+ selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch added to -mm tree

+ selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: selftests/memfd: clean up mapping in mfd_fail_write
has been added to the -mm tree.  Its filename is
     selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch

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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@oracle.com>
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@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>
---

 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 */
_

Patches currently in -mm which might be from mike.kravetz@oracle.com are

selftests-vm-cleanup-hugetlb-file-after-mremap-test.patch
selftests-memfd-clean-up-mapping-in-mfd_fail_write.patch
mm-enable-madv_dontneed-for-hugetlb-mappings.patch
selftests-vm-add-hugetlb-madvise-madv_dontneed-madv_remove-test.patch
userfaultfd-selftests-enable-hugetlb-remap-and-remove-event-testing.patch
hugetlb-clean-up-potential-spectre-issue-warnings.patch