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 4.9-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-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c51354c4a2866467dcc3bceb3dfb04958614475a
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 26546892cd54..faab09215c88 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -373,6 +373,7 @@ 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 */
