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 ...
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>
For kbuild to properly clean up these build artifacts in the subdirectory, even after CONFIG_KUNIT changed do disabled, the directory needs to be processed always. Pushing the special logic for hook.o into the kunit Makefile also makes the logic easier to understand. Link: https://lore.kernel.org/r/20250813-kunit-always-descend-v1-1-7bbd387ff13b@linutronix.de Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Pull non-MM updates from Andrew Morton:
"Significant patch series in this pull request:
- "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
us closer to being able to remove page->mapping
- "relayfs: misc changes" (Jason Xing) does some maintenance and
minor feature addition work in relayfs
- "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
us from static preallocation of the kdump crashkernel's working
memory over to dynamic allocation. So the difficulty of a-priori
estimation of the second kernel's needs is removed and the first
kernel obtains extra memory
- "generalize panic_print's dump function to be used by other
kernel parts" (Feng Tang) implements some consolidation and
rationalization of the various ways in which a failing kernel
splats information at the operator
* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
tools/getdelays: add backward compatibility for taskstats version
kho: add test for kexec handover
delaytop: enhance error logging and add PSI feature description
samples: Kconfig: fix spelling mistake "instancess" -> "instances"
fat: fix too many log in fat_chain_add()
scripts/spelling.txt: add notifer||notifier to spelling.txt
xen/xenbus: fix typo "notifer"
net: mvneta: fix typo "notifer"
drm/xe: fix typo "notifer"
cxl: mce: fix typo "notifer"
KVM: x86: fix typo "notifer"
MAINTAINERS: add maintainers for delaytop
ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
ucount: fix atomic_long_inc_below() argument type
kexec: enable CMA based contiguous allocation
stackdepot: make max number of pools boot-time configurable
lib/xxhash: remove unused functions
init/Kconfig: restore CONFIG_BROKEN help text
lib/raid6: update recov_rvv.c zero page usage
docs: update docs after introducing delaytop
...
Testing kexec handover requires a kernel driver that will generate some data and preserve it with KHO on the first boot and then restore that data and verify it was preserved properly after kexec. To facilitate such test, along with the kernel driver responsible for data generation, preservation and restoration add a script that runs a kernel in a VM with a minimal /init. The /init enables KHO, loads a kernel image for kexec and runs kexec reboot. After the boot of the kexeced kernel, the driver verifies that the data was properly preserved. [rppt@kernel.org: fix section mismatch] Link: https://lkml.kernel.org/r/aIiRC8fXiOXKbPM_@kernel.org Link: https://lkml.kernel.org/r/20250727083733.2590139-1-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull CRC updates from Eric Biggers: - Reorganize the architecture-optimized CRC code It now lives in lib/crc/$(SRCARCH)/ rather than arch/$(SRCARCH)/lib/, and it is no longer artificially split into separate generic and arch modules. This allows better inlining and dead code elimination The generic CRC code is also no longer exported, simplifying the API. (This mirrors the similar changes to SHA-1 and SHA-2 in lib/crypto/, which can be found in the "Crypto library updates" pull request) - Improve crc32c() performance on newer x86_64 CPUs on long messages by enabling the VPCLMULQDQ optimized code - Simplify the crypto_shash wrappers for crc32_le() and crc32c() Register just one shash algorithm for each that uses the (fully optimized) library functions, instead of unnecessarily providing direct access to the generic CRC code - Remove unused and obsolete drivers for hardware CRC engines - Remove CRC-32 combination functions that are no longer used - Add kerneldoc for crc32_le(), crc32_be(), and crc32c() - Convert the crc32() macro to an inline function * tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (26 commits) lib/crc: x86/crc32c: Enable VPCLMULQDQ optimization where beneficial lib/crc: x86: Reorganize crc-pclmul static_call initialization lib/crc: crc64: Add include/linux/crc64.h to kernel-api.rst lib/crc: crc32: Change crc32() from macro to inline function and remove cast nvmem: layouts: Switch from crc32() to crc32_le() lib/crc: crc32: Document crc32_le(), crc32_be(), and crc32c() lib/crc: Explicitly include <linux/export.h> lib/crc: Remove ARCH_HAS_* kconfig symbols lib/crc: x86: Migrate optimized CRC code into lib/crc/ lib/crc: sparc: Migrate optimized CRC code into lib/crc/ lib/crc: s390: Migrate optimized CRC code into lib/crc/ lib/crc: riscv: Migrate optimized CRC code into lib/crc/ lib/crc: powerpc: Migrate optimized CRC code into lib/crc/ lib/crc: mips: Migrate optimized CRC code into lib/crc/ lib/crc: loongarch: Migrate optimized CRC code into lib/crc/ lib/crc: arm64: Migrate optimized CRC code into lib/crc/ lib/crc: arm: Migrate optimized CRC code into lib/crc/ lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ lib/crc: Move files into lib/crc/ lib/crc32: Remove unused combination support ...
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
'panic_print' was introduced to help debugging kernel panic by dumping different kinds of system information like tasks' call stack, memory, ftrace buffer, etc. Actually this function could also be used to help debugging other cases like task-hung, soft/hard lockup, etc. where user may need the snapshot of system info at that time. Extract system info dump function related code from panic.c to separate file sys_info.[ch], for wider usage by other kernel parts for debugging. Also modify the macro names about singulars/plurals. Link: https://lkml.kernel.org/r/20250703021004.42328-3-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move all CRC files in lib/ into a subdirectory lib/crc/ to keep them from cluttering up the main lib/ directory. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Variable Length Arrays (VLAs) on the stack must not be used in the kernel.
Function parameter VLAs[1] should be usable, but -Wvla will warn for
those. For example, this will produce a warning but it is not using a
stack VLA:
int something(size_t n, int array[n]) { ...
Clang has no way yet to distinguish between the VLA types[2], so
depend on GCC for now to keep stack VLAs out of the tree by using GCC's
-Wvla-larger-than=N option (though GCC may split -Wvla similarly[3] to
how Clang is planning to).
While GCC 8+ supports -Wvla-larger-than, only 9+ supports ...=0[4],
so use -Wvla-larger-than=1. Adjust mm/kasan/Makefile to remove it from
CFLAGS (GCC <9 appears unable to disable the warning correctly[5]).
The VLA usage in lib/test_ubsan.c was removed in commit 9d7ca61b1366
("lib/test_ubsan.c: VLA no longer used in kernel") so the lib/Makefile
disabling of VLA checking can be entirely removed.
Link: https://en.cppreference.com/w/c/language/array [1]
Link: https://github.com/llvm/llvm-project/issues/57098 [2]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98217 [3]
Link: https://lore.kernel.org/lkml/7780883c-0ac8-4aaa-b850-469e33b50672@linux.ibm.com/ [4]
Link: https://lore.kernel.org/r/202505071331.4iOzqmuE-lkp@intel.com/ [5]
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Link: https://lore.kernel.org/r/20250418213235.work.532-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>