Re: GDB 6.0 Branch and ARM Multithreading Support

[Chris.Pedley@arm.com]

On 01/09/2003 17:25:01 gdb-owner wrote:
>On Mon, Sep 01, 2003 at 11:31:36AM +0100, Chris.Pedley@arm.com wrote:
>> Hi,
>>
>> I've cross compiled the GDB 6.0 branch for ARM Linux (host=arm-linux
>> target=arm-linux build=i686-linux) and can't get it to debug a
>> multithreaded program.  Attempting to debug a program that creates a
thread
>> results in:
>>
>> Program received signal SIG32, Real-time event 32.
>> 0x0000f2c0 in __sigsuspend (set=0xbffffc9c)
>> ...
>>
>> I've linked the program statically against unstripped libraries as I am
>> aware that people have had trouble debugging multithreaded applications
>> using a stripped pthread library.
>>
>> Any suggestions as to what is wrong?
>
>Does it display any messages about loading libthread_db?  Does it
>successfully map the library?

I don't get any messages about loading libthread_db, the only worrying
message is GDB starts up with:
"Symbol `PC' has different size in shared object, consider re-linking"

The test application presumably doesn't need to map libthread_db because
its linked statically?  cat /proc/<gdb pid>/maps includes:
0212000-40216000 r-xp 00000000 1f:02 8751864
/usr/lib/libthread_db-1.0.so
40216000-4021a000 ---p 00004000 1f:02 8751864
/usr/lib/libthread_db-1.0.so
4021a000-4021f000 rw-p 00000000 1f:02 8751864
/usr/lib/libthread_db-1.0.so

(By the way - call getpid() in gdb resulted in "Program received signal
SIGSEGV, Segmentation fault.")

>I tested native thread debugging on ARM recently (~ week ago) and it
>worked.  If you are using glibc 2.3.2 you will need the patch I sent to
>this list and libc-alpha a week or two ago.

The library I'm building against, and in my ARM Linux filesystem are both
glibc 2.3.  Does this need patching?

Thanks,
Chris

--
Chris Pedley,  Graduate Engineer
Intellectual Property Solutions Division
ARM Ltd, 110 Fulbourn Rd, Cambridge CB1 9NJ UK
Tel : +44 1223 400847     Fax: +44 1223 400410