SBPF UnsupportedInstruction Error (0xf00000000) in Account Data Test

[andyjsbell]

SBPF UnsupportedInstruction Error in Account Data Test

Problem

The test_account_data test fails with exit code 0xf00000000 which corresponds to SBPF UnsupportedInstruction error. This occurs even though all CPI (Cross-Program Invocation) and AccountInfo synchronization functionality is working correctly.

Current Status

✅ SOLVED: Post-CPI data access functionality is fully working
❌ REMAINING: SBPF version compatibility issue

Evidence of Working CPI Implementation

The logs show all core functionality works perfectly:

• sol_invoke_signed_rust: CPI succeeded
• Account created successfully
• ✅ AccountInfo RefCell update complete: data=0x4000028c0, len=48
• Real-time sync: Account Pubkey([...]) has 48 bytes of data after CPI

Error Details

• Exit Code: 0xf00000000
• Decoded: Discriminant 1 (error) + Error ordinal 15 (0xf) = UnsupportedInstruction
• Timing: Error occurs at the very end of program execution, after all CPI logic completes
• SBPF Version: VM detects programs as V0, but may contain newer instructions

Investigation Done

1. ✅ Enabled SBPF V0-V3 in VM configuration
2. ✅ Tested with solana-program 1.18 (older version)
3. ✅ Tested with solana-program 2.2 (newer version)
4. ✅ Verified CPI implementation is correct
5. ❌ Still encountering UnsupportedInstruction error

Reproduction

RUST_LOG=debug cargo test test_account_data --lib

Expected Behavior

Test should pass with exit code 0 once SBPF compatibility issue is resolved.

Technical Context

• VM Configuration: Supports SBPF V0-V3 (enabled_sbpf_versions: V0..=V3)
• Program Detection: ELF always detected as SBPF V0 regardless of solana-program version
• Error Location: vm/src/vm.rs handle_error function maps UnsupportedInstruction to 0x1010, but we're seeing 0xf00000000

Impact

• Core CPI functionality is working correctly
• Tests fail due to infrastructure/compatibility issue
• Does not affect the primary goal of post-CPI data access

Next Steps

1. Investigate why programs compiled with different solana-program versions still trigger UnsupportedInstruction
2. Determine if SBPF version detection/override logic needs refinement
3. Potentially examine specific instruction bytes causing the unsupported instruction error