| // Copyright 2017 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package goversion |
| |
| import ( |
| "encoding/binary" |
| "fmt" |
| "os" |
| ) |
| |
| type matcher [][]uint32 |
| |
| const ( |
| pWild uint32 = 0xff00 |
| pAddr uint32 = 0x10000 |
| pEnd uint32 = 0x20000 |
| pRelAddr uint32 = 0x30000 |
| |
| opMaybe = 1 + iota |
| opMust |
| opDone |
| opAnchor = 0x100 |
| opSub8 = 0x200 |
| opFlags = opAnchor | opSub8 |
| ) |
| |
| var amd64Matcher = matcher{ |
| {opMaybe | opAnchor, |
| // __rt0_amd64_darwin: |
| // JMP __rt0_amd64 |
| 0xe9, pWild | pAddr, pWild, pWild, pWild | pEnd, 0xcc, 0xcc, 0xcc, |
| }, |
| {opMaybe, |
| // _rt0_amd64_linux: |
| // lea 0x8(%rsp), %rsi |
| // mov (%rsp), %rdi |
| // lea ADDR(%rip), %rax # main |
| // jmpq *%rax |
| 0x48, 0x8d, 0x74, 0x24, 0x08, |
| 0x48, 0x8b, 0x3c, 0x24, 0x48, |
| 0x8d, 0x05, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0xff, 0xe0, |
| }, |
| {opMaybe, |
| // _rt0_amd64_linux: |
| // lea 0x8(%rsp), %rsi |
| // mov (%rsp), %rdi |
| // mov $ADDR, %eax # main |
| // jmpq *%rax |
| 0x48, 0x8d, 0x74, 0x24, 0x08, |
| 0x48, 0x8b, 0x3c, 0x24, |
| 0xb8, pWild | pAddr, pWild, pWild, pWild, |
| 0xff, 0xe0, |
| }, |
| {opMaybe, |
| // __rt0_amd64: |
| // mov (%rsp), %rdi |
| // lea 8(%rsp), %rsi |
| // jmp runtime.rt0_g0 |
| 0x48, 0x8b, 0x3c, 0x24, |
| 0x48, 0x8d, 0x74, 0x24, 0x08, |
| 0xe9, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0xcc, 0xcc, |
| }, |
| {opMaybe, |
| // _start (toward end) |
| // lea __libc_csu_fini(%rip), %r8 |
| // lea __libc_csu_init(%rip), %rcx |
| // lea ADDR(%rip), %rdi # main |
| // callq *xxx(%rip) |
| 0x4c, 0x8d, 0x05, pWild, pWild, pWild, pWild, |
| 0x48, 0x8d, 0x0d, pWild, pWild, pWild, pWild, |
| 0x48, 0x8d, 0x3d, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0xff, 0x15, |
| }, |
| {opMaybe, |
| // _start (toward end) |
| // push %rsp (1) |
| // mov $__libc_csu_fini, %r8 (7) |
| // mov $__libc_csu_init, %rcx (7) |
| // mov $ADDR, %rdi # main (7) |
| // callq *xxx(%rip) |
| 0x54, |
| 0x49, 0xc7, 0xc0, pWild, pWild, pWild, pWild, |
| 0x48, 0xc7, 0xc1, pWild, pWild, pWild, pWild, |
| 0x48, 0xc7, 0xc7, pAddr | pWild, pWild, pWild, pWild, |
| }, |
| {opMaybe | opAnchor, |
| // main: |
| // lea ADDR(%rip), %rax # rt0_go |
| // jmpq *%rax |
| 0x48, 0x8d, 0x05, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0xff, 0xe0, |
| }, |
| {opMaybe | opAnchor, |
| // main: |
| // mov $ADDR, %eax |
| // jmpq *%rax |
| 0xb8, pWild | pAddr, pWild, pWild, pWild, |
| 0xff, 0xe0, |
| }, |
| {opMaybe | opAnchor, |
| // main: |
| // JMP runtime.rt0_go(SB) |
| 0xe9, pWild | pAddr, pWild, pWild, pWild | pEnd, 0xcc, 0xcc, 0xcc, |
| }, |
| {opMust | opAnchor, |
| // rt0_go: |
| // mov %rdi, %rax |
| // mov %rsi, %rbx |
| // sub %0x27, %rsp |
| // and $0xfffffffffffffff0,%rsp |
| // mov %rax,0x10(%rsp) |
| // mov %rbx,0x18(%rsp) |
| 0x48, 0x89, 0xf8, |
| 0x48, 0x89, 0xf3, |
| 0x48, 0x83, 0xec, 0x27, |
| 0x48, 0x83, 0xe4, 0xf0, |
| 0x48, 0x89, 0x44, 0x24, 0x10, |
| 0x48, 0x89, 0x5c, 0x24, 0x18, |
| }, |
| {opMust, |
| // later in rt0_go: |
| // mov %eax, (%rsp) |
| // mov 0x18(%rsp), %rax |
| // mov %rax, 0x8(%rsp) |
| // callq runtime.args |
| // callq runtime.osinit |
| // callq runtime.schedinit (ADDR) |
| 0x89, 0x04, 0x24, |
| 0x48, 0x8b, 0x44, 0x24, 0x18, |
| 0x48, 0x89, 0x44, 0x24, 0x08, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild, pWild, pWild, pWild, |
| }, |
| {opMaybe, |
| // later in rt0_go: |
| // mov %eax, (%rsp) |
| // mov 0x18(%rsp), %rax |
| // mov %rax, 0x8(%rsp) |
| // callq runtime.args |
| // callq runtime.osinit |
| // callq runtime.schedinit (ADDR) |
| // lea other(%rip), %rdi |
| 0x89, 0x04, 0x24, |
| 0x48, 0x8b, 0x44, 0x24, 0x18, |
| 0x48, 0x89, 0x44, 0x24, 0x08, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0x48, 0x8d, 0x05, |
| }, |
| {opMaybe, |
| // later in rt0_go: |
| // mov %eax, (%rsp) |
| // mov 0x18(%rsp), %rax |
| // mov %rax, 0x8(%rsp) |
| // callq runtime.args |
| // callq runtime.osinit |
| // callq runtime.hashinit |
| // callq runtime.schedinit (ADDR) |
| // pushq $main.main |
| 0x89, 0x04, 0x24, |
| 0x48, 0x8b, 0x44, 0x24, 0x18, |
| 0x48, 0x89, 0x44, 0x24, 0x08, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild, pWild, pWild, pWild, |
| 0xe8, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0x68, |
| }, |
| {opDone | opSub8, |
| // schedinit (toward end) |
| // mov ADDR(%rip), %rax |
| // test %rax, %rax |
| // jne <short> |
| // movq $0x7, ADDR(%rip) |
| // |
| 0x48, 0x8b, 0x05, pWild, pWild, pWild, pWild, |
| 0x48, 0x85, 0xc0, |
| 0x75, pWild, |
| 0x48, 0xc7, 0x05, pWild | pAddr, pWild, pWild, pWild, 0x07, 0x00, 0x00, 0x00 | pEnd, |
| }, |
| {opDone | opSub8, |
| // schedinit (toward end) |
| // mov ADDR(%rip), %rbx |
| // cmp $0x0, %rbx |
| // jne <short> |
| // lea "unknown"(%rip), %rbx |
| // mov %rbx, ADDR(%rip) |
| // movq $7, (ADDR+8)(%rip) |
| 0x48, 0x8b, 0x1d, pWild, pWild, pWild, pWild, |
| 0x48, 0x83, 0xfb, 0x00, |
| 0x75, pWild, |
| 0x48, 0x8d, 0x1d, pWild, pWild, pWild, pWild, |
| 0x48, 0x89, 0x1d, pWild, pWild, pWild, pWild, |
| 0x48, 0xc7, 0x05, pWild | pAddr, pWild, pWild, pWild, 0x07, 0x00, 0x00, 0x00 | pEnd, |
| }, |
| {opDone, |
| // schedinit (toward end) |
| // cmpq $0x0, ADDR(%rip) |
| // jne <short> |
| // lea "unknown"(%rip), %rax |
| // mov %rax, ADDR(%rip) |
| // lea ADDR(%rip), %rax |
| // movq $7, 8(%rax) |
| 0x48, 0x83, 0x3d, pWild | pAddr, pWild, pWild, pWild, 0x00, |
| 0x75, pWild, |
| 0x48, 0x8d, 0x05, pWild, pWild, pWild, pWild, |
| 0x48, 0x89, 0x05, pWild, pWild, pWild, pWild, |
| 0x48, 0x8d, 0x05, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| 0x48, 0xc7, 0x40, 0x08, 0x07, 0x00, 0x00, 0x00, |
| }, |
| {opDone, |
| // schedinit (toward end) |
| // cmpq $0x0, ADDR(%rip) |
| // jne <short> |
| // movq $0x7, ADDR(%rip) |
| 0x48, 0x83, 0x3d, pWild | pAddr, pWild, pWild, pWild, 0x00, |
| 0x75, pWild, |
| 0x48, 0xc7, 0x05 | pEnd, pWild | pAddr, pWild, pWild, pWild, 0x07, 0x00, 0x00, 0x00, |
| }, |
| {opDone, |
| // test %eax, %eax |
| // jne <later> |
| // lea "unknown"(RIP), %rax |
| // mov %rax, ADDR(%rip) |
| 0x48, 0x85, 0xc0, 0x75, pWild, 0x48, 0x8d, 0x05, pWild, pWild, pWild, pWild, 0x48, 0x89, 0x05, pWild | pAddr, pWild, pWild, pWild | pEnd, |
| }, |
| {opDone, |
| // schedinit (toward end) |
| // mov ADDR(%rip), %rcx |
| // test %rcx, %rcx |
| // jne <short> |
| // movq $0x7, ADDR(%rip) |
| // |
| 0x48, 0x8b, 0x0d, pWild, pWild, pWild, pWild, |
| 0x48, 0x85, 0xc9, |
| 0x75, pWild, |
| 0x48, 0xc7, 0x05 | pEnd, pWild | pAddr, pWild, pWild, pWild, 0x07, 0x00, 0x00, 0x00, |
| }, |
| } |
| |
| var DebugMatch bool |
| |
| func (m matcher) match(f exe, addr uint64) (uint64, bool) { |
| data, err := f.ReadData(addr, 512) |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "data @%#x: %x\n", addr, data[:16]) |
| } |
| if err != nil { |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "match: %v\n", err) |
| } |
| return 0, false |
| } |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "data: %x\n", data[:32]) |
| } |
| Matchers: |
| for pc, p := range m { |
| op := p[0] |
| p = p[1:] |
| Search: |
| for i := 0; i <= len(data)-len(p); i++ { |
| a := -1 |
| e := -1 |
| if i > 0 && op&opAnchor != 0 { |
| break |
| } |
| for j := 0; j < len(p); j++ { |
| b := byte(p[j]) |
| m := byte(p[j] >> 8) |
| if data[i+j]&^m != b { |
| continue Search |
| } |
| if p[j]&pAddr != 0 { |
| a = j |
| } |
| if p[j]&pEnd != 0 { |
| e = j + 1 |
| } |
| } |
| // matched |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "match (%d) %#x+%d %x %x\n", pc, addr, i, p, data[i:i+len(p)]) |
| } |
| if a != -1 { |
| val := uint64(int32(binary.LittleEndian.Uint32(data[i+a:]))) |
| if e == -1 { |
| addr = val |
| } else { |
| addr += uint64(i+e) + val |
| } |
| if op&opSub8 != 0 { |
| addr -= 8 |
| } |
| } |
| if op&^opFlags == opDone { |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "done %x\n", addr) |
| } |
| return addr, true |
| } |
| if a != -1 { |
| // changed addr, so reload |
| data, err = f.ReadData(addr, 512) |
| if err != nil { |
| return 0, false |
| } |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "reload @%#x: %x\n", addr, data[:32]) |
| } |
| } |
| continue Matchers |
| } |
| // not matched |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "no match (%d) %#x %x %x\n", pc, addr, p, data[:32]) |
| } |
| if op&^opFlags == opMust { |
| return 0, false |
| } |
| } |
| // ran off end of matcher |
| return 0, false |
| } |
| |
| func readBuildVersionX86Asm(f exe) (isGo bool, buildVersion string) { |
| entry := f.Entry() |
| if entry == 0 { |
| if DebugMatch { |
| fmt.Fprintf(os.Stderr, "missing entry!\n") |
| } |
| return |
| } |
| addr, ok := amd64Matcher.match(f, entry) |
| if !ok { |
| return |
| } |
| v, err := readBuildVersion(f, addr, 16) |
| if err != nil { |
| return |
| } |
| return true, v |
| } |
