Pull s390 updates from Alexander Gordeev:

 - Use CIO device online variable instead of the internal FSM state to
   determine device availability during purge operations

 - Remove extra check of task_stack_page() because try_get_task_stack()
   already takes care of that when reading /proc/<pid>/wchan

 - Allow user-space to use the new SCLP action qualifier 4 for to
   provide NVMe SMART log data to the platform.

 - Send AP CHANGE uevents on successful bind and successful association
   to notify user-space about SE operations on AP queue devices

 - Add an s390dbf kernel parameter to configure debug log levels and
   area sizes during early boot

 - On arm64 the empty zero page is going to be mapped read-only. Do the
   same for s390 with an explicit set_memory_ro() call

 - Improve s390-specific bcr_serialize() and cpu_relax() implementations

 - Remove all unused variables to avoid allmodconfig W=1 build fails
   with latest clang-23

 - Cleanup default Kconfig values for s390 selftests

 - Add a s390-tod trace clock to allow comparing trace timestamps
   between different systems or virtual machines on s390

 - Remove the s390 implementation of strlcat() in favor of the generic
   variant

 - Make consistent the calling order between
   page_table_check_pte_clear() and secure page conversion across all
   code paths

 - Rearrange some fields within AP and zcrypt structs to reduce memory
   consumption and unused holes

 - Shorten GR_NUM and VX_NUM macros and move them to a separate header

 - Replace __get_free_page() with kmalloc() in few sources

 - Introduce an infrastructure for more efficient this_cpu operations.
   Eliminate conditional branches when PREEMPT_NONE is removed

 - Enable Rust support

 - Use z10 as minimum architecture level, similar to the boot code, to
   enforce a defined architecture level set

 - Improve and convert various mem*() helper functions to C. For that
   add .noinstr.text section to avoid orphaned warnings from the linker

 - Fix the function pointer type in __ret_from_fork() to correct the
   indirect call to match kernel thread return type of int

 - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
   loop on read from donated Ultravisor pages at unaligned addresses

* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
  s390: Revert support for DCACHE_WORD_ACCESS
  s390/process: Fix kernel thread function pointer type
  s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
  s390/memmove: Optimize backward copy case
  s390/string: Convert memset(16|32|64)() to C
  s390/string: Convert memcpy() to C
  s390/string: Convert memset() to C
  s390/string: Convert memmove() to C
  s390/string: Add -ffreestanding compile option to string.o
  s390: Add .noinstr.text to boot and purgatory linker scripts
  s390/purgatory: Enforce z10 minimum architecture level
  s390: Enable Rust support
  s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
  rust: helpers: Add memchr wrapper for string operations
  rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
  s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
  s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
  s390/ap: Fix locking issue in SE bind and associate sysfs functions
  s390/percpu: Provide arch_this_cpu_write() implementation
  s390/percpu: Provide arch_this_cpu_read() implementation
  ...

Enable building Rust code on s390 by wiring the architecture into the
kernel Rust infrastructure.

Add s390 to the Rust arch support documentation, provide the s390 Rust
target and required compiler flags, and set the bindgen target for
arch/s390. Adjust the Rust target generation and minimum rustc version
gating so the s390 setup is handled explicitly.

The Rust toolchain uses the "s390x" triple naming for the 64 bit target.

Rust support is currently incompatible with CONFIG_EXPOLINE, which
relies on compiler support for the -mindirect-branch= and
-mfunction_return= options. Therefore, select HAVE_RUST only when
EXPOLINE is disabled.

Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Gary Guo <gary@garyguo.net>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

Starting with Rust 1.98.0 (expected 2026-08-20), the target spec will not
support `x86-softfloat` anymore [1]. Instead, `softfloat` should be used,
which is an alias. Otherwise, one gets:

    error: error loading target specification: rustc-abi: invalid rustc abi: 'x86-softfloat'. allowed values: 'x86-sse2', 'softfloat' at line 3 column 32
      |
      = help: run `rustc --print target-list` for a list of built-in targets

Thus conditionally use one or the other depending on the version.

The alias has existed since Rust 1.95.0 (released 2026-04-16) [2], but
use the newer version instead to avoid changing how the build works for
existing compilers, at least until more testing takes place.

Cc: Ralf Jung <post@ralfj.de>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/157151 [1]
Link: https://github.com/rust-lang/rust/pull/151154 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260530114925.260754-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Starting with Rust 1.91.0 (expected 2025-10-30), the target spec format
has changed the type of the `target-pointer-width` key from string
to integer [1].

Thus conditionally use one or the other depending on the version.

Cc: Waffle Maybe <waffle.lapkin@gmail.com>
Link: https://github.com/rust-lang/rust/pull/144443 [1]
Link: https://lore.kernel.org/r/20250829195525.721664-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Some comments in Rust files use raw URLs (http://example.com) rather
than Markdown autolinks <URL>. This inconsistency makes the
documentation less uniform and harder to maintain.

This patch converts all remaining raw URLs in Rust code comments to use
the Markdown autolink format, maintaining consistency with the rest of
the codebase which already uses this style.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1153
Signed-off-by: Xizhe Yin <xizheyin@smail.nju.edu.cn>
Link: https://lore.kernel.org/r/509F0B66E3C1575D+20250407033441.5567-1-xizheyin@smail.nju.edu.cn
[ Used From form for Signed-off-by. Sorted tags. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Pull ARM and clkdev updates from Russell King:

 - Simplify ARM_MMU_KEEP usage

 - Add Rust support for ARM architecture version 7

 - Align IPIs reported in /proc/interrupts

 - require linker to support KEEP within OVERLAY

 - add KEEP() for ARM vectors

 - add __printf() attribute for clkdev functions

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
  ARM: 9445/1: clkdev: Mark some functions with __printf() attribute
  ARM: 9444/1: add KEEP() keyword to ARM_VECTORS
  ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE
  ARM: 9442/1: smp: Fix IPI alignment in /proc/interrupts
  ARM: 9441/1: rust: Enable Rust support for ARMv7
  ARM: 9439/1: arm32: simplify ARM_MMU_KEEP usage

This commit allows building ARMv7 kernels with Rust support.

The rust core library expects some __eabi_... functions
that are not implemented in the kernel.
Those functions are some float operations and __aeabi_uldivmod.
For now those are implemented with define_panicking_intrinsics!.

This is based on the code by Sven Van Asbroeck from the original
rust branch and inspired by the AArch version by Jamie Cunliffe.

I have tested the rust samples and a custom simple MMIO module
on hardware (De1SoC FPGA + Arm A9 CPU).

Tested-by: Rudraksha Gupta <guptarud@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

When using Rust on the x86 architecture, we are currently using the
unstable target.json feature to specify the compilation target. Rustc is
going to change how softfloat is specified in the target.json file on
x86, thus update generate_rust_target.rs to specify softfloat using the
new option.

Note that if you enable this parameter with a compiler that does not
recognize it, then that triggers a warning but it does not break the
build.

[ For future reference, this solves the following error:

        RUSTC L rust/core.o
      error: Error loading target specification: target feature
      `soft-float` is incompatible with the ABI but gets enabled in
      target spec. Run `rustc --print target-list` for a list of
      built-in targets

  - Miguel ]

Cc: <stable@vger.kernel.org> # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/136146
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> # for x86
Link: https://lore.kernel.org/r/20250203-rustc-1-86-x86-softfloat-v1-1-220a72a5003e@google.com
[ Added 6.13.y too to Cc: stable tag and added reasoning to avoid
  over-backporting. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Rust supports KASAN via LLVM, but prior to this patch, the flags aren't
set properly.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20240820194910.187826-4-mmaurer@google.com
[ Applied "SW_TAGS KASAN" nit. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.

Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.

Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.

Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
  a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>