core dump in hugetlbfs_test in 5.8.0-34.37 ADT test failure with linux 5.8.0-34.37

[Kelsey Steele]

Not a regression. Found occuring on previous kernels including 5.8.0-29.31

Testing failed on:
    amd64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/amd64/l/linux/20201218_030102_175b9@/log.gz
    arm64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/arm64/l/linux/20201217_165622_90478@/log.gz
    ppc64el: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/ppc64el/l/linux/20201217_103407_ff212@/log.gz
    s390x: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/s390x/l/linux/20201217_095421_b8712@/log.gz

09:03:05 DEBUG| [stdout] # selftests: memfd: run_hugetlbfs_test.sh
09:03:05 DEBUG| [stdout] # ./run_hugetlbfs_test.sh: line 47: [: -lt: unary operator expected
09:03:05 DEBUG| [stdout] # ./run_hugetlbfs_test.sh: line 60: 1125253 Aborted (core dumped) ./memfd_test hugetlbfs
09:03:06 DEBUG| [stdout] # Aborted (core dumped)
09:03:06 DEBUG| [stdout] ok 3 selftests: memfd: run_hugetlbfs_test.sh
09:03:06 DEBUG| [stdout] make[1]: Leaving directory '/tmp/autopkgtest.rVm8As/build.9pm/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/memfd'
09:03:06 DEBUG| [stdout] make: Leaving directory '/tmp/autopkgtest.rVm8As/build.9pm/src/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests'
09:03:06 INFO | ========== Summary ===========
09:03:06 INFO | No failed cases reported

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1910277

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Po-Hsu Lin (cypressyew)]

It looks like this failure comes from this "hugetlbfs sealing" test case:
https://github.com/torvalds/linux/commit/724978457fe29626bb6ce78e6c324c9d2648dcf7#diff-4e7dd2f5018b2be2ef6b3decbbb301809019580254f09335a85506a27cdc5b79

And this test case is part of the following kernel commit:
[0/6] memfd: add sealing to hugetlb-backed memory
https://lore.kernel.org/patchwork/cover/846262/

Maybe next is to check if these patches can make this test pass.

[Po-Hsu Lin (cypressyew)]

Bionic does not have this issue, as this test case does not exist there.