(Regression) EVMC fails to validate contract via Sentinel

[jwasinger]

Using the genesis provided here (which is the same as the ewasm testnet genesis for milestone 1), a transaction containing this wast fails to deploy:

(module
  (import "ethereum" "storageStore" (func $storageStore (param i32 i32)))
  (memory 1)
  (data (i32.const 0)  "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00") ;; Path                                                                                  
  (data (i32.const 32) "\cd\ab\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00") ;; Value                                                                                 
  (export "memory" (memory 0))
  (export "main" (func $main))
  (func $main

  )
)

The only output I get from Hera is:
"Sentinel has failed on contract. It is invalid."

Maybe this is intended (and the contract is in some way malformed according to wasm-chisel's validation specs), however it is completely opaque what the underlying reason for the failure is.

[chfast]

Can this be reproduces with testeth or any other tool? Can you add this as a JSON test to ewasm/tests?

[jwasinger]

I'm not sure. I don't think it can be tested for unless we want to write unit test cases for hard-coded sentinel contract bytecodes....

If we had more detailed output from the sentinel contract, it would make solving issues like this a lot easier.

[jwasinger]

I built a new version of the sentinel contract from source and tried to test a simple contract deployment. This bug persists.

My rustc version:

nightly-x86_64-unknown-linux-gnu (default)
rustc 1.38.0-nightly (4bb6b4a5e 2019-07-11)

How to reproduce locally (note: the wasm in this example is different than in the issue description. but they are both bare-bones simple and trigger the same bug):
https://github.com/jwasinger/ewasm-dev-env/tree/post-milestone-1

[jwasinger]

Executing message in Hera
Metering (input 120 bytes)...
Executing message in Hera
Executing with wabt...
Module failed to load.
Metering done (output 0 bytes, used 9223372036854775807 gas) with code=1
Sentinel has failed on contract. It is invalid.

It looks like the sentinel itself fails to load with whatever version of wabt is shipped with hera at current master branch.

[axic]

It seems that an old version of llvm always included a linker custom section and the milestone1 version of sentinel was probably compiled like that. Source: WebAssembly/wabt#842

Manually dropping all custom sections with chisel's repack feature makes it to work with wabt – at least confirmed with wasm2wat, which decodes without issues.

[jwasinger]

Executing message in Hera
Metering (input 120 bytes)...
Executing message in Hera
Executing with wabt...
wabt (execute): invalid section size: extends past end
Module failed to load.
Metering done (output 0 bytes, used 9223372036854775807 gas) with code=1
Sentinel has failed on contract. It is invalid.

^ I get this after updating all components, using a freshly built and chiseled sentinel contract.