Add munlock to s2n_free #195
Merged
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
Previously, pages for freed blobs would remain locked in resident memory even after calling s2n_free. According to http://linux.die.net/man/2/munlock: these pages would stay locked until the process exits. The mlocked bit field is added to help track which s2n_blobs need to be munlock'd when freed. Currently any *successfully* allocated blob will have mlocked == 1.
Prevents a race condition where another party may allocate locked memory. The logic here is convoluted because we still want to free the blob on munlock failure
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Outdated suggestions cannot be applied.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.
Previously, pages for freed blobs would remain locked in resident memory even
after calling s2n_free. According to http://linux.die.net/man/2/munlock:
these pages would stay locked until the process exits.
The mlocked bit field is added to help track which s2n_blobs need to be
munlock'd when freed. Currently any successfully allocated blob
will have mlocked == 1.
Decided to do this in a separate PR than #194 because it might need some work.