Loader-v3 programdata account size is not counted towards limit if executed through CPI

[tao-stones]

Problem

@Lichtso repots:

we are not accounting for loader-v3 programs executed through CPI here:
https://github.com/anza-xyz/agave/blob/177f722410eada6b44cd3f65d992d9a846f21106/svm/src/account_loader.rs#L280
Since it was added (in [#29743](https://github.com/solana-labs/solana/pull/29743)) it was changed once to account for loader-v3 programdata accounts, but only in top-level instructions ([#30703](https://github.com/solana-labs/solana/pull/30703)).

Only in top-level instructions we use program.account_size from the program cache which correctly includes the loader-v3 programdata account length. The else branch however does use account.data().len() which is the proxy account length.

Add a test to demonstrate it.

Proposed Solution

[jstarry]

I'd like to take on this task by refactoring the existing code and likely adding a feature gate to make this behavior consistent with other loaders.

[tao-stones]

I'd like to take on this task by refactoring the existing code and likely adding a feature gate to make this behavior consistent with other loaders.

@Lichtso do you have something in pipeline might potentially conflict with it?

[Lichtso]

Yes, but @jstarry and I already coordinated.

[jstarry]

FYI this will be addressed in @2501babe's loaded account data size SIMD here: solana-foundation/solana-improvement-documents#186

[ceciEstErmat]

I was looking at how exactly are CPI program executed and it's a bit confusing.
The executor seem to require the program to be in the cache - but nowhere in the CPI code is this one added into it.
How is this program data executed really ?

https://github.com/anza-xyz/agave/blob/master/programs/bpf_loader/src/lib.rs#L457

[Lichtso]

The executor seem to require the program to be in the cache - but nowhere in the CPI code is this one added into it.

It happens earlier in transaction loading as one can only CPI programs which are present in the transactions account keys:

agave/svm/src/transaction_processor.rs

Line 368 in 141db09

let program_cache_for_tx_batch = self.replenish_program_cache(

[ceciEstErmat]

Ah right I for some reason assumed it was loading only the actual program form top level ix - but it is the load account that does that :D
Thx !