linux-stable.git/tools/testing/selftests/vm/userfaultfd.c, branch linux-5.0.y

userfaultfd: selftest: recycle lock threads first

2018-10-26T23:26:35+00:00

Now we recycle the uffd servicing threads earlier than the lock threads.
It might happen that when the lock thread is still blocked at a pthread
mutex lock while the servicing thread has already quitted for the cpu so
the lock thread will be blocked forever and hang the test program.  To fix
the possible race, recycle the lock threads first.

This never happens with current missing-only tests, but when I start to
run the write-protection tests (the feature is not yet posted upstream) it
happens every time of the run possibly because in that new test we'll need
to service two page faults for each lock operation.

Link: http://lkml.kernel.org/r/20180930074259.18229-4-peterx@redhat.com
Signed-off-by: Peter Xu 
Acked-by: Mike Rapoport 
Cc: Shuah Khan 
Cc: Mike Kravetz 
Cc: Jerome Glisse 
Cc: Zi Yan 
Cc: "Kirill A . Shutemov" 
Cc: Shaohua Li 
Cc: Andrea Arcangeli 
Cc: "Dr . David Alan Gilbert" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: generalize read and poll

2018-10-26T23:26:35+00:00

We do very similar things in read and poll modes, but we're copying the
codes around.  Share the codes properly on reading the message and
handling the page fault to make the code cleaner.  Meanwhile this solves
previous mismatch of behaviors between the two modes on that the old code:

- did not check EAGAIN case in read() mode
- ignored BOUNCE_VERIFY check in read() mode

Link: http://lkml.kernel.org/r/20180930074259.18229-3-peterx@redhat.com
Signed-off-by: Peter Xu 
Acked-by: Mike Rapoport 
Cc: Shuah Khan 
Cc: Mike Kravetz 
Cc: Jerome Glisse 
Cc: Zi Yan 
Cc: "Kirill A . Shutemov" 
Cc: Shaohua Li 
Cc: Andrea Arcangeli 
Cc: "Dr . David Alan Gilbert" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: cleanup help messages

2018-10-26T23:26:35+00:00

Firstly, the help in the comment region is obsolete, now we support
three parameters.  Since at it, change it and move it into the help
message of the program.

Also, the help messages dumped here and there is obsolete too.  Use a
single usage() helper.

Link: http://lkml.kernel.org/r/20180930074259.18229-2-peterx@redhat.com
Signed-off-by: Peter Xu 
Acked-by: Mike Rapoport 
Cc: Shuah Khan 
Cc: Mike Kravetz 
Cc: Jerome Glisse 
Cc: Zi Yan 
Cc: "Kirill A . Shutemov" 
Cc: Shaohua Li 
Cc: Andrea Arcangeli 
Cc: "Dr . David Alan Gilbert" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

selftests: vm: return Kselftest Skip code for skipped tests

2018-06-18T15:11:10+00:00

When vm test is skipped because of unmet dependencies and/or unsupported
configuration, it exits with error which is treated as a fail by the
Kselftest framework. This leads to false negative result even when the
test could not be run.

Change it to return kselftest skip code when a test gets skipped to
clearly report that the test could not be run.

Kselftest framework SKIP code is 4 and the framework prints appropriate
messages to indicate that the test is skipped.

Signed-off-by: Shuah Khan (Samsung OSG) 
Acked-by: Mike Rapoport 
Signed-off-by: Shuah Khan (Samsung OSG)

userfaultfd: selftest: exercise -EEXIST only in background transfer

2017-10-13T23:18:32+00:00

I was stress testing some backports and with high load, after some time,
the latest version of the selftest showed some false positive in
connection with the uffdio_copy_retry.  This seems to fix it while still
exercising -EEXIST in the background transfer once in a while.

The fork child will quit after the last UFFDIO_COPY is run, so a
repeated UFFDIO_COPY may not return -EEXIST.  This change restricts the
-EEXIST stress to the background transfer where the memory can't go away
from under it.

Also updated uffdio_zeropage, so the interface is consistent.

Link: http://lkml.kernel.org/r/20171004171541.1495-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli 
Cc: Pavel Emelyanov 
Cc: Mike Rapoport 
Cc: "Dr. David Alan Gilbert" 
Cc: Mike Kravetz 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: explicit failure if the SIGBUS test failed

2017-09-07T00:27:29+00:00

Showing zero in the output isn't very self explanatory as a successful
result.  Show a more explicit error output if the test fails.

Link: http://lkml.kernel.org/r/20170802165145.22628-4-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli 
Cc: "Dr. David Alan Gilbert" 
Cc: Alexey Perevalov 
Cc: Maxime Coquelin 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: exercise UFFDIO_COPY/ZEROPAGE -EEXIST

2017-09-07T00:27:29+00:00

This will retry the UFFDIO_COPY/ZEROPAGE to verify it returns -EEXIST at
the first invocation and then later every 10 seconds.

In the filebacked MAP_SHARED case this also verifies the -EEXIST
triggered in the filesystem pagecache insertion, if the offset in the
file was not a hole.

shmem MAP_SHARED tries to index the newly allocated pagecache in the
radix tree before checking the pagetable so it doesn't need any
assistance to exercise that case.

hugetlbfs checks the pmd to be not none before trying to index the
hugetlbfs page in the radix tree, so it requires to run UFFDIO_COPY into
an alias mapping (the alternative would be to use MADV_DONTNEED to only
zap the pagetables, but that doesn't work on hugetlbfs).

[akpm@linux-foundation.org: fix uffdio_zeropage(), per Mike Kravetz]
Link: http://lkml.kernel.org/r/20170802165145.22628-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli 
Cc: "Dr. David Alan Gilbert" 
Cc: Alexey Perevalov 
Cc: Maxime Coquelin 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: add tests for UFFD_FEATURE_SIGBUS feature

2017-09-07T00:27:29+00:00

Add tests for UFFD_FEATURE_SIGBUS feature.  The tests will verify signal
delivery instead of userfault events.  Also, test use of UFFDIO_COPY to
allocate memory and retry accessing monitored area after signal
delivery.

Also fix a bug in uffd_poll_thread() where 'uffd' is leaked.

Link: http://lkml.kernel.org/r/1501552446-748335-3-git-send-email-prakash.sangappa@oracle.com
Signed-off-by: Prakash Sangappa 
Cc: Shuah Khan 
Cc: Andrea Arcangeli 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: enable testing of UFFDIO_ZEROPAGE for shmem

2017-09-07T00:27:28+00:00

Link: http://lkml.kernel.org/r/1497939652-16528-8-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Cc: "Kirill A. Shutemov" 
Cc: Andrea Arcangeli 
Cc: Hillf Danton 
Cc: Hugh Dickins 
Cc: Pavel Emelyanov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: selftest: combine all cases into a single executable

2017-05-03T22:52:10+00:00

Currently, selftest for userfaultfd is compiled three times: for
anonymous, shared and hugetlb memory.  Let's combine all the cases into
a single executable which will have a command line option for selection
of the test type.

Link: http://lkml.kernel.org/r/1490869741-5913-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Reviewed-by: Mike Kravetz 
Cc: Andrea Arcangeli 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds