[mgradwohl]

Description

On Linux, a service action sent through tasksmack-helper had to finish within PkexecBroker::CALL_TIMEOUT (10 s), the same limit as a read. The helper waits up to UnitWait::timeout (10 s) for each state change, with bus calls of up to 2 s around each wait, and a restart is a stop and then a start. So a slow service outlasted the 10 s:

• the UI said the action failed, although systemd carried it out;
• call()'s closeLocked() ended the helper session, so the next read or action asked for the password again.

PkexecBroker::call() now waits SERVICE_ACTION_TIMEOUT (60 s) for a ServiceActionRequest, and CALL_TIMEOUT (10 s) for anything else. The new callTimeoutFor() picks between them. callIfIdle() is unchanged.

With the longer wait, a stop request has to reach the call. BrokeredServiceActions::retried() asked the helper with an empty std::stop_token{}, so a cancel, or closing TaskSmack, waited out the whole action. It now passes the action's token. A stopped wait returns ServiceActionResult::stopRequested(), in retried() and in runAuthorized(). FakeBroker fails a call whose token is stopped with "cancelled", as PkexecBroker does.

Windows is unaffected: service actions don't go through its helper.

Fixes #3029

PR Size

Small: 6 files, about 90 lines.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Build/CI improvement

Checklist

• I have read the CONTRIBUTING guidelines
• My code follows the project's coding standards
• I have run clang-tidy and addressed any warnings
• I have run clang-format on my changes
• I have run pre-commit run --all-files or installed pre-commit hooks
• I have added tests that prove my fix/feature works
• All new and existing tests pass
• I have updated documentation as needed

Testing

PkexecBrokerTest.AServiceActionWaitsLongerThanTheHelperCanTake derives the helper's worst case from SystemdBus::UnitWait and SystemdBus::CALL_TIMEOUT_USEC: two state changes, each a wait plus four bus calls. It checks that a restart's timeout is longer than that, and that other requests keep CALL_TIMEOUT. If either constant grows past the client's wait, the test fails.

BrokeredServiceActionsTest.AStopRequestEndsTheWaitForTheHelper checks that a stopped token reaches the helper's call and comes back as a cancelled result, from restart() and from runAuthorized().

cmake --build --preset debug -j 4
TASKSMACK_REQUIRE_DISPLAY=1 TASKSMACK_REQUIRE_SDBUS=1 xvfb-run -a env -u WAYLAND_DISPLAY ctest --preset debug -j 4   # all pass
clang-tidy-22 -p build/debug --header-filter="^$PWD/src/" src/Platform/Linux/PkexecBroker.cpp tests/Platform/test_BrokerServer.cpp

Additional Notes

Found in a review of the #2728 helper PRs (#3002, #3013). The mutex is held for the longer wait, so a process action queued behind a slow service action waits too, and the sampler's callIfIdle() reads report "busy" and skip that refresh, as they already do behind any call.

🤖 Generated with Claude Code

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None