kernel/linux.git/tools/testing/selftests/vm/userfaultfd.c, branch v6.1.168

mm/selftest: uffd: explain the write missing fault check

2022-10-13T01:51:50+00:00

It's not obvious why we had a write check for each of the missing messages, especially when it should be a locking op. Add a rich comment for that, and also try to explain its good side and limitations, so that if someone hit it again for either a bug or a different glibc impl there'll be some clue to start with. Link: https://lkml.kernel.org/r/20221004193400.110155-4-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Mike Kravetz Reviewed-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Axel Rasmussen Cc: Mike Rapoport Cc: Nadav Amit Signed-off-by: Andrew Morton

selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory

2022-10-03T21:03:35+00:00

Add :collapse mod to userfaultfd selftest. Currently this mod is only valid for "shmem" test type, but could be used for other test types. When provided, memory allocated by ->allocate_area() will be hugepage-aligned enforced to be hugepage-sized. userfaultf_minor_test, after the UFFD-registered mapping has been populated by UUFD minor fault handler, attempt to MADV_COLLAPSE the UFFD-registered mapping to collapse the memory into a pmd-mapped THP. This test is meant to be a functional test of what occurs during UFFD-driven live migration of VMs backed by huge tmpfs where, after a hugepage-sized region has been successfully migrated (in native page-sized chunks, to avoid latency of fetched a hugepage over the network), we want to reclaim previous VM performance by remapping it at the PMD level. Link: https://lkml.kernel.org/r/20220907144521.3115321-11-zokeefe@google.com Link: https://lkml.kernel.org/r/20220922224046.1143204-11-zokeefe@google.com Signed-off-by: Zach O'Keefe Cc: Axel Rasmussen Cc: Chris Kennelly Cc: David Hildenbrand Cc: David Rientjes Cc: Hugh Dickins Cc: James Houghton Cc: "Kirill A. Shutemov" Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Minchan Kim Cc: Pasha Tatashin Cc: Peter Xu Cc: Rongwei Wang Cc: SeongJae Park Cc: Song Liu Cc: Vlastimil Babka Cc: Yang Shi Signed-off-by: Andrew Morton

userfaultfd: selftests: modify selftest to use /dev/userfaultfd

2022-09-12T03:25:49+00:00

We clearly want to ensure both userfaultfd(2) and /dev/userfaultfd keep working into the future, so just run the test twice, using each interface. Instead of always testing both userfaultfd(2) and /dev/userfaultfd, let the user choose which to test. As with other test features, change the behavior based on a new command line flag. Introduce the idea of "test mods", which are generic (not specific to a test type) modifications to the behavior of the test. This is sort of borrowed from this RFC patch series [1], but simplified a bit. The benefit is, in "typical" configurations this test is somewhat slow (say, 30sec or something). Testing both clearly doubles it, so it may not always be desirable, as users are likely to use one or the other, but never both, in the "real world". [1]: https://patchwork.kernel.org/project/linux-mm/patch/20201129004548.1619714-14-namit@vmware.com/ [axelrasmussen@google.com: modify selftest to exit with KSFT_SKIP *only* when features are unsupported, per Mike] Link: https://lkml.kernel.org/r/20220819205201.658693-4-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20220808175614.3885028-4-axelrasmussen@google.com Signed-off-by: Axel Rasmussen Acked-by: Peter Xu Acked-by: Mike Rapoport Cc: Al Viro Cc: Dave Hansen Cc: Dmitry V. Levin Cc: Gleb Fotengauer-Malinovskiy Cc: Hugh Dickins Cc: Jan Kara Cc: Jonathan Corbet Cc: Mel Gorman Cc: Mike Kravetz Cc: Shuah Khan Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zhang Yi Cc: Mike Rapoport Signed-off-by: Andrew Morton

userfaultfd: selftests: infinite loop in faulting_process

2022-07-04T01:08:43+00:00

On Android this test is getting stuck in an infinite loop due to indeterminate behavior: The local variables steps and signalled were being reset to 1 and 0 respectively after every jump back to sigsetjmp by siglongjmp in the signal handler. The test was incrementing them and expecting them to retain their incremented values. The documentation for siglongjmp says: All accessible objects have values as of the time sigsetjmp() was called, except that the values of objects of automatic storage duration which are local to the function containing the invocation of the corresponding sigsetjmp() which do not have volatile-qualified type and which are changed between the sigsetjmp() invocation and siglongjmp() call are indeterminate. Tagging steps and signalled with volatile enabled the test to pass. Link: https://lkml.kernel.org/r/20220613233321.431282-1-edliaw@google.com Signed-off-by: Edward Liaw Reviewed-by: Axel Rasmussen Cc: Shuah Khan Cc: Peter Xu Signed-off-by: Andrew Morton

userfaultfd/selftests: fix typo in comment

2022-06-17T02:48:31+00:00

Delete the redundant word 'in'. Link: https://lkml.kernel.org/r/20220610071244.59679-1-wangxiang@cdjrlc.com Signed-off-by: Xiang wangx Signed-off-by: Andrew Morton

userfaultfd/selftests: use swap() instead of open coding it

2022-05-13T14:20:12+00:00

Address the following coccicheck warning: tools/testing/selftests/vm/userfaultfd.c:1536:21-22: WARNING opportunity for swap(). tools/testing/selftests/vm/userfaultfd.c:1540:33-34: WARNING opportunity for swap(). by using swap() for the swapping of variable values and drop `tmp_area` that is not needed any more. `swap()` macro in userfaultfd.c is introduced in commit 681696862bc18 ("selftests: vm: remove dependecy from internal kernel macros") It has been tested with gcc (Debian 8.3.0-6) 8.3.0. Link: https://lkml.kernel.org/r/20220407123141.4998-1-guozhengkui@vivo.com Signed-off-by: Guo Zhengkui Reviewed-by: Muchun Song Reviewed-by: Shuah Khan Signed-off-by: Andrew Morton

selftests/uffd: enable uffd-wp for shmem/hugetlbfs

2022-05-13T14:20:12+00:00

After we added support for shmem and hugetlbfs, we can turn uffd-wp test on always now. Link: https://lkml.kernel.org/r/20220405014932.15212-1-peterx@redhat.com Signed-off-by: Peter Xu Cc: Alistair Popple Cc: Andrea Arcangeli Cc: Axel Rasmussen Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jerome Glisse Cc: "Kirill A . Shutemov" Cc: Matthew Wilcox Cc: Mike Kravetz Cc: Mike Rapoport Cc: Nadav Amit Signed-off-by: Andrew Morton

userfaultfd/selftests: enable hugetlb remap and remove event testing

2022-03-25T02:06:50+00:00

With MADV_DONTNEED support added to hugetlb mappings, mremap testing can also be enabled for hugetlb. Modify the tests to use madvise MADV_DONTNEED and MADV_REMOVE instead of fallocate hole puch for releasing hugetlb pages. Link: https://lkml.kernel.org/r/20220215002348.128823-4-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz Reviewed-by: Axel Rasmussen Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: Michal Hocko Cc: Mike Rapoport Cc: Mina Almasry Cc: Naoya Horiguchi Cc: Peter Xu Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'linux-kselftest-next-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2022-03-23T19:53:00+00:00

Pull Kselftest updates from Shuah Khan: "Several build and cleanup fixes: - removing obsolete config options - removing dependency on internal kernel macros - adding config options - several build fixes related to headers and install paths" * tag 'linux-kselftest-next-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (22 commits) selftests: Fix build when $(O) points to a relative path selftests: netfilter: fix a build error on openSUSE selftests: kvm: add generated file to the .gitignore selftests/exec: add generated files to .gitignore selftests: add kselftest_install to .gitignore selftests/rtc: continuously read RTC in a loop for 30s selftests/lkdtm: Add UBSAN config selftests/lkdtm: Remove dead config option selftests/exec: Rename file binfmt_script to binfmt_script.py selftests: Use -isystem instead of -I to include headers selftests: vm: remove dependecy from internal kernel macros selftests: vm: Add the uapi headers include variable selftests: mptcp: Add the uapi headers include variable selftests: net: Add the uapi headers include variable selftests: landlock: Add the uapi headers include variable selftests: kvm: Add the uapi headers include variable selftests: futex: Add the uapi headers include variable selftests: Correct the headers install path selftests: Add and export a kernel uapi headers path selftests: set the BUILD variable to absolute path ...

userfaultfd/selftests: fix uninitialized_var.cocci warning

2022-03-22T22:57:08+00:00

Fix following coccicheck warning: tools/testing/selftests/vm/userfaultfd.c:556:23-24: WARNING this kind of initialization is deprecated `unsigned long page_nr = *(&page_nr)` has the same form of uninitialized_var() macro. I remove the redundant assignement. It has been tested with gcc (Debian 8.3.0-6) 8.3.0. The patch which removed uninitialized_var() is: https://lore.kernel.org/all/20121028102007.GA7547@gmail.com/ And there is very few "/* GCC */" comments in the Linux kernel code now. Link: https://lkml.kernel.org/r/20220304082333.9252-1-guozhengkui@vivo.com Signed-off-by: Guo Zhengkui Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds