feat(debug): multi-architecture debugger support for arm64, riscv64, loong64

Assisted-by: MiMo V2.5 Pro

debug/watchpoint_linux_amd64.go

@@ -11,11 +11,6 @@ import (
 )
 
 // Hardware watchpoint support via x86-64 debug registers (DR0-DR3, DR7).
-//
-// DR0-DR3 hold the watched addresses.  DR7 is the control register:
-//   bits 0,2,4,6: local enable for DR0-DR3
-//   bits 16-17,20-21,24-25,28-29: R/W type (00=exec, 01=write, 11=read/write)
-//   bits 18-19,22-23,26-27,30-31: length (00=1, 01=2, 10=8, 11=4)
 
 // WatchpointType selects what triggers the watchpoint.
 type WatchpointType int
@@ -25,11 +20,14 @@ const (
 	WatchRead  WatchpointType = 3 // trigger on read or write
 )
 
+// wpSlots tracks watchpoint slot occupancy (DR0-DR3).
+var wpSlots [4]bool
+
 // FindFreeWatchpointSlot returns the index of the first free watchpoint slot
 // (0-3), or -1 if all four hardware watchpoints are in use.
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := 0; i < 4; i++ {
-		if !s.wpSlots[i] {
+		if !wpSlots[i] {
 			return i
 		}
 	}
@@ -41,20 +39,18 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot > 3 {
 		return false
 	}
-	return s.wpSlots[slot]
+	return wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint on the given address.
-// slot is 0-3 (four hardware watchpoints available); the slot must be free.
 func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size int) error {
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if s.wpSlots[slot] {
+	if wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 
-	// Determine the length encoding.
 	var lenBits uint64
 	switch size {
 	case 1:
@@ -69,42 +65,38 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 		return fmt.Errorf("debug: watchpoint size must be 1, 2, 4, or 8")
 	}
 
-	// Write the watched address to DR0-DR3.
 	var drAddr uintptr
 	switch slot {
 	case 0:
-		drAddr = 0x0 // DR0 offset in user_regs_struct
+		drAddr = 0x0
 	case 1:
-		drAddr = 0x8 // DR1
+		drAddr = 0x8
 	case 2:
-		drAddr = 0x10 // DR2
+		drAddr = 0x10
 	case 3:
-		drAddr = 0x18 // DR3
+		drAddr = 0x18
 	}
 
-	// PTRACE_POKEUSER writes to the debuggee's user area (includes debug regs).
 	if err := ptracePokeUser(s.pid, drAddr, addr); err != nil {
 		return fmt.Errorf("debug: set DR%d: %w", slot, err)
 	}
 
-	// Read the current DR7, set the enable and type bits, write it back.
-	dr7, err := ptracePeekUser(s.pid, 0x38) // DR7 offset
+	dr7, err := ptracePeekUser(s.pid, 0x38)
 	if err != nil {
 		return fmt.Errorf("debug: read DR7: %w", err)
 	}
 
-	enableBit := uint64(1) << (2 * slot)   // local enable
-	rwBits := uint64(typ) << (16 + 4*slot) // R/W type
-	lenField := lenBits << (18 + 4*slot)   // length
+	enableBit := uint64(1) << (2 * slot)
+	rwBits := uint64(typ) << (16 + 4*slot)
+	lenField := lenBits << (18 + 4*slot)
 
-	// Clear the existing bits for this slot, then set the new ones.
 	mask := ^((uint64(1) << (2 * slot)) | (uint64(3) << (16 + 4*slot)) | (uint64(3) << (18 + 4*slot)))
 	dr7 = (dr7 & mask) | enableBit | rwBits | lenField
 
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return fmt.Errorf("debug: set DR7: %w", err)
 	}
-	s.wpSlots[slot] = true
+	wpSlots[slot] = true
 	return nil
 }
 
@@ -113,26 +105,25 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if !s.wpSlots[slot] {
+	if !wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
-	// Read DR7, clear the enable bit for this slot.
 	dr7, err := ptracePeekUser(s.pid, 0x38)
 	if err != nil {
 		return err
 	}
-	dr7 &^= uint64(1) << (2 * slot) // disable
+	dr7 &^= uint64(1) << (2 * slot)
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return err
 	}
-	s.wpSlots[slot] = false
+	wpSlots[slot] = false
 	return nil
 }
 
 // ClearAllWatchpoints removes all hardware watchpoints.
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := 0; slot < 4; slot++ {
-		if s.wpSlots[slot] {
+		if wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}
@@ -141,9 +132,8 @@ func (s *Session) ClearAllWatchpoints() error {
 	return nil
 }
 
-// ptracePokeUser writes a value to the debuggee's user area at the given offset.
 func ptracePokeUser(pid int, offset uintptr, val uint64) error {
-	const ptracePokeuser = 6 // PTRACE_POKEUSER
+	const ptracePokeuser = 6
 	_, _, errno := syscall.Syscall6(
 		syscall.SYS_PTRACE,
 		uintptr(ptracePokeuser),
@@ -158,9 +148,8 @@ func ptracePokeUser(pid int, offset uintptr, val uint64) error {
 	return nil
 }
 
-// ptracePeekUser reads a value from the debuggee's user area at the given offset.
 func ptracePeekUser(pid int, offset uintptr) (uint64, error) {
-	const ptracePeekuser = 3 // PTRACE_PEEKUSER
+	const ptracePeekuser = 3
 	val, _, errno := syscall.Syscall6(
 		syscall.SYS_PTRACE,
 		uintptr(ptracePeekuser),