kernel/linux.git/arch/arm/Kconfig, branch master

ARM: 9463/1: Allow to enable RT

2026-04-24T14:14:59+00:00

All known issues have been adressed. Allow to select RT. Acked-by: Linus Walleij Reviewed-by: Arnd Bergmann Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Russell King (Oracle)

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

2026-02-20T20:21:00+00:00

Pull ARM updates from Russell King: - avoid %pK for ARM MM prints - implement ARCH_HAS_CC_CAN_LINK to ensure runnable user progs - handle BE8 and BE32 for user progs * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux: ARM: 9470/1: Handle BE8 vs BE32 in ARCH_CC_CAN_LINK ARM: 9469/1: Implement ARCH_HAS_CC_CAN_LINK ARM: 9467/1: mm: Don't use %pK through printk

ARM: 9470/1: Handle BE8 vs BE32 in ARCH_CC_CAN_LINK

2026-02-09T13:20:20+00:00

ARM big-endian has two different binary formats. BE8 and the older BE32. They are incompatible with each other. Handle those when evaluating ARCH_CC_CAN_LINK by using the respective configuration of the kernel itself. Fixes: 3df8585afd9b ("ARM: 9469/1: Implement ARCH_HAS_CC_CAN_LINK") Signed-off-by: Thomas Weißschuh Signed-off-by: Russell King (Oracle)

ARM: 9469/1: Implement ARCH_HAS_CC_CAN_LINK

2026-02-06T13:07:38+00:00

The generic CC_CAN_LINK detection does not handle different byte orders. This may lead to userprogs which are not actually runnable on the target kernel. Use architecture-specific logic supporting byte orders instead. Signed-off-by: Thomas Weißschuh Signed-off-by: Russell King (Oracle)

arm/paravirt: Use common code for paravirt_steal_clock()

2026-01-12T14:57:23+00:00

Remove the arch-specific variant of paravirt_steal_clock() and use the common one instead. This allows to remove paravirt.c and paravirt.h from arch/arm. Until all archs supporting Xen have been switched to the common code of paravirt_steal_clock(), drivers/xen/time.c needs to include asm/paravirt.h for those archs, while this is not necessary for arm any longer. Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov (AMD) Acked-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260105110520.21356-8-jgross@suse.com

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

2025-12-10T22:50:48+00:00

Pull ARM updates from Russell King: - disable jump label and high PTE for PREEMPT RT kernels - fix input operand modification in load_unaligned_zeropad() - fix hash_name() / fault path induced warnings - fix branch predictor hardening * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux: ARM: fix branch predictor hardening ARM: fix hash_name() fault ARM: allow __do_kernel_fault() to report execution of memory faults ARM: group is_permission_fault() with is_translation_fault() ARM: 9464/1: fix input-only operand modification in load_unaligned_zeropad() ARM: 9461/1: Disable HIGHPTE on PREEMPT_RT kernels ARM: 9459/1: Disable jump-label on PREEMPT_RT

ARM: 9461/1: Disable HIGHPTE on PREEMPT_RT kernels

2025-12-02T11:47:53+00:00

gup_pgd_range() is invoked with disabled interrupts and invokes __kmap_local_page_prot() via pte_offset_map(), gup_p4d_range(). With HIGHPTE enabled, __kmap_local_page_prot() invokes kmap_high_get() which uses a spinlock_t via lock_kmap_any(). This leads to an sleeping-while-atomic error on PREEMPT_RT because spinlock_t becomes a sleeping lock and must not be acquired in atomic context. The loop in map_new_virtual() uses wait_queue_head_t for wake up which also is using a spinlock_t. Since HIGHPTE is rarely needed at all, turn it off for PREEMPT_RT to allow the use of get_user_pages_fast(). [arnd: rework patch to turn off HIGHPTE instead of HAVE_PAST_GUP] Co-developed-by: Arnd Bergmann Acked-by: Linus Walleij Reviewed-by: Arnd Bergmann Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Russell King (Oracle)

ARM: 9459/1: Disable jump-label on PREEMPT_RT

2025-12-02T11:44:55+00:00

jump-labels are used to efficiently switch between two possible code paths. To achieve this, stop_machine() is used to keep the CPU in a known state while the opcode is modified. The usage of stop_machine() here leads to large latency spikes which can be observed on PREEMPT_RT. Jump labels may change the target during runtime and are not restricted to debug or "configuration/ setup" part of a PREEMPT_RT system where high latencies could be defined as acceptable. On 64-bit Arm, it is possible to use jump labels without the stop_machine() call, which architecturally provides a way to atomically change one 32-bit instruction word while keeping maintaining consistency, but this is not generally the case on 32-bit, in particular in thumb2 mode. Disable jump-label support on a PREEMPT_RT system when SMP is enabled. [bigeasy: Patch description.] [arnd: add !SMP case, extend changelog] Signed-off-by: Thomas Gleixner Cc: Mark Rutland Cc: Ard Biesheuvel Signed-off-by: Arnd Bergmann Reviewed-by: Linus Walleij Acked-by: Ard Biesheuvel Acked-by: Linus Walleij Reviewed-by: Arnd Bergmann Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Russell King (Oracle)

treewide: drop outdated compiler version remarks in Kconfig help texts

2025-11-12T18:00:14+00:00

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 Cc: Bill Wendling Cc: Justin Stitt Cc: Nathan Chancellor Cc: Russel King Signed-off-by: Andrew Morton

ARM: Select ARCH_USES_CFI_GENERIC_LLVM_PASS

2025-10-30T03:04:55+00:00

Prior to clang 22.0.0 [1], ARM did not have an architecture specific kCFI bundle lowering in the backend, which may cause issues. Select CONFIG_ARCH_USES_CFI_GENERIC_LLVM_PASS to enable use of __nocfi_generic. Link: https://github.com/llvm/llvm-project/commit/d130f402642fba3d065aacb506cb061c899558de [1] Link: https://github.com/ClangBuiltLinux/linux/issues/2124 Signed-off-by: Nathan Chancellor Link: https://patch.msgid.link/20251025-idpf-fix-arm-kcfi-build-error-v1-2-ec57221153ae@kernel.org Signed-off-by: Kees Cook