On 04-04 10:24, Pratyush Yadav wrote:
> From: "Pratyush Yadav (Google)" <[email protected]>
>
> Hi,
>
> This series adds some tests for memfd preservation across a live update.
> Currently memfd is only tested indirectly via luo_kexec_simple or
> luo_multi_session. Add a dedicated test suite for it.
>
> Patches 1 and 2 are preparatory, adding base framework and helpers, and
> the other patches each add a test. Some of the code is taken from the
> libluo patches [0] I sent a while ago.
>
> [0]
> https://lore.kernel.org/linux-mm/[email protected]/
Here are few observations that I noticed when I tried to run your tests:
1. The '-h' tells you nothing about --stage argument:
root@liveupdate-vm:~/liveupdate# ./luo_memfd -h
Usage: ./luo_memfd [-h|-l|-d] [-t|-T|-v|-V|-f|-F|-r name]
-h print help
-l list all tests
-d enable debug prints
-t name include test
-T name exclude test
-v name include variant
-V name exclude variant
-f name include fixture
-F name exclude fixture
-r name run specified test
...
2. '-l' does not work after you run stage1, do you keep /dev/liveupdate
open? That is not needed, we only need to keep session open.
root@liveupdate-vm:~/liveupdate# ./luo_memfd -l
1..0 # SKIP Failed to open /dev/liveupdate (Device or resource busy) device. Is
LUO enabled?
3. Stage 1 has proper [STAGE 1] prefix, but no [STAGE 2] prefix for
stage 2:
# Starting 4 tests from 1 test cases.
# RUN global.memfd_data ...
# [STAGE 1] Forking persistent child to hold sessions...
# [STAGE 1] Child PID: 245. Resources are pinned.
# [STAGE 1] You may now perform kexec reboot.
# OK global.memfd_data
ok 1 global.memfd_data
# RUN global.zero_memfd ...
# [STAGE 1] Forking persistent child to hold sessions...
# [STAGE 1] Child PID: 247. Resources are pinned.
# [STAGE 1] You may now perform kexec reboot.
# OK global.zero_memfd
ok 2 global.zero_memfd
# RUN global.preserved_ops ...
# OK global.preserved_ops
ok 3 global.preserved_ops
# RUN global.fallocate_memfd ...
# [STAGE 1] Forking persistent child to hold sessions...
# [STAGE 1] Child PID: 250. Resources are pinned.
# [STAGE 1] You may now perform kexec reboot.
# OK global.fallocate_memfd
ok 4 global.fallocate_memfd
# PASSED: 4 / 4 tests passed.
# Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0
./do_kexec
root@liveupdate-vm:~/liveupdate# ./luo_memfd
TAP version 13
1..4
# Starting 4 tests from 1 test cases.
# RUN global.memfd_data ...
# OK global.memfd_data
ok 1 global.memfd_data
# RUN global.zero_memfd ...
# OK global.zero_memfd
ok 2 global.zero_memfd
# RUN global.preserved_ops ...
# SKIP test only expected to run on stage 1
# OK global.preserved_ops
ok 3 global.preserved_ops # SKIP test only expected to run on stage 1
# RUN global.fallocate_memfd ...
# OK global.fallocate_memfd
ok 4 global.fallocate_memfd
# PASSED: 4 / 4 tests passed.
# 1 skipped test(s) detected. Consider enabling relevant config options to
improve coverage.
# Totals: pass:3 fail:0 xfail:0 xpass:0 skip:1 error:0
4. I also do not like that we now have duplicated stage parsing code in
luo_test(), perhaps we should add our own test_harness_run() variant
that depends on stage, and use it in both current tests, and the new
memfd tests.
Pasha
>
> Changes in v3:
> - Retry on EINTR instead of giving up in read_size() and write_size().
> - Use O_TRUNC in save_test_data().
> - Return the value of write_size() directly in create_random_memfd(). No
> need to check errno since write_size() already returns -errno.
> - Save errno before calling close() in create_random_memfd() to avoid
> overwriting the value.
> - Use memcmp() instead of open-coding the comparison loop.
> - Return value of test_harness_run() from main().
>
> Changes in v2:
> - Drop LIVEUPDATE_DEV since it isn't used.
> - Split luo_fd and stage declaration on separate lines.
> - Split all 2-stage tests into helper function for each test.
> - Fix wording and argument order when LUO_DEVICE fails to open.
> - Rename verify_fd_content() to verify_fd_content_read().
> - Advance buffer pointer in {read,write}_size().
> - Add a check to make sure current working directory is not on a tmpfs
> mount. If so, skip the tests since saved data files will be lost.
> - Rename RANDOM_DATA_FILE and RANDOM_DATA_FILE_FALLOCATE to
> MEMFD_DATA_FS_COPY and FALLOCATE_DATA_FS_COPY respectively. Also
> update the file names to reflect this naming convention.
> - Collect R-bys.
>
> Regards,
> Pratyush Yadav
>
> Pratyush Yadav (Google) (6):
> selftests/liveupdate: add framework for memfd tests
> selftests/liveupdate: add helper functions for memfd tests
> selftests/liveupdate: add test for memfd content preservation
> selftests/liveupdate: add test for zero-size memfd preservation
> selftests/liveupdate: add test for operations on a preserved memfd
> selftests/liveupdate: add fallocate test for memfd
>
> tools/testing/selftests/liveupdate/Makefile | 2 +
> .../testing/selftests/liveupdate/luo_memfd.c | 355 ++++++++++++++++++
> .../selftests/liveupdate/luo_test_utils.c | 191 +++++++++-
> .../selftests/liveupdate/luo_test_utils.h | 10 +
> 4 files changed, 557 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/liveupdate/luo_memfd.c
>
>
> base-commit: 98ddd87f9704ef2fc837ec2ca38877c364d8dada
> --
> 2.53.0.1213.gd9a14994de-goog
>
