Add a limit for the number of instructions in a function (#843)

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gdkchan 2019-12-14 18:18:51 -03:00 committed by GitHub
parent d925de2d0e
commit e5858e2c7d
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@ -10,6 +10,11 @@ namespace ARMeilleure.Decoders
{ {
static class Decoder static class Decoder
{ {
// We define a limit on the number of instructions that a function may have,
// this prevents functions being potentially too large, which would
// take too long to compile and use too much memory.
private const int MaxInstsPerFunction = 5000;
private delegate object MakeOp(InstDescriptor inst, ulong address, int opCode); private delegate object MakeOp(InstDescriptor inst, ulong address, int opCode);
private static ConcurrentDictionary<Type, MakeOp> _opActivators; private static ConcurrentDictionary<Type, MakeOp> _opActivators;
@ -36,10 +41,17 @@ namespace ARMeilleure.Decoders
Dictionary<ulong, Block> visited = new Dictionary<ulong, Block>(); Dictionary<ulong, Block> visited = new Dictionary<ulong, Block>();
int opsCount = 0;
Block GetBlock(ulong blkAddress) Block GetBlock(ulong blkAddress)
{ {
if (!visited.TryGetValue(blkAddress, out Block block)) if (!visited.TryGetValue(blkAddress, out Block block))
{ {
if (opsCount > MaxInstsPerFunction)
{
return null;
}
block = new Block(blkAddress); block = new Block(blkAddress);
workQueue.Enqueue(block); workQueue.Enqueue(block);
@ -92,6 +104,8 @@ namespace ARMeilleure.Decoders
FillBlock(memory, mode, currBlock, limitAddress); FillBlock(memory, mode, currBlock, limitAddress);
opsCount += currBlock.OpCodes.Count;
if (currBlock.OpCodes.Count != 0) if (currBlock.OpCodes.Count != 0)
{ {
// Set child blocks. "Branch" is the block the branch instruction // Set child blocks. "Branch" is the block the branch instruction