delve/pkg/proc/core/core.go
aarzilli 1ced7c3a60 proc: next should not skip lines with conditional bps
Conditional breakpoints with unmet conditions would cause next and step
to skip the line.

This breakpoint changes the Kind field of proc.Breakpoint from a single
value to a bit field, each breakpoint object can represent
simultaneously a user breakpoint and one internal breakpoint (of which
we have several different kinds).

The breakpoint condition for internal breakpoints is stored in the new
internalCond field of proc.Breakpoint so that it will not conflict with
user specified conditions.

The breakpoint setting code is changed to allow overlapping one
internal breakpoint on a user breakpoint, or a user breakpoint on an
existing internal breakpoint. All other combinations are rejected. The
breakpoint clearing code is changed to clear the UserBreakpoint bit and
only remove the phisical breakpoint if no other bits are set in the
Kind field. ClearInternalBreakpoints does the same thing but clearing
all bits that aren't the UserBreakpoint bit.

Fixes #844
2017-11-20 11:25:35 -08:00

415 lines
10 KiB
Go

package core
import (
"errors"
"fmt"
"go/ast"
"io"
"sync"
"github.com/derekparker/delve/pkg/proc"
)
// A SplicedMemory represents a memory space formed from multiple regions,
// each of which may override previously regions. For example, in the following
// core, the program text was loaded at 0x400000:
// Start End Page Offset
// 0x0000000000400000 0x000000000044f000 0x0000000000000000
// but then it's partially overwritten with an RW mapping whose data is stored
// in the core file:
// Type Offset VirtAddr PhysAddr
// FileSiz MemSiz Flags Align
// LOAD 0x0000000000004000 0x000000000049a000 0x0000000000000000
// 0x0000000000002000 0x0000000000002000 RW 1000
// This can be represented in a SplicedMemory by adding the original region,
// then putting the RW mapping on top of it.
type SplicedMemory struct {
readers []readerEntry
}
type readerEntry struct {
offset uintptr
length uintptr
reader proc.MemoryReader
}
// Add adds a new region to the SplicedMemory, which may override existing regions.
func (r *SplicedMemory) Add(reader proc.MemoryReader, off, length uintptr) {
if length == 0 {
return
}
end := off + length - 1
newReaders := make([]readerEntry, 0, len(r.readers))
add := func(e readerEntry) {
if e.length == 0 {
return
}
newReaders = append(newReaders, e)
}
inserted := false
// Walk through the list of regions, fixing up any that overlap and inserting the new one.
for _, entry := range r.readers {
entryEnd := entry.offset + entry.length - 1
switch {
case entryEnd < off:
// Entry is completely before the new region.
add(entry)
case end < entry.offset:
// Entry is completely after the new region.
if !inserted {
add(readerEntry{off, length, reader})
inserted = true
}
add(entry)
case off <= entry.offset && entryEnd <= end:
// Entry is completely overwritten by the new region. Drop.
case entry.offset < off && entryEnd <= end:
// New region overwrites the end of the entry.
entry.length = off - entry.offset
add(entry)
case off <= entry.offset && end < entryEnd:
// New reader overwrites the beginning of the entry.
if !inserted {
add(readerEntry{off, length, reader})
inserted = true
}
overlap := entry.offset - off
entry.offset += overlap
entry.length -= overlap
add(entry)
case entry.offset < off && end < entryEnd:
// New region punches a hole in the entry. Split it in two and put the new region in the middle.
add(readerEntry{entry.offset, off - entry.offset, entry.reader})
add(readerEntry{off, length, reader})
add(readerEntry{end + 1, entryEnd - end, entry.reader})
inserted = true
default:
panic(fmt.Sprintf("Unhandled case: existing entry is %v len %v, new is %v len %v", entry.offset, entry.length, off, length))
}
}
if !inserted {
newReaders = append(newReaders, readerEntry{off, length, reader})
}
r.readers = newReaders
}
// ReadMemory implements MemoryReader.ReadMemory.
func (r *SplicedMemory) ReadMemory(buf []byte, addr uintptr) (n int, err error) {
started := false
for _, entry := range r.readers {
if entry.offset+entry.length < addr {
if !started {
continue
}
return n, fmt.Errorf("hit unmapped area at %v after %v bytes", addr, n)
}
// Don't go past the region.
pb := buf
if addr+uintptr(len(buf)) > entry.offset+entry.length {
pb = pb[:entry.offset+entry.length-addr]
}
pn, err := entry.reader.ReadMemory(pb, addr)
n += pn
if err != nil || pn != len(pb) {
return n, err
}
buf = buf[pn:]
addr += uintptr(pn)
if len(buf) == 0 {
// Done, don't bother scanning the rest.
return n, nil
}
}
if n == 0 {
return 0, fmt.Errorf("offset %v did not match any regions", addr)
}
return n, nil
}
// OffsetReaderAt wraps a ReaderAt into a MemoryReader, subtracting a fixed
// offset from the address. This is useful to represent a mapping in an address
// space. For example, if program text is mapped in at 0x400000, an
// OffsetReaderAt with offset 0x400000 can be wrapped around file.Open(program)
// to return the results of a read in that part of the address space.
type OffsetReaderAt struct {
reader io.ReaderAt
offset uintptr
}
func (r *OffsetReaderAt) ReadMemory(buf []byte, addr uintptr) (n int, err error) {
return r.reader.ReadAt(buf, int64(addr-r.offset))
}
type Process struct {
bi proc.BinaryInfo
core *Core
breakpoints proc.BreakpointMap
currentThread *Thread
selectedGoroutine *proc.G
allGCache []*proc.G
}
type Thread struct {
th *LinuxPrStatus
fpregs []proc.Register
p *Process
}
var ErrWriteCore = errors.New("can not to core process")
var ErrShortRead = errors.New("short read")
var ErrContinueCore = errors.New("can not continue execution of core process")
func OpenCore(corePath, exePath string) (*Process, error) {
core, err := readCore(corePath, exePath)
if err != nil {
return nil, err
}
p := &Process{
core: core,
breakpoints: proc.NewBreakpointMap(),
bi: proc.NewBinaryInfo("linux", "amd64"),
}
for _, thread := range core.Threads {
thread.p = p
}
var wg sync.WaitGroup
err = p.bi.LoadBinaryInfo(exePath, &wg)
wg.Wait()
if err == nil {
err = p.bi.LoadError()
}
if err != nil {
return nil, err
}
for _, th := range p.core.Threads {
p.currentThread = th
break
}
p.selectedGoroutine, _ = proc.GetG(p.CurrentThread())
return p, nil
}
func (p *Process) BinInfo() *proc.BinaryInfo {
return &p.bi
}
func (p *Process) Recorded() (bool, string) { return true, "" }
func (p *Process) Restart(string) error { return ErrContinueCore }
func (p *Process) Direction(proc.Direction) error { return ErrContinueCore }
func (p *Process) When() (string, error) { return "", nil }
func (p *Process) Checkpoint(string) (int, error) { return -1, ErrContinueCore }
func (p *Process) Checkpoints() ([]proc.Checkpoint, error) { return nil, nil }
func (p *Process) ClearCheckpoint(int) error { return errors.New("checkpoint not found") }
func (thread *Thread) ReadMemory(data []byte, addr uintptr) (n int, err error) {
n, err = thread.p.core.ReadMemory(data, addr)
if err == nil && n != len(data) {
err = ErrShortRead
}
return n, err
}
func (thread *Thread) WriteMemory(addr uintptr, data []byte) (int, error) {
return 0, ErrWriteCore
}
func (t *Thread) Location() (*proc.Location, error) {
f, l, fn := t.p.bi.PCToLine(t.th.Reg.Rip)
return &proc.Location{PC: t.th.Reg.Rip, File: f, Line: l, Fn: fn}, nil
}
func (t *Thread) Breakpoint() proc.BreakpointState {
return proc.BreakpointState{}
}
func (t *Thread) ThreadID() int {
return int(t.th.Pid)
}
func (t *Thread) Registers(floatingPoint bool) (proc.Registers, error) {
r := &Registers{&t.th.Reg, nil}
if floatingPoint {
r.fpregs = t.fpregs
}
return r, nil
}
func (t *Thread) Arch() proc.Arch {
return t.p.bi.Arch
}
func (t *Thread) BinInfo() *proc.BinaryInfo {
return &t.p.bi
}
func (t *Thread) StepInstruction() error {
return ErrContinueCore
}
func (t *Thread) Blocked() bool {
return false
}
func (t *Thread) SetCurrentBreakpoint() error {
return nil
}
func (p *Process) Breakpoints() *proc.BreakpointMap {
return &p.breakpoints
}
func (p *Process) ClearBreakpoint(addr uint64) (*proc.Breakpoint, error) {
return nil, proc.NoBreakpointError{Addr: addr}
}
func (p *Process) ClearInternalBreakpoints() error {
return nil
}
func (p *Process) ContinueOnce() (proc.Thread, error) {
return nil, ErrContinueCore
}
func (p *Process) StepInstruction() error {
return ErrContinueCore
}
func (p *Process) RequestManualStop() error {
return nil
}
func (p *Process) ManualStopRequested() bool {
return false
}
func (p *Process) CurrentThread() proc.Thread {
return p.currentThread
}
func (p *Process) Detach(bool) error {
return nil
}
func (p *Process) Exited() bool {
return false
}
func (p *Process) AllGCache() *[]*proc.G {
return &p.allGCache
}
func (p *Process) Halt() error {
return nil
}
func (p *Process) Kill() error {
return nil
}
func (p *Process) Pid() int {
return p.core.Pid
}
func (p *Process) ResumeNotify(chan<- struct{}) {
}
func (p *Process) SelectedGoroutine() *proc.G {
return p.selectedGoroutine
}
func (p *Process) SetBreakpoint(addr uint64, kind proc.BreakpointKind, cond ast.Expr) (*proc.Breakpoint, error) {
return nil, ErrWriteCore
}
func (p *Process) SwitchGoroutine(gid int) error {
g, err := proc.FindGoroutine(p, gid)
if err != nil {
return err
}
if g == nil {
// user specified -1 and selectedGoroutine is nil
return nil
}
if g.Thread != nil {
return p.SwitchThread(g.Thread.ThreadID())
}
p.selectedGoroutine = g
return nil
}
func (p *Process) SwitchThread(tid int) error {
if th, ok := p.core.Threads[tid]; ok {
p.currentThread = th
p.selectedGoroutine, _ = proc.GetG(p.CurrentThread())
return nil
}
return fmt.Errorf("thread %d does not exist", tid)
}
func (p *Process) ThreadList() []proc.Thread {
r := make([]proc.Thread, 0, len(p.core.Threads))
for _, v := range p.core.Threads {
r = append(r, v)
}
return r
}
func (p *Process) FindThread(threadID int) (proc.Thread, bool) {
t, ok := p.core.Threads[threadID]
return t, ok
}
type Registers struct {
*LinuxCoreRegisters
fpregs []proc.Register
}
func (r *Registers) Slice() []proc.Register {
var regs = []struct {
k string
v uint64
}{
{"Rip", r.Rip},
{"Rsp", r.Rsp},
{"Rax", r.Rax},
{"Rbx", r.Rbx},
{"Rcx", r.Rcx},
{"Rdx", r.Rdx},
{"Rdi", r.Rdi},
{"Rsi", r.Rsi},
{"Rbp", r.Rbp},
{"R8", r.R8},
{"R9", r.R9},
{"R10", r.R10},
{"R11", r.R11},
{"R12", r.R12},
{"R13", r.R13},
{"R14", r.R14},
{"R15", r.R15},
{"Orig_rax", r.Orig_rax},
{"Cs", r.Cs},
{"Eflags", r.Eflags},
{"Ss", r.Ss},
{"Fs_base", r.Fs_base},
{"Gs_base", r.Gs_base},
{"Ds", r.Ds},
{"Es", r.Es},
{"Fs", r.Fs},
{"Gs", r.Gs},
}
out := make([]proc.Register, 0, len(regs))
for _, reg := range regs {
if reg.k == "Eflags" {
out = proc.AppendEflagReg(out, reg.k, reg.v)
} else {
out = proc.AppendQwordReg(out, reg.k, reg.v)
}
}
out = append(out, r.fpregs...)
return out
}