kernel/linux.git/samples/Kconfig, branch v6.18.21

samples: Kconfig: fix spelling mistake "instancess" -> "instances"

2025-08-02T19:01:41+00:00

There is a spelling mistake in the SAMPLE_TRACE_ARRAY config. Fix it. Link: https://lkml.kernel.org/r/20250724111715.141826-1-colin.i.king@gmail.com Signed-off-by: Colin Ian King Signed-off-by: Andrew Morton

samples: enhance hung_task detector test with read-write semaphore support

2025-07-20T02:08:26+00:00

Extend the hung_task detector test module to include read-write semaphore support alongside existing mutex and semaphore tests. This module now creates additional debugfs files under /hung_task, namely 'rw_semaphore_read' and 'rw_semaphore_write', in addition to 'mutex' and 'semaphore'. Reading these files with multiple processes triggers a prolonged sleep (256 seconds) while holding the respective lock, enabling hung_task detector testing for various locking mechanisms. This change builds on the extensible hung_task_tests module, adding read-write semaphore functionality to improve test coverage for kernel locking primitives. The implementation ensures proper lock handling and includes checks to prevent redundant data reads. Usage is: > cd /sys/kernel/debug/hung_task > cat mutex & cat mutex # Test mutex blocking > cat semaphore & cat semaphore # Test semaphore blocking > cat rw_semaphore_write \ & cat rw_semaphore_read # Test rwsem blocking > cat rw_semaphore_write \ & cat rw_semaphore_write # Test rwsem blocking Update the Kconfig description to reflect the addition of read-write semaphore debugfs files. Link: https://lkml.kernel.org/r/20250627072924.36567-4-lance.yang@linux.dev Signed-off-by: Zi Li Suggested-by: Masami Hiramatsu (Google) Cc: Anna Schumaker Cc: Boqun Feng Cc: Ingo Molnar Cc: Joel Granados Cc: John Stultz Cc: Kent Overstreet Cc: Mingzhe Yang Cc: Peter Zijlstra Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Tomasz Figa Cc: Waiman Long Cc: Will Deacon Cc: Yongliang Gao Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-06-01T02:12:53+00:00

Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...

samples: extend hung_task detector test with semaphore support

2025-05-12T00:54:08+00:00

Extend the existing hung_task detector test module to support multiple lock types, including mutex and semaphore, with room for future additions (e.g., spinlock, etc.). This module creates dummy files under /hung_task, such as 'mutex' and 'semaphore'. The read process on any of these files will sleep for enough long time (256 seconds) while holding the respective lock. As a result, the second process will wait on the lock for a prolonged duration and be detected by the hung_task detector. This change unifies the previous mutex-only sample into a single, extensible hung_task_tests module, reducing code duplication and improving maintainability. Usage is: > cd /sys/kernel/debug/hung_task > cat mutex & cat mutex # Test mutex blocking > cat semaphore & cat semaphore # Test semaphore blocking Update the Kconfig description to reflect multiple debugfs files support. Link: https://lkml.kernel.org/r/20250414145945.84916-4-ioworker0@gmail.com Signed-off-by: Lance Yang Signed-off-by: Zi Li Suggested-by: Masami Hiramatsu (Google) Acked-by: Masami Hiramatsu (Google) Cc: Anna Schumaker Cc: Boqun Feng Cc: Ingo Molnar Cc: Joel Granados Cc: John Stultz Cc: Kent Overstreet Cc: Mingzhe Yang Cc: Peter Zijlstra Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Tomasz Figa Cc: Waiman Long Cc: Will Deacon Cc: Yongliang Gao Signed-off-by: Andrew Morton

tsm-mr: Add tsm-mr sample code

2025-05-09T02:17:43+00:00

This sample kernel module demonstrates how to make MRs accessible to user mode through the tsm-mr library. Once loaded, this module registers a `miscdevice` that host a set of emulated measurement registers as shown in the directory tree below. /sys/class/misc/tsm_mr_sample └── measurements ├── config_mr ├── report_digest:sha512 ├── rtmr0:sha256 ├── rtmr1:sha384 ├── rtmr_crypto_agile:sha256 ├── rtmr_crypto_agile:sha384 └── static_mr:sha384 Among the MRs in this example: - `config_mr` demonstrates a hashless MR, like MRCONFIGID in Intel TDX or HOSTDATA in AMD SEV. - `static_mr` demonstrates a static MR. The suffix `:sha384` indicates its value is a sha384 digest. - `rtmr0` is an RTMR with `TSM_MR_F_WRITABLE` **cleared**, preventing direct extensions; as a result, the attribute `rtmr0:sha256` is read-only. - `rtmr1` is an RTMR with `TSM_MR_F_WRITABLE` **set**, permitting direct extensions; thus, the attribute `rtmr1:sha384` is writable. - `rtmr_crypto_agile` demonstrates a "single" MR that supports multiple hash algorithms. Each supported algorithm has a corresponding digest, usually referred to as a "bank" in TCG terminology. In this specific sample, the 2 banks are aliased to `rtmr0` and `rtmr1`, respectively. - `report_digest` contains the digest of the internal report structure living in this sample module's memory. It is to demonstrate the use of the `TSM_MR_F_LIVE` flag. Its value changes each time an RTMR is extended. Signed-off-by: Cedric Xing Reviewed-by: Dan Williams Acked-by: Dionna Amalie Glaze Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-2-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams

samples: add hung_task detector mutex blocking sample

2025-03-22T05:10:04+00:00

Add a hung_task detector mutex blocking test sample code. This module will create a dummy file on the debugfs. That file will cause the read process to sleep for enough long time (256 seconds) while holding a mutex. As a result, the second process will wait on the mutex for a prolonged duration and be detected by the hung_task detector. Usage is; > cd /sys/kernel/debug/hung_task > cat mutex & cat mutex and wait for hung_task message. [akpm@linux-foundation.org: make `hung_task_dir' static] Closes: https://lore.kernel.org/oe-kbuild-all/202503180827.4StpuFrD-lkp@intel.com/ Link: https://lkml.kernel.org/r/174046696281.2194069.4567490148001547311.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Cc: Anna Schumaker Cc: Boqun Feng Cc: Ingo Molnar Cc: Joel Granados Cc: Kent Overstreet Cc: Lance Yang Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Tomasz Figa Cc: Waiman Long Cc: Will Deacon Cc: Yongliang Gao Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-01-27T02:36:23+00:00

Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...

samples: add a skeleton of a sample DAMON module for working set size estimation

2025-01-14T06:40:57+00:00

Patch series "mm/damon: add sample modules". Implement a proactive cold memory regions reclaiming logic of prcl sample module using DAMOS. The logic treats memory regions that not accessed at all for five or more seconds as cold, and reclaim those as soon as found. This patch (of 5): Add a skeleton for a sample DAMON static module that can be used for estimating working set size of a given process. Note that it is a static module since DAMON is not exporting symbols to loadable modules for now. It exposes two module parameters, namely 'pid' and 'enable'. 'pid' will specify the process that the module will estimate the working set size of. 'enable' will receive whether to start or stop the estimation. Because this is just a skeleton, the parameters do nothing, though. The functionalities will be implemented by following commits. Link: https://lkml.kernel.org/r/20241210215030.85675-1-sj@kernel.org Link: https://lkml.kernel.org/r/20241210215030.85675-2-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

samples/check-exec: Add an enlighten "inc" interpreter and 28 tests

2024-12-19T01:00:29+00:00

Add a very simple script interpreter called "inc" that can evaluate two different commands (one per line): - "?" to initialize a counter from user's input; - "+" to increment the counter (which is set to 0 by default). It is enlighten to only interpret executable files according to AT_EXECVE_CHECK and the related securebits: # Executing a script with RESTRICT_FILE is only allowed if the script # is executable: ./set-exec -f -- ./inc script-exec.inc # Allowed ./set-exec -f -- ./inc script-noexec.inc # Denied # Executing stdin with DENY_INTERACTIVE is only allowed if stdin is an # executable regular file: ./set-exec -i -- ./inc -i < script-exec.inc # Allowed ./set-exec -i -- ./inc -i < script-noexec.inc # Denied # However, a pipe is not executable and it is then denied: cat script-noexec.inc | ./set-exec -i -- ./inc -i # Denied # Executing raw data (e.g. command argument) with DENY_INTERACTIVE is # always denied. ./set-exec -i -- ./inc -c "+" # Denied ./inc -c "$( Cc: Christian Brauner Cc: Kees Cook Cc: Paul Moore Cc: Serge Hallyn Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20241212174223.389435-8-mic@digikod.net Signed-off-by: Kees Cook

samples/check-exec: Add set-exec

2024-12-19T01:00:29+00:00

Add a simple tool to set SECBIT_EXEC_RESTRICT_FILE or SECBIT_EXEC_DENY_INTERACTIVE before executing a command. This is useful to easily test against enlighten script interpreters. Cc: Al Viro Cc: Christian Brauner Cc: Kees Cook Cc: Paul Moore Cc: Serge Hallyn Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20241212174223.389435-6-mic@digikod.net Signed-off-by: Kees Cook