diff --git a/debug/breakpoint.go b/debug/breakpoint.go
index ea42cd0..985efea 100644
--- a/debug/breakpoint.go
+++ b/debug/breakpoint.go
@@ -36,7 +36,7 @@ type Condition struct {
 func (c *Condition) Eval(regs *Regs) bool {
 	actual, ok := regs.RegValue(c.Reg)
 	if !ok {
-		return true // unknown register — don't block
+		return true // unknown register, don't block
 	}
 	var expected uint64
 	switch {
@@ -48,7 +48,7 @@ func (c *Condition) Eval(regs *Regs) bool {
 		}
 		expected = v
 	case c.MemAddr != 0:
-		// Register-memory comparison — requires a Session, not available here.
+		// Register-memory comparison, requires a Session, not available here.
 		// Fall back to treating as constant (the caller should resolve).
 		expected = c.Value
 	default:
@@ -72,8 +72,7 @@ func (c *Condition) Eval(regs *Regs) bool {
 	}
 }
 
-// Breakpoints manages the set of breakpoints for a Session.
-// Breakpoints manages software breakpoints for a debuggee.
+// Breakpoints manages the software breakpoints of one Session.
 type Breakpoints struct {
 	t   tracer
 	bps map[uint64]*Breakpoint
@@ -200,7 +199,7 @@ func (bm *Breakpoints) HandleTrap(regs *Regs) *Breakpoint {
 	}
 	// Check the condition (if any).
 	if bp.Cond != nil && !bp.Cond.Eval(regs) {
-		// Condition not met — restore the byte but do NOT rewind RIP.
+		// Condition not met, restore the byte but do NOT rewind RIP.
 		// The process continues from the next instruction (past the INT3).
 		word, err := bm.t.Peek(trapAddr)
 		if err == nil {
diff --git a/debug/debug_test.go b/debug/debug_test.go
index 63a7a8a..bb47ed7 100644
--- a/debug/debug_test.go
+++ b/debug/debug_test.go
@@ -275,8 +275,7 @@ func TestBreakpointInfo(t *testing.T) {
 }
 
 func TestWatchpointSlotTracking(t *testing.T) {
-	wpSlots = [4]bool{} // reset
-	s := &Session{}
+	s := &Session{} // per-session slots start free
 
 	// All four slots are free initially.
 	for i := range 4 {
@@ -289,8 +288,8 @@ func TestWatchpointSlotTracking(t *testing.T) {
 	}
 
 	// Manually mark slots 0 and 2 as used (simulating successful SetWatchpoint).
-	wpSlots[0] = true
-	wpSlots[2] = true
+	s.wpSlots[0] = true
+	s.wpSlots[2] = true
 
 	if !s.IsWatchpointSlotUsed(0) {
 		t.Error("slot 0 should be in use")
@@ -318,7 +317,7 @@ func TestWatchpointSlotTracking(t *testing.T) {
 
 	// Mark all slots used: FindFreeWatchpointSlot returns -1.
 	for i := range 4 {
-		wpSlots[i] = true
+		s.wpSlots[i] = true
 	}
 	if got := s.FindFreeWatchpointSlot(); got != -1 {
 		t.Errorf("FindFreeWatchpointSlot() with all slots used = %d, want -1", got)
diff --git a/debug/ptrace_linux.go b/debug/ptrace_linux.go
index 0d0c13c..bd5ad95 100644
--- a/debug/ptrace_linux.go
+++ b/debug/ptrace_linux.go
@@ -22,7 +22,8 @@ type Session struct {
 	cmd      *exec.Cmd
 	stopped  bool
 	exited   bool
-	codeBase uint64 // base address of the JIT code in the debuggee
+	codeBase uint64   // base address of the JIT code in the debuggee
+	wpSlots  [16]bool // hardware watchpoint slots in use (DR0-DR3, arm64 BADVR0-15)
 }
 
 // Launch starts the debuggee subprocess (gasm debug --target ...) and
diff --git a/debug/watchpoint_linux_amd64.go b/debug/watchpoint_linux_amd64.go
index 7c0affb..560a98b 100644
--- a/debug/watchpoint_linux_amd64.go
+++ b/debug/watchpoint_linux_amd64.go
@@ -20,14 +20,11 @@ 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 := range 4 {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -39,7 +36,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot > 3 {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint on the given address.
@@ -47,7 +44,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 
@@ -96,7 +93,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return fmt.Errorf("debug: set DR7: %w", err)
 	}
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -105,7 +102,7 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot > 3 {
 		return fmt.Errorf("debug: watchpoint slot must be 0-3")
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 	dr7, err := ptracePeekUser(s.pid, 0x38)
@@ -116,14 +113,14 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if err := ptracePokeUser(s.pid, 0x38, dr7); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 // ClearAllWatchpoints removes all hardware watchpoints.
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := range 4 {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}
diff --git a/debug/watchpoint_linux_arm64.go b/debug/watchpoint_linux_arm64.go
index 3003e3d..871ef83 100644
--- a/debug/watchpoint_linux_arm64.go
+++ b/debug/watchpoint_linux_arm64.go
@@ -22,9 +22,6 @@ const (
 	WatchRead  WatchpointType = 3
 )
 
-// wpSlots tracks watchpoint slot occupancy.
-var wpSlots [16]bool // arm64 supports up to 16 watchpoints
-
 const maxWatchpoints = 16
 
 // hwBreakState mirrors the kernel's struct user_hwdebug_state.
@@ -45,7 +42,7 @@ const (
 
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := range maxWatchpoints {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -56,7 +53,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot >= maxWatchpoints {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint on the given address.
@@ -64,7 +61,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 
@@ -105,7 +102,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 		return fmt.Errorf("debug: set watchpoint: %w", err)
 	}
 
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -113,7 +110,7 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 
@@ -126,13 +123,13 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if err := s.setHWBreakState(state); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := 0; slot < maxWatchpoints; slot++ {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}
diff --git a/debug/watchpoint_linux_loong64.go b/debug/watchpoint_linux_loong64.go
index ef7f4ad..dd90a85 100644
--- a/debug/watchpoint_linux_loong64.go
+++ b/debug/watchpoint_linux_loong64.go
@@ -21,14 +21,11 @@ const (
 	WatchRead  WatchpointType = 3
 )
 
-// wpSlots tracks watchpoint slot occupancy.
-var wpSlots [4]bool
-
 const maxWatchpoints = 4
 
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := range maxWatchpoints {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -39,7 +36,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot >= maxWatchpoints {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint.
@@ -47,7 +44,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 	if size != 1 && size != 2 && size != 4 && size != 8 {
@@ -85,7 +82,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 		return fmt.Errorf("debug: set watchpoint control: %w", err)
 	}
 
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -93,20 +90,20 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 
 	if err := ptracePokeUser(s.pid, uintptr(0x1001+slot*8), 0); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := 0; slot < maxWatchpoints; slot++ {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}
diff --git a/debug/watchpoint_linux_riscv64.go b/debug/watchpoint_linux_riscv64.go
index 00dd802..c7c8a59 100644
--- a/debug/watchpoint_linux_riscv64.go
+++ b/debug/watchpoint_linux_riscv64.go
@@ -21,14 +21,11 @@ const (
 	WatchRead  WatchpointType = 3
 )
 
-// wpSlots tracks watchpoint slot occupancy.
-var wpSlots [4]bool
-
 const maxWatchpoints = 4
 
 func (s *Session) FindFreeWatchpointSlot() int {
 	for i := range maxWatchpoints {
-		if !wpSlots[i] {
+		if !s.wpSlots[i] {
 			return i
 		}
 	}
@@ -39,7 +36,7 @@ func (s *Session) IsWatchpointSlotUsed(slot int) bool {
 	if slot < 0 || slot >= maxWatchpoints {
 		return false
 	}
-	return wpSlots[slot]
+	return s.wpSlots[slot]
 }
 
 // SetWatchpoint installs a hardware watchpoint.
@@ -47,7 +44,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if wpSlots[slot] {
+	if s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d already in use", slot)
 	}
 	if size != 1 && size != 2 && size != 4 && size != 8 {
@@ -87,7 +84,7 @@ func (s *Session) SetWatchpoint(slot int, addr uint64, typ WatchpointType, size
 		return fmt.Errorf("debug: set watchpoint control: %w", err)
 	}
 
-	wpSlots[slot] = true
+	s.wpSlots[slot] = true
 	return nil
 }
 
@@ -95,7 +92,7 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if slot < 0 || slot >= maxWatchpoints {
 		return fmt.Errorf("debug: watchpoint slot must be 0-%d", maxWatchpoints-1)
 	}
-	if !wpSlots[slot] {
+	if !s.wpSlots[slot] {
 		return fmt.Errorf("debug: watchpoint slot %d is not in use", slot)
 	}
 
@@ -103,13 +100,13 @@ func (s *Session) ClearWatchpoint(slot int) error {
 	if err := ptracePokeUser(s.pid, uintptr(0x1001+slot*8), 0); err != nil {
 		return err
 	}
-	wpSlots[slot] = false
+	s.wpSlots[slot] = false
 	return nil
 }
 
 func (s *Session) ClearAllWatchpoints() error {
 	for slot := 0; slot < maxWatchpoints; slot++ {
-		if wpSlots[slot] {
+		if s.wpSlots[slot] {
 			if err := s.ClearWatchpoint(slot); err != nil {
 				return err
 			}