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memory-opt: add check for input, output and return bytes for precompile #571

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Jun 28, 2023
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memory-opt: add check for input, output and return bytes for precompile #571

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83 changes: 55 additions & 28 deletions zkevm-circuits/src/evm_circuit/execution/callop.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -981,34 +981,61 @@ impl<F: Field> ExecutionGadget<F> for CallOpGadget<F> {
output_rws,
return_rws,
) = if is_precompiled(&callee_address.to_address()) {
let input_bytes_begin = cd_offset.as_usize();
let input_bytes_end = cd_offset.as_usize() + cd_length.as_usize();
let input_bytes_begin_slot = input_bytes_begin - input_bytes_begin % 32;
let input_bytes_end_slot = input_bytes_end - input_bytes_end % 32;
let input_bytes_word_count = (input_bytes_end_slot - input_bytes_begin_slot + 32) / 32;
// input may not be aligned to 32 bytes. actual input is [start_offset..end_offset]
let input_bytes_start_offset = input_bytes_begin - input_bytes_begin_slot;
let input_bytes_end_offset = input_bytes_end - input_bytes_begin_slot;

let output_bytes_end = precompile_return_length.as_usize();
let output_bytes_end_slot = output_bytes_end - output_bytes_end % 32;
let output_bytes_word_count = (output_bytes_end_slot + 32) / 32;

let return_bytes_length = min(rd_length.as_usize(), output_bytes_end);
let callee_memory_end_slot = return_bytes_length - return_bytes_length % 32;
let return_bytes_begin = rd_offset.as_usize();
let return_bytes_end = return_bytes_begin + return_bytes_length;
let return_bytes_begin_slot = return_bytes_begin - return_bytes_begin % 32;
let return_bytes_end_slot = return_bytes_end - return_bytes_end % 32;
let return_bytes_slot_count = max(
callee_memory_end_slot,
return_bytes_end_slot - return_bytes_begin_slot,
);
let return_bytes_word_count = return_bytes_slot_count / 32 + 1;
// return data may not be aligned to 32 bytes. actual return data is
// [start_offset..end_offset]
let return_bytes_start_offset = return_bytes_begin - return_bytes_begin_slot;
let return_bytes_end_offset = return_bytes_end - return_bytes_begin_slot;
let [input_bytes_start_offset, input_bytes_end_offset, input_bytes_word_count] =
// Correspond to this check in bus-mapping.
// <https://github.com/scroll-tech/zkevm-circuits/blob/25dd32aa316ec842ffe79bb8efe9f05f86edc33e/bus-mapping/src/evm/opcodes/callop.rs#L349>
if cd_length.is_zero() {
[0; 3]
} else {
let begin = cd_offset.as_usize();
let end = cd_offset.as_usize() + cd_length.as_usize();
let begin_slot = begin - begin % 32;
let end_slot = end - end % 32;

// input may not be aligned to 32 bytes. actual input is
// [start_offset..end_offset]
let start_offset = begin - begin_slot;
let end_offset = end - begin_slot;
let word_count = (end_slot - begin_slot + 32) / 32;

[start_offset, end_offset, word_count]
};

let [output_bytes_end, output_bytes_word_count] =
// Correspond to this check in bus-mapping.
// <https://github.com/scroll-tech/zkevm-circuits/blob/25dd32aa316ec842ffe79bb8efe9f05f86edc33e/bus-mapping/src/evm/opcodes/callop.rs#L387>
if cd_length.is_zero() || precompile_return_length.is_zero() {
[0; 2]
} else {
let end = precompile_return_length.as_usize();
let end_slot = end - end % 32;

[end, (end_slot + 32) / 32]
};

let [return_bytes_start_offset, return_bytes_end_offset, return_bytes_word_count] =
// Correspond to this check in bus-mapping.
// <https://github.com/scroll-tech/zkevm-circuits/blob/25dd32aa316ec842ffe79bb8efe9f05f86edc33e/bus-mapping/src/evm/opcodes/callop.rs#L416>
if cd_length.is_zero() || precompile_return_length.is_zero() || rd_length.is_zero()
{
[0; 3]
} else {
let length = min(rd_length.as_usize(), output_bytes_end);
let begin = rd_offset.as_usize();
let end = begin + length;

let begin_slot = begin - begin % 32;
let end_slot = end - end % 32;
let slot_count = max(length - length % 32, end_slot - begin_slot);

// return data may not be aligned to 32 bytes. actual return data is
// [start_offset..end_offset]
let start_offset = begin - begin_slot;
let end_offset = end - begin_slot;
let word_count = slot_count / 32 + 1;

[start_offset, end_offset, word_count]
};

trace!("rw_offset {rw_offset}");
trace!(
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