i think everytime you load it and unload it you may get different addresses
so you want a few more things in the [Host](gdb) section before loading a module these stepd should allow you to debug a module_init routine 1) from http://kgdb.linsyssoft.com/downloads/miscmacros we get an idea how to address modules from within gdb #Miscellaneous macros define lsmod set $mod = (struct module*)module_list # the last module is the kernel, ignore it while $mod != &kernel_module printf "%p\t%s\n", (long)$mod, ($mod)->name set $mod = $mod->next end end 2) you need a break point in module.c (sys_init_module) where we have the mod pointer in hand and are about to call init. like here in 2.4.26 /* Initialize the module. */ atomic_set(&mod->uc.usecount,1); mod->flags |= MOD_INITIALIZING; if (mod->init && (error = mod->init()) != 0) { 3) so when you set this break point you want to do something like this: (gdb)break module.c:553 # note the breakpoint number xx (gdb)commands xx printf "add-symbol-file %s\t%p\n", ($mod)->name, (long)$mod + $mod->size_of_struct end Note the extra size_of_struct to point to the correct area. Cut-and-Paste the resulting line into your gdb window. Assuming the path to your module is in the gdb session 'dir' path (if not you can point it to using a path to the .o) your symbols should load and you should be able to step into mod->init() with code you can read. db Mikado wrote: > > - How can I debug loadable modules at run time? > > Here is my way: > > ( /tmp/mymodule.ko exists on both [Host] and [UML] ) > + [Host] # gdb linux > + [Host] (gdb) ... > + [Host] (gdb) r <params> > + [UML] # insmod /tmp/mymodule.ko > + [UML] # cat /sys/module/mymodule/sections/{.text,.bss,.data} > + [Host] (gdb) add-symbol-file /tmp/mymodule.ko <.text_addr> -s .bss > <.bss_addr> -s .data <.data_addr> > + ... > > Tell me if I was wrong, thanks! > > - How can I set breakpoint at module's init function? > > After add module's symbol, I set breakpoint at init function then > 'rmmod' then re-'insmod' but gdb didn't break at init function. What was > wrong? > > - Sometimes gdb can't follow source codes in '.h' header files. Did I > miss something? > > Thanks in advance, > Mikado.
signature.asc
Description: OpenPGP digital signature
