bpf/verifier: pruning branches based on no intersection between domains #10508
Conversation
This file contains hidden or 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
harishankarv
force-pushed
the
bpf-next
branch
2 times, most recently
from
38d6b91 to
348f10a
Compare
When verifying branches that compare two registers, if we can determine that the possible value ranges of the two registers do not intersect based on their unsigned and signed min/max values and tnums, we can conclude that certain branch outcomes are impossible. This patch adds checks for intersection between the unsigned ranges/signed ranges and tnums of registers. If no intersection exists, we can prune the impossible branch. Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
harishankarv
force-pushed
the
bpf-next
branch
from
348f10a to
6615253
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
0de3956 to
2d78e4d
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
2 times, most recently
from
5007636 to
0ac68c9
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
When verifying branches that compare two registers, if we can determine that the possible value ranges of the two registers do not intersect based on their unsigned and signed min/max values and tnums, we can conclude that certain branch outcomes are impossible. This patch adds checks for intersection between the unsigned ranges/signed ranges and tnums of registers. If no intersection exists, we can prune the impossible branch.