Spectre Mitigations in Microsoft's C/C++ Compiler in 2024
The snippet can be accessed without any authentication.
Authored by
Griffin, Matt J Dr (PG/R - Comp Sci & Elec Eng)
Paul Kocher's 2018 blog post titled Spectre Mitigations in Microsoft's C/C++ Compiler highlighted 15 victim functions which demonstrate Spectre vulnerabilities. These functions were used as a litmus test to evaluate the Spectre mitigations provided by Microsoft's C compiler (MSVC).
After 6 years and many cumulative updates to MSVC, I decided to test how MSVC fairs against these examples in 2024. I used MSVC to compile x86-64 binaries on Windows with SDK in a Docker container. Further details on the method is provided in https://gitlab.surrey.ac.uk/mg00634/spectre-db.
7 of the victim functions have now been patched (up from 2 in the original post). These are Examples 1, 2, 3, 4, 11, 12 and 14. Attached are the code listings generated by MSVC.
ex.cod 17.99 KiB
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v01
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 1\ex01.c
; COMDAT victim_function_v01
_TEXT SEGMENT
x$ = 8
victim_function_v01 PROC ; COMDAT
; 5 : if (x < array1_size) {
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 24 jae SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x] * 512];
00009 0f ae e8 lfence
0000c 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00013 0f b6 84 0a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx]
0001b 48 c1 e0 09 shl rax, 9
0001f 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00027 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
; 8 : }
0002d c3 ret 0
victim_function_v01 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC leakByteLocalFunction_v02
PUBLIC victim_function_v02
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 2\ex02.c
; COMDAT victim_function_v02
_TEXT SEGMENT
x$ = 8
victim_function_v02 PROC ; COMDAT
; 9 : if (x < array1_size) {
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 24 jae SHORT $LN4@victim_fun
; 10 : leakByteLocalFunction_v02(array1[x]);
00009 0f ae e8 lfence
0000c 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
; 4 : temp &= array2[(k)* 512];
00013 0f b6 84 0a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx]
0001b 48 c1 e0 09 shl rax, 9
0001f 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00027 20 05 00 00 00
00 and BYTE PTR temp, al
$LN4@victim_fun:
; 11 : }
; 12 : }
0002d c3 ret 0
victim_function_v02 ENDP
_TEXT ENDS
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 2\ex02.c
; COMDAT leakByteLocalFunction_v02
_TEXT SEGMENT
k$ = 8
leakByteLocalFunction_v02 PROC ; COMDAT
; 4 : temp &= array2[(k)* 512];
00000 0f b6 c1 movzx eax, cl
00003 48 8d 0d 00 00
00 00 lea rcx, OFFSET FLAT:array2
0000a c1 e0 09 shl eax, 9
0000d 0f b6 04 08 movzx eax, BYTE PTR [rax+rcx]
00011 20 05 00 00 00
00 and BYTE PTR temp, al
; 5 : }
00017 c3 ret 0
leakByteLocalFunction_v02 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC leakByteNoinlineFunction
PUBLIC victim_function_v03
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 3\ex03.c
; COMDAT victim_function_v03
_TEXT SEGMENT
x$ = 8
victim_function_v03 PROC ; COMDAT
; 9 : if (x < array1_size)
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 13 jae SHORT $LN2@victim_fun
; 10 : leakByteNoinlineFunction(array1[x]);
00009 0f ae e8 lfence
0000c 48 8d 05 00 00
00 00 lea rax, OFFSET FLAT:array1
00013 0f b6 0c 08 movzx ecx, BYTE PTR [rax+rcx]
00017 e9 00 00 00 00 jmp leakByteNoinlineFunction
$LN2@victim_fun:
; 11 : }
0001c c3 ret 0
victim_function_v03 ENDP
_TEXT ENDS
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 3\ex03.c
; COMDAT leakByteNoinlineFunction
_TEXT SEGMENT
k$ = 8
leakByteNoinlineFunction PROC ; COMDAT
; 4 : temp &= array2[(k)* 512];
00000 0f b6 c1 movzx eax, cl
00003 48 8d 0d 00 00
00 00 lea rcx, OFFSET FLAT:array2
0000a c1 e0 09 shl eax, 9
0000d 0f b6 04 08 movzx eax, BYTE PTR [rax+rcx]
00011 20 05 00 00 00
00 and BYTE PTR temp, al
; 5 : }
00017 c3 ret 0
leakByteNoinlineFunction ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v04
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 4\ex04.c
; COMDAT victim_function_v04
_TEXT SEGMENT
x$ = 8
victim_function_v04 PROC ; COMDAT
; 5 : if (x < array1_size)
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 24 jae SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x << 1] * 512];
00009 0f ae e8 lfence
0000c 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00013 0f b6 84 4a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx*2]
0001b 48 c1 e0 09 shl rax, 9
0001f 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00027 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
0002d c3 ret 0
victim_function_v04 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v05
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 5\ex05.c
; COMDAT victim_function_v05
_TEXT SEGMENT
x$ = 8
victim_function_v05 PROC ; COMDAT
; 5 : size_t i;
; 6 : if (x < array1_size) {
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 2d jae SHORT $LN3@victim_fun
; 7 : for (i = x - 1; i >= 0; i--)
00009 0f b6 15 00 00
00 00 movzx edx, BYTE PTR temp
00010 4c 8d 05 00 00
00 00 lea r8, OFFSET FLAT:__ImageBase
00017 49 8d 80 ff ff
ff ff lea rax, QWORD PTR array1[r8-1]
0001e 48 03 c1 add rax, rcx
$LL4@victim_fun:
; 8 : temp &= array2[array1[i] * 512];
00021 0f b6 08 movzx ecx, BYTE PTR [rax]
00024 48 8d 40 ff lea rax, QWORD PTR [rax-1]
00028 48 c1 e1 09 shl rcx, 9
0002c 42 22 94 01 00
00 00 00 and dl, BYTE PTR array2[rcx+r8]
00034 eb eb jmp SHORT $LL4@victim_fun
$LN3@victim_fun:
; 9 : }
; 10 : }
00036 c3 ret 0
victim_function_v05 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v06
EXTRN array_size_mask:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 6\ex06.c
; COMDAT victim_function_v06
_TEXT SEGMENT
x$ = 8
victim_function_v06 PROC ; COMDAT
; 5 : if ((x & array_size_mask) == x)
00000 48 8b 05 00 00
00 00 mov rax, QWORD PTR array_size_mask
00007 48 23 c1 and rax, rcx
0000a 48 3b c1 cmp rax, rcx
0000d 75 21 jne SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x] * 512];
0000f 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00016 0f b6 84 0a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx]
0001e 48 c1 e0 09 shl rax, 9
00022 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
0002a 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
00030 c3 ret 0
victim_function_v06 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v07
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
_BSS SEGMENT
?last_x@?1??victim_function_v07@@9@9 DQ 01H DUP (?) ; `victim_function_v07'::`2'::last_x
_BSS ENDS
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 7\ex07.c
; COMDAT victim_function_v07
_TEXT SEGMENT
x$ = 8
victim_function_v07 PROC ; COMDAT
; 5 : static size_t last_x = 0;
; 6 : if (x == last_x)
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR ?last_x@?1??victim_function_v07@@9@9
00007 75 21 jne SHORT $LN2@victim_fun
; 7 : temp &= array2[array1[x] * 512];
00009 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00010 0f b6 84 0a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx]
00018 48 c1 e0 09 shl rax, 9
0001c 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00024 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 8 : if (x < array1_size)
0002a 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00031 73 07 jae SHORT $LN3@victim_fun
; 9 : last_x = x;
00033 48 89 0d 00 00
00 00 mov QWORD PTR ?last_x@?1??victim_function_v07@@9@9, rcx
$LN3@victim_fun:
; 10 : }
0003a c3 ret 0
victim_function_v07 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v08
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 8\ex08.c
; COMDAT victim_function_v08
_TEXT SEGMENT
x$ = 8
victim_function_v08 PROC ; COMDAT
; 5 : temp &= array2[array1[x < array1_size ? (x + 1) : 0] * 512];
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 05 jae SHORT $LN3@victim_fun
00009 48 ff c1 inc rcx
0000c eb 02 jmp SHORT $LN4@victim_fun
$LN3@victim_fun:
0000e 33 c9 xor ecx, ecx
$LN4@victim_fun:
00010 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00017 0f b6 84 11 00
00 00 00 movzx eax, BYTE PTR array1[rcx+rdx]
0001f 48 c1 e0 09 shl rax, 9
00023 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
0002b 20 05 00 00 00
00 and BYTE PTR temp, al
; 6 : }
00031 c3 ret 0
victim_function_v08 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v09
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 9\ex09.c
; COMDAT victim_function_v09
_TEXT SEGMENT
x$ = 8
x_is_safe$ = 16
victim_function_v09 PROC ; COMDAT
; 5 : if (*x_is_safe)
00000 83 3a 00 cmp DWORD PTR [rdx], 0
00003 74 21 je SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x] * 512];
00005 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
0000c 0f b6 84 11 00
00 00 00 movzx eax, BYTE PTR array1[rcx+rdx]
00014 48 c1 e0 09 shl rax, 9
00018 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00020 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
00026 c3 ret 0
victim_function_v09 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v10
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 10\ex10.c
; COMDAT victim_function_v10
_TEXT SEGMENT
x$ = 8
k$ = 16
victim_function_v10 PROC ; COMDAT
; 5 : if (x < array1_size) {
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 19 jae SHORT $LN3@victim_fun
; 6 : if (array1[x] == k)
00009 48 8d 05 00 00
00 00 lea rax, OFFSET FLAT:array1
00010 38 14 01 cmp BYTE PTR [rcx+rax], dl
00013 75 0d jne SHORT $LN3@victim_fun
; 7 : temp &= array2[0];
00015 0f b6 05 00 00
00 00 movzx eax, BYTE PTR array2
0001c 20 05 00 00 00
00 and BYTE PTR temp, al
$LN3@victim_fun:
; 8 : }
; 9 : }
00022 c3 ret 0
victim_function_v10 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v11
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 11\ex11.c
; COMDAT victim_function_v11
_TEXT SEGMENT
x$ = 8
victim_function_v11 PROC ; COMDAT
; 5 : if (x < array1_size)
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 3b jae SHORT $LN2@victim_fun
; 6 : temp = memcmp(&temp, array2 + (array1[x] * 512), 1);
00009 0f ae e8 lfence
0000c 48 8d 05 00 00
00 00 lea rax, OFFSET FLAT:array1
00013 0f b6 0c 08 movzx ecx, BYTE PTR [rax+rcx]
00017 48 8d 05 00 00
00 00 lea rax, OFFSET FLAT:array2
0001e 48 c1 e1 09 shl rcx, 9
00022 48 03 c8 add rcx, rax
00025 0f b6 05 00 00
00 00 movzx eax, BYTE PTR temp
0002c 3a 01 cmp al, BYTE PTR [rcx]
0002e 75 09 jne SHORT $LN4@victim_fun
00030 33 c0 xor eax, eax
00032 88 05 00 00 00
00 mov BYTE PTR temp, al
; 7 : }
00038 c3 ret 0
$LN4@victim_fun:
; 6 : temp = memcmp(&temp, array2 + (array1[x] * 512), 1);
00039 1b c0 sbb eax, eax
0003b 83 c8 01 or eax, 1
0003e 88 05 00 00 00
00 mov BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
00044 c3 ret 0
victim_function_v11 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v12
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 12\ex12.c
; COMDAT victim_function_v12
_TEXT SEGMENT
x$ = 8
y$ = 16
victim_function_v12 PROC ; COMDAT
; 5 : if ((x + y) < array1_size)
00000 48 8d 04 11 lea rax, QWORD PTR [rcx+rdx]
00004 48 3b 05 00 00
00 00 cmp rax, QWORD PTR array1_size
0000b 73 2b jae SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x + y] * 512];
0000d 0f ae e8 lfence
00010 4c 8d 05 00 00
00 00 lea r8, OFFSET FLAT:__ImageBase
00017 49 8d 80 00 00
00 00 lea rax, QWORD PTR array1[r8]
0001e 48 03 c1 add rax, rcx
00021 0f b6 04 10 movzx eax, BYTE PTR [rax+rdx]
00025 48 c1 e0 09 shl rax, 9
00029 42 0f b6 84 00
00 00 00 00 movzx eax, BYTE PTR array2[rax+r8]
00032 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
00038 c3 ret 0
victim_function_v12 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC is_x_safe
PUBLIC victim_function_v13
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 13\ex13.c
; COMDAT victim_function_v13
_TEXT SEGMENT
x$ = 8
victim_function_v13 PROC ; COMDAT
; 3 : __forceinline int is_x_safe(size_t x) { if (x < array1_size) return 1; return 0; }
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 21 jae SHORT $LN2@victim_fun
; 7 : if (is_x_safe(x))
; 8 : temp &= array2[array1[x] * 512];
00009 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
00010 0f b6 84 0a 00
00 00 00 movzx eax, BYTE PTR array1[rdx+rcx]
00018 48 c1 e0 09 shl rax, 9
0001c 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
00024 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 9 : }
0002a c3 ret 0
victim_function_v13 ENDP
_TEXT ENDS
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 13\ex13.c
; COMDAT is_x_safe
_TEXT SEGMENT
x$ = 8
is_x_safe PROC ; COMDAT
; 3 : __forceinline int is_x_safe(size_t x) { if (x < array1_size) return 1; return 0; }
00000 33 c0 xor eax, eax
00002 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00009 0f 92 c0 setb al
0000c c3 ret 0
is_x_safe ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v14
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 14\ex14.c
; COMDAT victim_function_v14
_TEXT SEGMENT
x$ = 8
victim_function_v14 PROC ; COMDAT
; 5 : if (x < array1_size)
00000 48 3b 0d 00 00
00 00 cmp rcx, QWORD PTR array1_size
00007 73 2b jae SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[x ^ 255] * 512];
00009 0f ae e8 lfence
0000c 48 81 f1 ff 00
00 00 xor rcx, 255 ; 000000ffH
00013 48 8d 15 00 00
00 00 lea rdx, OFFSET FLAT:__ImageBase
0001a 0f b6 84 11 00
00 00 00 movzx eax, BYTE PTR array1[rcx+rdx]
00022 48 c1 e0 09 shl rax, 9
00026 0f b6 84 10 00
00 00 00 movzx eax, BYTE PTR array2[rax+rdx]
0002e 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
00034 c3 ret 0
victim_function_v14 ENDP
_TEXT ENDS
END
; Listing generated by Microsoft (R) Optimizing Compiler Version 19.38.33135.0
include listing.inc
INCLUDELIB MSVCRT
INCLUDELIB OLDNAMES
PUBLIC victim_function_v15
EXTRN array1_size:QWORD
EXTRN array1:BYTE
EXTRN array2:BYTE
EXTRN temp:BYTE
EXTRN __ImageBase:BYTE
; Function compile flags: /Ogtpy
; File C:\BCB\Paul Kocher\Example 15\ex15.c
; COMDAT victim_function_v15
_TEXT SEGMENT
x$ = 8
victim_function_v15 PROC ; COMDAT
; 5 : if (*x < array1_size)
00000 48 8b 01 mov rax, QWORD PTR [rcx]
00003 48 3b 05 00 00
00 00 cmp rax, QWORD PTR array1_size
0000a 73 21 jae SHORT $LN2@victim_fun
; 6 : temp &= array2[array1[*x] * 512];
0000c 48 8d 0d 00 00
00 00 lea rcx, OFFSET FLAT:__ImageBase
00013 0f b6 84 08 00
00 00 00 movzx eax, BYTE PTR array1[rax+rcx]
0001b 48 c1 e0 09 shl rax, 9
0001f 0f b6 84 08 00
00 00 00 movzx eax, BYTE PTR array2[rax+rcx]
00027 20 05 00 00 00
00 and BYTE PTR temp, al
$LN2@victim_fun:
; 7 : }
0002d c3 ret 0
victim_function_v15 ENDP
_TEXT ENDS
END-
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