Rework bounds checking for atomic operations #5239
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
Before, we would do a `heap_addr` to translate the given Wasm memory address into a native memory address and pass it into the libcall that implemented the atomic operation, which would then treat the address as a Wasm memory address and pass it to `validate_atomic_addr` to be bounds checked a second time. This is a bit nonsensical, as we are validating a native memory address as if it were a Wasm memory address. Now, we no longer do a `heap_addr` to translate the Wasm memory address to a native memory address. Instead, we pass the Wasm memory address to the libcall, and the libcall is responsible for doing the bounds check (by calling `validate_atomic_addr` with the correct type of memory address now).
abrown
approved these changes
Nov 10, 2022
This was referenced Nov 10, 2022
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Outdated suggestions cannot be applied.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.
Before, we would do a
heap_addrto translate the given Wasm memory address into a native memory address and pass it into the libcall that implemented the atomic operation, which would then treat the address as a Wasm memory address and pass it tovalidate_atomic_addrto be bounds checked a second time. This is a bit nonsensical, as we are validating a native memory address as if it were a Wasm memory address.Now, we no longer do a
heap_addrto translate the Wasm memory address to a native memory address. Instead, we pass the Wasm memory address to the libcall, and the libcall is responsible for doing the bounds check (by callingvalidate_atomic_addrwith the correct type of memory address now).