[EVM] Cannot call subnet precompile methods from another smart contract

[gztensor]

The example smart contract gets error "Error(InvalidCode(Opcode(94)))", when calling setHyperParameter:

pragma solidity ^0.8.3;

address constant ISUBTENSOR_SUBNET_ADDRESS = 0x0000000000000000000000000000000000000803;

interface ISubnet {
    /// Registers a new network without specifying details.
    function registerNetwork() external payable;

    function getServingRateLimit(uint16 netuid) external view returns (uint64);

    function setServingRateLimit(
        uint16 netuid,
        uint64 servingRateLimit
    ) external payable;
}

contract Subnet {
    function setHyperParameter(uint16 netuid, uint64 value) external {
        ISubnet subnetPrecompile = ISubnet(ISUBTENSOR_SUBNET_ADDRESS);
        (bool success, ) = ISUBTENSOR_SUBNET_ADDRESS.call(
            abi.encodeWithSelector(
                subnetPrecompile.setServingRateLimit.selector,
                netuid,
                value
            )
        );
        require(success, "Subnet call failed");
    }
}

[ales-otf]

I tried it on subnet-hyperparameter branch and couldn't reproduce it with this MPR: https://github.com/ales-otf/contract-in-contract-mpr

I modified the contract to call a getter for simplicity, as for setters there are additional checks.

To run the MPR, you need Alith account (5Fghzk1AJt88PeFEzuRfXzbPchiBbsVGTTXcdx599VdZzkTA) to be prefunded. Then:

npx hardhat run scripts/deploy.js --network subtensorEvm

[open-junius]

thanks. let me try your test code.

[ales-otf]

For the context, we discussed it more with Junius personally. And he suggested trying reproducing it with a setter instead. I've updated the code (same repo, latest commit) in MPR to dispatch setServingRateLimit. And I still see the same behavior. The contract is called, and the method is triggered correctly. It obviously won't work in the MPR, because it's a sudo call. I don't know what is ETH private key for Alice to test it, but anyway it failed on origin check and the node returned an error right after my print:

or with text:

2024-12-24 18:17:36 I'm ok!    
2024-12-24 18:17:36 Dispatch failed. Error: DispatchErrorWithPostInfo { post_info: PostDispatchInfo { actual_weight: None, pays_fee: Pays::Yes }, error: BadOrigin }    

So if we talk about calling contract from within a contract, the issue is most likely in the test setup. As the method is dispatched.

But notice that if you really want to test/trigger something like setServingRateLimit, you should also call it from sudo account as it's a sudo call. Also, I'm not sure whether it should be wrapped into sudo->call extrinsic, or just calling it from sudo would work.

[ales-otf]

For ref, here is where I put my "I'm ok" log:

fn dispatch(
    handle: &mut impl PrecompileHandle,
    call: RuntimeCall,
    smart_contract_address: &str,
) -> PrecompileResult {
    let account_id =
        <HashedAddressMapping<BlakeTwo256> as AddressMapping<AccountId32>>::into_account_id(
            handle.context().caller,
        );
	log::error!("I'm ok!");

    // Transfer the amount back to the caller before executing the staking operation
    // let caller = handle.context().caller;
    let amount = handle.context().apparent_value;

    if !amount.is_zero() {
        transfer_back_to_caller(smart_contract_address, &account_id, amount)?;
    }

    let result = call.dispatch(RawOrigin::Signed(account_id.clone()).into());
    match &result {
        Ok(post_info) => log::info!("Dispatch succeeded. Post info: {:?}", post_info),
        Err(dispatch_error) => log::error!("Dispatch failed. Error: {:?}", dispatch_error),
    }
    match result {
        Ok(_) => Ok(PrecompileOutput {
            exit_status: ExitSucceed::Returned,
            output: vec![],
        }),
        Err(_) => Err(PrecompileFailure::Error {
            exit_status: ExitError::Other("Subtensor call failed".into()),
        }),
    }
}

[ales-otf]

For the context, we discussed it more with Junius personally. And he suggested trying reproducing it with a setter instead. I've updated the code (same repo, latest commit) in MPR to dispatch setServingRateLimit. And I still see the same behavior. The contract is called, and the method is triggered correctly. It obviously won't work in the MPR, because it's a sudo call. I don't know what is ETH private key for Alice to test it, but anyway it failed on origin check and the node returned an error right after my print:

or with text:

2024-12-24 18:17:36 I'm ok!    
2024-12-24 18:17:36 Dispatch failed. Error: DispatchErrorWithPostInfo { post_info: PostDispatchInfo { actual_weight: None, pays_fee: Pays::Yes }, error: BadOrigin }    

So if we talk about calling contract from within a contract, the issue is most likely in the test setup. As the method is dispatched.

But notice that if you really want to test/trigger something like setServingRateLimit, you should also call it from sudo account as it's a sudo call. Also, I'm not sure whether it should be wrapped into sudo->call extrinsic, or just calling it from sudo would work.

Just realized, that I forgot to push the changes. I've also deleted the code locally, as Junius figured out this issue. Let me know if you need it, and I'll rewrite it.