fix(aya): BSS Sections must be filled with zeros #1073
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
Users have reported issues with programs failing the verifier when they are attempting to read or write to variables that the compiler places in the .bss section. Add a test that places variables in each section and exercises read and write operations on them. Signed-off-by: Dave Tucker <[email protected]>
This provides more useful failure messages when integration tests fail Signed-off-by: Dave Tucker <[email protected]>
The loader should fill bss maps with zeros according to the size of the ELF section. Failure to do so yields weird verifier messages as follows: ``` cannot access ptr member ops with moff 0 in struct bpf_map with off 0 size 4 ``` Reference to this in the cilium/ebpf code is here [1]. I could not find a reference in libbpf. 1: https://github.com/cilium/ebpf/blob/d0c8fc19376a9276cf5310c288d1eae99ed39eb3/elf_reader.go#L1159-L1165 Signed-off-by: Dave Tucker <[email protected]>
✅ Deploy Preview for aya-rs-docs ready!
To edit notification comments on pull requests, go to your Netlify site configuration. |
mergify
bot
added
aya
alessandrod
approved these changes
Nov 1, 2024
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Outdated suggestions cannot be applied.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.
See individual commits.
In summary, we need to fill BSS sections with 0's up to the size of the ELF section.
Otherwise access to these variables will fail with the following verifier error:
Fixes: #1002