proc: do not assign temporary breakpoint IDs (#2650)

Internal breakpoints do not need IDs and assigning them from a counter
separate from the user ID counter can be a cause of confusion.
If a user breakpoint is overlayed on top of a pre-existing internal
breakpoint the temporary ID will be surfaced as if it was a user ID,
possibly conflicting with another user ID.
If a temporary breakpoint is overlayed on top of a pre-existing user
breakpoint and the user breakpoint is first deleted and then
re-created, the user ID will be resurrected along with the breakpoint,
instead of allocating a fresh one.

This change removes internal breakpoint IDs entirely, only user
breakpoints receive an ID.
This commit is contained in:
Alessandro Arzilli
2021-09-29 12:01:37 +02:00
committed by GitHub
parent b8f8cd82a6
commit a97da22762
8 changed files with 78 additions and 60 deletions

View File

@ -27,6 +27,8 @@ const (
unrecoveredPanicID = -1
fatalThrowID = -2
NoLogicalID = -1000 // Logical breakpoint ID for breakpoints internal breakpoints.
)
// Breakpoint represents a physical breakpoint. Stores information on the break
@ -41,7 +43,6 @@ type Breakpoint struct {
Addr uint64 // Address breakpoint is set for.
OriginalData []byte // If software breakpoint, the data we replace with breakpoint instruction.
Name string // User defined name of the breakpoint
LogicalID int // ID of the logical breakpoint that owns this physical breakpoint
WatchExpr string
WatchType WatchType
@ -74,6 +75,8 @@ type Breaklet struct {
// stepping).
Kind BreakpointKind
LogicalID int // ID of the logical breakpoint that owns this physical breakpoint
// Cond: if not nil the breakpoint will be triggered only if evaluating Cond returns true
Cond ast.Expr
@ -175,7 +178,16 @@ func (wtype WatchType) withSize(sz uint8) WatchType {
var ErrHWBreakUnsupported = errors.New("hardware breakpoints not implemented")
func (bp *Breakpoint) String() string {
return fmt.Sprintf("Breakpoint %d at %#v %s:%d", bp.LogicalID, bp.Addr, bp.File, bp.Line)
return fmt.Sprintf("Breakpoint %d at %#v %s:%d", bp.LogicalID(), bp.Addr, bp.File, bp.Line)
}
func (bp *Breakpoint) LogicalID() int {
for _, breaklet := range bp.Breaklets {
if breaklet.Kind == UserBreakpoint {
return breaklet.LogicalID
}
}
return NoLogicalID
}
// VerboseDescr returns a string describing parts of the breakpoint struct
@ -448,8 +460,7 @@ type BreakpointMap struct {
// the last resume operation
WatchOutOfScope []*Breakpoint
breakpointIDCounter int
internalBreakpointIDCounter int
breakpointIDCounter int
}
// NewBreakpointMap creates a new BreakpointMap.
@ -610,11 +621,22 @@ func (t *Target) setBreakpointInternal(addr uint64, kind BreakpointKind, wtype W
newBreaklet := &Breaklet{Kind: kind, Cond: cond}
if kind == UserBreakpoint {
newBreaklet.HitCount = map[int]uint64{}
bpmap.breakpointIDCounter++
newBreaklet.LogicalID = bpmap.breakpointIDCounter
}
if bp, ok := bpmap.M[addr]; ok {
if !bp.canOverlap(kind) {
return bp, BreakpointExistsError{bp.File, bp.Line, bp.Addr}
}
if kind == UserBreakpoint {
bp.Tracepoint = false
bp.TraceReturn = false
bp.Goroutine = false
bp.Stacktrace = 0
bp.Variables = nil
bp.LoadArgs = nil
bp.LoadLocals = nil
}
bp.Breaklets = append(bp.Breaklets, newBreaklet)
return bp, nil
}
@ -655,14 +677,6 @@ func (t *Target) setBreakpointInternal(addr uint64, kind BreakpointKind, wtype W
return nil, err
}
if kind != UserBreakpoint {
bpmap.internalBreakpointIDCounter++
newBreakpoint.LogicalID = bpmap.internalBreakpointIDCounter
} else {
bpmap.breakpointIDCounter++
newBreakpoint.LogicalID = bpmap.breakpointIDCounter
}
newBreakpoint.Breaklets = append(newBreakpoint.Breaklets, newBreaklet)
bpmap.M[addr] = newBreakpoint
@ -675,8 +689,13 @@ func (t *Target) SetBreakpointWithID(id int, addr uint64) (*Breakpoint, error) {
bpmap := t.Breakpoints()
bp, err := t.SetBreakpoint(addr, UserBreakpoint, nil)
if err == nil {
bp.LogicalID = id
bpmap.breakpointIDCounter--
for _, breaklet := range bp.Breaklets {
if breaklet.Kind == UserBreakpoint {
breaklet.LogicalID = id
bpmap.breakpointIDCounter--
break
}
}
}
return bp, err
}
@ -693,13 +712,13 @@ func (bp *Breakpoint) canOverlap(kind BreakpointKind) bool {
}
// ClearBreakpoint clears the breakpoint at addr.
func (t *Target) ClearBreakpoint(addr uint64) (*Breakpoint, error) {
func (t *Target) ClearBreakpoint(addr uint64) error {
if valid, err := t.Valid(); !valid {
return nil, err
return err
}
bp, ok := t.Breakpoints().M[addr]
if !ok {
return nil, NoBreakpointError{Addr: addr}
return NoBreakpointError{Addr: addr}
}
for i := range bp.Breaklets {
@ -710,18 +729,18 @@ func (t *Target) ClearBreakpoint(addr uint64) (*Breakpoint, error) {
_, err := t.finishClearBreakpoint(bp)
if err != nil {
return nil, err
return err
}
if bp.WatchExpr != "" && bp.watchStackOff != 0 {
// stack watchpoint, must remove all its WatchOutOfScopeBreakpoints/StackResizeBreakpoints
err := t.clearStackWatchBreakpoints(bp)
if err != nil {
return bp, err
return err
}
}
return bp, nil
return nil
}
// ClearSteppingBreakpoints removes all stepping breakpoints from the map,

View File

@ -251,7 +251,7 @@ func TestCheckpoints(t *testing.T) {
// Delete breakpoint, move back to checkpoint then next twice and check
// output of 'when' again
_, err = p.ClearBreakpoint(bp.Addr)
err = p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint")
p.Restart(fmt.Sprintf("c%d", cpid))
g, _ = proc.FindGoroutine(p, 1)
@ -283,7 +283,7 @@ func TestIssue1376(t *testing.T) {
withTestRecording("continuetestprog", t, func(p *proc.Target, fixture protest.Fixture) {
bp := setFunctionBreakpoint(p, t, "main.main")
assertNoError(p.Continue(), t, "Continue (forward)")
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint")
assertNoError(p.ChangeDirection(proc.Backward), t, "Switching to backward direction")
assertNoError(p.Continue(), t, "Continue (backward)")

View File

@ -360,7 +360,7 @@ func TestClearBreakpointBreakpoint(t *testing.T) {
withTestProcess("testprog", t, func(p *proc.Target, fixture protest.Fixture) {
bp := setFunctionBreakpoint(p, t, "main.sleepytime")
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint()")
data, err := dataAtAddr(p.Memory(), bp.Addr)
@ -384,7 +384,7 @@ type nextTest struct {
func countBreakpoints(p *proc.Target) int {
bpcount := 0
for _, bp := range p.Breakpoints().M {
if bp.LogicalID >= 0 {
if bp.LogicalID() >= 0 {
bpcount++
}
}
@ -473,7 +473,7 @@ func testseq2Args(wd string, args []string, buildFlags protest.BuildFlags, t *te
if traceTestseq2 {
t.Log("clearing initial breakpoint")
}
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint() returned an error")
}
case contReverseNext:
@ -503,7 +503,7 @@ func testseq2Args(wd string, args []string, buildFlags protest.BuildFlags, t *te
t.Log("continue")
}
assertNoError(p.Continue(), t, "Continue() returned an error")
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint() returned an error")
}
@ -596,7 +596,7 @@ func TestNextConcurrent(t *testing.T) {
f, ln := currentLineNumber(p, t)
initV := evalVariable(p, t, "n")
initVval, _ := constant.Int64Val(initV.Value)
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint()")
for _, tc := range testcases {
g, err := proc.GetG(p.CurrentThread())
@ -1086,11 +1086,11 @@ func TestContinueMulti(t *testing.T) {
}
assertNoError(err, t, "Continue()")
if bp := p.CurrentThread().Breakpoint(); bp.LogicalID == bp1.LogicalID {
if bp := p.CurrentThread().Breakpoint(); bp.LogicalID() == bp1.LogicalID() {
mainCount++
}
if bp := p.CurrentThread().Breakpoint(); bp.LogicalID == bp2.LogicalID {
if bp := p.CurrentThread().Breakpoint(); bp.LogicalID() == bp2.LogicalID() {
sayhiCount++
}
}
@ -2415,12 +2415,12 @@ func TestStepConcurrentDirect(t *testing.T) {
bp := setFileBreakpoint(p, t, fixture.Source, 37)
assertNoError(p.Continue(), t, "Continue()")
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint()")
for _, b := range p.Breakpoints().M {
if b.Name == proc.UnrecoveredPanic {
_, err := p.ClearBreakpoint(b.Addr)
err := p.ClearBreakpoint(b.Addr)
assertNoError(err, t, "ClearBreakpoint(unrecovered-panic)")
break
}
@ -2480,7 +2480,7 @@ func TestStepConcurrentPtr(t *testing.T) {
for _, b := range p.Breakpoints().M {
if b.Name == proc.UnrecoveredPanic {
_, err := p.ClearBreakpoint(b.Addr)
err := p.ClearBreakpoint(b.Addr)
assertNoError(err, t, "ClearBreakpoint(unrecovered-panic)")
break
}
@ -2972,7 +2972,7 @@ func TestRecursiveNext(t *testing.T) {
withTestProcess("increment", t, func(p *proc.Target, fixture protest.Fixture) {
bp := setFunctionBreakpoint(p, t, "main.Increment")
assertNoError(p.Continue(), t, "Continue")
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint")
assertNoError(p.Next(), t, "Next 1")
assertNoError(p.Next(), t, "Next 2")
@ -4509,12 +4509,12 @@ func TestCallConcurrent(t *testing.T) {
returned := testCallConcurrentCheckReturns(p, t, gid1, -1)
curthread := p.CurrentThread()
if curbp := curthread.Breakpoint(); curbp.Breakpoint == nil || curbp.LogicalID != bp.LogicalID || returned > 0 {
if curbp := curthread.Breakpoint(); curbp.Breakpoint == nil || curbp.LogicalID() != bp.LogicalID() || returned > 0 {
t.Logf("skipping test, the call injection terminated before we hit a breakpoint in a different thread")
return
}
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint() returned an error")
gid2 := p.SelectedGoroutine().ID
@ -5551,7 +5551,7 @@ func TestWatchpointStack(t *testing.T) {
t.Errorf("wrong number of out-of-scope watchpoints after watchpoint goes out of scope: %d", len(p.Breakpoints().WatchOutOfScope))
}
_, err = p.ClearBreakpoint(retaddr)
err = p.ClearBreakpoint(retaddr)
assertNoError(err, t, "ClearBreakpoint")
if len(p.Breakpoints().M) != clearlen {

View File

@ -104,7 +104,7 @@ func TestScope(t *testing.T) {
}
scopeCheck.ok = true
_, err := p.ClearBreakpoint(bp.Addr)
err := p.ClearBreakpoint(bp.Addr)
assertNoError(err, t, "ClearBreakpoint")
}
})

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@ -137,7 +137,7 @@ func (t *Target) clearStackWatchBreakpoints(watchpoint *Breakpoint) error {
// user is notified of the watchpoint going out of scope.
func watchpointOutOfScope(t *Target, watchpoint *Breakpoint) {
t.Breakpoints().WatchOutOfScope = append(t.Breakpoints().WatchOutOfScope, watchpoint)
_, err := t.ClearBreakpoint(watchpoint.Addr)
err := t.ClearBreakpoint(watchpoint.Addr)
if err != nil {
log := logflags.DebuggerLogger()
log.Errorf("could not clear out-of-scope watchpoint: %v", err)

View File

@ -325,7 +325,7 @@ func (t *Target) Detach(kill bool) error {
}
for _, bp := range t.Breakpoints().M {
if bp != nil {
_, err := t.ClearBreakpoint(bp.Addr)
err := t.ClearBreakpoint(bp.Addr)
if err != nil {
return err
}

View File

@ -21,7 +21,7 @@ import (
func ConvertBreakpoint(bp *proc.Breakpoint) *Breakpoint {
b := &Breakpoint{
Name: bp.Name,
ID: bp.LogicalID,
ID: bp.LogicalID(),
FunctionName: bp.FunctionName,
File: bp.File,
Line: bp.Line,
@ -68,10 +68,10 @@ func ConvertBreakpoints(bps []*proc.Breakpoint) []*Breakpoint {
r := make([]*Breakpoint, 0, len(bps))
for _, bp := range bps {
if len(r) > 0 {
if r[len(r)-1].ID == bp.LogicalID {
if r[len(r)-1].ID == bp.LogicalID() {
r[len(r)-1].Addrs = append(r[len(r)-1].Addrs, bp.Addr)
continue
} else if r[len(r)-1].ID > bp.LogicalID {
} else if r[len(r)-1].ID > bp.LogicalID() {
panic("input not sorted")
}
}

View File

@ -722,13 +722,13 @@ func createLogicalBreakpoint(d *Debugger, addrs []uint64, requestedBp *api.Break
bps[i], err = p.SetBreakpointWithID(id, addrs[i])
} else {
bps[i], err = p.SetBreakpoint(addrs[i], proc.UserBreakpoint, nil)
if err == nil {
id = bps[i].LogicalID()
}
}
if err != nil {
break
}
if i > 0 {
bps[i].LogicalID = bps[0].LogicalID
}
err = copyBreakpointInfo(bps[i], requestedBp)
if err != nil {
break
@ -742,7 +742,7 @@ func createLogicalBreakpoint(d *Debugger, addrs []uint64, requestedBp *api.Break
if bp == nil {
continue
}
if _, err1 := p.ClearBreakpoint(bp.Addr); err1 != nil {
if err1 := p.ClearBreakpoint(bp.Addr); err1 != nil {
err = fmt.Errorf("error while creating breakpoint: %v, additionally the breakpoint could not be properly rolled back: %v", err, err1)
return nil, err
}
@ -901,17 +901,20 @@ func (d *Debugger) clearBreakpoint(requestedBp *api.Breakpoint) (*api.Breakpoint
return bp, nil
}
var bps []*proc.Breakpoint
var clearedBp *api.Breakpoint
var errs []error
clear := func(addr uint64) {
bp, err := d.target.ClearBreakpoint(addr)
if clearedBp == nil {
bp := d.target.Breakpoints().M[addr]
if bp != nil {
clearedBp = api.ConvertBreakpoint(bp)
}
}
err := d.target.ClearBreakpoint(addr)
if err != nil {
errs = append(errs, fmt.Errorf("address %#x: %v", addr, err))
}
if bp != nil {
bps = append(bps, bp)
}
}
clearAddr := true
@ -934,18 +937,14 @@ func (d *Debugger) clearBreakpoint(requestedBp *api.Breakpoint) (*api.Breakpoint
}
}
if len(bps) == 0 {
if clearedBp == nil {
return nil, fmt.Errorf("unable to clear breakpoint %d: %v", requestedBp.ID, buf.String())
}
return nil, fmt.Errorf("unable to clear breakpoint %d (partial): %s", requestedBp.ID, buf.String())
}
clearedBp := api.ConvertBreakpoints(bps)
if len(clearedBp) == 0 {
return nil, nil
}
d.log.Infof("cleared breakpoint: %#v", clearedBp)
return clearedBp[0], nil
return clearedBp, nil
}
// Breakpoints returns the list of current breakpoints.
@ -998,7 +997,7 @@ func (d *Debugger) FindBreakpoint(id int) *api.Breakpoint {
func (d *Debugger) findBreakpoint(id int) []*proc.Breakpoint {
var bps []*proc.Breakpoint
for _, bp := range d.target.Breakpoints().M {
if bp.IsUser() && bp.LogicalID == id {
if bp.LogicalID() == id {
bps = append(bps, bp)
}
}
@ -2181,11 +2180,11 @@ func (v breakpointsByLogicalID) Len() int { return len(v) }
func (v breakpointsByLogicalID) Swap(i, j int) { v[i], v[j] = v[j], v[i] }
func (v breakpointsByLogicalID) Less(i, j int) bool {
if v[i].LogicalID == v[j].LogicalID {
if v[i].LogicalID() == v[j].LogicalID() {
if v[i].WatchType != v[j].WatchType {
return v[i].WatchType > v[j].WatchType // if a logical breakpoint contains a watchpoint let the watchpoint sort first
}
return v[i].Addr < v[j].Addr
}
return v[i].LogicalID < v[j].LogicalID
return v[i].LogicalID() < v[j].LogicalID()
}