linux-stable.git/arch/openrisc/kernel, branch master

arch, mm: consolidate empty_zero_page

2026-04-05T20:53:01+00:00

Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of
ZERO_PAGE() to 4.

Every architecture defines empty_zero_page that way or another, but for the
most of them it is always a page aligned page in BSS and most definitions
of ZERO_PAGE do virt_to_page(empty_zero_page).

Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the
core MM and drop these definitions in architectures that do not implement
colored zero page (MIPS and s390).

ZERO_PAGE() remains a macro because turning it to a wrapper for a static
inline causes severe pain in header dependencies.

For the most part the change is mechanical, with these being noteworthy:

* alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot
  parameters. Switching to a generic empty_zero_page removes the aliasing
  and keeps ZERO_PGE for boot parameters only
* arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of
  ZERO_PAGE() is kept intact.
* m68k/parisc/um: allocated empty_zero_page from memblock,
  although they do not support zero page coloring and having it in BSS
  will work fine.
* sparc64 can have empty_zero_page in BSS rather allocate it, but it
  can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE()
  but instead of allocating it, make mem_map_zero point to
  empty_zero_page.
* sh: used empty_zero_page for boot parameters at the very early boot.
  Rename the parameters page to boot_params_page and let sh use the generic
  empty_zero_page.
* hexagon: had an amusing comment about empty_zero_page

	/* A handy thing to have if one has the RAM. Declared in head.S */

  that unfortunately had to go :)

Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Helge Deller 		[parisc]
Tested-by: Helge Deller 		[parisc]
Reviewed-by: Christophe Leroy (CS GROUP) 
Acked-by: Dave Hansen 
Acked-by: Catalin Marinas 
Acked-by: Magnus Lindholm 	[alpha]
Acked-by: Dinh Nguyen 	[nios2]
Acked-by: Andreas Larsson 	[sparc]
Acked-by: David Hildenbrand (Arm) 
Acked-by: Liam R. Howlett 
Cc: "Borislav Petkov (AMD)" 
Cc: David S. Miller 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Lorenzo Stoakes 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Suren Baghdasaryan 
Cc: Vineet Gupta 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

kbuild: Split .modinfo out from ELF_DETAILS

2026-02-26T18:50:19+00:00

Commit 3e86e4d74c04 ("kbuild: keep .modinfo section in
vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it
from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and
ELF_DETAILS was present in all architecture specific vmlinux linker
scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and
COMMON_DISCARDS may be used by other linker scripts, such as the s390
and x86 compressed boot images, which may not expect to have a .modinfo
section. In certain circumstances, this could result in a bootloader
failing to load the compressed kernel [1].

Commit ddc6cbef3ef1 ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with
SecureBoot trailer") recently addressed this for the s390 bzImage but
the same bug remains for arm, parisc, and x86. The presence of .modinfo
in the x86 bzImage was the root cause of the issue worked around with
commit d50f21091358 ("kbuild: align modinfo section for Secureboot
Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes
lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its
MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition.

Split .modinfo out from ELF_DETAILS into its own macro and handle it in
all vmlinux linker scripts. Discard .modinfo in the places where it was
previously being discarded from being in COMMON_DISCARDS, as it has
never been necessary in those uses.

Cc: stable@vger.kernel.org
Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped")
Reported-by: Ed W 
Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1]
Tested-by: Ed W  # x86_64
Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org
Signed-off-by: Nathan Chancellor

openrisc: Fix IPIs on simple multicore systems

2026-01-16T16:38:56+00:00

Commit c05671846451 ("openrisc: sleep instead of spin on secondary
wait") fixed OpenRISC SMP Linux for QEMU. However, stability was never
achieved on FPGA development boards.  This is because the above patch
has a step to unmask IPIs on non-boot cpu's but on hardware without
power management, IPIs remain masked.

This meant that IPI's were never actually working on the simple SMP
systems we run on development boards.  The systems booted but stability
was very suspect.

Add the ability to unmask IPI's on the non-boot cores.  This is done by
making the OMPIC IRQs proper percpu IRQs.  We can then use the
enabled_percpu_irq() to unmask IRQ on the non-boot cpus.

Update the or1k PIC driver to use a flow handler that can switch between
percpu and the configured level or edge flow handlers at runtime.
This mechanism is inspired by that done in the J-Core AIC driver.

Signed-off-by: Stafford Horne 
Acked-by: Thomas Gleixner

Merge tag 'for-linus' of https://github.com/openrisc/linux

2025-10-05T17:02:54+00:00

Pull OpenRISC updates from Stafford Horne:
 "I picked up one series from Chen Miao, our Google Summer of Code
  contributor, which adds OpenRISC support for static keys"

* tag 'for-linus' of https://github.com/openrisc/linux:
  openrisc: Add jump label support
  openrisc: Regenerate defconfigs.
  openrisc: Add R_OR1K_32_PCREL relocation type module support
  openrisc: Add text patching API support

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

2025-09-30T17:35:11+00:00

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()

arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c

2025-09-25T07:57:15+00:00

The include/generated/asm-offsets.h is generated in Kbuild during
compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to
generate another similar offset header file, circular dependency can
happen.

For example, we want to generate a offset file include/generated/test.h,
which is included in include/sched/sched.h. If we generate asm-offsets.h
first, it will fail, as include/sched/sched.h is included in asm-offsets.c
and include/generated/test.h doesn't exist; If we generate test.h first,
it can't success neither, as include/generated/asm-offsets.h is included
by it.

In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular
dependency. We can generate asm-offsets.h first, and if the
COMPILE_OFFSETS is defined, we don't include the "generated/test.h".

And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this
purpose.

Signed-off-by: Menglong Dong 
Signed-off-by: Peter Zijlstra (Intel)

openrisc: Add jump label support

2025-09-11T10:27:59+00:00

Supported a complete jump_label implementation based on the ARM64 and
RV64 version and add the CONFIG_JUMP_LABEL=y to the defconfig.

Testing was conducted using a dedicated test module jump-label-test,
provided in the link below. For detailed steps, please refer to the
README also at the provided link.

Link: https://github.com/ChenMiaoi/GSoC-2025-Final-Report/tree/main/tests/jump-label-test

Test Environment:
  - Hardware: QEMU emulated OR1K
  - Kernel Version: 6.17.0-rc3-dirty
  - Configs: CONFIG_MODULES=y,CONFIG_MODULE_UNLOAD=y
  - Toolchain: or1k-none-linux-musl-gcc 15.1.0

Test Results:
$ insmod jump_label_test.ko
[   32.590000] Jump label performance test module loaded
[   35.250000] Normal branch time: 1241327150 ns (124 ns per iteration)
[   35.250000] Jump label (false) time: 706422700 ns (70 ns per iteration)
[   35.250000] Jump label (true) time: 708913450 ns (70 ns per iteration)
$ rmmod jump_label_test.ko
[   72.210000] Jump label test module unloaded

The results show approximately 43% improvement in branch performance
when using jump labels compared to traditional branches.

Link: https://lore.kernel.org/openrisc/aLsZ9S3X0OpKy1RM@antec/T/#u
Signed-off-by: chenmiao 
Signed-off-by: Stafford Horne

openrisc: Add R_OR1K_32_PCREL relocation type module support

2025-09-11T10:27:59+00:00

To ensure the proper functioning of the jump_label test module, this patch
adds support for the R_OR1K_32_PCREL relocation type for any modules. The
implementation calculates the PC-relative offset by subtracting the
instruction location from the target value and stores the result at the
specified location.

Signed-off-by: chenmiao 
Signed-off-by: Stafford Horne

openrisc: Add text patching API support

2025-09-11T10:27:59+00:00

Add text patching api's to use in subsequent jump_label implementation.  We use
a new fixmap FIX_TEXT_POKE0 entry to temporarily override MMU mappings to allow
read only text pages to be written to.

Previously, __set_fix was marked with __init as it was only used during the
EARLYCON stage. Now that TEXT_POKE mappings require post-init usage
(e.g., FIX_TEXT_POKE0), keeping __init would cause runtime bugs whenset_fixmap
accesses invalid memory. Thus, we remove the __init flag to ensure __set_fix
remains valid beyond initialization.

A new function patch_insn_write is exposed to allow single instruction patching.

Link: https://lore.kernel.org/openrisc/aJIC8o1WmVHol9RY@antec/T/#t

Signed-off-by: chenmiao 
Signed-off-by: Stafford Horne

arch: copy_thread: pass clone_flags as u64

2025-09-01T13:31:34+00:00

With the introduction of clone3 in commit 7f192e3cd316 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.

While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.

Thus, this commit fixes all relevant interfaces of the copy_thread
function that is called from copy_process to consistently pass
clone_flags as u64, so that no truncation to 32-bit integers occurs on
32-bit architectures.

Signed-off-by: Simon Schuster 
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-3-53fcf5577d57@siemens-energy.com
Fixes: c5febea0956fd387 ("fork: Pass struct kernel_clone_args into copy_thread")
Acked-by: Guo Ren (Alibaba Damo Academy) 
Acked-by: Andreas Larsson  # sparc
Acked-by: David Hildenbrand 
Acked-by: Geert Uytterhoeven  # m68k
Reviewed-by: Arnd Bergmann 
Signed-off-by: Christian Brauner