kernel/tools/testing/selftests/mm/Makefile, branch linux-rolling-stable

selftests/mm: add -Wunreachable-code and fix warnings

2025-09-21T21:22:34Z

Patch series "selftests/mm: Add -Wunreachable-code and fix warnings". Add -Wunreachable-code to selftests and remove dead code from generated warnings. This patch (of 2): Enable -Wunreachable-code flag to catch dead code and fix them. 1. Remove the dead code and write a comment instead: hmm-tests.c:2033:3: warning: code will never be executed [-Wunreachable-code] perror("Should not reach this\n"); ^~~~~~ 2. ksft_exit_fail_msg() calls exit(). So cleanup isn't done. Replace it with ksft_print_msg(). split_huge_page_test.c:301:3: warning: code will never be executed [-Wunreachable-code] goto cleanup; ^~~~~~~~~~~~ 3. Remove duplicate inline. pkey_sighandler_tests.c:44:15: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier] static inline __always_inline Link: https://lkml.kernel.org/r/20250912123025.1271051-1-usama.anjum@collabora.com Link: https://lkml.kernel.org/r/20250912123025.1271051-2-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum Reviewed-by: Sidhartha Kumar Reviewed-by: Kevin Brodsky Acked-by: David Hildenbrand Reviewed-by: Zi Yan Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Jason Gunthorpe Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mariano Pache Cc: Michal Hocko Cc: Mike Rapoport Cc: Ryan Roberts Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/mm: test that rmap behaves as expected

2025-09-13T23:55:13Z

As David suggested, currently we don't have a high level test case to verify the behavior of rmap. This patch introduce the verification on rmap by migration. The general idea is if migrate one shared page between processes, this would be reflected in all related processes. Otherwise, we have problem in rmap. Currently it covers following four scenarios: * anonymous page * shmem page * pagecache page * ksm page Link: https://lkml.kernel.org/r/20250819080047.10063-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang Suggested-by: David Hildenbrand Cc: David Hildenbrand Cc: Lorenzo Stoakes Cc: Rik van Riel Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Harry Yoo Signed-off-by: Andrew Morton

selftests: prctl: introduce tests for disabling THPs completely

2025-09-13T23:55:06Z

The test will set the global system THP setting to never, madvise or always depending on the fixture variant and the 2M setting to inherit before it starts (and reset to original at teardown). The fixture setup will also test if PR_SET_THP_DISABLE prctl call can be made to disable all THPs and skip if it fails. This tests if the process can: - successfully get the policy to disable THPs completely. - never get a hugepage when the THPs are completely disabled with the prctl, including with MADV_HUGE and MADV_COLLAPSE. - successfully reset the policy of the process. - after reset, only get hugepages with: - MADV_COLLAPSE when policy is set to never. - MADV_HUGE and MADV_COLLAPSE when policy is set to madvise. - always when policy is set to "always". - never get a THP with MADV_NOHUGEPAGE. - repeat the above tests in a forked process to make sure the policy is carried across forks. [usamaarif642@gmail.com: return after executing test in child process] Link: https://lkml.kernel.org/r/2d0ea708-ecba-4021-b6ca-e93f1413d60a@gmail.com [usamaarif642@gmail.com: include linux/mman.h for prctl_thp_disable] Link: https://lkml.kernel.org/r/20250910204609.1720498-1-usamaarif642@gmail.com Link: https://lore.kernel.org/all/c8249725-e91d-4c51-b9bb-40305e61e20d@sirena.org.uk/ Link: https://lkml.kernel.org/r/20250815135549.130506-7-usamaarif642@gmail.com Signed-off-by: Usama Arif Acked-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Arnd Bergmann Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Jann Horn Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Liam Howlett Cc: Mariano Pache Cc: Michal Hocko Cc: Mike Rapoport Cc: Rik van Riel Cc: Ryan Roberts Cc: SeongJae Park Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yafang Cc: Zi Yan Signed-off-by: Andrew Morton

selftests/mm: add process_madvise() tests

2025-08-02T19:06:08Z

Add tests for process_madvise(), focusing on verifying behavior under various conditions including valid usage and error cases. [lianux.mm@gmail.com: v7] Link: https://lkml.kernel.org/r/20250729113109.12272-1-lianux.mm@gmail.com Link: https://lkml.kernel.org/r/20250729113109.12272-1-lianux.mm@gmail.com Link: https://lkml.kernel.org/r/20250721114614.40996-1-lianux.mm@gmail.com Signed-off-by: wang lian Suggested-by: Lorenzo Stoakes Suggested-by: David Hildenbrand Suggested-by: Zi Yan Suggested-by: Mark Brown Acked-by: SeongJae Park Reviewed-by: Zi Yan Tested-by: Zi Yan Cc: Christian Brauner Cc: Jann Horn Cc: Kairui Song Cc: Liam Howlett Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/mm: add simple VM_PFNMAP tests based on mmap'ing /dev/mem

2025-05-22T21:55:36Z

Let's test some basic functionality using /dev/mem. These tests will implicitly cover some PAT (Page Attribute Handling) handling on x86. These tests will only run when /dev/mem access to the first two pages in physical address space is possible and allowed; otherwise, the tests are skipped. On current x86-64 with PAT inside a VM, all tests pass: TAP version 13 1..6 # Starting 6 tests from 1 test cases. # RUN pfnmap.madvise_disallowed ... # OK pfnmap.madvise_disallowed ok 1 pfnmap.madvise_disallowed # RUN pfnmap.munmap_split ... # OK pfnmap.munmap_split ok 2 pfnmap.munmap_split # RUN pfnmap.mremap_fixed ... # OK pfnmap.mremap_fixed ok 3 pfnmap.mremap_fixed # RUN pfnmap.mremap_shrink ... # OK pfnmap.mremap_shrink ok 4 pfnmap.mremap_shrink # RUN pfnmap.mremap_expand ... # OK pfnmap.mremap_expand ok 5 pfnmap.mremap_expand # RUN pfnmap.fork ... # OK pfnmap.fork ok 6 pfnmap.fork # PASSED: 6 / 6 tests passed. # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 However, we are able to trigger: [ 27.888251] x86/PAT: pfnmap:1790 freeing invalid memtype [mem 0x00000000-0x00000fff] There are probably more things worth testing in the future, such as MAP_PRIVATE handling. But this set of tests is sufficient to cover most of the things we will rework regarding PAT handling. Link: https://lkml.kernel.org/r/20250509153033.952746-1-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Shuah Khan Cc: Ingo Molnar Cc: Peter Xu Cc: Dev Jain Signed-off-by: Andrew Morton

tools/testing/selftests: assert that anon merge cases behave as expected

2025-05-12T00:48:26Z

Prior to the recently applied commit that permits this merge, mprotect()'ing a faulted VMA, adjacent to an unfaulted VMA, such that the two share characteristics would fail to merge due to what appear to be unintended consequences of commit 965f55dea0e3 ("mmap: avoid merging cloned VMAs"). Now we have fixed this bug, assert that we can indeed merge anonymous VMAs this way. Also assert that forked source/target VMAs are equally rejected. Previously, all empty target anon merges with one VMA faulted and the other unfaulted would be rejected incorrectly, now we ensure that unforked merge, but forked do not. Additionally, add the new test file to the MEMORY MAPPING section in MAINTAINERS, as these tests are explicitly memory mapping related. Link: https://lkml.kernel.org/r/2b69330274a3b71721f7042c5eabe91143934415.1744104124.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Yeoreum Yun Cc: David Hildenbrand Cc: Jann Horn Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Rik van Riel Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Yang Signed-off-by: Andrew Morton

selftests/mm: rename guard-pages to guard-regions

2025-03-17T05:06:15Z

The feature formerly referred to as guard pages is more correctly referred to as 'guard regions', as in fact no pages are ever allocated in the process of installing the regions. To avoid confusion, rename the tests accordingly. [lorenzo.stoakes@oracle.com: fix guard regions invocation] Link: https://lkml.kernel.org/r/13426c71-d069-4407-9340-b227ff8b8736@lucifer.local Link: https://lkml.kernel.org/r/1c3cd04a3f69b5756b94bda701ac88325a9be18b.1739469950.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: Vlastimil Babka Cc: David Hildenbrand Cc: Jann Horn Cc: John Hubbard Cc: Kalesh Singh Cc: Liam Howlett Cc: Matthew Wilcox Cc: "Paul E . McKenney" Cc: Shuah Khan Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

selftests/mm: introduce uffd-wp-mremap regression test

2025-01-26T04:22:31Z

Introduce a test that registers a range of memory for UFFDIO_WRITEPROTECT_MODE_WP without UFFD_FEATURE_EVENT_REMAP. First check that the uffd-wp bit is set for every PTE in the range. Then mremap() the range to a new location and check that the uffd-wp bit is clear for every PTE in the range. Run the test for small folios, all supported THP sizes and all supported hugetlb sizes, and for swapped out memory, shared and private. There was previously a bug in the kernel where the uffd-wp bits remained set in all PTEs for this case, after fixing the kernel, the tests all pass. Link: https://lkml.kernel.org/r/20250107144755.1871363-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts Cc: David Hildenbrand Cc: Jann Horn Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Mark Rutland Cc: Muchun Song Cc: Peter Xu Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/mm: use sys_pkey helpers consistently

2025-01-14T06:40:56Z

sys_pkey_alloc, sys_pkey_free and sys_mprotect_pkey are currently used in protections_keys.c, while pkey_sighandler_tests.c calls the libc wrappers directly (e.g. pkey_mprotect()). This is probably ok when using glibc (those symbols appeared a while ago), but Musl does not currently provide them. The logging in the helpers from pkey-helpers.h can also come in handy. Make things more consistent by using the sys_pkey helpers in pkey_sighandler_tests.c too. To that end their implementation is moved to a common .c file (pkey_util.c). This also enables calling is_pkeys_supported() outside of protections_keys.c, since it relies on sys_pkey_{alloc,free}. [kevin.brodsky@arm.com: fix dependency on pkey_util.c] Link: https://lkml.kernel.org/r/20241216092849.2140850-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20241209095019.1732120-12-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Cc: Aruna Ramakrishna Cc: Catalin Marinas Cc: Dave Hansen Cc: Joey Gouly Cc: Keith Lucas Cc: Ryan Roberts Cc: Shuah Khan Signed-off-by: Andrew Morton

selftests/mm: build with -O2

2025-01-14T06:40:54Z

The mm kselftests are currently built with no optimisation (-O0). It's unclear why, and besides being obviously suboptimal, this also prevents the pkeys tests from working as intended. Let's build all the tests with -O2. [kevin.brodsky@arm.com: silence unused-result warnings] Link: https://lkml.kernel.org/r/20250107170110.2819685-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20241209095019.1732120-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Cc: Aruna Ramakrishna Cc: Catalin Marinas Cc: Dave Hansen Cc: Joey Gouly Cc: Keith Lucas Cc: Ryan Roberts Cc: Shuah Khan Signed-off-by: Andrew Morton