That was already the limit with KASAN enabled, and the 32-bit x86 build ends up having a couple of drm cases that have stack frames _just_ over 1kB on my allmodconfig test. So the minimal fix for this build issue for now is to just bump the limit and make it independent of KASAN. [ Side note: XTENSA already used 1.5k and PARISC uses 2k, so 1280 is still relatively conservative ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull non-MM updates from Andrew Morton: - "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet completes the removal of this legacy IDR API - "panic: introduce panic status function family" from Jinchao Wang provides a number of cleanups to the panic code and its various helpers, which were rather ad-hoc and scattered all over the place - "tools/delaytop: implement real-time keyboard interaction support" from Fan Yu adds a few nice user-facing usability changes to the delaytop monitoring tool - "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos Petrongonas fixes a panic which was happening with the combination of EFI and KHO - "Squashfs: performance improvement and a sanity check" from Phillip Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere 150x speedup was measured for a well-chosen microbenchmark - plus another 50-odd singleton patches all over the place * tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits) Squashfs: reject negative file sizes in squashfs_read_inode() kallsyms: use kmalloc_array() instead of kmalloc() MAINTAINERS: update Sibi Sankar's email address Squashfs: add SEEK_DATA/SEEK_HOLE support Squashfs: add additional inode sanity checking lib/genalloc: fix device leak in of_gen_pool_get() panic: remove CONFIG_PANIC_ON_OOPS_VALUE ocfs2: fix double free in user_cluster_connect() checkpatch: suppress strscpy warnings for userspace tools cramfs: fix incorrect physical page address calculation kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit Squashfs: fix uninit-value in squashfs_get_parent kho: only fill kimage if KHO is finalized ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name() kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock coccinelle: platform_no_drv_owner: handle also built-in drivers coccinelle: of_table: handle SPI device ID tables lib/decompress: use designated initializers for struct compress_format efi: support booting with kexec handover (KHO) ...
Pull bitmap updates from Yury Norov: - FIELD_PREP_WM16() consolidation (Nicolas) - bitmaps for Rust (Burak) - __fls() fix for arc (Kees) * tag 'bitmap-for-6.18' of https://github.com/norov/linux: (25 commits) rust: add dynamic ID pool abstraction for bitmap rust: add find_bit_benchmark_rust module. rust: add bitmap API. rust: add bindings for bitops.h rust: add bindings for bitmap.h phy: rockchip-pcie: switch to FIELD_PREP_WM16 macro clk: sp7021: switch to FIELD_PREP_WM16 macro PCI: dw-rockchip: Switch to FIELD_PREP_WM16 macro PCI: rockchip: Switch to FIELD_PREP_WM16* macros net: stmmac: dwmac-rk: switch to FIELD_PREP_WM16 macro ASoC: rockchip: i2s-tdm: switch to FIELD_PREP_WM16_CONST macro drm/rockchip: dw_hdmi: switch to FIELD_PREP_WM16* macros phy: rockchip-usb: switch to FIELD_PREP_WM16 macro drm/rockchip: inno-hdmi: switch to FIELD_PREP_WM16 macro drm/rockchip: dw_hdmi_qp: switch to FIELD_PREP_WM16 macro phy: rockchip-samsung-dcphy: switch to FIELD_PREP_WM16 macro drm/rockchip: vop2: switch to FIELD_PREP_WM16 macro drm/rockchip: dsi: switch to FIELD_PREP_WM16* macros phy: rockchip-emmc: switch to FIELD_PREP_WM16 macro drm/rockchip: lvds: switch to FIELD_PREP_WM16 macro ...
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 ...
Pull hardening updates from Kees Cook:
"One notable addition is the creation of the 'transitional' keyword for
kconfig so CONFIG renaming can go more smoothly.
This has been a long-standing deficiency, and with the renaming of
CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will soon have KCFI
support), this came up again.
The breadth of the diffstat is mainly this renaming.
- Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva)
- lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
(Junjie Cao)
- Add str_assert_deassert() helper (Lad Prabhakar)
- gcc-plugins: Remove TODO_verify_il for GCC >= 16
- kconfig: Fix BrokenPipeError warnings in selftests
- kconfig: Add transitional symbol attribute for migration support
- kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI"
* tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
lib/string_choices: Add str_assert_deassert() helper
kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI
kconfig: Add transitional symbol attribute for migration support
kconfig: Fix BrokenPipeError warnings in selftests
gcc-plugins: Remove TODO_verify_il for GCC >= 16
stddef: Introduce __TRAILING_OVERLAP()
stddef: Remove token-pasting in TRAILING_OVERLAP()
lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
There's really no need for this since it's 0 or 1 when
CONFIG_PANIC_ON_OOPS is disabled/enabled, so just use IS_ENABLED()
instead. The extra symbol goes back to the original code adding it in
commit 2a01bb3885c9 ("panic: Make panic_on_oops configurable").
Link: https://lkml.kernel.org/r/20250924094303.18521-2-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
Microbenchmark protected by a config FIND_BIT_BENCHMARK_RUST,
following `find_bit_benchmark.c` but testing the Rust Bitmap API.
We add a fill_random() method protected by the config in order to
maintain the abstraction.
The sample output from the benchmark, both C and Rust version:
find_bit_benchmark.c output:
```
Start testing find_bit() with random-filled bitmap
[ 438.101937] find_next_bit: 860188 ns, 163419 iterations
[ 438.109471] find_next_zero_bit: 912342 ns, 164262 iterations
[ 438.116820] find_last_bit: 726003 ns, 163419 iterations
[ 438.130509] find_nth_bit: 7056993 ns, 16269 iterations
[ 438.139099] find_first_bit: 1963272 ns, 16270 iterations
[ 438.173043] find_first_and_bit: 27314224 ns, 32654 iterations
[ 438.180065] find_next_and_bit: 398752 ns, 73705 iterations
[ 438.186689]
Start testing find_bit() with sparse bitmap
[ 438.193375] find_next_bit: 9675 ns, 656 iterations
[ 438.201765] find_next_zero_bit: 1766136 ns, 327025 iterations
[ 438.208429] find_last_bit: 9017 ns, 656 iterations
[ 438.217816] find_nth_bit: 2749742 ns, 655 iterations
[ 438.225168] find_first_bit: 721799 ns, 656 iterations
[ 438.231797] find_first_and_bit: 2819 ns, 1 iterations
[ 438.238441] find_next_and_bit: 3159 ns, 1 iterations
```
find_bit_benchmark_rust.rs output:
```
[ 451.182459] find_bit_benchmark_rust:
[ 451.186688] Start testing find_bit() Rust with random-filled bitmap
[ 451.194450] next_bit: 777950 ns, 163644 iterations
[ 451.201997] next_zero_bit: 918889 ns, 164036 iterations
[ 451.208642] Start testing find_bit() Rust with sparse bitmap
[ 451.214300] next_bit: 9181 ns, 654 iterations
[ 451.222806] next_zero_bit: 1855504 ns, 327026 iterations
```
Here are the results from 32 samples, with 95% confidence interval.
The microbenchmark was built with RUST_BITMAP_HARDENED=n and run on a
machine that did not execute other processes.
Random-filled bitmap:
+-----------+-------+-----------+--------------+-----------+-----------+
| Benchmark | Lang | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_bit/ | C | 825.07 | 53.89 | 806.40 | 843.74 |
| next_bit | Rust | 870.91 | 46.29 | 854.88 | 886.95 |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_zero/| C | 933.56 | 56.34 | 914.04 | 953.08 |
| next_zero | Rust | 945.85 | 60.44 | 924.91 | 966.79 |
+-----------+-------+-----------+--------------+-----------+-----------+
Rust appears 5.5% slower for next_bit, 1.3% slower for next_zero.
Sparse bitmap:
+-----------+-------+-----------+--------------+-----------+-----------+
| Benchmark | Lang | Mean (ms) | Std Dev (ms) | 95% CI Lo | 95% CI Hi |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_bit/ | C | 13.17 | 6.21 | 11.01 | 15.32 |
| next_bit | Rust | 14.30 | 8.27 | 11.43 | 17.17 |
+-----------+-------+-----------+--------------+-----------+-----------+
| find_zero/| C | 1859.31 | 82.30 | 1830.80 | 1887.83 |
| next_zero | Rust | 1908.09 | 139.82 | 1859.65 | 1956.54 |
+-----------+-------+-----------+--------------+-----------+-----------+
Rust appears 8.5% slower for next_bit, 2.6% slower for next_zero.
In summary, taking the arithmetic mean of all slow-downs, we can say
the Rust API has a 4.5% slowdown.
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Suggested-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Burak Emir <bqe@google.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Add KUnit tests for ffs()-family bit scanning functions: ffs(), __ffs(), fls(), __fls(), fls64(), __ffs64(), and ffz(). The tests validate mathematical relationships (e.g. ffs(x) == __ffs(x) + 1), and test zero values, power-of-2 patterns, maximum values, and sparse bit patterns. Build and run tested with everything I could reach with KUnit: $ ./tools/testing/kunit/kunit.py run --arch=x86_64 ffs $ ./tools/testing/kunit/kunit.py run --arch=i386 ffs $ ./tools/testing/kunit/kunit.py run --arch=arm64 --make_options "CROSS_COMPILE=aarch64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=arm --make_options "CROSS_COMPILE=arm-linux-gnueabihf-" ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpc ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpc32 ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpcle ffs $ ./tools/testing/kunit/kunit.py run --arch=riscv --make_options "CROSS_COMPILE=riscv64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=riscv32 --make_options "CROSS_COMPILE=riscv64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=s390 --make_options "CROSS_COMPILE=s390x-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=m68k ffs $ ./tools/testing/kunit/kunit.py run --arch=loongarch ffs $ ./tools/testing/kunit/kunit.py run --arch=mips --make_options "CROSS_COMPILE=mipsel-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sparc --make_options "CROSS_COMPILE=sparc64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sparc64 --make_options "CROSS_COMPILE=sparc64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=alpha --make_options "CROSS_COMPILE=alpha-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sh --make_options "CROSS_COMPILE=sh4-linux-gnu-" ffs Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250804164417.1612371-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
Now that the minimum supported version of LLVM for building the kernel has been bumped to 15.0.0, the CLANG_VERSION check for older than 14.0.0 is always false, so remove it. Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250821-bump-min-llvm-ver-15-v2-10-635f3294e5f0@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>