ec8dc3a10d
updates vendored version of x86asm, adds a symbol lookup function to pass to the disassembler. This will show global symbol names in the disassembly like go tool objdump does.
117 lines
3.1 KiB
Go
117 lines
3.1 KiB
Go
package proc
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import "sort"
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type AsmInstruction struct {
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Loc Location
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DestLoc *Location
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Bytes []byte
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Breakpoint bool
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AtPC bool
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Inst *ArchInst
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}
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type AssemblyFlavour int
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const (
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GNUFlavour = AssemblyFlavour(iota)
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IntelFlavour
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GoFlavour
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)
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// Disassemble disassembles target memory between startPC and endPC, marking
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// the current instruction being executed in goroutine g.
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// If currentGoroutine is set and thread is stopped at a CALL instruction Disassemble will evaluate the argument of the CALL instruction using the thread's registers
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// Be aware that the Bytes field of each returned instruction is a slice of a larger array of size endPC - startPC
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func Disassemble(dbp Process, g *G, startPC, endPC uint64) ([]AsmInstruction, error) {
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if dbp.Exited() {
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return nil, &ProcessExitedError{Pid: dbp.Pid()}
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}
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if g == nil {
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ct := dbp.CurrentThread()
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regs, _ := ct.Registers(false)
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return disassemble(ct, regs, dbp.Breakpoints(), dbp.BinInfo(), startPC, endPC, false)
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}
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var regs Registers
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var mem MemoryReadWriter = dbp.CurrentThread()
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if g.Thread != nil {
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mem = g.Thread
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regs, _ = g.Thread.Registers(false)
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}
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return disassemble(mem, regs, dbp.Breakpoints(), dbp.BinInfo(), startPC, endPC, false)
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}
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func disassemble(memrw MemoryReadWriter, regs Registers, breakpoints *BreakpointMap, bi *BinaryInfo, startPC, endPC uint64, singleInstr bool) ([]AsmInstruction, error) {
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mem := make([]byte, int(endPC-startPC))
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_, err := memrw.ReadMemory(mem, uintptr(startPC))
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if err != nil {
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return nil, err
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}
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r := make([]AsmInstruction, 0, len(mem)/15)
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pc := startPC
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var curpc uint64
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if regs != nil {
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curpc = regs.PC()
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}
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for len(mem) > 0 {
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bp, atbp := breakpoints.M[pc]
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if atbp {
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for i := range bp.OriginalData {
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mem[i] = bp.OriginalData[i]
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}
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}
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file, line, fn := bi.PCToLine(pc)
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loc := Location{PC: pc, File: file, Line: line, Fn: fn}
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inst, err := asmDecode(mem, pc)
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if err == nil {
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atpc := (regs != nil) && (curpc == pc)
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destloc := resolveCallArg(inst, atpc, regs, memrw, bi)
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r = append(r, AsmInstruction{Loc: loc, DestLoc: destloc, Bytes: mem[:inst.Len], Breakpoint: atbp, AtPC: atpc, Inst: inst})
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pc += uint64(inst.Size())
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mem = mem[inst.Size():]
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} else {
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r = append(r, AsmInstruction{Loc: loc, Bytes: mem[:1], Breakpoint: atbp, Inst: nil})
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pc++
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mem = mem[1:]
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}
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if singleInstr {
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break
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}
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}
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return r, nil
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}
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// Looks up symbol (either functions or global variables) at address addr.
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// Used by disassembly formatter.
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func (bi *BinaryInfo) symLookup(addr uint64) (string, uint64) {
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fn := bi.PCToFunc(addr)
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if fn != nil {
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if fn.Entry == addr {
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// only report the function name if it's the exact address because it's
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// easier to read the absolute address than function_name+offset.
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return fn.Name, fn.Entry
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}
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return "", 0
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}
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i := sort.Search(len(bi.packageVars), func(i int) bool {
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return bi.packageVars[i].addr >= addr
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})
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if i >= len(bi.packageVars) {
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return "", 0
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}
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if bi.packageVars[i].addr > addr {
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// report previous variable + offset if i-th variable starts after addr
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i--
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}
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if i > 0 {
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return bi.packageVars[i].name, bi.packageVars[i].addr
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}
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return "", 0
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}
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