LBS dependency on THP"

* tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  MAINTAINERS: add German Maglione as virtiofs co-maintainer
  fs: inline step_into() and walk_component()
  fs: tidy up step_into() & friends before inlining
  orangefs: use inode_update_timestamps directly
  btrfs: fix the comment on btrfs_update_time
  btrfs: use vfs_utimes to update file timestamps
  fs: export vfs_utimes
  fs: lift the FMODE_NOCMTIME check into file_update_time_flags
  fs: refactor file timestamp update logic
  include/linux/fs.h: trivial fix: regualr -> regular
  fs/splice.c: trivial fix: pipes -> pipe's
  fs: mark lookup_slow() as noinline
  fs: add predicts based on nd->depth
  fs: move mntput_no_expire() slowpath into a dedicated routine
  fs: remove spurious exports in fs/file_attr.c
  watch_queue: Use local kmap in post_one_notification()
  fs: touch up predicts in path lookup
  fs: move fd_install() slowpath into a dedicated routine and provide commentary
  fs: hide dentry_cache behind runtime const machinery
  fs: touch predicts in do_dentry_open()
  ...
2025-12-01 08:44:26 -08:00
Andrew Donnellan 2bd1337a12 KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
Switch to using the generic infrastructure to check for and handle pending
work before transitioning into guest mode.

xfer_to_guest_mode_handle_work() does a few more things than the current
code does when deciding whether or not to exit the __vcpu_run() loop. The
exittime tests from kvm-unit-tests, in my tests, were within a few percent
compared to before this series, which is within noise tolerance.

Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
[frankja@linux.ibm.com: Removed semicolon]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-28 10:11:14 +01:00
Heiko Carstens d0139059e3 KVM: s390: Enable and disable interrupts in entry code
Move enabling and disabling of interrupts around the SIE instruction to
entry code. Enabling interrupts only after the __TI_sie flag has been set
guarantees that the SIE instruction is not executed if an interrupt happens
between enabling interrupts and the execution of the SIE instruction.
Interrupt handlers and machine check handler forward the PSW to the
sie_exit label in such cases.

This is a prerequisite for VIRT_XFER_TO_GUEST_WORK to prevent that guest
context is entered when e.g. a scheduler IPI, indicating that a reschedule
is required, happens right before the SIE instruction, which could lead to
long delays.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-27 15:39:46 +01:00
Andrew Donnellan c067847c52 KVM: s390: Add signal_exits counter
Add a signal_exits counter for s390, as exists on arm64, loongarch, mips,
powerpc, riscv and x86.

This is used by kvm_handle_signal_exit(), which we will use when we
later enable CONFIG_VIRT_XFER_TO_GUEST_WORK.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-27 15:39:46 +01:00
Heiko Carstens 1c93edfd50 s390/entry: Use lay instead of aghik
Use the lay instruction instead of aghik. aghik is only available since
z196, therefore compiling the kernel for z10 results in this error:

   arch/s390/kernel/entry.S: Assembler messages:
   arch/s390/kernel/entry.S:165: Error: Unrecognized opcode: `aghik'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511261518.nBbQN5h7-lkp@intel.com/
Fixes: f5730d44e0 ("s390: Add stackprotector support")
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-26 12:28:23 +01:00
Paolo Bonzini de8e8ebb1a KVM TDX changes for 6.19:
- Overhaul the TDX code to address systemic races where KVM (acting on behalf
    of userspace) could inadvertantly trigger lock contention in the TDX-Module,
    which KVM was either working around in weird, ugly ways, or was simply
    oblivious to (as proven by Yan tripping several KVM_BUG_ON()s with clever
    selftests).
 
  - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a vCPU if
    creating said vCPU failed partway through.
 
  - Fix a few sparse warnings (bad annotation, 0 != NULL).
 
  - Use struct_size() to simplify copying capabilities to userspace.
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Merge tag 'kvm-x86-tdx-6.19' of https://github.com/kvm-x86/linux into HEAD

KVM TDX changes for 6.19:

 - Overhaul the TDX code to address systemic races where KVM (acting on behalf
   of userspace) could inadvertantly trigger lock contention in the TDX-Module,
   which KVM was either working around in weird, ugly ways, or was simply
   oblivious to (as proven by Yan tripping several KVM_BUG_ON()s with clever
   selftests).

 - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a vCPU if
   creating said vCPU failed partway through.

 - Fix a few sparse warnings (bad annotation, 0 != NULL).

 - Use struct_size() to simplify copying capabilities to userspace.
2025-11-26 09:36:37 +01:00
Heiko Carstens 509c34924d s390/vdso: Get rid of -m64 flag handling
The compiler/assembler flag -m64 is added and removed at two locations.
This pointless exercise is a leftover to keep the 31 and 64 bit vdso
Makefiles as symmetrical as possible. Given that the 31 bit vdso code
does not exist anymore, remove the -m64 flag handling.

Suggested-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-25 15:28:08 +01:00
Heiko Carstens c0087d807a s390/vdso: Rename vdso64 to vdso
Since compat is gone there is only a 64 bit vdso left.
Remove the superfluous "64" suffix everywhere.

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-25 15:28:07 +01:00
Heiko Carstens b3bdfdf1f9 s390: Rename head64.S to head.S
All the code is 64 bit, therefore remove the superfluous suffix.

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-25 15:28:07 +01:00
Jens Remus 5e811b922e s390/vdso: Use common STABS_DEBUG and DWARF_DEBUG macros
This simplifies the vDSO linker script.  The ELF_DETAILS macro was not
used in addition, as done on arm64 and powerpc, as that would introduce
an empty .modinfo section.

Note that this rearranges the .comment section to follow after all of
the debug sections.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-25 15:28:07 +01:00
Lorenzo Stoakes 9ff30bb9ab mm: remove non_swap_entry() and use softleaf helpers instead
There is simply no need for the hugely confusing concept of 'non-swap'
swap entries now we have the concept of softleaf entries and relevant
softleaf_xxx() helpers.

Adjust all callers to use these instead and remove non_swap_entry()
altogether.

No functional change intended.

Link: https://lkml.kernel.org/r/2562093f37f4a9cffea0447058014485eb50aaaf.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Xu <weixugc@google.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 15:08:51 -08:00
Claudio Imbrenda 1452468447 KVM: s390: fix missing present bit for gmap puds
For hugetlbs, gmap puds have the present bit set.  For normal puds (which
point to ptes), the bit is not set.  This is in contrast to the normal
userspace puds, which always have the bit set for present pmds.

This causes issues when ___pte_offset_map() is modified to only check for
the present bit.

The solution to the problem is simply to always set the present bit for
present gmap pmds.

Link: https://lkml.kernel.org/r/20251028130150.57379-2-imbrenda@linux.ibm.com
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/lkml/20251017144924.10034-1-borntraeger@linux.ibm.com/
Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Mika Penttilä <mpenttil@redhat.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 15:08:47 -08:00
Menglong Dong ae4a3160d1 bpf: specify the old and new poke_type for bpf_arch_text_poke
In the origin logic, the bpf_arch_text_poke() assume that the old and new
instructions have the same opcode. However, they can have different opcode
if we want to replace a "call" insn with a "jmp" insn.

Therefore, add the new function parameter "old_t" along with the "new_t",
which are used to indicate the old and new poke type. Meanwhile, adjust
the implement of bpf_arch_text_poke() for all the archs.

"BPF_MOD_NOP" is added to make the code more readable. In
bpf_arch_text_poke(), we still check if the new and old address is NULL to
determine if nop insn should be used, which I think is more safe.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20251118123639.688444-6-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-24 09:47:03 -08:00
Heiko Carstens f5730d44e0 s390: Add stackprotector support
Stackprotector support was previously unavailable on s390 because by
default compilers generate code which is not suitable for the kernel:
the canary value is accessed via thread local storage, where the address
of thread local storage is within access registers 0 and 1.

Using those registers also for the kernel would come with a significant
performance impact and more complicated kernel entry/exit code, since
access registers contents would have to be exchanged on every kernel entry
and exit.

With the upcoming gcc 16 release new compiler options will become available
which allow to generate code suitable for the kernel. [1]

Compiler option -mstack-protector-guard=global instructs gcc to generate
stackprotector code that refers to a global stackprotector canary value via
symbol __stack_chk_guard. Access to this value is guaranteed to occur via
larl and lgrl instructions.

Furthermore, compiler option -mstack-protector-guard-record generates a
section containing all code addresses that reference the canary value.

To allow for per task canary values the instructions which load the address
of __stack_chk_guard are patched so they access a lowcore field instead: a
per task canary value is available within the task_struct of each task, and
is written to the per-cpu lowcore location on each context switch.

Also add sanity checks and debugging option to be consistent with other
kernel code patching mechanisms.

Full debugging output can be enabled with the following kernel command line
options:

debug_stackprotector
bootdebug
ignore_loglevel
earlyprintk
dyndbg="file stackprotector.c +p"

Example debug output:

stackprot: 0000021e402d4eda: c010005a9ae3 -> c01f00070240

where "<insn address>: <old insn> -> <new insn>".

[1] gcc commit 0cd1f03939d5 ("s390: Support global stack protector")

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:21 +01:00
Heiko Carstens 1d7764cfe3 s390/modules: Simplify module_finalize() slightly
Preinitialize the return value, and break out the for loop in
module_finalize() in case of an error to get rid of an ifdef.

This makes it easier to add additional code, which may also depend
on config options.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:21 +01:00
Heiko Carstens c3d17464f0 s390: Remove KMSG_COMPONENT macro
The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel
message catalog" which never made it upstream.

Remove the macro in order to get rid of a pointless indirection. Replace
all users with the string it defines. In almost all cases this leads to a
simple replacement like this:

 - #define KMSG_COMPONENT "appldata"
 - #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 + #define pr_fmt(fmt) "appldata: " fmt

Except for some special cases this is just mechanical/scripted work.

Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:21 +01:00
Heiko Carstens e950d1f84d s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
Since the rework of the kernel virtual address space [1] the module area
and the kernel image are within the same 4GB area. Therefore there is no
need for the weak per cpu workaround for modules anymore. Remove it.

[1] commit c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:20 +01:00
Eric Biggers c7dcb041ce crypto: ansi_cprng - Remove unused ansi_cprng algorithm
Remove ansi_cprng, since it's obsolete and unused, as confirmed at
https://lore.kernel.org/r/aQxpnckYMgAAOLpZ@gondor.apana.org.au/

This was originally added in 2008, apparently as a FIPS approved random
number generator.  Whether this has ever belonged upstream is
questionable.  Either way, ansi_cprng is no longer usable for this
purpose, since it's been superseded by the more modern algorithms in
crypto/drbg.c, and FIPS itself no longer allows it.  (NIST SP 800-131A
Rev 1 (2015) says that RNGs based on ANSI X9.31 will be disallowed after
2015.  NIST SP 800-131A Rev 2 (2019) confirms they are now disallowed.)

Therefore, there is no reason to keep it around.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Haotian Zhang <vulab@iscas.ac.cn>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-11-22 10:04:50 +08:00
Peter Zijlstra 2ace527183 Merge branch 'objtool/core'
Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-11-21 11:21:20 +01:00
Eric Farman 44acac00be KVM: s390: vsie: Check alignment of BSCA header
The VSIE code currently checks that the BSCA struct fits within
a page, and returns a validity exception 0x003b if it doesn't.
The BSCA is pinned in memory rather than shadowed (see block
comment at end of kvm_s390_cpu_feat_init()), so enforcing the
CPU entries to be on the same pinned page makes sense.

Except those entries aren't going to be used below the guest,
and according to the definition of that validity exception only
the header of the BSCA (everything but the CPU entries) needs to
be within a page. Adjust the alignment check to account for that.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-21 10:33:57 +01:00
Janosch Frank 8e8678e740 KVM: s390: Add capability that forwards operation exceptions
Setting KVM_CAP_S390_USER_OPEREXEC will forward all operation
exceptions to user space. This also includes the 0x0000 instructions
managed by KVM_CAP_S390_USER_INSTR0. It's helpful if user space wants
to emulate instructions which do not (yet) have an opcode.

While we're at it refine the documentation for
KVM_CAP_S390_USER_INSTR0.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-21 10:26:03 +01:00
Peter Zijlstra c04507ac50 sched: Provide and use set_need_resched_current()
set_tsk_need_resched(current) requires set_preempt_need_resched(current) to
work correctly outside of the scheduler.

Provide set_need_resched_current() which wraps this correctly and replace
all the open coded instances.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251116174750.665769842@linutronix.de
2025-11-20 22:26:09 +01:00
Al Viro 2a3d40476b convert hypfs
just have hypfs_create_file() do the usual simple_start_creating()/
d_make_persistent()/simple_done_creating() and that's it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-17 23:59:27 -05:00
Al Viro 723c2ba859 hypfs: swich hypfs_create_u64() to returning int
same story as for hypfs_create_str()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-17 23:59:27 -05:00
Al Viro 63f76f51fe hypfs: switch hypfs_create_str() to returning int
Every single caller only cares about PTR_ERR_OR_ZERO() of return value...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-17 23:59:27 -05:00
Al Viro 781716cd4a hypfs: don't pin dentries twice
hypfs dentries end up with refcount 2 when they are not busy.
Refcount 1 is enough to keep them pinned, and going that way
allows to simplify things nicely:
	* don't need to drop an extra reference before the
call of kill_litter_super() in ->kill_sb(); all we need
there is to reset the cleanup list - everything on it will
be taken out automatically.
	* we can make use of simple_recursive_removal() on
tree rebuilds; just make sure that only children of root
end up in the cleanup list and hypfs_delete_tree() becomes
much simpler

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-17 23:59:27 -05:00
Heiko Carstens 4ac286c4a8 s390/syscalls: Switch to generic system call table generation
The s390 syscall.tbl format differs slightly from most others, and
therefore requires an s390 specific system call table generation
script.

With compat support gone use the opportunity to switch to generic
system call table generation. The abi for all 64 bit system calls is
now common, since there is no need to specify if system call entry
points are only for 64 bit anymore.

Furthermore create the system call table in C instead of assembler
code in order to get type checking for all system call functions
contained within the table.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:39 +01:00