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core/vm: EIP-2315, JUMPSUB for the EVM (#20619)

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* core/vm: implement EIP 2315, subroutines for the EVM

* core/vm: eip 2315 - lintfix + check jump dest validity + check ret stack size constraints

  logger: markdown-friendly traces, validate jumpdest, more testcase, correct opcodes

* core/vm: update subroutines acc to eip: disallow walk-into

* core/vm/eips: gas cost changes for subroutines

* core/vm: update opcodes for EIP-2315

* core/vm: define RETURNSUB as a 'jumping' operation + review concerns

Co-authored-by: Martin Holst Swende <martin@swende.se>
This commit is contained in:
Greg Colvin
2020-06-02 04:30:16 -06:00
committed by GitHub
parent a35382de94
commit cd57d5cd38
15 changed files with 529 additions and 52 deletions
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32
core/vm/contract.go
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@ -83,7 +83,7 @@ func NewContract(caller ContractRef, object ContractRef, value *big.Int, gas uin
func (c *Contract) validJumpdest(dest *big.Int) bool {
udest := dest.Uint64()
// PC cannot go beyond len(code) and certainly can't be bigger than 63bits.
// PC cannot go beyond len(code) and certainly can't be bigger than 63 bits.
// Don't bother checking for JUMPDEST in that case.
if dest.BitLen() >= 63 || udest >= uint64(len(c.Code)) {
return false
@ -92,16 +92,32 @@ func (c *Contract) validJumpdest(dest *big.Int) bool {
if OpCode(c.Code[udest]) != JUMPDEST {
return false
}
// Do we have it locally already?
if c.analysis != nil {
return c.analysis.codeSegment(udest)
return c.isCode(udest)
}
func (c *Contract) validJumpSubdest(udest uint64) bool {
// PC cannot go beyond len(code) and certainly can't be bigger than 63 bits.
// Don't bother checking for BEGINSUB in that case.
if int64(udest) < 0 || udest >= uint64(len(c.Code)) {
return false
}
// If we have the code hash (but no analysis), we should look into the
// parent analysis map and see if the analysis has been made previously
// Only BEGINSUBs allowed for destinations
if OpCode(c.Code[udest]) != BEGINSUB {
return false
}
return c.isCode(udest)
}
// isCode returns true if the provided PC location is an actual opcode, as
// opposed to a data-segment following a PUSHN operation.
func (c *Contract) isCode(udest uint64) bool {
// Do we have a contract hash already?
if c.CodeHash != (common.Hash{}) {
// Does parent context have the analysis?
analysis, exist := c.jumpdests[c.CodeHash]
if !exist {
// Do the analysis and save in parent context
// We do not need to store it in c.analysis
analysis = codeBitmap(c.Code)
c.jumpdests[c.CodeHash] = analysis
}
@ -113,7 +129,9 @@ func (c *Contract) validJumpdest(dest *big.Int) bool {
// in state trie. In that case, we do an analysis, and save it locally, so
// we don't have to recalculate it for every JUMP instruction in the execution
// However, we don't save it within the parent context
c.analysis = codeBitmap(c.Code)
if c.analysis == nil {
c.analysis = codeBitmap(c.Code)
}
return c.analysis.codeSegment(udest)
}