From: Mike Kravetz mike.kravetz@oracle.com

[ 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@oracle.com Signed-off-by: Mike Kravetz mike.kravetz@oracle.com Cc: Joel Fernandes joel@joelfernandes.org Cc: Shuah Khan shuah@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/memfd/memfd_test.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c index 845e5f67b6f02..cf4c5276eb06a 100644 --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -416,6 +416,7 @@ 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 */