git rekt — mgba.git: 3b1d3292dd69864591fec6517eb4fa9cbc941852

GBA Cheats: Fix holding onto pointers that may get invalidated

Jeffrey Pfau jeffrey@endrift.com

Tue, 20 Sep 2016 12:09:28 -0700

commit

3b1d3292dd69864591fec6517eb4fa9cbc941852

parent

1cb054ec67ea7b1e7e9162c1e74bd4ab254efb74

6 files changed, 42 insertions(+), 35 deletions(-)

jump to

CHANGES

src/gba/cheats.c

src/gba/cheats.h

src/gba/cheats/codebreaker.c

src/gba/cheats/gameshark.c

src/gba/cheats/parv3.c

M CHANGES → CHANGES

@@ -2,6 +2,7 @@ 0.6.0: (Future)
 Bugfixes:
  - GB MBC: Fix MBC7 when size is incorrectly specified
  - GB Video: Setting LYC=LY during mode 2 should trigger an IRQ
+ - GBA Cheats: Fix holding onto pointers that may get invalidated
 Misc:
  - All: Only update version info if needed

M src/gba/cheats.c → src/gba/cheats.c

@@ -75,9 +75,9 @@ static struct mCheatSet* GBACheatSetCreate(struct mCheatDevice* device, const char* name) {
 	UNUSED(device);
 	struct GBACheatSet* set = malloc(sizeof(*set));
 	mCheatSetInit(&set->d, name);
-	set->incompleteCheat = 0;
+	set->incompleteCheat = -1;
 	set->incompletePatch = 0;
-	set->currentBlock = 0;
+	set->currentBlock = -1;
 	set->gsaVersion = 0;
 	set->cbRngState = 0;
 	set->cbMaster = 0;

M src/gba/cheats.h → src/gba/cheats.h

@@ -12,6 +12,7 @@ #include "arm/arm.h"
 #include "core/cheats.h"
 
 #define MAX_ROM_PATCHES 4
+#define COMPLETE ((size_t) -1)
 
 enum GBACheatType {
 	GBA_CHEAT_AUTODETECT,
@@ -143,9 +144,9 @@ bool applied;
 		bool exists;
 	} romPatches[MAX_ROM_PATCHES];
 
-	struct mCheat* incompleteCheat;
+	size_t incompleteCheat;
 	struct GBACheatPatch* incompletePatch;
-	struct mCheat* currentBlock;
+	size_t currentBlock;
 
 	int gsaVersion;
 	uint32_t gsaSeeds[4];

M src/gba/cheats/codebreaker.c → src/gba/cheats/codebreaker.c

@@ -197,11 +197,12 @@
 	enum GBACodeBreakerType type = op1 >> 28;
 	struct mCheat* cheat = NULL;
 
-	if (cheats->incompleteCheat) {
-		cheats->incompleteCheat->repeat = op1 & 0xFFFF;
-		cheats->incompleteCheat->addressOffset = op2;
-		cheats->incompleteCheat->operandOffset = 0;
-		cheats->incompleteCheat = 0;
+	if (cheats->incompleteCheat != COMPLETE) {
+		struct mCheat* incompleteCheat = mCheatListGetPointer(&cheats->d.list, cheats->incompleteCheat);
+		incompleteCheat->repeat = op1 & 0xFFFF;
+		incompleteCheat->addressOffset = op2;
+		incompleteCheat->operandOffset = 0;
+		cheats->incompleteCheat = COMPLETE;
 		return true;
 	}
 
@@ -233,7 +234,7 @@ case CB_FILL:
 		cheat = mCheatListAppend(&cheats->d.list);
 		cheat->type = CHEAT_ASSIGN;
 		cheat->width = 2;
-		cheats->incompleteCheat = cheat;
+		cheats->incompleteCheat = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	case CB_FILL_8:
 		mLOG(CHEATS, STUB, "CodeBreaker code %08X %04X not supported", op1, op2);

M src/gba/cheats/gameshark.c → src/gba/cheats/gameshark.c

@@ -91,13 +91,14 @@ bool GBACheatAddGameSharkRaw(struct GBACheatSet* cheats, uint32_t op1, uint32_t op2) {
 	enum GBAGameSharkType type = op1 >> 28;
 	struct mCheat* cheat = 0;
 
-	if (cheats->incompleteCheat) {
+	if (cheats->incompleteCheat != COMPLETE) {
+		struct mCheat* incompleteCheat = mCheatListGetPointer(&cheats->d.list, cheats->incompleteCheat);
 		if (cheats->remainingAddresses > 0) {
 			cheat = mCheatListAppend(&cheats->d.list);
 			cheat->type = CHEAT_ASSIGN;
 			cheat->width = 4;
 			cheat->address = op1;
-			cheat->operand = cheats->incompleteCheat->operand;
+			cheat->operand = incompleteCheat->operand;
 			cheat->repeat = 1;
 			--cheats->remainingAddresses;
 		}
@@ -106,12 +107,12 @@ cheat = mCheatListAppend(&cheats->d.list);
 			cheat->type = CHEAT_ASSIGN;
 			cheat->width = 4;
 			cheat->address = op2;
-			cheat->operand = cheats->incompleteCheat->operand;
+			cheat->operand = incompleteCheat->operand;
 			cheat->repeat = 1;
 			--cheats->remainingAddresses;
 		}
 		if (cheats->remainingAddresses == 0) {
-			cheats->incompleteCheat = 0;
+			cheats->incompleteCheat = COMPLETE;
 		}
 		return true;
 	}
@@ -141,7 +142,7 @@ cheat = mCheatListAppend(&cheats->d.list);
 		cheat->type = CHEAT_ASSIGN;
 		cheat->width = 4;
 		cheat->address = op2;
-		cheats->incompleteCheat = cheat;
+		cheats->incompleteCheat = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	case GSA_PATCH:
 		cheats->romPatches[0].address = (op1 & 0xFFFFFF) << 1;

M src/gba/cheats/parv3.c → src/gba/cheats/parv3.c

@@ -53,18 +53,20 @@ return (x & 0xFFFFF) | ((x << 4) & 0x0F000000);
 }
 
 static void _parEndBlock(struct GBACheatSet* cheats) {
-	size_t size = mCheatListSize(&cheats->d.list) - mCheatListIndex(&cheats->d.list, cheats->currentBlock);
-	if (cheats->currentBlock->repeat) {
-		cheats->currentBlock->negativeRepeat = size - cheats->currentBlock->repeat;
+	size_t size = mCheatListSize(&cheats->d.list) - cheats->currentBlock;
+	struct mCheat* currentBlock = mCheatListGetPointer(&cheats->d.list, cheats->currentBlock);
+	if (currentBlock->repeat) {
+		currentBlock->negativeRepeat = size - currentBlock->repeat;
 	} else {
-		cheats->currentBlock->repeat = size;
+		currentBlock->repeat = size;
 	}
-	cheats->currentBlock = 0;
+	cheats->currentBlock = COMPLETE;
 }
 
 static void _parElseBlock(struct GBACheatSet* cheats) {
-	size_t size = mCheatListSize(&cheats->d.list) - mCheatListIndex(&cheats->d.list, cheats->currentBlock);
-	cheats->currentBlock->repeat = size;
+	size_t size = mCheatListSize(&cheats->d.list) - cheats->currentBlock;
+	struct mCheat* currentBlock = mCheatListGetPointer(&cheats->d.list, cheats->currentBlock);
+	currentBlock->repeat = size;
 }
 
 static bool _addPAR3Cond(struct GBACheatSet* cheats, uint32_t op1, uint32_t op2) {
@@ -98,10 +100,10 @@ break;
 	case PAR3_ACTION_BLOCK:
 		cheat->repeat = 0;
 		cheat->negativeRepeat = 0;
-		if (cheats->currentBlock) {
+		if (cheats->currentBlock != COMPLETE) {
 			_parEndBlock(cheats);
 		}
-		cheats->currentBlock = cheat;
+		cheats->currentBlock = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	}
 
@@ -175,13 +177,13 @@ cheats->romPatches[3].exists = true;
 		cheats->incompletePatch = &cheats->romPatches[3];
 		break;
 	case PAR3_OTHER_ENDIF:
-		if (cheats->currentBlock) {
+		if (cheats->currentBlock != COMPLETE) {
 			_parEndBlock(cheats);
 			return true;
 		}
 		return false;
 	case PAR3_OTHER_ELSE:
-		if (cheats->currentBlock) {
+		if (cheats->currentBlock != COMPLETE) {
 			_parElseBlock(cheats);
 			return true;
 		}
@@ -190,19 +192,19 @@ case PAR3_OTHER_FILL_1:
 		cheat = mCheatListAppend(&cheats->d.list);
 		cheat->address = _parAddr(op2);
 		cheat->width = 1;
-		cheats->incompleteCheat = cheat;
+		cheats->incompleteCheat = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	case PAR3_OTHER_FILL_2:
 		cheat = mCheatListAppend(&cheats->d.list);
 		cheat->address = _parAddr(op2);
 		cheat->width = 2;
-		cheats->incompleteCheat = cheat;
+		cheats->incompleteCheat = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	case PAR3_OTHER_FILL_4:
 		cheat = mCheatListAppend(&cheats->d.list);
 		cheat->address = _parAddr(op2);
 		cheat->width = 3;
-		cheats->incompleteCheat = cheat;
+		cheats->incompleteCheat = mCheatListIndex(&cheats->d.list, cheat);
 		break;
 	}
 	return true;
@@ -214,12 +216,13 @@ cheats->incompletePatch->newValue = op1;
 		cheats->incompletePatch = 0;
 		return true;
 	}
-	if (cheats->incompleteCheat) {
-		cheats->incompleteCheat->operand = op1 & (0xFFFFFFFFU >> ((4 - cheats->incompleteCheat->width) * 8));
-		cheats->incompleteCheat->addressOffset = op2 >> 24;
-		cheats->incompleteCheat->repeat = (op2 >> 16) & 0xFF;
-		cheats->incompleteCheat->addressOffset = (op2 & 0xFFFF) * cheats->incompleteCheat->width;
-		cheats->incompleteCheat = 0;
+	if (cheats->incompleteCheat != COMPLETE) {
+		struct mCheat* incompleteCheat = mCheatListGetPointer(&cheats->d.list, cheats->incompleteCheat);
+		incompleteCheat->operand = op1 & (0xFFFFFFFFU >> ((4 - incompleteCheat->width) * 8));
+		incompleteCheat->addressOffset = op2 >> 24;
+		incompleteCheat->repeat = (op2 >> 16) & 0xFF;
+		incompleteCheat->addressOffset = (op2 & 0xFFFF) * incompleteCheat->width;
+		cheats->incompleteCheat = COMPLETE;
 		return true;
 	}

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