Promote breakpoints back up to process

proctl/proctl_linux_amd64.go

@@ -3,6 +3,7 @@
 package proctl
 
 import (
+	"bytes"
 	"debug/gosym"
 	"encoding/binary"
 	"fmt"
@@ -24,10 +25,32 @@ type DebuggedProcess struct {
 	Symbols       []elf.Symbol
 	GoSymTable    *gosym.Table
 	FrameEntries  *frame.FrameDescriptionEntries
+	BreakPoints   map[uint64]*BreakPoint
 	Threads       map[int]*ThreadContext
 	CurrentThread *ThreadContext
 }
 
+// Represents a single breakpoint. Stores information on the break
+// point including the byte of data that originally was stored at that
+// address.
+type BreakPoint struct {
+	FunctionName string
+	File         string
+	Line         int
+	Addr         uint64
+	OriginalData []byte
+}
+
+type BreakPointExistsError struct {
+	file string
+	line int
+	addr uintptr
+}
+
+func (bpe BreakPointExistsError) Error() string {
+	return fmt.Sprintf("Breakpoint exists at %s:%d at %x", bpe.file, bpe.line, bpe.addr)
+}
+
 func AttachBinary(name string) (*DebuggedProcess, error) {
 	proc := exec.Command(name)
 	proc.Stdout = os.Stdout
@@ -48,8 +71,9 @@ func AttachBinary(name string) (*DebuggedProcess, error) {
 // Returns a new DebuggedProcess struct with sensible defaults.
 func NewDebugProcess(pid int) (*DebuggedProcess, error) {
 	debuggedProc := DebuggedProcess{
-		Pid:     pid,
-		Threads: make(map[int]*ThreadContext),
+		Pid:         pid,
+		Threads:     make(map[int]*ThreadContext),
+		BreakPoints: make(map[uint64]*BreakPoint),
 	}
 
 	_, err := debuggedProc.AttachThread(pid)
@@ -149,10 +173,9 @@ func (dbp *DebuggedProcess) addThread(tid int) (*ThreadContext, error) {
 	}
 
 	tctxt := &ThreadContext{
-		Id:          tid,
-		Process:     dbp,
-		Regs:        new(syscall.PtraceRegs),
-		BreakPoints: make(map[uint64]*BreakPoint),
+		Id:      tid,
+		Process: dbp,
+		Regs:    new(syscall.PtraceRegs),
 	}
 
 	if tid == dbp.Pid {
@@ -164,16 +187,67 @@ func (dbp *DebuggedProcess) addThread(tid int) (*ThreadContext, error) {
 	return tctxt, nil
 }
 
+// Sets a breakpoint in the running process.
+func (dbp *DebuggedProcess) Break(addr uintptr) (*BreakPoint, error) {
+	var (
+		int3         = []byte{0xCC}
+		f, l, fn     = dbp.GoSymTable.PCToLine(uint64(addr))
+		originalData = make([]byte, 1)
+	)
+
+	if fn == nil {
+		return nil, InvalidAddressError{address: addr}
+	}
+
+	_, err := syscall.PtracePeekData(dbp.CurrentThread.Id, addr, originalData)
+	if err != nil {
+		return nil, err
+	}
+
+	if bytes.Equal(originalData, int3) {
+		return nil, BreakPointExistsError{f, l, addr}
+	}
+
+	_, err = syscall.PtracePokeData(dbp.CurrentThread.Id, addr, int3)
+	if err != nil {
+		return nil, err
+	}
+
+	breakpoint := &BreakPoint{
+		FunctionName: fn.Name,
+		File:         f,
+		Line:         l,
+		Addr:         uint64(addr),
+		OriginalData: originalData,
+	}
+
+	dbp.BreakPoints[uint64(addr)] = breakpoint
+
+	return breakpoint, nil
+}
+
+// Clears a breakpoint.
+func (dbp *DebuggedProcess) Clear(pc uint64) (*BreakPoint, error) {
+	bp, ok := dbp.BreakPoints[pc]
+	if !ok {
+		return nil, fmt.Errorf("No breakpoint currently set for %#v", pc)
+	}
+
+	_, err := syscall.PtracePokeData(dbp.CurrentThread.Id, uintptr(bp.Addr), bp.OriginalData)
+	if err != nil {
+		return nil, err
+	}
+
+	delete(dbp.BreakPoints, pc)
+
+	return bp, nil
+}
+
 // Returns the status of the current main thread context.
 func (dbp *DebuggedProcess) Status() *syscall.WaitStatus {
 	return dbp.CurrentThread.Status
 }
 
-// Returns the breakpoints of the current main thread context.
-func (dbp *DebuggedProcess) BreakPoints() map[uint64]*BreakPoint {
-	return dbp.CurrentThread.BreakPoints
-}
-
 // Finds the executable from /proc/<pid>/exe and then
 // uses that to parse the following information:
 // * Dwarf .debug_frame section
@@ -257,16 +331,6 @@ func (iae InvalidAddressError) Error() string {
 	return fmt.Sprintf("Invalid address %#v\n", iae.address)
 }
 
-// Sets a breakpoint in the running process.
-func (dbp *DebuggedProcess) Break(addr uintptr) (*BreakPoint, error) {
-	return dbp.CurrentThread.Break(addr)
-}
-
-// Clears a breakpoint.
-func (dbp *DebuggedProcess) Clear(pc uint64) (*BreakPoint, error) {
-	return dbp.CurrentThread.Clear(pc)
-}
-
 func (dbp *DebuggedProcess) CurrentPC() (uint64, error) {
 	return dbp.CurrentThread.CurrentPC()
 }
@@ -429,7 +493,7 @@ func wait(dbp *DebuggedProcess, pid int, options int) (int, *syscall.WaitStatus,
 			for _, th := range dbp.Threads {
 				if th.Id == pid {
 					pc, _ := th.CurrentPC()
-					_, ok := th.BreakPoints[pc-1]
+					_, ok := dbp.BreakPoints[pc-1]
 					if ok {
 						return pid, &status, nil
 					} else {

proctl/proctl_test.go

@@ -169,7 +169,7 @@ func TestClearBreakPoint(t *testing.T) {
 			t.Fatalf("Breakpoint was not cleared data: %#v, int3: %#v", data, int3)
 		}
 
-		if len(p.BreakPoints()) != 0 {
+		if len(p.BreakPoints) != 0 {
 			t.Fatal("Breakpoint not removed internally")
 		}
 	})
@@ -229,7 +229,7 @@ func TestNext(t *testing.T) {
 			}
 		}
 
-		if len(p.BreakPoints()) != 1 {
+		if len(p.BreakPoints) != 1 {
 			t.Fatal("Not all breakpoints were cleaned up")
 		}
 	})

proctl/threads_linux_amd64.go

@@ -18,22 +18,10 @@ import (
 // ThreadContext represents a single thread of execution in the
 // traced program.
 type ThreadContext struct {
-	Id          int
-	Process     *DebuggedProcess
-	Status      *syscall.WaitStatus
-	Regs        *syscall.PtraceRegs
-	BreakPoints map[uint64]*BreakPoint
-}
-
-// Represents a single breakpoint. Stores information on the break
-// point including the byte of data that originally was stored at that
-// address.
-type BreakPoint struct {
-	FunctionName string
-	File         string
-	Line         int
-	Addr         uint64
-	OriginalData []byte
+	Id      int
+	Process *DebuggedProcess
+	Status  *syscall.WaitStatus
+	Regs    *syscall.PtraceRegs
 }
 
 type Variable struct {
@@ -42,16 +30,6 @@ type Variable struct {
 	Type  string
 }
 
-type BreakPointExistsError struct {
-	file string
-	line int
-	addr uintptr
-}
-
-func (bpe BreakPointExistsError) Error() string {
-	return fmt.Sprintf("Breakpoint exists at %s:%d at %x", bpe.file, bpe.line, bpe.addr)
-}
-
 // Obtains register values from the debugged process.
 func (thread *ThreadContext) Registers() (*syscall.PtraceRegs, error) {
 	err := syscall.PtraceGetRegs(thread.Id, thread.Regs)
@@ -80,62 +58,6 @@ func (thread *ThreadContext) CurrentPC() (uint64, error) {
 	return regs.PC(), nil
 }
 
-// Sets a breakpoint in the running process.
-func (thread *ThreadContext) Break(addr uintptr) (*BreakPoint, error) {
-	var (
-		int3         = []byte{0xCC}
-		f, l, fn     = thread.Process.GoSymTable.PCToLine(uint64(addr))
-		originalData = make([]byte, 1)
-	)
-
-	if fn == nil {
-		return nil, InvalidAddressError{address: addr}
-	}
-
-	_, err := syscall.PtracePeekData(thread.Id, addr, originalData)
-	if err != nil {
-		return nil, err
-	}
-
-	if bytes.Equal(originalData, int3) {
-		return nil, BreakPointExistsError{f, l, addr}
-	}
-
-	_, err = syscall.PtracePokeData(thread.Id, addr, int3)
-	if err != nil {
-		return nil, err
-	}
-
-	breakpoint := &BreakPoint{
-		FunctionName: fn.Name,
-		File:         f,
-		Line:         l,
-		Addr:         uint64(addr),
-		OriginalData: originalData,
-	}
-
-	thread.BreakPoints[uint64(addr)] = breakpoint
-
-	return breakpoint, nil
-}
-
-// Clears a breakpoint.
-func (thread *ThreadContext) Clear(pc uint64) (*BreakPoint, error) {
-	bp, ok := thread.BreakPoints[pc]
-	if !ok {
-		return nil, fmt.Errorf("No breakpoint currently set for %#v", pc)
-	}
-
-	_, err := syscall.PtracePokeData(thread.Id, uintptr(bp.Addr), bp.OriginalData)
-	if err != nil {
-		return nil, err
-	}
-
-	delete(thread.BreakPoints, pc)
-
-	return bp, nil
-}
-
 func (thread *ThreadContext) Continue() error {
 	// Stepping first will ensure we are able to continue
 	// past a breakpoint if that's currently where we are stopped.
@@ -154,10 +76,10 @@ func (thread *ThreadContext) Step() (err error) {
 		return err
 	}
 
-	bp, ok := thread.BreakPoints[regs.PC()-1]
+	bp, ok := thread.Process.BreakPoints[regs.PC()-1]
 	if ok {
 		// Clear the breakpoint so that we can continue execution.
-		_, err = thread.Clear(bp.Addr)
+		_, err = thread.Process.Clear(bp.Addr)
 		if err != nil {
 			return err
 		}
@@ -171,7 +93,7 @@ func (thread *ThreadContext) Step() (err error) {
 
 		// Restore breakpoint now that we have passed it.
 		defer func() {
-			_, err = thread.Break(uintptr(bp.Addr))
+			_, err = thread.Process.Break(uintptr(bp.Addr))
 		}()
 	}
 
@@ -195,7 +117,7 @@ func (thread *ThreadContext) Next() (err error) {
 		return err
 	}
 
-	if _, ok := thread.BreakPoints[pc-1]; ok {
+	if _, ok := thread.Process.BreakPoints[pc-1]; ok {
 		// Decrement the PC to be before
 		// the breakpoint instruction.
 		pc--
@@ -251,7 +173,7 @@ func (thread *ThreadContext) continueToReturnAddress(pc uint64, fde *frame.Frame
 		// has not had a chance to modify its' stack
 		// and change our offset.
 		addr := thread.Process.ReturnAddressFromOffset(0)
-		bp, err := thread.Break(uintptr(addr))
+		bp, err := thread.Process.Break(uintptr(addr))
 		if err != nil {
 			if _, ok := err.(BreakPointExistsError); !ok {
 				return err
@@ -280,14 +202,14 @@ func (thread *ThreadContext) continueToReturnAddress(pc uint64, fde *frame.Frame
 }
 
 func (thread *ThreadContext) clearTempBreakpoint(pc uint64) error {
-	if bp, ok := thread.BreakPoints[pc]; ok {
+	if bp, ok := thread.Process.BreakPoints[pc]; ok {
 		regs, err := thread.Registers()
 		if err != nil {
 			return err
 		}
 
 		// Reset program counter to our restored instruction.
-		bp, err = thread.Clear(bp.Addr)
+		bp, err = thread.Process.Clear(bp.Addr)
 		if err != nil {
 			return err
 		}