Dave Grothe wrote:
>
> Amit:
>
> There is a 2.4.0 version of kgdb on our ftp site:
> ftp://ftp.gcom.com/pub/linux/src/kgdb. I mirrored your version of gdb
> and loadmodule.sh there.
>
> Have a look at the README file and see if I go it right. If not, send
> me some corrections and I will update it.
>
> Does your version of gdb solve the global variable problem?
Yes.
Thanks to Elena Zanoni, gdb (developement version) can now calculate
correctly addresses of dynamically loaded object files. I have not been
following gdb developement for sometime and am not sure when symbol
address
calculation fix is going to appear in a gdb stable version.
Elena, any idea when the fix will make it to a prebuilt gdb from a
redhat
release?
For the time being I have built a gdb developement version. It can be
used
for module debugging with loadmodule.sh script.
The problem with calculating of module addresses with previous versions
of gdb was as follows:
gdb did not use base address of a section while calculating address of
a symbol in the section in an object file loaded via 'add-symbol-file'.
It used address of .text segment instead. Due to this addresses of
symbols
in .data, .bss etc. (e.g. global variables) were calculated incorrectly.
Above mentioned fix allow gdb to use base address of a segment while
calculating address of a symbol in it. It adds a parameter '-s' to
'add-symbol-file' command for specifying base address of a segment.
loadmodule.sh script works as follows.
1. Copy a module file to target machine.
2. Load the module on the target machine using insmod with -m parameter.
insmod produces a module load map which contains base addresses of all
sections in the module and addresses of symbols in the module file.
3. Find all sections and their base addresses in the module from
the module map.
4. Generate a script that loads the module file. The script uses
'add-symbol-file' and specifies address of text segment followed by
addresses of all segments in the module.
Here is an example gdb script produced by loadmodule.sh script.
add-symbol-file foo 0xd082c060 -s .text.lock 0xd08cbfb5
-s .fixup 0xd08cfbdf -s .rodata 0xd08cfde0 -s __ex_table 0xd08e3b38
-s .data 0xd08e3d00 -s .bss 0xd08ec8c0 -s __ksymtab 0xd08ee838
With this command gdb can calculate addresses of symbols in ANY segment
in a module file.
Regards.
-- Amit Kale Veritas Software ( http://www.veritas.com )- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Fri Jun 23 2000 - 21:00:26 EST