[loong64][codegen] Avoid memory access under stack pointer

zjiaz · V8 LUCI CQ · commit 6b1b9bca2a8f · 2025-07-25T04:12:36.000-07:00
According to LoongArch ABI doc chapter 8.2: "Procedures must not assume the persistence on-stack data of which the addresses lie below the stack pointer." Change-Id: I92735e052227495ac9884c4290b57eaffbf905e1 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6786372 Auto-Submit: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn> Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Commit-Queue: Matthias Liedtke <mliedtke@chromium.org> Cr-Commit-Position: refs/heads/main@{#101634}
diff --git a/src/codegen/loong64/macro-assembler-loong64.cc b/src/codegen/loong64/macro-assembler-loong64.cc
@@ -1627,21 +1627,24 @@ void MacroAssembler::LoadIsolateField(Register dst, IsolateFieldId id) {
 }
 
 void MacroAssembler::MultiPush(RegList regs) {
-  int16_t stack_offset = 0;
+  int16_t num_to_push = regs.Count();
+  int16_t stack_offset = num_to_push * kSystemPointerSize;
 
+  Sub_d(sp, sp, Operand(stack_offset));
   for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
     if ((regs.bits() & (1 << i)) != 0) {
       stack_offset -= kSystemPointerSize;
       St_d(ToRegister(i), MemOperand(sp, stack_offset));
     }
   }
-  addi_d(sp, sp, stack_offset);
 }
 
 void MacroAssembler::MultiPush(RegList regs1, RegList regs2) {
   DCHECK((regs1 & regs2).is_empty());
-  int16_t stack_offset = 0;
+  int16_t num_to_push = regs1.Count() + regs2.Count();
+  int16_t stack_offset = num_to_push * kSystemPointerSize;
 
+  Sub_d(sp, sp, Operand(stack_offset));
   for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
     if ((regs1.bits() & (1 << i)) != 0) {
       stack_offset -= kSystemPointerSize;
@@ -1654,15 +1657,16 @@ void MacroAssembler::MultiPush(RegList regs1, RegList regs2) {
       St_d(ToRegister(i), MemOperand(sp, stack_offset));
     }
   }
-  addi_d(sp, sp, stack_offset);
 }
 
 void MacroAssembler::MultiPush(RegList regs1, RegList regs2, RegList regs3) {
   DCHECK((regs1 & regs2).is_empty());
   DCHECK((regs1 & regs3).is_empty());
   DCHECK((regs2 & regs3).is_empty());
-  int16_t stack_offset = 0;
+  int16_t num_to_push = regs1.Count() + regs2.Count() + regs3.Count();
+  int16_t stack_offset = num_to_push * kSystemPointerSize;
 
+  Sub_d(sp, sp, Operand(stack_offset));
   for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
     if ((regs1.bits() & (1 << i)) != 0) {
       stack_offset -= kSystemPointerSize;
@@ -1681,7 +1685,6 @@ void MacroAssembler::MultiPush(RegList regs1, RegList regs2, RegList regs3) {
       St_d(ToRegister(i), MemOperand(sp, stack_offset));
     }
   }
-  addi_d(sp, sp, stack_offset);
 }
 
 void MacroAssembler::MultiPop(RegList regs) {
@@ -4171,9 +4174,8 @@ void MacroAssembler::EnterFrame(StackFrame::Type type) {
 
 void MacroAssembler::LeaveFrame(StackFrame::Type type) {
   ASM_CODE_COMMENT(this);
-  addi_d(sp, fp, 2 * kSystemPointerSize);
-  Ld_d(ra, MemOperand(fp, 1 * kSystemPointerSize));
-  Ld_d(fp, MemOperand(fp, 0 * kSystemPointerSize));
+  Move(sp, fp);
+  Pop(ra, fp);
 }
 
 void MacroAssembler::EnterExitFrame(Register scratch, int stack_space,

Original file line number	Diff line number	Diff line change
`@@ -1627,21 +1627,24 @@ void MacroAssembler::LoadIsolateField(Register dst, IsolateFieldId id) {`
`1627`	`1627`	`}`
`1628`	`1628`
`1629`	`1629`	`void MacroAssembler::MultiPush(RegList regs) {`
`1630`		`- int16_t stack_offset = 0;`
	`1630`	`+ int16_t num_to_push = regs.Count();`
	`1631`	`+ int16_t stack_offset = num_to_push * kSystemPointerSize;`
`1631`	`1632`
	`1633`	`+ Sub_d(sp, sp, Operand(stack_offset));`
`1632`	`1634`	`for (int16_t i = kNumRegisters - 1; i >= 0; i--) {`
`1633`	`1635`	`if ((regs.bits() & (1 << i)) != 0) {`
`1634`	`1636`	`stack_offset -= kSystemPointerSize;`
`1635`	`1637`	`St_d(ToRegister(i), MemOperand(sp, stack_offset));`
`1636`	`1638`	`}`
`1637`	`1639`	`}`
`1638`		`- addi_d(sp, sp, stack_offset);`
`1639`	`1640`	`}`
`1640`	`1641`
`1641`	`1642`	`void MacroAssembler::MultiPush(RegList regs1, RegList regs2) {`
`1642`	`1643`	`DCHECK((regs1 & regs2).is_empty());`
`1643`		`- int16_t stack_offset = 0;`
	`1644`	`+ int16_t num_to_push = regs1.Count() + regs2.Count();`
	`1645`	`+ int16_t stack_offset = num_to_push * kSystemPointerSize;`
`1644`	`1646`
	`1647`	`+ Sub_d(sp, sp, Operand(stack_offset));`
`1645`	`1648`	`for (int16_t i = kNumRegisters - 1; i >= 0; i--) {`
`1646`	`1649`	`if ((regs1.bits() & (1 << i)) != 0) {`
`1647`	`1650`	`stack_offset -= kSystemPointerSize;`
`@@ -1654,15 +1657,16 @@ void MacroAssembler::MultiPush(RegList regs1, RegList regs2) {`
`1654`	`1657`	`St_d(ToRegister(i), MemOperand(sp, stack_offset));`
`1655`	`1658`	`}`
`1656`	`1659`	`}`
`1657`		`- addi_d(sp, sp, stack_offset);`
`1658`	`1660`	`}`
`1659`	`1661`
`1660`	`1662`	`void MacroAssembler::MultiPush(RegList regs1, RegList regs2, RegList regs3) {`
`1661`	`1663`	`DCHECK((regs1 & regs2).is_empty());`
`1662`	`1664`	`DCHECK((regs1 & regs3).is_empty());`
`1663`	`1665`	`DCHECK((regs2 & regs3).is_empty());`
`1664`		`- int16_t stack_offset = 0;`
	`1666`	`+ int16_t num_to_push = regs1.Count() + regs2.Count() + regs3.Count();`
	`1667`	`+ int16_t stack_offset = num_to_push * kSystemPointerSize;`
`1665`	`1668`
	`1669`	`+ Sub_d(sp, sp, Operand(stack_offset));`
`1666`	`1670`	`for (int16_t i = kNumRegisters - 1; i >= 0; i--) {`
`1667`	`1671`	`if ((regs1.bits() & (1 << i)) != 0) {`
`1668`	`1672`	`stack_offset -= kSystemPointerSize;`
`@@ -1681,7 +1685,6 @@ void MacroAssembler::MultiPush(RegList regs1, RegList regs2, RegList regs3) {`
`1681`	`1685`	`St_d(ToRegister(i), MemOperand(sp, stack_offset));`
`1682`	`1686`	`}`
`1683`	`1687`	`}`
`1684`		`- addi_d(sp, sp, stack_offset);`
`1685`	`1688`	`}`
`1686`	`1689`
`1687`	`1690`	`void MacroAssembler::MultiPop(RegList regs) {`
`@@ -4171,9 +4174,8 @@ void MacroAssembler::EnterFrame(StackFrame::Type type) {`
`4171`	`4174`
`4172`	`4175`	`void MacroAssembler::LeaveFrame(StackFrame::Type type) {`
`4173`	`4176`	`ASM_CODE_COMMENT(this);`
`4174`		`- addi_d(sp, fp, 2 * kSystemPointerSize);`
`4175`		`- Ld_d(ra, MemOperand(fp, 1 * kSystemPointerSize));`
`4176`		`- Ld_d(fp, MemOperand(fp, 0 * kSystemPointerSize));`
	`4177`	`+ Move(sp, fp);`
	`4178`	`+ Pop(ra, fp);`
`4177`	`4179`	`}`
`4178`	`4180`
`4179`	`4181`	`void MacroAssembler::EnterExitFrame(Register scratch, int stack_space,`