Re: debugging a dynamically loaded library

Mike Krogh
2001-09-18T14:11:00Z

Kevin,

Can you tell me if any more progress has been made with this problem?
Do you have any ETA on when a resolution might be available? Since
your email address is at 'cygnus.com', I'm assuming that you might be
one of the maintainers of gdb. If not, any suggestions on who I might
contact would be appreciated!

Anything I might be able to do?

Thanks!

Mike

> On Aug 29, 4:07pm, H . J . Lu wrote:
>> > (gdb) b main.c:23
>> > Breakpoint 1 at 0x80487fc: file main.c, line 23.
>> > (gdb) r
>> > Starting program: /home/kev/ctests/dynlib/main
>> >
>> > Breakpoint 1, main (argc=1, argv=0xbffffa2c) at main.c:23
>> > 23 init = dlsym(handle, "dso_init");
>> > (gdb) b dso_init
>> > Breakpoint 2 at 0x400188a2: file dso.c, line 10.
>>
>> For some reason, it doesn't work for me:
>>
>> GNU gdb 2001-08-29-cvs (MI_OUT)
>> ....
>> (gdb) b main.c:23
>> Breakpoint 1 at 0x8048820: file main.c, line 23.
>> (gdb) r
>> Starting program: /home/hjl/bugs/gdb/dlopen/main
>>
>> Breakpoint 1, main (argc=1, argv=0xbffff804) at main.c:23
>> 23 init = dlsym(handle, "dso_init");
>> (gdb) b dso_init
>> Cannot access memory at address 0x123
>> (gdb) p dso_init
>> $1 = {<text variable, no debug info>} 0x40017800 <dso_init>
>> (gdb) info shared
>> >From To Syms Read Shared Object Library
>> 0x400281d0 0x40028fc0 Yes /lib/libdl.so.2
>> 0x40047400 0x40147080 Yes /lib/i686/libc.so.6
>> 0x40001eb0 0x40012f20 Yes /lib/ld-linux.so.2
>> 0x400176d0 0x400178b0 Yes ./dso.so
>>
>> I am using glibc 2.2.4 on x86. It seems that gdb doesn't add the base
>> address of ./dso.so.

> H. J.,

> Could you try

> http://sources.redhat.com/ml/gdb-patches/2001-09/msg00003.html

> and let me know if it fixes the above problem?

> Thanks,

> Kevin

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