kernel/linux.git/Documentation/features, branch v6.18.21

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

Documentation/features: Update feature lists for 6.17-rc7

2025-09-25T17:17:56+00:00

It seems that ./Documentation/features/scripts/features-refresh.sh was most recently used in December 2022, with the latest kernel release v6.1-rc7 at that time (see commit 7f2e60ff51ca ("Documentation/features: Update feature lists for 6.1") to update the feature lists in this subdirectory. All further changes to Documentation/features/ since then have probably been done manually, without checking for changes in other architectures and features, that missed to update this part of the documentation. Running ./Documentation/features/scripts/features-refresh.sh now showed seven changes of supported features in various architectures (one in arc, two in parisc, one in riscv, one in openrisc, and two in um), which were not reflected yet in the current documentation. To confirm the sanity of this script's suggested changes, I checked if the commit messages confirm that the features have in fact been added in the following commits: - commit f122668ddcce ("ARC: Add eBPF JIT support") - commit 4800a6215e33 ("parisc: Wire up eBPF JIT compiler") - commit a869b8c29f86 ("riscv: enable mseal sysmap for RV64") - commit 2f681ba4b352 ("um: move thread info into task") - commit 3f17fed21491 ("um: switch to regset API and depend on XSTATE") - commit 7ce8716e2769 ("openrisc: Add HAVE_REGS_AND_STACK_ACCESS_API support") - commit b5ff52be8913 ("parisc: Convert to generic clockevents") So, update all documents to the current state with features-refresh.sh. Signed-off-by: Lukas Bulwahn Signed-off-by: Jonathan Corbet Message-ID: <20250925073634.112142-1-lukas.bulwahn@redhat.com>

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

LoongArch: Enable ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS

2025-05-30T13:45:42+00:00

Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on LoongArch, covering the vdso. Link: https://lore.kernel.org/all/25bad37f-273e-4626-999c-e1890be96182@lucifer.local/ Acked-by: Liam R. Howlett Acked-by: Lorenzo Stoakes Reviewed-by: Jeff Xu Tested-by: Yuli Wang Signed-off-by: Yuli Wang Signed-off-by: Huacai Chen

mseal sysmap: add arch-support txt

2025-04-01T22:17:17+00:00

Add Documentation/features/core/mseal_sys_mappings/arch-support.txt N/A: the arch is 32bits only and mseal is not supported in 32 bits, therefore N/A (until mseal is available in 32 bits kernel). [jeffxu@chromium.org: update to v3] Link: https://lkml.kernel.org/r/20250324151537.1106542-2-jeffxu@google.com Link: https://lkml.kernel.org/r/20250321032627.4147562-2-jeffxu@google.com Signed-off-by: Jeff Xu Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Eric Dumaze Cc: Geert Uytterhoeven Cc: guoweikang Cc: Heiko Carstens Cc: Kevin Brodsky Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Meghana Malladi Cc: Qi Zheng Cc: Sven Schnelle Cc: Thomas Weißschuh Cc: Vasily Gorbik Signed-off-by: Andrew Morton

scripts: get_feat.pl: substitute s390x with s390

2025-03-12T22:25:50+00:00

Both get_feat.pl and list-arch.sh use uname -m to get the machine hardware name to figure out the current architecture if no architecture is specified with a command line option. This doesn't work for s390, since for 64 bit kernels the hardware name is s390x, while the architecture name within the kernel, as well as in all feature files is s390. Therefore substitute s390x with s390 similar to what is already done for x86_64 and i386. Signed-off-by: Heiko Carstens Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250312155219.3597768-1-hca@linux.ibm.com

Documentation: riscv: Remove KPROBES_ON_FTRACE

2025-02-04T17:06:19+00:00

Since commit 7caa9765465f60 ("ftrace: riscv: move from REGS to ARGS"), kprobe on ftrace is not supported by riscv. And commit 3308172276db5d ("trace: riscv: Remove deprecated kprobe on ftrace support") removed the relevant code, but left out the documentation, so fix that. Signed-off-by: Chen Pei Reviewed-by: Charlie Jenkins Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250108020342.4172-1-cp0613@linux.alibaba.com

riscv: Add qspinlock support

2024-11-11T15:33:20+00:00

In order to produce a generic kernel, a user can select CONFIG_COMBO_SPINLOCKS which will fallback at runtime to the ticket spinlock implementation if Zabha or Ziccrse are not present. Note that we can't use alternatives here because the discovery of extensions is done too late and we need to start with the qspinlock implementation because the ticket spinlock implementation would pollute the spinlock value, so let's use static keys. This is largely based on Guo's work and Leonardo reviews at [1]. Link: https://lore.kernel.org/linux-riscv/20231225125847.2778638-1-guoren@kernel.org/ [1] Signed-off-by: Guo Ren Signed-off-by: Alexandre Ghiti Reviewed-by: Andrea Parri Link: https://lore.kernel.org/r/20241103145153.105097-14-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt

x86: remove PG_uncached

2024-09-04T04:15:46+00:00

Convert x86 to use PG_arch_2 instead of PG_uncached and remove PG_uncached. Link: https://lkml.kernel.org/r/20240821193445.2294269-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

LoongArch: Add ARCH_HAS_DEBUG_VM_PGTABLE support

2024-07-20T14:40:59+00:00

Add ARCH_HAS_DEBUG_VM_PGTABLE selection in Kconfig, in order to make corresponding vm debug features usable on LoongArch. Also update the corresponding arch-support.txt document. Signed-off-by: Huacai Chen