Pull KVM updates from Paolo Bonzini:
"Loongarch:
- Add more CPUCFG mask bits
- Improve feature detection
- Add lazy load support for FPU and binary translation (LBT) register
state
- Fix return value for memory reads from and writes to in-kernel
devices
- Add support for detecting preemption from within a guest
- Add KVM steal time test case to tools/selftests
ARM:
- Add support for FEAT_IDST, allowing ID registers that are not
implemented to be reported as a normal trap rather than as an UNDEF
exception
- Add sanitisation of the VTCR_EL2 register, fixing a number of
UXN/PXN/XN bugs in the process
- Full handling of RESx bits, instead of only RES0, and resulting in
SCTLR_EL2 being added to the list of sanitised registers
- More pKVM fixes for features that are not supposed to be exposed to
guests
- Make sure that MTE being disabled on the pKVM host doesn't give it
the ability to attack the hypervisor
- Allow pKVM's host stage-2 mappings to use the Force Write Back
version of the memory attributes by using the "pass-through'
encoding
- Fix trapping of ICC_DIR_EL1 on GICv5 hosts emulating GICv3 for the
guest
- Preliminary work for guest GICv5 support
- A bunch of debugfs fixes, removing pointless custom iterators
stored in guest data structures
- A small set of FPSIMD cleanups
- Selftest fixes addressing the incorrect alignment of page
allocation
- Other assorted low-impact fixes and spelling fixes
RISC-V:
- Fixes for issues discoverd by KVM API fuzzing in
kvm_riscv_aia_imsic_has_attr(), kvm_riscv_aia_imsic_rw_attr(), and
kvm_riscv_vcpu_aia_imsic_update()
- Allow Zalasr, Zilsd and Zclsd extensions for Guest/VM
- Transparent huge page support for hypervisor page tables
- Adjust the number of available guest irq files based on MMIO
register sizes found in the device tree or the ACPI tables
- Add RISC-V specific paging modes to KVM selftests
- Detect paging mode at runtime for selftests
s390:
- Performance improvement for vSIE (aka nested virtualization)
- Completely new memory management. s390 was a special snowflake that
enlisted help from the architecture's page table management to
build hypervisor page tables, in particular enabling sharing the
last level of page tables. This however was a lot of code (~3K
lines) in order to support KVM, and also blocked several features.
The biggest advantages is that the page size of userspace is
completely independent of the page size used by the guest:
userspace can mix normal pages, THPs and hugetlbfs as it sees fit,
and in fact transparent hugepages were not possible before. It's
also now possible to have nested guests and guests with huge pages
running on the same host
- Maintainership change for s390 vfio-pci
- Small quality of life improvement for protected guests
x86:
- Add support for giving the guest full ownership of PMU hardware
(contexted switched around the fastpath run loop) and allowing
direct access to data MSRs and PMCs (restricted by the vPMU model).
KVM still intercepts access to control registers, e.g. to enforce
event filtering and to prevent the guest from profiling sensitive
host state. This is more accurate, since it has no risk of
contention and thus dropped events, and also has significantly less
overhead.
For more information, see the commit message for merge commit
bf2c3138ae ("Merge tag 'kvm-x86-pmu-6.20' ...")
- Disallow changing the virtual CPU model if L2 is active, for all
the same reasons KVM disallows change the model after the first
KVM_RUN
- Fix a bug where KVM would incorrectly reject host accesses to PV
MSRs when running with KVM_CAP_ENFORCE_PV_FEATURE_CPUID enabled,
even if those were advertised as supported to userspace,
- Fix a bug with protected guest state (SEV-ES/SNP and TDX) VMs,
where KVM would attempt to read CR3 configuring an async #PF entry
- Fail the build if EXPORT_SYMBOL_GPL or EXPORT_SYMBOL is used in KVM
(for x86 only) to enforce usage of EXPORT_SYMBOL_FOR_KVM_INTERNAL.
Only a few exports that are intended for external usage, and those
are allowed explicitly
- When checking nested events after a vCPU is unblocked, ignore
-EBUSY instead of WARNing. Userspace can sometimes put the vCPU
into what should be an impossible state, and spurious exit to
userspace on -EBUSY does not really do anything to solve the issue
- Also throw in the towel and drop the WARN on INIT/SIPI being
blocked when vCPU is in Wait-For-SIPI, which also resulted in
playing whack-a-mole with syzkaller stuffing architecturally
impossible states into KVM
- Add support for new Intel instructions that don't require anything
beyond enumerating feature flags to userspace
- Grab SRCU when reading PDPTRs in KVM_GET_SREGS2
- Add WARNs to guard against modifying KVM's CPU caps outside of the
intended setup flow, as nested VMX in particular is sensitive to
unexpected changes in KVM's golden configuration
- Add a quirk to allow userspace to opt-in to actually suppress EOI
broadcasts when the suppression feature is enabled by the guest
(currently limited to split IRQCHIP, i.e. userspace I/O APIC).
Sadly, simply fixing KVM to honor Suppress EOI Broadcasts isn't an
option as some userspaces have come to rely on KVM's buggy behavior
(KVM advertises Supress EOI Broadcast irrespective of whether or
not userspace I/O APIC supports Directed EOIs)
- Clean up KVM's handling of marking mapped vCPU pages dirty
- Drop a pile of *ancient* sanity checks hidden behind in KVM's
unused ASSERT() macro, most of which could be trivially triggered
by the guest and/or user, and all of which were useless
- Fold "struct dest_map" into its sole user, "struct rtc_status", to
make it more obvious what the weird parameter is used for, and to
allow fropping these RTC shenanigans if CONFIG_KVM_IOAPIC=n
- Bury all of ioapic.h, i8254.h and related ioctls (including
KVM_CREATE_IRQCHIP) behind CONFIG_KVM_IOAPIC=y
- Add a regression test for recent APICv update fixes
- Handle "hardware APIC ISR", a.k.a. SVI, updates in
kvm_apic_update_apicv() to consolidate the updates, and to
co-locate SVI updates with the updates for KVM's own cache of ISR
information
- Drop a dead function declaration
- Minor cleanups
x86 (Intel):
- Rework KVM's handling of VMCS updates while L2 is active to
temporarily switch to vmcs01 instead of deferring the update until
the next nested VM-Exit.
The deferred updates approach directly contributed to several bugs,
was proving to be a maintenance burden due to the difficulty in
auditing the correctness of deferred updates, and was polluting
"struct nested_vmx" with a growing pile of booleans
- Fix an SGX bug where KVM would incorrectly try to handle EPCM page
faults, and instead always reflect them into the guest. Since KVM
doesn't shadow EPCM entries, EPCM violations cannot be due to KVM
interference and can't be resolved by KVM
- Fix a bug where KVM would register its posted interrupt wakeup
handler even if loading kvm-intel.ko ultimately failed
- Disallow access to vmcb12 fields that aren't fully supported,
mostly to avoid weirdness and complexity for FRED and other
features, where KVM wants enable VMCS shadowing for fields that
conditionally exist
- Print out the "bad" offsets and values if kvm-intel.ko refuses to
load (or refuses to online a CPU) due to a VMCS config mismatch
x86 (AMD):
- Drop a user-triggerable WARN on nested_svm_load_cr3() failure
- Add support for virtualizing ERAPS. Note, correct virtualization of
ERAPS relies on an upcoming, publicly announced change in the APM
to reduce the set of conditions where hardware (i.e. KVM) *must*
flush the RAP
- Ignore nSVM intercepts for instructions that are not supported
according to L1's virtual CPU model
- Add support for expedited writes to the fast MMIO bus, a la VMX's
fastpath for EPT Misconfig
- Don't set GIF when clearing EFER.SVME, as GIF exists independently
of SVM, and allow userspace to restore nested state with GIF=0
- Treat exit_code as an unsigned 64-bit value through all of KVM
- Add support for fetching SNP certificates from userspace
- Fix a bug where KVM would use vmcb02 instead of vmcb01 when
emulating VMLOAD or VMSAVE on behalf of L2
- Misc fixes and cleanups
x86 selftests:
- Add a regression test for TPR<=>CR8 synchronization and IRQ masking
- Overhaul selftest's MMU infrastructure to genericize stage-2 MMU
support, and extend x86's infrastructure to support EPT and NPT
(for L2 guests)
- Extend several nested VMX tests to also cover nested SVM
- Add a selftest for nested VMLOAD/VMSAVE
- Rework the nested dirty log test, originally added as a regression
test for PML where KVM logged L2 GPAs instead of L1 GPAs, to
improve test coverage and to hopefully make the test easier to
understand and maintain
guest_memfd:
- Remove kvm_gmem_populate()'s preparation tracking and half-baked
hugepage handling. SEV/SNP was the only user of the tracking and it
can do it via the RMP
- Retroactively document and enforce (for SNP) that
KVM_SEV_SNP_LAUNCH_UPDATE and KVM_TDX_INIT_MEM_REGION require the
source page to be 4KiB aligned, to avoid non-trivial complexity for
something that no known VMM seems to be doing and to avoid an API
special case for in-place conversion, which simply can't support
unaligned sources
- When populating guest_memfd memory, GUP the source page in common
code and pass the refcounted page to the vendor callback, instead
of letting vendor code do the heavy lifting. Doing so avoids a
looming deadlock bug with in-place due an AB-BA conflict betwee
mmap_lock and guest_memfd's filemap invalidate lock
Generic:
- Fix a bug where KVM would ignore the vCPU's selected address space
when creating a vCPU-specific mapping of guest memory. Actually
this bug could not be hit even on x86, the only architecture with
multiple address spaces, but it's a bug nevertheless"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (267 commits)
KVM: s390: Increase permitted SE header size to 1 MiB
MAINTAINERS: Replace backup for s390 vfio-pci
KVM: s390: vsie: Fix race in acquire_gmap_shadow()
KVM: s390: vsie: Fix race in walk_guest_tables()
KVM: s390: Use guest address to mark guest page dirty
irqchip/riscv-imsic: Adjust the number of available guest irq files
RISC-V: KVM: Transparent huge page support
RISC-V: KVM: selftests: Add Zalasr extensions to get-reg-list test
RISC-V: KVM: Allow Zalasr extensions for Guest/VM
KVM: riscv: selftests: Add riscv vm satp modes
KVM: riscv: selftests: add Zilsd and Zclsd extension to get-reg-list test
riscv: KVM: allow Zilsd and Zclsd extensions for Guest/VM
RISC-V: KVM: Skip IMSIC update if vCPU IMSIC state is not initialized
RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_rw_attr()
RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_has_attr()
RISC-V: KVM: Remove unnecessary 'ret' assignment
KVM: s390: Add explicit padding to struct kvm_s390_keyop
KVM: LoongArch: selftests: Add steal time test case
LoongArch: KVM: Add paravirt vcpu_is_preempted() support in guest side
LoongArch: KVM: Add paravirt preempt feature in hypervisor side
...
Pull RISC-V updates from Paul Walmsley:
- Add support for control flow integrity for userspace processes.
This is based on the standard RISC-V ISA extensions Zicfiss and
Zicfilp
- Improve ptrace behavior regarding vector registers, and add some
selftests
- Optimize our strlen() assembly
- Enable the ISO-8859-1 code page as built-in, similar to ARM64, for
EFI volume mounting
- Clean up some code slightly, including defining copy_user_page() as
copy_page() rather than memcpy(), aligning us with other
architectures; and using max3() to slightly simplify an expression
in riscv_iommu_init_check()
* tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
riscv: lib: optimize strlen loop efficiency
selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function
selftests: riscv: verify ptrace accepts valid vector csr values
selftests: riscv: verify ptrace rejects invalid vector csr inputs
selftests: riscv: verify syscalls discard vector context
selftests: riscv: verify initial vector state with ptrace
selftests: riscv: test ptrace vector interface
riscv: ptrace: validate input vector csr registers
riscv: csr: define vtype register elements
riscv: vector: init vector context with proper vlenb
riscv: ptrace: return ENODATA for inactive vector extension
kselftest/riscv: add kselftest for user mode CFI
riscv: add documentation for shadow stack
riscv: add documentation for landing pad / indirect branch tracking
riscv: create a Kconfig fragment for shadow stack and landing pad support
arch/riscv: add dual vdso creation logic and select vdso based on hw
arch/riscv: compile vdso with landing pad and shadow stack note
riscv: enable kernel access to shadow stack memory via the FWFT SBI call
riscv: add kernel command line option to opt out of user CFI
riscv/hwprobe: add zicfilp / zicfiss enumeration in hwprobe
...
Pull MM updates from Andrew Morton:
- "powerpc/64s: do not re-activate batched TLB flush" makes
arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)
It adds a generic enter/leave layer and switches architectures to use
it. Various hacks were removed in the process.
- "zram: introduce compressed data writeback" implements data
compression for zram writeback (Richard Chang and Sergey Senozhatsky)
- "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
page ranges for hugepages. Large improvements during demand faulting
are demonstrated (David Hildenbrand)
- "memcg cleanups" tidies up some memcg code (Chen Ridong)
- "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
stats" improves DAMOS stat's provided information, deterministic
control, and readability (SeongJae Park)
- "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
issues in the hugetlb cgroup charging selftests (Li Wang)
- "Fix va_high_addr_switch.sh test failure - again" addresses several
issues in the va_high_addr_switch test (Chunyu Hu)
- "mm/damon/tests/core-kunit: extend existing test scenarios" improves
the KUnit test coverage for DAMON (Shu Anzai)
- "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
transiently return -EAGAIN (Shivank Garg)
- "arch, mm: consolidate hugetlb early reservation" reworks and
consolidates a pile of straggly code related to reservation of
hugetlb memory from bootmem and creation of CMA areas for hugetlb
(Mike Rapoport)
- "mm: clean up anon_vma implementation" cleans up the anon_vma
implementation in various ways (Lorenzo Stoakes)
- "tweaks for __alloc_pages_slowpath()" does a little streamlining of
the page allocator's slowpath code (Vlastimil Babka)
- "memcg: separate private and public ID namespaces" cleans up the
memcg ID code and prevents the internal-only private IDs from being
exposed to userspace (Shakeel Butt)
- "mm: hugetlb: allocate frozen gigantic folio" cleans up the
allocation of frozen folios and avoids some atomic refcount
operations (Kefeng Wang)
- "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
of memory betewwn the active and inactive LRUs and adds auto-tuning
of the ratio-based quotas and of monitoring intervals (SeongJae Park)
- "Support page table check on PowerPC" makes
CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)
- "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
nodes_and() and nodes_andnot() propagate the return values from the
underlying bit operations, enabling some cleanup in calling code
(Yury Norov)
- "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
some DAMON internal interfaces (SeongJae Park)
- "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
in khupaged and fixes a scan limit accounting issue (Shivank Garg)
- "mm: balloon infrastructure cleanups" goes to town on the balloon
infrastructure and its page migration function. Mainly cleanups, also
some locking simplification (David Hildenbrand)
- "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
additional tracepoints to the page reclaim code (Jiayuan Chen)
- "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
part of Marco's kernel-wide migration from the legacy workqueue APIs
over to the preferred unbound workqueues (Marco Crivellari)
- "Various mm kselftests improvements/fixes" provides various unrelated
improvements/fixes for the mm kselftests (Kevin Brodsky)
- "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
folio allocation, mainly by avoiding unnecessary work in
pfn_range_valid_contig() (Kefeng Wang)
- "selftests/damon: improve leak detection and wss estimation
reliability" improves the reliability of two of the DAMON selftests
(SeongJae Park)
- "mm/damon: cleanup kdamond, damon_call(), damos filter and
DAMON_MIN_REGION" does some cleanup work in the core DAMON code
(SeongJae Park)
- "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
performs maintenance work on the DAMON documentation (SeongJae Park)
- "mm: add and use vma_assert_stabilised() helper" refactors and cleans
up the core VMA code. The main aim here is to be able to use the mmap
write lock's lockdep state to perform various assertions regarding
the locking which the VMA code requires (Lorenzo Stoakes)
- "mm, swap: swap table phase II: unify swapin use" removes some old
swap code (swap cache bypassing and swap synchronization) which
wasn't working very well. Various other cleanups and simplifications
were made. The end result is a 20% speedup in one benchmark (Kairui
Song)
- "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
available on 64-bit alpha, loongarch, mips, parisc, and um. Various
cleanups were performed along the way (Qi Zheng)
* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
mm/memory: handle non-split locks correctly in zap_empty_pte_table()
mm: move pte table reclaim code to memory.c
mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
um: mm: enable MMU_GATHER_RCU_TABLE_FREE
parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
zsmalloc: make common caches global
mm: add SPDX id lines to some mm source files
mm/zswap: use %pe to print error pointers
mm/vmscan: use %pe to print error pointers
mm/readahead: fix typo in comment
mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
mm: refactor vma_map_pages to use vm_insert_pages
mm/damon: unify address range representation with damon_addr_range
mm/cma: replace snprintf with strscpy in cma_new_area
...
KVM/riscv changes for 6.20
- Fixes for issues discoverd by KVM API fuzzing in
kvm_riscv_aia_imsic_has_attr(), kvm_riscv_aia_imsic_rw_attr(),
and kvm_riscv_vcpu_aia_imsic_update()
- Allow Zalasr, Zilsd and Zclsd extensions for Guest/VM
- Add riscv vm satp modes in KVM selftests
- Transparent huge page support for G-stage
- Adjust the number of available guest irq files based on
MMIO register sizes in DeviceTree or ACPI
Pull x86 paravirt updates from Borislav Petkov:
- A nice cleanup to the paravirt code containing a unification of the
paravirt clock interface, taming the include hell by splitting the
pv_ops structure and removing of a bunch of obsolete code (Juergen
Gross)
* tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted()
x86/paravirt: Remove trailing semicolons from alternative asm templates
x86/pvlocks: Move paravirt spinlock functions into own header
x86/paravirt: Specify pv_ops array in paravirt macros
x86/paravirt: Allow pv-calls outside paravirt.h
objtool: Allow multiple pv_ops arrays
x86/xen: Drop xen_mmu_ops
x86/xen: Drop xen_cpu_ops
x86/xen: Drop xen_irq_ops
x86/paravirt: Move pv_native_*() prototypes to paravirt.c
x86/paravirt: Introduce new paravirt-base.h header
x86/paravirt: Move paravirt_sched_clock() related code into tsc.c
x86/paravirt: Use common code for paravirt_steal_clock()
riscv/paravirt: Use common code for paravirt_steal_clock()
loongarch/paravirt: Use common code for paravirt_steal_clock()
arm64/paravirt: Use common code for paravirt_steal_clock()
arm/paravirt: Use common code for paravirt_steal_clock()
sched: Move clock related paravirt code to kernel/sched
paravirt: Remove asm/paravirt_api_clock.h
x86/paravirt: Move thunk macros to paravirt_types.h
...
Shadow stack instructions are taken from the Zimop ISA extension,
which is mandated on RVA23. Any userspace with shadow stack
instructions in it will fault on hardware that doesn't have support
for Zimop. Thus, a shadow stack-enabled userspace can't be run on
hardware that doesn't support Zimop.
It's not known how Linux userspace providers will respond to this kind
of binary fragmentation. In order to keep kernel portable across
different hardware, 'arch/riscv/kernel/vdso_cfi' is created which has
Makefile logic to compile 'arch/riscv/kernel/vdso' sources with CFI
flags, and 'arch/riscv/kernel/vdso.c' is modified to select the
appropriate vdso depending on whether the underlying CPU implements
the Zimop extension. Since the offset of vdso symbols will change due
to having two different vdso binaries, there is added logic to include
a new generated vdso offset header and dynamically select the offset
(like for rt_sigreturn).
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Acked-by: Charles Mirabile <cmirabil@redhat.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-24-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
User mode tasks compiled with Zicfilp may call indirectly into the
vdso (like hwprobe indirect calls). Add support for compiling landing
pads into the vdso. Landing pad instructions in the vdso will be
no-ops for tasks which have not enabled landing pads. Furthermore, add
support for the C sources of the vdso to be compiled with shadow stack
and landing pads enabled as well.
Landing pad and shadow stack instructions are emitted only when the
VDSO_CFI cflags option is defined during compile.
Signed-off-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-23-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description, issues reported by checkpatch]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Add a kernel command line option to disable part or all
of user CFI. User backward CFI and forward CFI can be controlled
independently. The kernel command line parameter "riscv_nousercfi" can
take the following values:
- "all" : Disable forward and backward cfi both
- "bcfi" : Disable backward cfi
- "fcfi" : Disable forward cfi
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-21-b55691eacf4f@rivosinc.com
[pjw@kernel.org: fixed warnings from checkpatch; cleaned up patch description, doc, printk text]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
We've run out of bits to describe RISC-V ISA extensions in our initial
hwprobe key, RISCV_HWPROBE_KEY_IMA_EXT_0. So, let's add
RISCV_HWPROBE_KEY_IMA_EXT_1, along with the framework to set the
appropriate hwprobe tuple, and add testing for it.
Based on a suggestion from Andrew Jones <andrew.jones@oss.qualcomm.com>,
also fix the documentation for RISCV_HWPROBE_KEY_IMA_EXT_0.
Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Expose a new register type NT_RISCV_USER_CFI for risc-v CFI status and
state. Intentionally, both landing pad and shadow stack status and
state are rolled into the CFI state. Creating two different
NT_RISCV_USER_XXX would not be useful and would waste a note
type. Enabling, disabling and locking the CFI feature is not allowed
via ptrace set interface. However, setting 'elp' state or setting
shadow stack pointer are allowed via the ptrace set interface. It is
expected that 'gdb' might need to fixup 'elp' state or 'shadow stack'
pointer.
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-19-b55691eacf4f@rivosinc.com
[pjw@kernel.org: updated to apply; cleaned patch description and comments; addressed checkpatch issues]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Save the shadow stack pointer in the sigcontext structure when
delivering a signal. Restore the shadow stack pointer from sigcontext
on sigreturn.
As part of the save operation, the kernel uses the 'ssamoswap'
instruction to save a snapshot of the current shadow stack on the
shadow stack itself (this can be called a "save token"). During
restore on sigreturn, the kernel retrieves the save token from the top
of the shadow stack and validates it. This ensures that user mode
can't arbitrarily pivot to any shadow stack address without having a
token and thus provides a strong security assurance during the window
between signal delivery and sigreturn.
Use an ABI-compatible way of saving/restoring the shadow stack pointer
into the signal stack. This follows the vector extension, where extra
registers are placed in a form of extension header + extension body in
the stack. The extension header indicates the size of the extra
architectural states plus the size of header itself, and a magic
identifier for the extension. Then, the extension body contains the
new architectural states in the form defined by uapi.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de>
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-17-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned patch description, code comments; resolved checkpatch warning]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
The Zicfiss and Zicfilp extensions introduce a new exception, the
'software check exception', in the privileged ISA, with cause code =
18. This patch implements support for software check exceptions.
Additionally, the patch implements a CFI violation handler which
checks the code in the xtval register. If xtval=2, the software check
exception happened because of an indirect branch that didn't land on a
4 byte aligned PC or on a 'lpad' instruction, or the label value
embedded in 'lpad' didn't match the label value set in the x7
register. If xtval=3, the software check exception happened due to a
mismatch between the link register (x1 or x5) and the top of shadow
stack (on execution of `sspopchk`).
In case of a CFI violation, SIGSEGV is raised with code=SEGV_CPERR.
SEGV_CPERR was introduced by the x86 shadow stack patches.
To keep uprobes working, handle the uprobe event first before
reporting the CFI violation in the software check exception
handler. This is because, when the landing pad is activated, if the
uprobe point is set at the lpad instruction at the beginning of a
function, the system triggers a software check exception instead of an
ebreak exception due to the exception priority. This would prevent
uprobe from working.
Reviewed-by: Zong Li <zong.li@sifive.com>
Co-developed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-15-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up the patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Implement an architecture-agnostic prctl() interface for setting and
getting shadow stack status. The prctls implemented are
PR_GET_SHADOW_STACK_STATUS, PR_SET_SHADOW_STACK_STATUS and
PR_LOCK_SHADOW_STACK_STATUS.
As part of PR_SET_SHADOW_STACK_STATUS/PR_GET_SHADOW_STACK_STATUS, only
PR_SHADOW_STACK_ENABLE is implemented because RISCV allows each mode to
write to their own shadow stack using 'sspush' or 'ssamoswap'.
PR_LOCK_SHADOW_STACK_STATUS locks the current shadow stack enablement
configuration.
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-12-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Userspace specifies CLONE_VM to share address space and spawn new
thread. 'clone' allows userspace to specify a new stack for a new
thread. However there is no way to specify a new shadow stack base
address without changing the API. This patch allocates a new shadow
stack whenever CLONE_VM is given.
In case of CLONE_VFORK, the parent is suspended until the child
finishes; thus the child can use the parent's shadow stack. In case of
!CLONE_VM, COW kicks in because entire address space is copied from
parent to child.
'clone3' is extensible and can provide mechanisms for specifying the
shadow stack as an input parameter. This is not settled yet and is
being extensively discussed on the mailing list. Once that's settled,
this code should be adapted.
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-11-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
'fork' implements copy-on-write (COW) by making pages readonly in both
child and parent.
ptep_set_wrprotect() and pte_wrprotect() clear _PAGE_WRITE in PTE.
The assumption is that the page is readable and, on a fault,
copy-on-write happens.
To implement COW on shadow stack pages, clearing the W bit makes them
XWR = 000. This will result in the wrong PTE setting, which allows no
permissions, but with V=1 and the PFN field pointing to the final
page. Instead, the desired behavior is to turn it into a readable
page, take an access (load/store) fault on sspush/sspop (shadow stack)
and then perform COW on such pages. This way regular reads would still
be allowed and not lead to COW maintaining current behavior of COW on
non-shadow stack but writeable memory.
On the other hand, this doesn't interfere with existing COW for
read-write memory. The assumption is always that _PAGE_READ must have
been set, and thus, setting _PAGE_READ is harmless.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-9-b55691eacf4f@rivosinc.com
[pjw@kernel.org: clarify patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
pte_mkwrite() creates PTEs with WRITE encodings for the underlying
architecture. The underlying architecture can have two types of
writeable mappings: one that can be written using regular store
instructions, and another one that can only be written using
specialized store instructions (like shadow stack stores).
pte_mkwrite can select write PTE encoding based on VMA range (i.e.
VM_SHADOW_STACK)
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-8-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
'arch_calc_vm_prot_bits' is implemented on risc-v to return VM_READ |
VM_WRITE if PROT_WRITE is specified. Similarly 'riscv_sys_mmap' is
updated to convert all incoming PROT_WRITE to (PROT_WRITE | PROT_READ).
This is to make sure that any existing apps using PROT_WRITE still work.
Earlier 'protection_map[VM_WRITE]' used to pick read-write PTE encodings.
Now 'protection_map[VM_WRITE]' will always pick PAGE_SHADOWSTACK PTE
encodings for shadow stack. The above changes ensure that existing apps
continue to work because underneath, the kernel will be picking
'protection_map[VM_WRITE|VM_READ]' PTE encodings.
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-6-b55691eacf4f@rivosinc.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Carve out space in the RISC-V architecture-specific thread struct for
cfi status and shadow stack in usermode.
This patch:
- defines a new structure cfi_status with status bit for cfi feature
- defines shadow stack pointer, base and size in cfi_status structure
- defines offsets to new member fields in thread in asm-offsets.c
- saves and restores shadow stack pointer on trap entry (U --> S) and exit
(S --> U)
Shadow stack save/restore is gated on feature availability and is
implemented using alternatives. CSR_SSP can be context-switched in
'switch_to' as well, but as soon as kernel shadow stack support gets
rolled in, the shadow stack pointer will need to be switched at trap
entry/exit point (much like 'sp'). It can be argued that a kernel
using a shadow stack deployment scenario may not be as prevalent as
user mode using this feature. But even if there is some minimal
deployment of kernel shadow stack, that means that it needs to be
supported. Thus save/restore of shadow stack pointer is implemented
in entry.S instead of in 'switch_to.h'.
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-5-b55691eacf4f@rivosinc.com
[pjw@kernel.org: cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
The Zicfiss and Zicfilp extensions are enabled via b3 and b2 in
*envcfg CSRs. menvcfg controls enabling for S/HS mode. henvcfg
controls enabling for VS. senvcfg controls enabling for U/VU mode.
The Zicfilp extension extends *status CSRs to hold an 'expected
landing pad' bit. A trap or interrupt can occur between an indirect
jmp/call and target instruction. The 'expected landing pad' bit from
the CPU is recorded into the xstatus CSR so that when the supervisor
performs xret, the 'expected landing pad' state of the CPU can be
restored.
Zicfiss adds one new CSR, CSR_SSP, which contains the current shadow
stack pointer.
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-4-b55691eacf4f@rivosinc.com
[pjw@kernel.org: grouped CSR_SSP macro with the other CSR macros; clarified patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
This patch adds support for detecting the RISC-V ISA extensions
Zicfiss and Zicfilp. Zicfiss and Zicfilp stand for the unprivileged
integer spec extensions for shadow stack and indirect branch tracking,
respectively.
This patch looks for Zicfiss and Zicfilp in the device tree and
accordingly lights up the corresponding bits in the cpu feature
bitmap. Furthermore this patch adds detection utility functions to
return whether shadow stack or landing pads are supported by the cpu.
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6
Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-3-b55691eacf4f@rivosinc.com
[pjw@kernel.org: updated to apply; cleaned up patch description]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Currently, the implementation of copy_user_page() is identical to
copy_page().
Align riscv with other architectures (alpha, arc, arm64, hexagon,
longarch, m68k, openrisc, s390, um, xtensa) and map copy_user_page()
to copy_page() given that their implementation is identical.
In addition to following a common pattern, this centralizes the
implementation. Any changes to the underlying page copy logic (e.g.,
for CHERI) will now automatically propagate to copy_user_page().
Signed-off-by: Florian Schmaus <florian.schmaus@codasip.com>
Link: https://patch.msgid.link/20260113134025.905627-1-florian.schmaus@codasip.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
After commit bdce162f2e ("riscv: Use 64-bit variable for output in
__get_user_asm"), there is a warning when building for 32-bit RISC-V:
In file included from include/linux/uaccess.h:13,
from include/linux/sched/task.h:13,
from include/linux/sched/signal.h:9,
from include/linux/rcuwait.h:6,
from include/linux/mm.h:36,
from include/linux/migrate.h:5,
from mm/migrate.c:16:
mm/migrate.c: In function 'do_pages_move':
arch/riscv/include/asm/uaccess.h:115:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
115 | (x) = (__typeof__(x))__tmp; \
| ^
arch/riscv/include/asm/uaccess.h:198:17: note: in expansion of macro '__get_user_asm'
198 | __get_user_asm("lb", (x), __gu_ptr, label); \
| ^~~~~~~~~~~~~~
arch/riscv/include/asm/uaccess.h:218:9: note: in expansion of macro '__get_user_nocheck'
218 | __get_user_nocheck(x, ptr, __gu_failed); \
| ^~~~~~~~~~~~~~~~~~
arch/riscv/include/asm/uaccess.h:255:9: note: in expansion of macro '__get_user_error'
255 | __get_user_error(__gu_val, __gu_ptr, __gu_err); \
| ^~~~~~~~~~~~~~~~
arch/riscv/include/asm/uaccess.h:285:17: note: in expansion of macro '__get_user'
285 | __get_user((x), __p) : \
| ^~~~~~~~~~
mm/migrate.c:2358:29: note: in expansion of macro 'get_user'
2358 | if (get_user(p, pages + i))
| ^~~~~~~~
Add an intermediate cast to 'unsigned long', which is guaranteed to be the same
width as a pointer, before the cast to the type of the output variable to clear
up the warning.
Fixes: bdce162f2e ("riscv: Use 64-bit variable for output in __get_user_asm")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601210526.OT45dlOZ-lkp@intel.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260121-riscv-fix-int-to-pointer-cast-v1-1-b83eebe57c76@kernel.org
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Patch series "mm: folio_zero_user: clear page ranges", v11.
This series adds clearing of contiguous page ranges for hugepages.
The series improves on the current discontiguous clearing approach in two
ways:
- clear pages in a contiguous fashion.
- use batched clearing via clear_pages() wherever exposed.
The first is useful because it allows us to make much better use of
hardware prefetchers.
The second, enables advertising the real extent to the processor. Where
specific instructions support it (ex. string instructions on x86; "mops"
on arm64 etc), a processor can optimize based on this because, instead of
seeing a sequence of 8-byte stores, or a sequence of 4KB pages, it sees a
larger unit being operated on.
For instance, AMD Zen uarchs (for extents larger than LLC-size) switch to
a mode where they start eliding cacheline allocation. This is helpful not
just because it results in higher bandwidth, but also because now the
cache is not evicting useful cachelines and replacing them with zeroes.
Demand faulting a 64GB region shows performance improvement:
$ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5
baseline +series
(GBps +- %stdev) (GBps +- %stdev)
pg-sz=2MB 11.76 +- 1.10% 25.34 +- 1.18% [*] +115.47% preempt=*
pg-sz=1GB 24.85 +- 2.41% 39.22 +- 2.32% + 57.82% preempt=none|voluntary
pg-sz=1GB (similar) 52.73 +- 0.20% [#] +112.19% preempt=full|lazy
[*] This improvement is because switching to sequential clearing
allows the hardware prefetchers to do a much better job.
[#] For pg-sz=1GB a large part of the improvement is because of the
cacheline elision mentioned above. preempt=full|lazy improves upon
that because, not needing explicit invocations of cond_resched() to
ensure reasonable preemption latency, it can clear the full extent
as a single unit. In comparison the maximum extent used for
preempt=none|voluntary is PROCESS_PAGES_NON_PREEMPT_BATCH (32MB).
When provided the full extent the processor forgoes allocating
cachelines on this path almost entirely.
(The hope is that eventually, in the fullness of time, the lazy
preemption model will be able to do the same job that none or
voluntary models are used for, allowing us to do away with
cond_resched().)
Raghavendra also tested previous version of the series on AMD Genoa and
sees similar improvement [1] with preempt=lazy.
$ perf bench mem map -p $page-size -f populate -s 64GB -l 10
base patched change
pg-sz=2MB 12.731939 GB/sec 26.304263 GB/sec 106.6%
pg-sz=1GB 26.232423 GB/sec 61.174836 GB/sec 133.2%
This patch (of 8):
Let's drop all variants that effectively map to clear_page() and provide
it in a generic variant instead.
We'll use the macro clear_user_page to indicate whether an architecture
provides it's own variant.
Also, clear_user_page() is only called from the generic variant of
clear_user_highpage(), so define it only if the architecture does not
provide a clear_user_highpage(). And, for simplicity define it in
linux/highmem.h.
Note that for parisc, clear_page() and clear_user_page() map to
clear_page_asm(), so we can just get rid of the custom clear_user_page()
implementation. There is a clear_user_page_asm() function on parisc, that
seems to be unused. Not sure what's up with that.
Link: https://lkml.kernel.org/r/20260107072009.1615991-1-ankur.a.arora@oracle.com
Link: https://lkml.kernel.org/r/20260107072009.1615991-2-ankur.a.arora@oracle.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Co-developed-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After commit f6bff7827a ("riscv: uaccess: use 'asm_goto_output' for
get_user()"), which was the first commit that started using asm goto
with outputs on RISC-V, builds of clang built with assertions enabled
start crashing in certain files that use get_user() with:
clang: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:12743: Register FollowCopyChain(MachineRegisterInfo &, Register): Assertion `MI->getOpcode() == TargetOpcode::COPY && "start of copy chain MUST be COPY"' failed.
Internally, LLVM generates an addiw instruction when the output of the
inline asm (which may be any scalar type) needs to be sign extended for
ABI reasons, such as a later function call, so that basic block does not
have to do it.
Use a temporary 64-bit variable as the output of the inline assembly in
__get_user_asm() and explicitly cast it to truncate it if necessary,
avoiding the addiw that triggers the assertion.
Link: https://github.com/ClangBuiltLinux/linux/issues/2092
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260116-riscv-wa-llvm-asm-goto-outputs-assertion-failure-v3-1-55b5775f989b@kernel.org
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Paravirt clock related functions are available in multiple archs.
In order to share the common parts, move the common static keys
to kernel/sched/ and remove them from the arch specific files.
Make a common paravirt_steal_clock() implementation available in
kernel/sched/cputime.c, guarding it with a new config option
CONFIG_HAVE_PV_STEAL_CLOCK_GEN, which can be selected by an arch
in case it wants to use that common variant.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260105110520.21356-7-jgross@suse.com
All architectures supporting CONFIG_PARAVIRT share the same contents
of asm/paravirt_api_clock.h:
#include <asm/paravirt.h>
So remove all incarnations of asm/paravirt_api_clock.h and remove the
only place where it is included, as there asm/paravirt.h is included
anyway.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> # powerpc, scheduler bits
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260105110520.21356-6-jgross@suse.com
The arch/riscv/include/asm/bitops.h does not functionally require
including /linux/irqflags.h. Additionally, adding
arch/riscv/include/asm/percpu.h causes a circular inclusion:
kernel/bounds.c
->include/linux/log2.h
->include/linux/bitops.h
->arch/riscv/include/asm/bitops.h
->include/linux/irqflags.h
->include/linux/find.h
->return val ? __ffs(val) : size;
->arch/riscv/include/asm/bitops.h
The compilation log is as follows:
CC kernel/bounds.s
In file included from ./include/linux/bitmap.h:11,
from ./include/linux/cpumask.h:12,
from ./arch/riscv/include/asm/processor.h:55,
from ./arch/riscv/include/asm/thread_info.h:42,
from ./include/linux/thread_info.h:60,
from ./include/asm-generic/preempt.h:5,
from ./arch/riscv/include/generated/asm/preempt.h:1,
from ./include/linux/preempt.h:79,
from ./arch/riscv/include/asm/percpu.h:8,
from ./include/linux/irqflags.h:19,
from ./arch/riscv/include/asm/bitops.h:14,
from ./include/linux/bitops.h:68,
from ./include/linux/log2.h:12,
from kernel/bounds.c:13:
./include/linux/find.h: In function 'find_next_bit':
./include/linux/find.h:66:30: error: implicit declaration of function '__ffs' [-Wimplicit-function-declaration]
66 | return val ? __ffs(val) : size;
| ^~~~~
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Link: https://patch.msgid.link/20251216014721.42262-2-cuiyunhui@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Let's not call atomic_long_xchg() on something that's not an
atomic_long_t, and just use xchg() instead. Continues the cleanup
from commit 546e42c8c6 ("riscv: Use an atomic xchg in
pudp_huge_get_and_clear()"),
Cc: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When !CONFIG_SMP, there's no need for atomic operations in
ptep_get_and_clear(), so, similar to x86, let's not use atomics in
this case.
Cc: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Paul Walmsley <pjw@kernel.org>
