From: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Subject: selftests/memfd: clean up mapping in mfd_fail_write 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> --- tools/testing/selftests/memfd/memfd_test.c | 1 + 1 file changed, 1 insertion(+) --- a/tools/testing/selftests/memfd/memfd_test.c~selftests-memfd-clean-up-mapping-in-mfd_fail_write +++ a/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 */ _
