mpmc_concurrent_queue_test excluded from ASan/UBSan due to fake-stack alignment false positive

[VukPavicRTRK]

Description

MPMCConcurrentQueue has alignas(64) members (m_head, m_tail, m_stopped). ASan's fake stack does not honor over-alignment, so when a test fixture embeds the queue as a value member, UBSan reports a misaligned reference at constructor entry (mpmc_concurrent_queue.hpp:87) before any queue logic executes. The test is otherwise clean.

Currently worked around with:

tags = ["no-asan"]

in concurrency/BUILD.

Analysis results

No response

Solution

Three options:

1. Add alignas(CacheLineSize) to the class itself - declares the alignment requirement as part of the type.
2. Add a UBSan alignment suppression in score_cpp_policies for score::lcm::internal::MPMCConcurrentQueue.
3. Heap-allocate the queue in test fixtures (std::make_unique<...>()).

Error Occurrence Rate

Reproducible

How to reproduce

Remove no-asan from the target, then run:

bazel test --config=asan_ubsan_lsan --config=x86_64-linux \
  //score/launch_manager/daemon/src/common/concurrency:mpmc_concurrent_queue_test \
  --test_tag_filters= \
  --verbose_failures

Supporting Information

No response

Classification

Minor

First Affected Release

not released (main)

Last Affected Release

not released (main)

Expected Fixed Release

before release (main)

Category

• Safety Relevant
• Security Relevant

[MaciejKaszynski]

I don't think the unique_ptr or score_cpp_policies suggestions should be used just so we don't propagate this to other parts of the code.