1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
| # REQUIRES: x86
# RUN: llvm-mc -triple x86_64-windows-msvc %s -filetype=obj -o %t.obj
# RUN: lld-link %t.obj -guard:cf -out:%t.exe -entry:main
# RUN: llvm-readobj --file-headers --coff-load-config %t.exe | FileCheck %s
# CHECK: ImageBase: 0x140000000
# CHECK: LoadConfig [
# CHECK: SEHandlerTable: 0x0
# CHECK: SEHandlerCount: 0
# CHECK: GuardCFCheckFunction: 0x0
# CHECK: GuardCFCheckDispatch: 0x0
# CHECK: GuardCFFunctionTable: 0x14000{{.*}}
# CHECK: GuardCFFunctionCount: 1
# CHECK: GuardFlags: 0x10500
# CHECK: GuardAddressTakenIatEntryTable: 0x0
# CHECK: GuardAddressTakenIatEntryCount: 0
# CHECK: GuardLongJumpTargetTable: 0x14000{{.*}}
# CHECK: GuardLongJumpTargetCount: 1
# CHECK: ]
# CHECK: GuardLJmpTable [
# CHECK-NEXT: 0x14000{{.*}}
# CHECK-NEXT: ]
# This assembly is reduced from C code like:
# #include <setjmp.h>
# jmp_buf buf;
# void g() { longjmp(buf, 1); }
# void f() {
# if (setjmp(buf))
# return;
# g();
# }
# int main() { f(); }
# We need @feat.00 to have 0x800 to indicate /guard:cf.
.def @feat.00;
.scl 3;
.type 0;
.endef
.globl @feat.00
@feat.00 = 0x801
.def f; .scl 2; .type 32; .endef
.globl f
f:
pushq %rbp
subq $32, %rsp
leaq 32(%rsp), %rbp
leaq buf(%rip), %rcx
leaq -32(%rbp), %rdx
callq _setjmp
.Lljmp1:
testl %eax, %eax
je .LBB1_1
addq $32, %rsp
popq %rbp
retq
.LBB1_1: # %if.end
leaq buf(%rip), %rcx
movl $1, %edx
callq longjmp
ud2
# Record the longjmp target.
.section .gljmp$y,"dr"
.symidx .Lljmp1
.text
# Provide setjmp/longjmp stubs.
.def _setjmp; .scl 2; .type 32; .endef
.globl _setjmp
_setjmp:
retq
.def longjmp; .scl 2; .type 32; .endef
.globl longjmp
longjmp:
retq
.def main; .scl 2; .type 32; .endef
.globl main # -- Begin function main
main: # @main
subq $40, %rsp
callq f
xorl %eax, %eax
addq $40, %rsp
retq
.comm buf,256,4 # @buf
.section .rdata,"dr"
.globl _load_config_used
_load_config_used:
.long 256
.fill 124, 1, 0
.quad __guard_fids_table
.quad __guard_fids_count
.long __guard_flags
.fill 12, 1, 0
.quad __guard_iat_table
.quad __guard_iat_count
.quad __guard_longjmp_table
.quad __guard_fids_count
.fill 84, 1, 0
|