sched: Move clock related paravirt code to kernel/sched

Paravirt clock related functions are available in multiple archs.

In order to share the common parts, move the common static keys
to kernel/s

sched: Move clock related paravirt code to kernel/sched

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

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treewide: drop outdated compiler version remarks in Kconfig help texts

As of writing, Documentation/Changes states the minimal versions of GNU C
being 8.1, Clang being 15.0.0 and binutils being 2.30

treewide: drop outdated compiler version remarks in Kconfig help texts

As of writing, Documentation/Changes states the minimal versions of GNU C
being 8.1, Clang being 15.0.0 and binutils being 2.30. A few Kconfig help
texts are pointing out that specific GCC and Clang versions are needed,
but by now, those pointers to versions, such later than 4.0, later than
4.4, or clang later than 5.0, are obsolete and unlikely to be found by
users configuring their kernel builds anyway.

Drop these outdated remarks in Kconfig help texts referring to older
compiler and binutils versions. No functional change.

Link: https://lkml.kernel.org/r/20251010082138.185752-1-lukas.bulwahn@redhat.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@redhat.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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compiler_types: Introduce __nocfi_generic

There are two different ways that LLVM can expand kCFI operand bundles
in LLVM IR: generically in the middle end or using an architecture
specific sequence

compiler_types: Introduce __nocfi_generic

There are two different ways that LLVM can expand kCFI operand bundles
in LLVM IR: generically in the middle end or using an architecture
specific sequence when lowering LLVM IR to machine code in the backend.
The generic pass allows any architecture to take advantage of kCFI but
the expansion of these bundles in the middle end can mess with
optimizations that may turn indirect calls into direct calls when the
call target is known at compile time, such as after inlining.

Add __nocfi_generic, dependent on an architecture selecting
CONFIG_ARCH_USES_CFI_GENERIC_LLVM_PASS, to disable kCFI bundle
generation in functions where only the generic kCFI pass may cause
problems.

Link: https://github.com/ClangBuiltLinux/linux/issues/2124
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20251025-idpf-fix-arm-kcfi-build-error-v1-1-ec57221153ae@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

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rust: cfi: only 64-bit arm and x86 support CFI_CLANG

The kernel uses the standard rustc targets for non-x86 targets, and out
of those only 64-bit arm's target has kcfi support enabled. For x86, the

rust: cfi: only 64-bit arm and x86 support CFI_CLANG

The kernel uses the standard rustc targets for non-x86 targets, and out
of those only 64-bit arm's target has kcfi support enabled. For x86, the
custom 64-bit target enables kcfi.

The HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC config option that allows
CFI_CLANG to be used in combination with RUST does not check whether the
rustc target supports kcfi. This breaks the build on riscv (and
presumably 32-bit arm) when CFI_CLANG and RUST are enabled at the same
time.

Ordinarily, a rustc-option check would be used to detect target support
but unfortunately rustc-option filters out the target for reasons given
in commit 46e24a545cdb4 ("rust: kasan/kbuild: fix missing flags on first
build"). As a result, if the host supports kcfi but the target does not,
e.g. when building for riscv on x86_64, the build would remain broken.

Instead, make HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC depend on the only
two architectures where the target used supports it to fix the build.

CC: stable@vger.kernel.org
Fixes: ca627e636551e ("rust: cfi: add support for CFI_CLANG with Rust")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250908-distill-lint-1ae78bcf777c@spud
Signed-off-by: Paul Walmsley <pjw@kernel.org>

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Merge tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild updates from Nathan Chancellor:

- Extend modules.builtin.modinfo to include module aliases from

Merge tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild updates from Nathan Chancellor:

- Extend modules.builtin.modinfo to include module aliases from
MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such
as kmod) can verify that a particular module alias will be handled by
a builtin module

- Bump the minimum version of LLVM for building the kernel to 15.0.0

- Upgrade several userspace API checks in headers_check.pl to errors

- Unify and consolidate CONFIG_WERROR / W=e handling

- Turn assembler and linker warnings into errors with CONFIG_WERROR /
W=e

- Respect CONFIG_WERROR / W=e when building userspace programs
(userprogs)

- Enable -Werror unconditionally when building host programs
(hostprogs)

- Support copy_file_range() and data segment alignment in gen_init_cpio
to improve performance on filesystems that support reflinks such as
btrfs and XFS

- Miscellaneous small changes to scripts and configuration files

* tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits)
modpost: Initialize builtin_modname to stop SIGSEGVs
Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds
kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o
modpost: Create modalias for builtin modules
modpost: Add modname to mod_device_table alias
scsi: Always define blogic_pci_tbl structure
kbuild: extract modules.builtin.modinfo from vmlinux.unstripped
kbuild: keep .modinfo section in vmlinux.unstripped
kbuild: always create intermediate vmlinux.unstripped
s390: vmlinux.lds.S: Reorder sections
KMSAN: Remove tautological checks
objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY
lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs
riscv: Unconditionally use linker relaxation
riscv: Remove version check for LTO_CLANG selects
powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault()
mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER
arm64: Remove tautological LLVM Kconfig conditions
ARM: Clean up definition of ARM_HAS_GROUP_RELOCS
...

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Merge tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO updates from Thomas Gleixner:

- Further consolidation of the VDSO infrastructure and the commo

Merge tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO updates from Thomas Gleixner:

- Further consolidation of the VDSO infrastructure and the common data
store

- Simplification of the related Kconfig logic

- Improve the VDSO selftest suite

* tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests: vDSO: Drop vdso_test_clock_getres
selftests: vDSO: vdso_test_abi: Add tests for clock_gettime64()
selftests: vDSO: vdso_test_abi: Test CPUTIME clocks
selftests: vDSO: vdso_test_abi: Use explicit indices for name array
selftests: vDSO: vdso_test_abi: Drop clock availability tests
selftests: vDSO: vdso_test_abi: Use ksft_finished()
selftests: vDSO: vdso_test_abi: Correctly skip whole test with missing vDSO
selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper
vdso: Add struct __kernel_old_timeval forward declaration to gettime.h
vdso: Gate VDSO_GETRANDOM behind HAVE_GENERIC_VDSO
vdso: Drop Kconfig GENERIC_VDSO_TIME_NS
vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE
vdso: Drop kconfig GENERIC_COMPAT_VDSO
vdso: Drop kconfig GENERIC_VDSO_32
riscv: vdso: Untangle Kconfig logic
time: Build generic update_vsyscall() only with generic time vDSO
vdso/gettimeofday: Remove !CONFIG_TIME_NS stubs
vdso: Move ENABLE_COMPAT_VDSO from core to arm64
ARM: VDSO: Remove cntvct_ok global variable
vdso/datastore: Gate time data behind CONFIG_GENERIC_GETTIMEOFDAY

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Merge tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull TIF bit unification updates from Thomas Gleixner:
"A set of changes to consolidate the generic TIF (th

Merge tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull TIF bit unification updates from Thomas Gleixner:
"A set of changes to consolidate the generic TIF (thread info flag)
bits accross architectures.

All architectures define the same set of generic TIF bits. This makes
it pointlessly hard to add a new generic TIF bit or to change an
existing one.

Provide a generic variant and convert the architectures which utilize
the generic entry code over to use it. The TIF space is divided into
16 generic bits and 16 architecture specific bits, which turned out to
provide enough space on both sides"

* tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
LoongArch: Fix bitflag conflict for TIF_FIXADE
riscv: Use generic TIF bits
loongarch: Use generic TIF bits
s390/entry: Remove unused TIF flags
s390: Use generic TIF bits
x86: Use generic TIF bits
asm-generic: Provide generic TIF infrastructure

show more ...

Merge tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
"Core scheduler changes:

- Make migrate_{en,dis}able() inline

Merge tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
"Core scheduler changes:

- Make migrate_{en,dis}able() inline, to improve performance
(Menglong Dong)

- Move STDL_INIT() functions out-of-line (Peter Zijlstra)

- Unify the SCHED_{SMT,CLUSTER,MC} Kconfig (Peter Zijlstra)

Fair scheduling:

- Defer throttling to when tasks exit to user-space, to reduce the
chance & impact of throttle-preemption with held locks and other
resources (Aaron Lu, Valentin Schneider)

- Get rid of sched_domains_curr_level hack for tl->cpumask(), as the
warning was getting triggered on certain topologies (Peter
Zijlstra)

Misc cleanups & fixes:

- Header cleanups (Menglong Dong)

- Fix race in push_dl_task() (Harshit Agarwal)"

* tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix some typos in include/linux/preempt.h
sched: Make migrate_{en,dis}able() inline
rcu: Replace preempt.h with sched.h in include/linux/rcupdate.h
arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c
sched/fair: Do not balance task to a throttled cfs_rq
sched/fair: Do not special case tasks in throttled hierarchy
sched/fair: update_cfs_group() for throttled cfs_rqs
sched/fair: Propagate load for throttled cfs_rq
sched/fair: Get rid of throttled_lb_pair()
sched/fair: Task based throttle time accounting
sched/fair: Switch to task based throttle model
sched/fair: Implement throttle task work and related helpers
sched/fair: Add related data structure for task based throttle
sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig
sched: Move STDL_INIT() functions out-of-line
sched/fair: Get rid of sched_domains_curr_level hack for tl->cpumask()
sched/deadline: Fix race in push_dl_task()

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kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI

The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI,

kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI

The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).

Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

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asm-generic: Provide generic TIF infrastructure

Common TIF bits do not have to be defined by every architecture. They can
be defined in a generic header.

That allows adding generic TIF bits without

asm-generic: Provide generic TIF infrastructure

Common TIF bits do not have to be defined by every architecture. They can
be defined in a generic header.

That allows adding generic TIF bits without chasing a gazillion of
architecture headers, which is again a unjustified burden on anyone who
works on generic infrastructure as it always needs a boat load of work to
keep existing architecture code working when adding new stuff.

While it is not as horrible as the ignorance of the generic entry
infrastructure, it is a welcome mechanism to make architecture people
rethink their approach of just leaching generic improvements into
architecture code and thereby making it accumulatingly harder to maintain
and improve generic code. It's about time that this changes.

Provide the infrastructure and split the TIF space in half, 16 generic and
16 architecture specific bits.

This could probably be extended by TIF_SINGLESTEP and BLOCKSTEP, but those
are only used in architecture specific code. So leave them alone for now.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

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vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE

All users of the generic vDSO library also use the generic vDSO datastore.

Remove the now unnecessary Kconfig symbol.

Signed-off-by: Thomas Weißschuh <th

vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE

All users of the generic vDSO library also use the generic vDSO datastore.

Remove the now unnecessary Kconfig symbol.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-9-d9b65750e49f@linutronix.de

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sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig

Like many Kconfig symbols, SCHED_{SMT,CLUSTER,MC} are duplicated
across arch/*/Kconfig. Try and clean up a little.

Suggested-by: Christophe Leroy <ch

sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig

Like many Kconfig symbols, SCHED_{SMT,CLUSTER,MC} are duplicated
across arch/*/Kconfig. Try and clean up a little.

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> # powerpc
Link: https://lkml.kernel.org/r/20250826094358.GG3245006@noisy.programming.kicks-ass.net

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arch/Kconfig: Drop always true condition from RANDOMIZE_KSTACK_OFFSET

Now that the minimum supported version of LLVM for building the kernel
has been bumped to 15.0.0, the second depends line in
RAN

arch/Kconfig: Drop always true condition from RANDOMIZE_KSTACK_OFFSET

Now that the minimum supported version of LLVM for building the kernel
has been bumped to 15.0.0, the second depends line in
RANDOMIZE_KSTACK_OFFSET is always true, so it can be removed.

Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250821-bump-min-llvm-ver-15-v2-2-635f3294e5f0@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

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Merge tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull initial deferred unwind infrastructure from Steven Rostedt:
"This is the core infrast

Merge tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull initial deferred unwind infrastructure from Steven Rostedt:
"This is the core infrastructure for the deferred unwinder that is
required for sframes[1]. Several other patch series are based on this
work although those patch series are not dependent on each other. In
order to simplify the development, having this core series upstream
will allow the other series to be worked on in parallel. The other
series are:

- The two patches to implement x86 support [2] [3]

- The s390 work [4]

- The perf work [5]

- The ftrace work [6]

- The sframe work [7]

And more is on the way.

The core infrastructure adds the following in kernel APIs:

- int unwind_user_faultable(struct unwind_stacktrace *trace);

Performs a user space stack trace that may fault user pages in.

- int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func);

Allows a tracer to register with the unwind deferred
infrastructure.

- int unwind_deferred_request(struct unwind_work *work, u64 *cookie);

Used when a tracer request a deferred trace. Can be called from
interrupt or NMI context.

- void unwind_deferred_cancel(struct unwind_work *work);

Called by a tracer to unregister from the deferred unwind
infrastructure.

- void unwind_deferred_task_exit(struct task_struct *task);

Called by task exit code to flush any pending unwind requests.

- void unwind_task_init(struct task_struct *task);

Called by do_fork() to initialize the task struct for the
deferred unwinder.

- void unwind_task_free(struct task_struct *task);

Called by do_exit() to free up any resources used by the
deferred unwinder.

None of the above is actually compiled unless an architecture enables it,
which none currently do"

Link: https://sourceware.org/binutils/wiki/sframe [1]
Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.260781923@kernel.org/ [2]
Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.432327787@kernel.org/ [3]
Link: https://lore.kernel.org/linux-trace-kernel/20250710163522.3195293-1-jremus@linux.ibm.com/ [4]
Link: https://lore.kernel.org/linux-trace-kernel/20250718164119.089692174@kernel.org/ [5]
Link: https://lore.kernel.org/linux-trace-kernel/20250424192612.505622711@goodmis.org/ [6]
Link: https://lore.kernel.org/linux-trace-kernel/20250717012848.927473176@kernel.org/ [7]

* tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
unwind: Finish up unwind when a task exits
unwind deferred: Use SRCU unwind_deferred_task_work()
unwind: Add USED bit to only have one conditional on way back to user space
unwind deferred: Add unwind_completed mask to stop spurious callbacks
unwind deferred: Use bitmask to determine which callbacks to call
unwind_user/deferred: Make unwind deferral requests NMI-safe
unwind_user/deferred: Add deferred unwinding interface
unwind_user/deferred: Add unwind cache
unwind_user/deferred: Add unwind_user_faultable()
unwind_user: Add user space unwinding API with frame pointer support

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Merge tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CPU mitigation updates from Borislav Petkov:

- Untangle the Retbleed from the ITS mitigation on

Merge tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CPU mitigation updates from Borislav Petkov:

- Untangle the Retbleed from the ITS mitigation on Intel. Allow for ITS
to enable stuffing independently from Retbleed, do some cleanups to
simplify and streamline the code

- Simplify SRSO and make mitigation types selection more versatile
depending on the Retbleed mitigation selection. Simplify code some

- Add the second part of the attack vector controls which provide a lot
friendlier user interface to the speculation mitigations than
selecting each one by one as it is now.

Instead, the selection of whole attack vectors which are relevant to
the system in use can be done and protection against only those
vectors is enabled, thus giving back some performance to the users

* tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
x86/bugs: Print enabled attack vectors
x86/bugs: Add attack vector controls for TSA
x86/pti: Add attack vector controls for PTI
x86/bugs: Add attack vector controls for ITS
x86/bugs: Add attack vector controls for SRSO
x86/bugs: Add attack vector controls for L1TF
x86/bugs: Add attack vector controls for spectre_v2
x86/bugs: Add attack vector controls for BHI
x86/bugs: Add attack vector controls for spectre_v2_user
x86/bugs: Add attack vector controls for retbleed
x86/bugs: Add attack vector controls for spectre_v1
x86/bugs: Add attack vector controls for GDS
x86/bugs: Add attack vector controls for SRBDS
x86/bugs: Add attack vector controls for RFDS
x86/bugs: Add attack vector controls for MMIO
x86/bugs: Add attack vector controls for TAA
x86/bugs: Add attack vector controls for MDS
x86/bugs: Define attack vectors relevant for each bug
x86/Kconfig: Add arch attack vector support
cpu: Define attack vectors
...

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Merge tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic entry code updates from Thomas Gleixner:

- Split the code into syscall and exception/interru

Merge tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic entry code updates from Thomas Gleixner:

- Split the code into syscall and exception/interrupt parts to ease the
conversion of ARM[64] to the generic entry infrastructure

- Extend syscall user dispatching to support a single intercepted range
instead of the default single non-intercepted range. That allows
monitoring/analysis of a specific executable range, e.g. a library,
and also provides flexibility for sandboxing scenarios

- Cleanup and extend the user dispatch selftest

* tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
entry: Split generic entry into generic exception and syscall entry
selftests: Add tests for PR_SYS_DISPATCH_INCLUSIVE_ON
syscall_user_dispatch: Add PR_SYS_DISPATCH_INCLUSIVE_ON
selftests: Fix errno checking in syscall_user_dispatch test

show more ...

unwind_user: Add user space unwinding API with frame pointer support

Introduce a generic API for unwinding user stacks.

In order to expand user space unwinding to be able to handle more complex
sce

unwind_user: Add user space unwinding API with frame pointer support

Introduce a generic API for unwinding user stacks.

In order to expand user space unwinding to be able to handle more complex
scenarios, such as deferred unwinding and reading user space information,
create a generic interface that all architectures can use that support the
various unwinding methods.

This is an alternative method for handling user space stack traces from
the simple stack_trace_save_user() API. This does not replace that
interface, but this interface will be used to expand the functionality of
user space stack walking.

None of the structures introduced will be exposed to user space tooling.

Support for frame pointer unwinding is added. For an architecture to
support frame pointer unwinding it needs to enable
CONFIG_HAVE_UNWIND_USER_FP and define ARCH_INIT_USER_FP_FRAME.

By encoding the frame offsets in struct unwind_user_frame, much of this
code can also be reused for future unwinder implementations like sframe.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Link: https://lore.kernel.org/20250729182404.975790139@kernel.org
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Co-developed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/all/20250710164301.3094-2-mathieu.desnoyers@efficios.com/
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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stackleak: Rename STACKLEAK to KSTACK_ERASE

In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:

- Add the new top-level CONFIG_KSTACK_ERA

stackleak: Rename STACKLEAK to KSTACK_ERASE

In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:

- Add the new top-level CONFIG_KSTACK_ERASE option which will be
implemented either with the stackleak GCC plugin, or with the Clang
stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
for what it does rather than what it protects against), but leave as
many of the internals alone as possible to avoid even more churn.

While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

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x86/Kconfig: Add arch attack vector support

ARCH_HAS_CPU_ATTACK_VECTORS should be set for architectures which implement
the new attack-vector based controls for CPU mitigations. If an arch does
not

x86/Kconfig: Add arch attack vector support

ARCH_HAS_CPU_ATTACK_VECTORS should be set for architectures which implement
the new attack-vector based controls for CPU mitigations. If an arch does
not support attack-vector based controls then an attempt to use them
results in a warning.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250707183316.1349127-4-david.kaplan@amd.com

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entry: Split generic entry into generic exception and syscall entry

Currently CONFIG_GENERIC_ENTRY enables both the generic exception
entry logic and the generic syscall entry logic, which are other

entry: Split generic entry into generic exception and syscall entry

Currently CONFIG_GENERIC_ENTRY enables both the generic exception
entry logic and the generic syscall entry logic, which are otherwise
loosely coupled.

Introduce separate config options for these so that architectures can
select the two independently. This will make it easier for
architectures to migrate to generic entry code.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/20250213130007.1418890-2-ruanjinjie@huawei.com
Link: https://lore.kernel.org/all/20250624-generic-entry-split-v1-1-53d5ef4f94df@linaro.org

[Linus Walleij: rebase onto v6.16-rc1]

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fs/resctrl: Add boiler plate for external resctrl code

Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
for the common parts of the resctrl interface and make X86_CPU_RESCTRL
select

fs/resctrl: Add boiler plate for external resctrl code

Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
for the common parts of the resctrl interface and make X86_CPU_RESCTRL
select this.

Adding an include of asm/resctrl.h to linux/resctrl.h allows the
/fs/resctrl files to switch over to using this header instead.

Co-developed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-16-james.morse@arm.com

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Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- Improve performance in gendwarfksyms

- Remove depreca

Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- Improve performance in gendwarfksyms

- Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

- Support CONFIG_HEADERS_INSTALL for ARCH=um

- Use more relative paths to sources files for better reproducibility

- Support the loong64 Debian architecture

- Add Kbuild bash completion

- Introduce intermediate vmlinux.unstripped for architectures that need
static relocations to be stripped from the final vmlinux

- Fix versioning in Debian packages for -rc releases

- Treat missing MODULE_DESCRIPTION() as an error

- Convert Nios2 Makefiles to use the generic rule for built-in DTB

- Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
kbuild: rpm-pkg: build a debuginfo RPM
kconfig: merge_config: use an empty file as initfile
nios2: migrate to the generic rule for built-in DTB
rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
kbuild: pacman-pkg: hardcode module installation path
kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
modpost: require a MODULE_DESCRIPTION()
kbuild: make all file references relative to source root
x86: drop unnecessary prefix map configuration
kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
kbuild: Add a help message for "headers"
kbuild: deb-pkg: remove "version" variable in mkdebian
kbuild: deb-pkg: fix versioning for -rc releases
Documentation/kbuild: Fix indentation in modules.rst example
x86: Get rid of Makefile.postlink
kbuild: Create intermediate vmlinux build with relocations preserved
kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
kbuild: link-vmlinux.sh: Make output file name configurable
kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
Revert "kheaders: Ignore silly-rename files"
...

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kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch spec

kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch specific tools
consume these static relocations in order to construct relocation tables
for KASLR.

The fact that vmlinux is created, consumed and subsequently updated goes
against the typical, declarative paradigm used by Make, which is based
on rules and dependencies. So as a first step towards cleaning this up,
introduce a Kconfig symbol to declare that the arch wants to consume the
static relocations emitted into vmlinux. This will be wired up further
in subsequent patches.

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

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vdso: Add generic architecture-specific data storage

Some architectures need to expose architecture-specific data to the vDSO.

Enable the generic vDSO storage mechanism to both store and map this
d

vdso: Add generic architecture-specific data storage

Some architectures need to expose architecture-specific data to the vDSO.

Enable the generic vDSO storage mechanism to both store and map this
data. Some architectures require more than a single page, like LoongArch,
so prepare for that usecase, too.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-7-13a4669dfc8c@linutronix.de

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m68k: Use kernel's generic muldi3 libgcc function

Use the kernels own generic lib/muldi3.c implementation of muldi3 for
68K machines. Some 68K CPUs support 64bit multiplies so move the arch
specific

m68k: Use kernel's generic muldi3 libgcc function

Use the kernels own generic lib/muldi3.c implementation of muldi3 for
68K machines. Some 68K CPUs support 64bit multiplies so move the arch
specific umul_ppmm() macro into a header file that is included by
lib/muldi3.c. That way it can take advantage of the single instruction
when available.

There does not appear to be any existing mechanism for the generic
lib/muldi3.c code to pick up an external arch definition of umul_ppmm().
Create an arch specific libgcc.h that can optionally be included by
the system include/linux/libgcc.h to allow for this.

Somewhat oddly there is also a similar definition of umul_ppmm() in
the non-architecture code in lib/crypto/mpi/longlong.h for a wide range
or machines. Its presence ends up complicating the include setup and
means not being able to use something like compiler.h instead. Actually
there is a few other defines of umul_ppmm() macros spread around in
various architectures, but not directly usable for the m68k case.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/20231113133209.1367286-1-gerg@linux-m68k.org
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

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