kernel/queue: Re-introduce race workaround #25908
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The timeout changes accidentally reverted the workaround introduced in commit b173e43 ("kernel/queue: Fix spurious NULL exit condition when using timeouts"): because k_poll() does not atomically release a lock, the usage in k_queue is inherently racy: a queue element can be removed from a queue after k_poll() has returned but before the thread gets to the list. This results in an early return with a NULL value. Reintroduce the looping around k_poll(), updated to the newer timeout API. Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The timeout changes accidentally reverted the workaround introduced in
commit b173e43 ("kernel/queue: Fix spurious NULL exit condition
when using timeouts"): because k_poll() does not atomically release a
lock, the usage in k_queue is inherently racy: a queue element can be
removed from a queue after k_poll() has returned but before the thread
gets to the list. This results in an early return with a NULL value.
Reintroduce the looping around k_poll(), updated to the newer timeout
API.
Signed-off-by: Andy Ross andrew.j.ross@intel.com