Debugging symbols on kernel module

[Andriy Voskoboinyk]

Hi,

for debugging purposes I'm adding next line in make.conf:

CFLAGS+=	-O0 -g

Works for modules but not for the kernel
(KSTACK_PAGES needs to be increased for the whole kernel build).

> Hi all,
>
> I am working on a kernel module but am getting some unexpected code  
> execution. Dtrace probes reveal that the kernel executes:  
> "rtwn.ko`r88ee_init_bb+0x219" and then jumps to an unexpected function.
>
> I would like to track down exactly which line that is. I compiled the  
> module with this:
>
> # make DEBUG_FLAGS=-g3 -C sys/modules/rtwn/
>
> This produced the rtwn.ko.debug and rtwn.ko.full files. But when I load  
> them, I still do not have debugging symbols:
>
> $ kgdb rtwn.ko
> GNU gdb (GDB) 8.0 [GDB v8.0 for FreeBSD]
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> Reading symbols from rtwn.ko...Reading symbols from  
> /usr/src/sys/modules/rtwn/rtwn.ko.debug...(no debugging symbols  
> found)...done.
> (no debugging symbols found)...done.
> (kgdb) file rtwn.ko.debug
> Reading symbols from rtwn.ko.debug...(no debugging symbols found)...done.
> (kgdb) file rtwn.ko.full
> Reading symbols from rtwn.ko.full...(no debugging symbols found)...done.
>
> How do I properly load debugging symbols for the module?
>
> Thanks,
>
> Farhan Khan
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