From a91e6822349b6daa30a311f75b7d824739e5823d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Sat, 14 Oct 2017 15:42:48 +0300
Subject: [PATCH] core/vm: check opcode stack before readonly enforcement
---
core/vm/interpreter.go | 23 ++++++++++-------------
1 file changed, 10 insertions(+), 13 deletions(-)
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 94b922c79..516438509 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -138,10 +138,10 @@ func (in *Interpreter) Run(snapshot int, contract *Contract, input []byte) (ret
pc = uint64(0) // program counter
cost uint64
// copies used by tracer
- stackCopy = newstack() // stackCopy needed for Tracer since stack is mutated by 63/64 gas rule
- pcCopy uint64 // needed for the deferred Tracer
- gasCopy uint64 // for Tracer to log gas remaining before execution
- logged bool // deferred Tracer should ignore already logged steps
+ stackCopy = newstack() // stackCopy needed for Tracer since stack is mutated by 63/64 gas rule
+ pcCopy uint64 // needed for the deferred Tracer
+ gasCopy uint64 // for Tracer to log gas remaining before execution
+ logged bool // deferred Tracer should ignore already logged steps
)
contract.Input = input
@@ -169,22 +169,19 @@ func (in *Interpreter) Run(snapshot int, contract *Contract, input []byte) (ret
}
}
- // get the operation from the jump table matching the opcode
+ // Get the operation from the jump table matching the opcode and validate the
+ // stack and make sure there enough stack items available to perform the operation
operation := in.cfg.JumpTable[op]
- if err := in.enforceRestrictions(op, operation, stack); err != nil {
- return nil, err
- }
-
- // if the op is invalid abort the process and return an error
if !operation.valid {
return nil, fmt.Errorf("invalid opcode 0x%x", int(op))
}
-
- // validate the stack and make sure there enough stack items available
- // to perform the operation
if err := operation.validateStack(stack); err != nil {
return nil, err
}
+ // If the operation is valid, enforce and write restrictions
+ if err := in.enforceRestrictions(op, operation, stack); err != nil {
+ return nil, err
+ }
var memorySize uint64
// calculate the new memory size and expand the memory to fit
--
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