Fwd: Bug 4289: Debugging and dissasembly

[James Trotter]

---------- Forwarded message ----------
From: James Trotter 
Date: Jan 14, 2006 3:22 PM
Subject: Re: Bug 4289: Debugging and dissasembly
To: Eric Pouech

On 1/14/06, Eric Pouech  wrote:
> James Trotter wrote:
> > Hi!
> >
> > A few days ago I filed this bug:
>
> http://bugs.winehq.org/show_bug.cgi?id=4289
> > Alexandre commented that there most likely was some stack corruption,
> > and that I should try and disassemble a few instructions before the
> > crash and look for API calls.
> >
> > Now, I haven't used gdb or winedbg that much before, and I'm a bit
> > uncertain what to do. I understand that using the disassemble
> > [<addr>][,<addr>] command, the debugger will disassemble that address
> > space. Given the stack trace as in the bug report, which addresses,
> > exactly, should I disassemble?
>
> before 0x007ab8f1
> A+
>
> --
> Eric Pouech

Sure, but how much before 0x007ab8f1?

For instance, Is this helpful?

WineDbg starting on pid 0xa
In 32 bit mode.
0x7fcfba16 start_process+0xb6
[/home/james/development/wine/regression_testing/2005-07-18/wine/dlls/kernel/process.c:996]
in kernel32: pushl    %edi
996             ExitProcess( entry( peb ) );
Wine-dbg>cont
First chance exception: page fault on read access to 0x20202020 in 32-bit
code (0x007ab8f1).
Register dump:
 CS:0073 SS:007b DS:007b ES:007b FS:1007 GS:0033
 EIP:007ab8f1 ESP:7facaba4 EBP:00000000 EFLAGS:00210246(   - 00      -RIZP1)
 EAX:20202020 EBX:00000001 ECX:7facb450 EDX:00000000
 ESI:7facb328 EDI:7beb4460
Stack dump:
0x7facaba4:  20202020 00002711 00000000 7facb328
0x7facabb4:  7facabe0 007aaf30 7facb218 7facaf60
0x7facabc4:  00000000 00002711 40c38800 7facb328
0x7facabd4:  7facac90 0084566a 00000007 7fd0e900
0x7facabe4:  0078e3ca 00000000 7facaf60 00400000
0x7facabf4:  7fd39206 7facaf60 00000000 7fd39206
0200: sel=1007 base=b7f81000 limit=00001f97 32-bit rw-
Backtrace:
=>1 0x007ab8f1 in iwd2 (+0x3ab8f1) (0x00000000)
0x007ab8f1: movl        0x0(%eax),%ecx
Wine-dbg>disassemble 0x007ab800, 0x007ab8f1
0x007ab800: addb        %bh,0x0(%ebx)
0x007ab802: int $0x74
0x007ab804: pop %ss
0x007ab805: cmpl        %ebx,0x390(%ecx)
0x007ab80b: jz  0x007ab81c
0x007ab80d: addl        $0x394,%ecx
0x007ab813: pushl       %ecx
0x007ab814: call        *%edi
0x007ab816: movl        0x008cf6d8,%ecx
0x007ab81c: movl        0x13c(%esi),%eax
0x007ab822: cmpl        %ebp,%eax
0x007ab824: jz  0x007ab838
0x007ab826: movl        0x0(%eax),%ecx
0x007ab828: pushl       %eax
0x007ab829: call        *0x8(%ecx)
0x007ab82c: movl        %ebp,0x13c(%esi)
0x007ab832: movl        0x008cf6d8,%ecx
0x007ab838: cmpl        %ebp,%ecx
0x007ab83a: jz  0x007ab84d
0x007ab83c: cmpl        %ebx,0x390(%ecx)
0x007ab842: jz  0x007ab84d
0x007ab844: addl        $0x394,%ecx
0x007ab84a: pushl       %ecx
0x007ab84b: call        *%edi
0x007ab84d: leal        0x128(%esi),%ecx
0x007ab853: call        0x007c22d0
0x007ab858: movl        %ebp,0x140(%esi)
0x007ab85e: movl        0x008cf6d8,%eax
0x007ab863: cmpl        %ebp,%eax
0x007ab865: jz  0x007ab87b
0x007ab867: cmpl        %ebx,0x390(%eax)
0x007ab86d: jz  0x007ab87b
0x007ab86f: addl        $916,%eax
0x007ab874: pushl       %eax
0x007ab875: call        *0x8472c8 -> 0x7beb4180 RtlLeaveCriticalSection
[/home/james/development/wine/regression_testing/2005-07-18/wine/dlls/ntdll/critsection.c:407]
in ntdll
0x007ab87b: cmpl        %ebp,0x90(%esi)
0x007ab881: jz  0x007ab8a4
0x007ab883: leal        0x84(%esi),%edi
0x007ab889: movl        %edi,%ecx
0x007ab88b: call        0x007fbe77
0x007ab890: cmpl        %ebp,%eax
0x007ab892: jz  0x007ab89c
0x007ab894: movl        0x0(%eax),%edx
0x007ab896: pushl       %ebx
0x007ab897: movl        %eax,%ecx
0x007ab899: call        *0x4(%edx)
0x007ab89c: cmpl        %ebp,0x90(%esi)
0x007ab8a2: jnz 0x007ab889
0x007ab8a4: cmpl        %ebp,0xac(%esi)
0x007ab8aa: jz  0x007ab8d8
0x007ab8ac: leal        0xa0(%esi),%ebx
0x007ab8b2: movl        %ebx,%ecx
0x007ab8b4: call        0x007fbe77
0x007ab8b9: movl        %eax,%edi
0x007ab8bb: movl        0x58(%edi),%eax
0x007ab8be: cmpl        %ebp,%eax
0x007ab8c0: jz  0x007ab8cb
0x007ab8c2: movl        0x0(%eax),%ecx
0x007ab8c4: pushl       %eax
0x007ab8c5: call        *0x8(%ecx)
0x007ab8c8: movl        %ebp,0x58(%edi)
0x007ab8cb: cmpl        %ebp,0xac(%esi)
0x007ab8d1: jnz 0x007ab8b2
0x007ab8d3: movl        $0x1,%ebx
0x007ab8d8: cmpl        %ebp,0x4(%esi)
0x007ab8db: jz  0x007ab8f9
0x007ab8dd: movl        0x8(%esi),%eax
0x007ab8e0: cmpl        %ebp,%eax
0x007ab8e2: jz  0x007ab8ed
0x007ab8e4: movl        0x0(%eax),%edx
0x007ab8e6: pushl       %eax
0x007ab8e7: call        *0x8(%edx)
0x007ab8ea: movl        %ebp,0x8(%esi)
0x007ab8ed: movl        0x4(%esi),%eax
0x007ab8f0: pushl       %eax
0x007ab8f1: movl        0x0(%eax),%ecx
Wine-dbg>

Thanks,
James