Rework bounds checking for atomic operations#5239
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fitzgen merged 1 commit intoNov 10, 2022
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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
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I think this makes sense to me.
This was referenced Nov 10, 2022
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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).