How to debug an exception handler ?

[Laurent Pinchart]

Hi everybody,

I have a windows program which raises an exception as part of its normal 
execution (it tries to call int 0x01). The program setups an exception 
handler, catches the exception, and resumes it execution after the call to 
int 0x01. This works fine when run in wine.

However, when I try to run the program in winedbg, the debugger catches the 
exeception, interrupts the program execution, prints a register dump, stack 
dump & backtrace, and waits. If I continue the execution using 'cont' (after 
incrementing $eip by 2 to skip int 0x01), the program continues but the 
exception handler installed bu the user program is not called.

I was wondering if it was a bug or a normal behaviour, and if it is normal 
behaviour, is there a workaround ?

Thanks in advance for your help.

Laurent Pinchart

[Tony Lambregts]

Laurent Pinchart wrote:
> Hi everybody,
>
> I have a windows program which raises an exception as part of its normal 
> execution (it tries to call int 0x01). The program setups an exception 
> handler, catches the exception, and resumes it execution after the call to 
> int 0x01. This works fine when run in wine.
>
> However, when I try to run the program in winedbg, the debugger catches the 
> exeception, interrupts the program execution, prints a register dump, stack 
> dump & backtrace, and waits. If I continue the execution using 'cont' (after 
> incrementing $eip by 2 to skip int 0x01), the program continues but the 
> exception handler installed bu the user program is not called.
>
> I was wondering if it was a bug or a normal behaviour, and if it is normal 
> behaviour, is there a workaround ?
>
> Thanks in advance for your help.
>
> Laurent Pinchart

Keep in mind that I am NOT a wine guru but it looks like copy protection 
to me. My guess it you use trace relay the same thing will occure as 
when you use the debugger.

Tony Lambregts

[Laurent Pinchart]

> > I have a windows program which raises an exception as part of its normal
> > execution (it tries to call int 0x01). The program setups an exception
> > handler, catches the exception, and resumes it execution after the call to
> > int 0x01. This works fine when run in wine.
> >
> > However, when I try to run the program in winedbg, the debugger catches
> > the exeception, interrupts the program execution, prints a register dump,
> > stack dump & backtrace, and waits. If I continue the execution using
> > 'cont' (after incrementing $eip by 2 to skip int 0x01), the program
> > continues but the exception handler installed bu the user program is not
> > called.
> >
> > I was wondering if it was a bug or a normal behaviour, and if it is normal
> > behaviour, is there a workaround ?
>
> Keep in mind that I am NOT a wine guru but it looks like copy protection
> to me. My guess it you use trace relay the same thing will occure as
> when you use the debugger.

Thanks for your answer, but I want to use the debugger because I need to put 
a breakpoint at some point in the code and check some register values there.

Laurent Pinchart

PS: Yes, it's copy protection

[Francois Gouget]

On Sat, 6 Apr 2002, Laurent Pinchart wrote:
[...]
> I was wondering if it was a bug or a normal behaviour, and if it is normal
> behaviour, is there a workaround ?

Did you try pass?

See:
http://wine.codeweavers.com/docs/wine-devel/dbg-commands.shtml#AEN576

--
Francois Gouget         fgouget(a)free.fr        http://fgouget.free.fr/
                     Avoid the Gates of Hell - use Linux.

[Laurent Pinchart]

> > I was wondering if it was a bug or a normal behaviour, and if it is
> > normal behaviour, is there a workaround ?
>
> Did you try pass?
>
> See:
> http://wine.codeweavers.com/docs/wine-devel/dbg-commands.shtml#AEN576

I had missed it. Thanks a lot.

Laurent Pinchart

[Laurent Pinchart]

> [...]
> > I was wondering if it was a bug or a normal behaviour, and if it is
> > normal behaviour, is there a workaround ?
>
> Did you try pass?

Sorry, spoke too fast :-(

I get this when I try pass.

Wine-dbg>pass
Invalid address for breakpoint 1, disabling it
Invalid address for breakpoint 2, disabling it
Invalid address for breakpoint 3, disabling it
Invalid address for breakpoint 4, disabling it
Process of pid=08071a50 has terminated

The process shouldn't terminate so fast.

Laurent Pinchart

[Eric Pouech]

> I get this when I try pass.
>
> Wine-dbg>pass
> Invalid address for breakpoint 1, disabling it
> Invalid address for breakpoint 2, disabling it
> Invalid address for breakpoint 3, disabling it
> Invalid address for breakpoint 4, disabling it
> Process of pid=08071a50 has terminated
>
> The process shouldn't terminate so fast.

this should be fixed in latest CVS.
A+