Re: No line number info debugging kernel modules with gdb 6.6.90.20070926-cvs (gdb 6.7 branch)

Jon Ringle
2007-09-29T02:27:19Z

Daniel Jacobowitz wrote:
> On Fri, Sep 28, 2007 at 09:28:34PM -0400, Jon Ringle wrote:
>
>> So, do I need to put all the sections that I find in
>> /sys/module/dstdrv/sections/.[a-z]* on the target
>>
>
> Probably.
>
>
I created the following helper script on the target:
[root@isc1 ~]# cat /usr/local/bin/add-symbol-file
#! /bin/bash

MODULE=$1
for f in $(ls -1 /sys/module/${MODULE}/sections/.[a-z]*|grep -E -v
'/.text$');
do
echo -n "-s $(basename $f) $(cat $f) ";
done
echo
[root@isc1 ~]# add-symbol-file dstdrv
-s .bss 0xbf137180 -s .data 0xbf136f30 -s .exit.text 0xbf134638 -s
.gnu.linkonce.this_module 0xbf137040 -s .init.text 0xbf13b000 -s .rodata
0xbf1346c0 -s .rodata.str1.8 0xbf1348f0 -s .strtab 0xbf136800 -s .symtab
0xbf135940

Then I defined the following gdb command:
ringlej@crossdev:~/WAVE/Build7/Platform/Volcano/os/kernel/linux$ cat
.gdbinit
define load_kernel_module
shell echo -n "add-symbol-file $arg1 " > .load_kernel_module.tmp
shell echo -n "$(ssh $arg0 cat /sys/module/$(basename $arg1
.ko)/sections/.text) " >> .load_kernel_module.tmp
shell echo "$(ssh $arg0 /usr/local/bin/add-symbol-file $(basename $arg1
.ko))" >> .load_kernel_module.tmp
shell echo "directory $(dirname $arg1)" >> .load_kernel_module.tmp
source .load_kernel_module.tmp
shell rm .load_kernel_module.tmp
end

ringlej@crossdev:~/WAVE/Build7/Platform/Volcano/os/kernel/linux$
~/build/armeb-linux-gdb-6.7/gdb/gdb vmlinux
GNU gdb 6.6.90.20070926-cvs
Copyright (C) 2007 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=i686-pc-linux-gnu
--target=armeb-linux"...
(gdb) target remote bdilab:2001
Remote debugging using bdilab:2001
default_idle () at include/asm/thread_info.h:92
92 register unsigned long sp asm ("sp");
(gdb) load_kernel_module root@ixp.ringle.lan
../../kernel-modules/dst/dstdrv.ko
add symbol table from file "../../kernel-modules/dst/dstdrv.ko" at
.text_addr = 0xbf131000
.bss_addr = 0xbf137180
.data_addr = 0xbf136f30
.exit.text_addr = 0xbf134638
.gnu.linkonce.this_module_addr = 0xbf137040
.init.text_addr = 0xbf13b000
.rodata_addr = 0xbf1346c0
.rodata.str1.8_addr = 0xbf1348f0
.strtab_addr = 0xbf136800
.symtab_addr = 0xbf135940
warning: section .strtab not found in
/home/ringlej/WAVE/Build7/Platform/Volcano/os/kernel-modules/dst/dstdrv.ko
warning: section .symtab not found in
/home/ringlej/WAVE/Build7/Platform/Volcano/os/kernel-modules/dst/dstdrv.ko
(gdb) show directories
Source directories searched:
/home/ringlej/WAVE/Build7/Platform/Volcano/os/kernel/linux-2.6.16.29/../../kernel-modules/dst:$cdir:$cwd
(gdb) b vert_dst_nopage_mmap
Breakpoint 1 at 0xbf13427c
(gdb) list vert_dst_nopage_mmap
No line number known for vert_dst_nopage_mmap.