Re: Remote Debugging

[Fernando Nasser <fnasser@cygnus.com>]

Yu Xuanwei wrote:
> 
> Hi, Folks:
> 
> I am a rookie. I want to know something about remote debugging:
> 
> 1. On target: The gdbserver manipulates target application, which is
> stripped.
> 
> 2. On host: GDB run "target remote ..." to customize the target.
> 
> Then where is the symbol file for target application? Should I native
> compile the target application on host? Or ...?
> 

Nope.  You cross compile your executable with "-g".  Create a stripped copy 
(not necessary if you don't care about file sizes in the target) and copy
the stripped version to the target.  Load it with gdbserver.

On the host side:  gdb <your-complete-executable-with-debug-info>
and proceed as you mentioned.

But please, before you try to go any further, print a copy of the 
"Debugging with GDB" manual.  It is in the doc directory (you can make it in
various flavors - ps among them).  It is also available as an info topic 
if GDB is correctly installed on your system.

 

-- 
Fernando Nasser
Red Hat - Toronto                       E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9
From Denset.Serralta@radisys.com Fri Dec 01 11:55:00 2000
From: Denset.Serralta@radisys.com
To: Jim Blandy <jimb@zwingli.cygnus.com>
Cc: gdb@sources.redhat.com
Subject: Re: GDB does not step into or over "sleep" function
Date: Fri, 01 Dec 2000 11:55:00 -0000
Message-id: <OF9A6588DE.02D8BDD2-ON852569A8.006B6937@radisys.com>
X-SW-Source: 2000-12/msg00004.html
Content-length: 3359

                                                                                                                        
                    Jim Blandy                                                                                          
                    <jimb@zwingli.cygn        To:     Denset.Serralta@radisys.com                                       
                    us.com>                   cc:     gdb@sources.redhat.com                                            
                    Sent by:                  Subject:     Re: GDB does not step into or over "sleep" function          
                    gdb-owner@sources.                                                                                  
                    redhat.com                                                                                          
                                                                                                                        
                                                                                                                        
                    11/28/00 08:07 PM                                                                                   
                                                                                                                        
                                                                                                                        






Jim Blandy wrote:
>Let me make sure I understand.  If you have code like this:
>
>    ... some code ...
>    ProcessSleep (...);
>    ... some more code ...
>
>and you set a breakpoint on the `some more code' line, your program
>hangs and never reaches the breakpoint.

>But if you run the program without GDB, it sleeps the expected amount
>of time, and then continues normally.


Thanks for responding

You are correct. The breakpoint in  "...some more code ..." is never
reached. We are suspecting
at the moment that it is a problem with the ProcessSleep function since the
hang occurrs when we
'step into' or 'step over' it. What we don't know is whether it is a
problem with our underlying kernel
functions or whether GDB has a problem with a "sleep" function which
allocates a semaphore,
blocks on it subject to a user specified timeout and then returns the
semaphore. We are leaning
to suspecting that it is a problem with our custom kernel (i.e. GDB is
innocent). However I thought
I would ask the GDB group, with all the combined experience developing GDB,
just in case they
saw something obvious.

Thanks again
Denset.Serralta@radisys.com


>Denset.Serralta@radisys.com writes:
>> We are using GDB 4.18 on an NT host to debug target software running on
a
>> PowerPC based adapter. We are using a function called ProcessSleep which
is
>> a call to our kernel.  It basically allocates a semaphore, blocks on it
>> subject to a user specified timeout and then returns the semaphore.One
>> problem we can't seem to get around though is that if the process being
>> debugged makes a 'ProcessSleep' call, the debugger never gains control
when
>> we step over it.  Even if we set a breakpoint past the call and let it
run,
>> it never returns.  A status utility that we have shows the process as
>> queued, but we never regain control.  Does anybody know any reason(s)
why
>> this should happen.