linux/Documentation/dev-tools, branch v6.3

Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-02-24T01:09:35Z

Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...

Merge tag 'linux-kselftest-kunit-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2023-02-23T17:40:14Z

Pull KUnit update from Shuah Khan: - add Function Redirection API to isolate the code being tested from other parts of the kernel. Documentation/dev-tools/kunit/api/functionredirection.rst has the details. * tag 'linux-kselftest-kunit-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: kunit: Add printf attribute to fail_current_test_impl lib/hashtable_test.c: add test for the hashtable structure Documentation: Add Function Redirection API docs kunit: Expose 'static stub' API to redirect functions kunit: Add "hooks" to call into KUnit when it's built as a module kunit: kunit.py extract handlers tools/testing/kunit/kunit.py: remove redundant double check

Documentation: Add Function Redirection API docs

2023-02-08T21:28:17Z

Added a new page (functionredirection.rst) that describes the Function Redirection (static stubbing) API. This page will be expanded if we add, for example, ftrace-based stubbing. In addition, 1. Updated the api/index.rst page to create an entry for function redirection api 2. Updated the toctree to be hidden, reducing redundancy on the generated page. Signed-off-by: Sadiya Kazi Co-developed-by: Daniel Latypov Signed-off-by: Daniel Latypov Co-developed-by: David Gow Signed-off-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: Add "hooks" to call into KUnit when it's built as a module

2023-02-08T21:26:25Z

KUnit has several macros and functions intended for use from non-test code. These hooks, currently the kunit_get_current_test() and kunit_fail_current_test() macros, didn't work when CONFIG_KUNIT=m. In order to support this case, the required functions and static data need to be available unconditionally, even when KUnit itself is not built-in. The new 'hooks.c' file is therefore always included, and has both the static key required for kunit_get_current_test(), and a table of function pointers in struct kunit_hooks_table. This is filled in with the real implementations by kunit_install_hooks(), which is kept in hooks-impl.h and called when the kunit module is loaded. This can be extended for future features which require similar "hook" behaviour, such as static stubs, by simply adding new entries to the struct, and the appropriate code to set them. Fixed white-space errors during commit: Shuah Khan Resolved merge conflicts with: db105c37a4d6 ("kunit: Export kunit_running()") This patch supersedes the above. Shuah Khan Signed-off-by: David Gow Reviewed-by: Rae Moar Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

Documentation: coccinelle: Escape --options to fix Sphinx output

2023-01-31T20:55:44Z

Without such escaping, -- is rendered as – (en dash). Signed-off-by: Jonathan Neuschäfer Acked-by: Julia Lawall Link: https://lore.kernel.org/r/20230129151408.1525324-1-j.neuschaefer@gmx.net Signed-off-by: Jonathan Corbet

docs/scripts/gdb: add necessary make scripts_gdb step

2023-01-26T18:21:05Z

In order to debug the kernel successfully with gdb you need to run 'make scripts_gdb' nowadays. This was changed with the following commit: Commit 67274c083438340ad16c ("scripts/gdb: delay generation of gdb constants.py") In order to have a complete guide for beginners this remark should be added to the offial documentation. Signed-off-by: Jakob Koschel Link: https://lore.kernel.org/r/20230112-documentation-gdb-v2-1-292785c43dc9@gmail.com Signed-off-by: Jonathan Corbet

kasan: allow sampling page_alloc allocations for HW_TAGS

2023-01-19T01:12:45Z

As Hardware Tag-Based KASAN is intended to be used in production, its performance impact is crucial. As page_alloc allocations tend to be big, tagging and checking all such allocations can introduce a significant slowdown. Add two new boot parameters that allow to alleviate that slowdown: - kasan.page_alloc.sample, which makes Hardware Tag-Based KASAN tag only every Nth page_alloc allocation with the order configured by the second added parameter (default: tag every such allocation). - kasan.page_alloc.sample.order, which makes sampling enabled by the first parameter only affect page_alloc allocations with the order equal or greater than the specified value (default: 3, see below). The exact performance improvement caused by using the new parameters depends on their values and the applied workload. The chosen default value for kasan.page_alloc.sample.order is 3, which matches both PAGE_ALLOC_COSTLY_ORDER and SKB_FRAG_PAGE_ORDER. This is done for two reasons: 1. PAGE_ALLOC_COSTLY_ORDER is "the order at which allocations are deemed costly to service", which corresponds to the idea that only large and thus costly allocations are supposed to sampled. 2. One of the workloads targeted by this patch is a benchmark that sends a large amount of data over a local loopback connection. Most multi-page data allocations in the networking subsystem have the order of SKB_FRAG_PAGE_ORDER (or PAGE_ALLOC_COSTLY_ORDER). When running a local loopback test on a testing MTE-enabled device in sync mode, enabling Hardware Tag-Based KASAN introduces a ~50% slowdown. Applying this patch and setting kasan.page_alloc.sampling to a value higher than 1 allows to lower the slowdown. The performance improvement saturates around the sampling interval value of 10 with the default sampling page order of 3. This lowers the slowdown to ~20%. The slowdown in real scenarios involving the network will likely be better. Enabling page_alloc sampling has a downside: KASAN misses bad accesses to a page_alloc allocation that has not been tagged. This lowers the value of KASAN as a security mitigation. However, based on measuring the number of page_alloc allocations of different orders during boot in a test build, sampling with the default kasan.page_alloc.sample.order value affects only ~7% of allocations. The rest ~93% of allocations are still checked deterministically. Link: https://lkml.kernel.org/r/129da0614123bb85ed4dd61ae30842b2dd7c903f.1671471846.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Jann Horn Cc: Mark Brand Cc: Peter Collingbourne Signed-off-by: Andrew Morton

Merge tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2022-12-13T00:42:57Z

Pull KUnit updates from Shuah Khan: "Several enhancements, fixes, clean-ups, documentation updates, improvements to logging and KTAP compliance of KUnit test output: - log numbers in decimal and hex - parse KTAP compliant test output - allow conditionally exposing static symbols to tests when KUNIT is enabled - make static symbols visible during kunit testing - clean-ups to remove unused structure definition" * tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits) Documentation: dev-tools: Clarify requirements for result description apparmor: test: make static symbols visible during kunit testing kunit: add macro to allow conditionally exposing static symbols to tests kunit: tool: make parser preserve whitespace when printing test log Documentation: kunit: Fix "How Do I Use This" / "Next Steps" sections kunit: tool: don't include KTAP headers and the like in the test log kunit: improve KTAP compliance of KUnit test output kunit: tool: parse KTAP compliant test output mm: slub: test: Use the kunit_get_current_test() function kunit: Use the static key when retrieving the current test kunit: Provide a static key to check if KUnit is actively running tests kunit: tool: make --json do nothing if --raw_ouput is set kunit: tool: tweak error message when no KTAP found kunit: remove KUNIT_INIT_MEM_ASSERTION macro Documentation: kunit: Remove redundant 'tips.rst' page Documentation: KUnit: reword description of assertions Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication kunit: eliminate KUNIT_INIT_*_ASSERT_STRUCT macros kunit: tool: remove redundant file.close() call in unit test kunit: tool: unit tests all check parser errors, standardize formatting a bit ...

Documentation: dev-tools: Clarify requirements for result description

2022-12-12T21:13:48Z

Currently the KTAP specification says that a test result line is [][ # [] []] and the description of a test can be "any sequence of words (can't include #)" which specifies that there may be more than one word but does not specify anything other than those words which might be used to separate the words which probably isn't what we want. Given that practically we have tests using a range of separators for words including combinations of spaces and combinations of other symbols like underscores or punctuation let's just clarify that the description can contain any character other than # (marking the start of the directive/diagnostic) or newline (marking the end of this test result). Signed-off-by: Mark Brown Reviewed-by: Kees Cook Reviewed-by: David Gow Signed-off-by: Shuah Khan

Documentation: kunit: Fix "How Do I Use This" / "Next Steps" sections

2022-12-12T21:13:48Z

The "How Do I Use This" section of index.rst and "Next Steps" section of start.rst were just copies of the table of contents, and therefore weren't really useful either when looking a sphinx generated output (which already had the TOC visible) or when reading the source (where it's just a list of files that ls could give you). Instead, provide a small number of concrete next steps, and a bit more description about what the pages contain. This also removes the broken reference to 'tips.rst', which was previously removed. Fixed git am whitespace complaints during commit: Shuah Khan Fixes: 4399c737a97d ("Documentation: kunit: Remove redundant 'tips.rst' page") Signed-off-by: David Gow Reviewed-by: Sadiya Kazi Reviewed-by: Bagas Sanjaya Signed-off-by: Shuah Khan