53 lines
1.3 KiB
Go
53 lines
1.3 KiB
Go
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build linux && amd64
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package debug
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import (
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"fmt"
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"golang.org/x/arch/x86/x86asm"
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)
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// Disassemble decodes the instruction at the given address in the debuggee's
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// memory and returns its text representation and length in bytes.
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func (s *Session) Disassemble(addr uint64) (string, int, error) {
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// Read up to 15 bytes (max x86 instruction length).
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mem, err := s.ReadMemory(addr, 15)
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if err != nil {
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// Try a shorter read if we're near a page boundary.
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mem, err = s.ReadMemory(addr, 1)
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if err != nil {
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return "", 0, err
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}
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}
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inst, err := x86asm.Decode(mem, 64)
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if err != nil {
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return "???", 1, nil
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}
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text := x86asm.IntelSyntax(inst, addr, nil)
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return text, inst.Len, nil
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}
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// DisassembleN decodes up to n instructions starting at addr and returns
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// them as a formatted string with addresses and byte offsets.
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func (s *Session) DisassembleN(addr uint64, n int) string {
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var result string
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pc := addr
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for i := 0; i < n; i++ {
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text, length, err := s.Disassemble(pc)
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if err != nil {
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result += fmt.Sprintf(" %#08x: <error: %v>\n", pc, err)
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break
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}
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result += fmt.Sprintf(" %#08x: %s\n", pc, text)
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if length == 0 {
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length = 1
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}
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pc += uint64(length)
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}
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return result
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}
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