Author Topic: Debugging symbols for own procedures  (Read 127 times)

jj2007

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Debugging symbols for own procedures
« on: April 03, 2021, 07:51:41 PM »
I am using x64Dbg with 64-bit code, and it's nugging me because while I do see symbols for WinAPI calls, I don't see any for my own procedures. Example:
Code: [Select]
include \Masm32\MasmBasic\Res\JBasic.inc ; ## builds in 32- or 64-bit mode with UAsm, ML, AsmC ##
usedeb=1 ; use/don't use the deb macro
.code
SayHi proc arg1:SIZE_P
  jinvoke MessageBox, 0, rcx, Chr$("Hi"), MB_OK or MB_SETFOREGROUND
  ret
SayHi endp
Init ; OPT_64 1 ; put 0 for 32 bit, 1 for 64 bit assembly
  ; int 3
  jinvoke SayHi, Chr$("Wow, it works!!!!")
EndOfCode
OPT_Symbols 1 ; RichMasm option: A: /Zi /Zf, L: /debug

Disassembly:
Code: [Select]
0000000140001000  | 55                   | push rbp                          |
0000000140001001  | 48:8D6C24 F0         | lea rbp,qword ptr [rsp-10]        | [rsp-10]:"ÃÌÌÌÌÌMessageBoxA"
0000000140001006  | 8365 00 00           | and dword ptr [rbp],0             |
000000014000100A  | 48:83C5 04           | add rbp,4                         |
000000014000100E  | 48:3BEC              | cmp rbp,rsp                       |
0000000140001011  | 78 F3                | js 140001006                      |
0000000140001013  | 48:81EC 90000000     | sub rsp,90                        |
000000014000101A  | 41:B9 00000100       | mov r9d,10000                     | r9d:" Á¾w"
0000000140001020  | 4C:8D05 F11F0000     | lea r8,qword ptr [140003018]      |
0000000140001027  | 48:8BD1              | mov rdx,rcx                       |
000000014000102A  | 33C9                 | xor ecx,ecx                       |
000000014000102C  | FF15 5E210000        | call qword ptr [<&MessageBoxA>]   |
0000000140001032  | C9                   | leave                             |
0000000140001033  | C3                   | ret                               |
0000000140001034  | C8 8000 00           | enter 80,0                        |
0000000140001038  | E8 2A000000          | call 140001067                    | own proc: no symbols!
000000014000103D  | 33C9                 | xor ecx,ecx                       |
000000014000103F  | FF15 53210000        | call qword ptr [<&SetLastError>]  |
0000000140001045  | FF15 55210000        | call qword ptr [<&GetProcessHeap> |
000000014000104B  | 48:8905 1E210000     | mov qword ptr [140003170],rax     |
0000000140001052  | CC                   | int3                              |
0000000140001053  | 48:8D0D C11F0000     | lea rcx,qword ptr [14000301B]     | 000000014000301B:"Wow, it works!!!!"
000000014000105A  | E8 A1FFFFFF          | call 140001000                    | own proc: no symbols!
000000014000105F  | 33C9                 | xor ecx,ecx                       |
0000000140001061  | FF15 41210000        | call qword ptr [<&RtlExitUserProc |
0000000140001067  | 48:8D0D BF1F0000     | lea rcx,qword ptr [14000302D]     | 000000014000302D:"user32"
000000014000106E  | 48:8D15 0B210000     | lea rdx,qword ptr [140003180]     | 0000000140003180:&"MZ"
0000000140001075  | E8 21000000          | call 14000109B                    | own proc: no symbols!
000000014000107A  | C3                   | ret                               |

Question: is that a "feature" of X64Dbg only, do other debuggers behave the same, is there any option that I may have overlooked?

I found a workaround, see attached executables (both have an int 3), but it would be easier to just use an option... :cool:

LiaoMi

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Re: Debugging symbols for own procedures
« Reply #1 on: April 03, 2021, 08:13:04 PM »
I am using x64Dbg with 64-bit code, and it's nugging me because while I do see symbols for WinAPI calls, I don't see any for my own procedures. Example:
Code: [Select]
include \Masm32\MasmBasic\Res\JBasic.inc ; ## builds in 32- or 64-bit mode with UAsm, ML, AsmC ##
usedeb=1 ; use/don't use the deb macro
.code
SayHi proc arg1:SIZE_P
  jinvoke MessageBox, 0, rcx, Chr$("Hi"), MB_OK or MB_SETFOREGROUND
  ret
SayHi endp
Init ; OPT_64 1 ; put 0 for 32 bit, 1 for 64 bit assembly
  ; int 3
  jinvoke SayHi, Chr$("Wow, it works!!!!")
EndOfCode
OPT_Symbols 1 ; RichMasm option: A: /Zi /Zf, L: /debug

Disassembly:
Code: [Select]
0000000140001000  | 55                   | push rbp                          |
0000000140001001  | 48:8D6C24 F0         | lea rbp,qword ptr [rsp-10]        | [rsp-10]:"ÃÌÌÌÌÌMessageBoxA"
0000000140001006  | 8365 00 00           | and dword ptr [rbp],0             |
000000014000100A  | 48:83C5 04           | add rbp,4                         |
000000014000100E  | 48:3BEC              | cmp rbp,rsp                       |
0000000140001011  | 78 F3                | js 140001006                      |
0000000140001013  | 48:81EC 90000000     | sub rsp,90                        |
000000014000101A  | 41:B9 00000100       | mov r9d,10000                     | r9d:" Á¾w"
0000000140001020  | 4C:8D05 F11F0000     | lea r8,qword ptr [140003018]      |
0000000140001027  | 48:8BD1              | mov rdx,rcx                       |
000000014000102A  | 33C9                 | xor ecx,ecx                       |
000000014000102C  | FF15 5E210000        | call qword ptr [<&MessageBoxA>]   |
0000000140001032  | C9                   | leave                             |
0000000140001033  | C3                   | ret                               |
0000000140001034  | C8 8000 00           | enter 80,0                        |
0000000140001038  | E8 2A000000          | call 140001067                    | own proc: no symbols!
000000014000103D  | 33C9                 | xor ecx,ecx                       |
000000014000103F  | FF15 53210000        | call qword ptr [<&SetLastError>]  |
0000000140001045  | FF15 55210000        | call qword ptr [<&GetProcessHeap> |
000000014000104B  | 48:8905 1E210000     | mov qword ptr [140003170],rax     |
0000000140001052  | CC                   | int3                              |
0000000140001053  | 48:8D0D C11F0000     | lea rcx,qword ptr [14000301B]     | 000000014000301B:"Wow, it works!!!!"
000000014000105A  | E8 A1FFFFFF          | call 140001000                    | own proc: no symbols!
000000014000105F  | 33C9                 | xor ecx,ecx                       |
0000000140001061  | FF15 41210000        | call qword ptr [<&RtlExitUserProc |
0000000140001067  | 48:8D0D BF1F0000     | lea rcx,qword ptr [14000302D]     | 000000014000302D:"user32"
000000014000106E  | 48:8D15 0B210000     | lea rdx,qword ptr [140003180]     | 0000000140003180:&"MZ"
0000000140001075  | E8 21000000          | call 14000109B                    | own proc: no symbols!
000000014000107A  | C3                   | ret                               |

Question: is that a "feature" of X64Dbg only, do other debuggers behave the same, is there any option that I may have overlooked?

I found a workaround, see attached executables (both have an int 3), but it would be easier to just use an option... :cool:

Hi jj2007,

and where is your pdb file? In the past, the pdb was only loaded when the filenames were the same. But my pdb is loaded normally.

Biterider

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Re: Debugging symbols for own procedures
« Reply #2 on: April 03, 2021, 08:42:52 PM »
Hi
Maybe related, but I had issues using VS integrated debugger. The problem was and still is, that nested symbols were not resolved and an error message was displayed in the locals pane. I solved it using the linker from Visual Studio 14.0 that plays nicely with UASM. Even the latest versions of both SW are not fully compatible.

Biterider

jj2007

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Re: Debugging symbols for own procedures
« Reply #3 on: April 03, 2021, 09:30:08 PM »
Actually, it's an awful mess! I have four ml64 and 8 link** versions, plus UAsm, AsmC, polink (2 versions), but the only combination that creates a pdb file (without effect btw) is
Code: [Select]
Microsoft (R) Macro Assembler (x64) Version 14.10.24930.0
Microsoft (R) Incremental Linker Version 14.10.24930.0

Right now I am playing with various assembler (/Zi /Zd /Zf) and linker (/debug /cv) options, but I see nowhere the pdb and ilk files that I remember to have seen in the past :rolleyes:

Thanks, LiaoMi and Biterider. Do you actually see your own symbols?

Biterider

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Re: Debugging symbols for own procedures
« Reply #4 on: April 03, 2021, 09:41:54 PM »
Hi JJ
Yes, in the described combination.


Biterider

jj2007

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Re: Debugging symbols for own procedures
« Reply #5 on: April 03, 2021, 09:54:00 PM »
Wow, I got one working combi :thumbsup:
Code: [Select]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\msobj140.dll
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\link.exe
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\lib.exe
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\x86_amd64\ml64.exe
BAD: C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\ml64.exe

Unfortunately, no luck with UAsm64 and AsmC (\Masm32\bin\AsmC.exe /c /Zp8 /Zi /Zd /Zf /Zne /win64 \Masm32\MasmBasic\Res\Short.asm):
Code: [Select]
Microsoft (R) Incremental Linker Version 14.00.24215.1
Copyright (C) Microsoft Corporation.  All rights reserved.

   Creating library Short.lib and object Short.exp
Short.obj : fatal error LNK1318: Unexpected PDB error; OK (0) ''

LiaoMi

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Re: Debugging symbols for own procedures
« Reply #6 on: April 04, 2021, 01:33:38 AM »
Many changes have been made since version 14.00  :biggrin:

Quote
Microsoft (R) Incremental Linker Version 14.00.24215.1
Copyright (C) Microsoft Corporation.  All rights reserved.

   Creating library Short.lib and object Short.exp
Short.obj : fatal error LNK1318: Unexpected PDB error; OK (0) ''

=> https://developercommunity.visualstudio.com/t/fatal-error-lnk1318-unexpected-pdb-error-ok-0/225957

I did a test on the following versions:
12.0.21005.1
14.0.24210.0
14.28.29337.0 <- My main version

I made tests with my sample, the results were the same everywhere except in one case, UASM and ASMC releases do not show local labels in the debugger, the main function is visible as 0000000140001000 <mainmasm_20210403_161702.$$000000>, ml64 - 0000000140001000 <mainmasm_20210403_161611.mainCRTStartup> and all local labels are visible - 0000000140001060         | 74 00        | JE      <mainmasm_20210403_161611._ERROR>.

UASM
Code: [Select]
mainMasm

 Timestamp is 6068789f (Sat Apr 03 16:15:59 2021)

 Preferred load address is 0000000140000000

 Start         Length     Name                   Class
 0001:00000000 000000baH .text                   CODE
 0002:00000000 00000040H .rdata                  DATA
 0002:00000040 00000000H .edata                  DATA
 0002:00000040 00000074H .rdata$debug            DATA
 0003:00000000 0000006cH .data                   DATA
 0003:00000070 00000008H .bss                    DATA

  Address         Publics by Value              Rva+Base               Lib:Object

 0000:00000000       ___safe_se_handler_table   0000000000000000     <absolute>
 0000:00000000       ___safe_se_handler_count   0000000000000000     <absolute>
 0000:00000000       __guard_fids_count         0000000000000000     <absolute>
 0000:00000000       __guard_flags              0000000000000000     <absolute>
 0000:00000000       __guard_fids_table         0000000000000000     <absolute>
 0001:00000000       mainCRTStartup             0000000140001000 f   mainMasm.obj
 0001:00000000       $$000000                   0000000140001000     mainMasm.obj
 0001:00000076       ProcTestingName            0000000140001076 f   mainMasm.obj
 0003:00000000       threadMsg                  0000000140003000     mainMasm.obj
 0003:00000007       rtlMsg                     0000000140003007     mainMasm.obj
 0003:0000001c       rtlMsg2                    000000014000301c     mainMasm.obj
 0003:00000038       errMsg                     0000000140003038     mainMasm.obj
 0003:0000003e       Val1                       000000014000303e     mainMasm.obj
 0003:00000040       Val2                       0000000140003040     mainMasm.obj
 0003:00000044       COA                        0000000140003044     mainMasm.obj
 0003:00000064       ValX                       0000000140003064     mainMasm.obj
 0003:00000070       gData                      0000000140003070     mainMasm.obj

 entry point at        0001:00000000

 Static symbols

ASMC
Code: [Select]
mainMasm

 Timestamp is 606878de (Sat Apr 03 16:17:02 2021)

 Preferred load address is 0000000140000000

 Start         Length     Name                   Class
 0001:00000000 000000baH .text                   CODE
 0002:00000000 00000040H .rdata                  DATA
 0002:00000040 00000000H .edata                  DATA
 0002:00000040 00000074H .rdata$debug            DATA
 0003:00000000 0000006cH .data                   DATA
 0003:00000070 00000008H .bss                    DATA

  Address         Publics by Value              Rva+Base               Lib:Object

 0000:00000000       ___safe_se_handler_table   0000000000000000     <absolute>
 0000:00000000       ___safe_se_handler_count   0000000000000000     <absolute>
 0000:00000000       __guard_fids_count         0000000000000000     <absolute>
 0000:00000000       __guard_flags              0000000000000000     <absolute>
 0000:00000000       __guard_fids_table         0000000000000000     <absolute>
 0001:00000000       mainCRTStartup             0000000140001000 f   mainMasm.obj
 0001:00000000       $$000000                   0000000140001000     mainMasm.obj
 0001:00000076       ProcTestingName            0000000140001076 f   mainMasm.obj
 0003:00000000       threadMsg                  0000000140003000     mainMasm.obj
 0003:00000007       rtlMsg                     0000000140003007     mainMasm.obj
 0003:0000001c       rtlMsg2                    000000014000301c     mainMasm.obj
 0003:00000038       errMsg                     0000000140003038     mainMasm.obj
 0003:0000003e       Val1                       000000014000303e     mainMasm.obj
 0003:00000040       Val2                       0000000140003040     mainMasm.obj
 0003:00000044       COA                        0000000140003044     mainMasm.obj
 0003:00000064       ValX                       0000000140003064     mainMasm.obj
 0003:00000070       gData                      0000000140003070     mainMasm.obj

 entry point at        0001:00000000

 Static symbols

ML64
Code: [Select]
Start         Length     Name                   Class
 0001:00000000 000000baH .text$mn                CODE
 0002:00000000 00000040H .rdata                  DATA
 0002:00000040 00000000H .edata                  DATA
 0002:00000040 00000074H .rdata$debug            DATA
 0003:00000000 0000006cH .data                   DATA
 0003:00000070 00000008H .bss                    DATA

  Address         Publics by Value              Rva+Base               Lib:Object

 0000:00000000       __guard_flags              0000000000000000     <absolute>
 0000:00000000       __guard_fids_table         0000000000000000     <absolute>
 0000:00000000       __guard_fids_count         0000000000000000     <absolute>
 0000:00000000       ___safe_se_handler_count   0000000000000000     <absolute>
 0000:00000000       ___safe_se_handler_table   0000000000000000     <absolute>
 0001:00000000       mainCRTStartup             0000000140001000 f   mainMasm.obj
 0001:00000076       ProcTestingName            0000000140001076 f   mainMasm.obj

 entry point at        0001:00000000

 Static symbols

 0001:00000000       $$000000                   0000000140001000     mainMasm.obj
 0003:00000000       threadMsg                  0000000140003000     mainMasm.obj
 0003:00000007       rtlMsg                     0000000140003007     mainMasm.obj
 0003:0000001c       rtlMsg2                    000000014000301c     mainMasm.obj
 0003:00000038       errMsg                     0000000140003038     mainMasm.obj
 0003:0000003e       Val1                       000000014000303e     mainMasm.obj
 0003:00000040       Val2                       0000000140003040     mainMasm.obj
 0003:00000044       COA                        0000000140003044     mainMasm.obj
 0003:00000064       ValX                       0000000140003064     mainMasm.obj
 0003:00000070       gData                      0000000140003070     mainMasm.obj

Probably this is a problem of the debugger itself  :icon_idea:
« Last Edit: April 08, 2021, 08:48:41 PM by LiaoMi »