This is a note to let you know that I've just added the patch titled selftests/memfd: clean up mapping in mfd_fail_write to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 351ef217bf3de081dfd0d2c61a8f1aa8443c9ab8 Author: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Date: Fri Feb 25 19:11:26 2022 -0800 selftests/memfd: clean up mapping in mfd_fail_write [ Upstream commit fda153c89af344d21df281009a9d046cf587ea0f ] Running the memfd script ./run_hugetlbfs_test.sh will often end in error as follows: memfd-hugetlb: CREATE memfd-hugetlb: BASIC memfd-hugetlb: SEAL-WRITE memfd-hugetlb: SEAL-FUTURE-WRITE memfd-hugetlb: SEAL-SHRINK fallocate(ALLOC) failed: No space left on device ./run_hugetlbfs_test.sh: line 60: 166855 Aborted (core dumped) ./memfd_test hugetlbfs opening: ./mnt/memfd fuse: DONE If no hugetlb pages have been preallocated, run_hugetlbfs_test.sh will allocate 'just enough' pages to run the test. In the SEAL-FUTURE-WRITE test the mfd_fail_write routine maps the file, but does not unmap. As a result, two hugetlb pages remain reserved for the mapping. When the fallocate call in the SEAL-SHRINK test attempts allocate all hugetlb pages, it is short by the two reserved pages. Fix by making sure to unmap in mfd_fail_write. Link: https://lkml.kernel.org/r/20220219004340.56478-1-mike.kravetz@xxxxxxxxxx Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c index 192a2899bae8..94df2692e6e4 100644 --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -455,6 +455,7 @@ static void mfd_fail_write(int fd) printf("mmap()+mprotect() didn't fail as expected\n"); abort(); } + munmap(p, mfd_def_size); } /* verify PUNCH_HOLE fails */