On Mon, Apr 22, 2013 at 6:00 AM, arshad hussain <arshad.super@gmail.com> wrote:

On Mon, Apr 22, 2013 at 5:58 AM, arshad hussain <arshad.super@gmail.com> wrote:

...

On Fri, Apr 19, 2013 at 11:55 PM, Sankar P <sankar.curiosity@gmail.com> wrote:

...

Hi,

I have written a kernel module which I build using:

Makefile (edited a bit) ========== obj-m := simple.o simple-objs := s.o

make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

=======

Everything builds fine. But my kernel module caused an oops and the message was something like:

myfunctionname +0x2507 +5679

or some hexadecimal gibberish. I know that I can use some external tool to find out what these addresses mean. But, is there a way I can get the kernel oops message to print these information along with line number ?

Is there a way to build the kernel module with debug symbols ? In user space, I usually do "-g" or "-ggdb" and it will give me line numbers and filenames neatly while dumping stacktrace. Is there a similar facility available for out of tree kernel modules too ?

Even if I give :

$ CFLAGS="-ggdb" make

The output file size (.ko) is not changed.

Can someone help me with building kernel modules with debug info and get the filename and line numbers printed in the oops messages / coredump ?

Thanks.

-- Sankar P http://psankar.blogspot.com

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"myfunctionname +0x2507 +5679"

It's not hex gibberish. What it saying is that, at the time of crash the EIP was pointing withing function "myfunctionname" and offset 0x2507 bytes. Use objdump binary to more detail of your simple.ko

Thanks. But is there not a way to get the line numbers and filenames printed automatically instead of the memory addresses ? For example, in gdb, in userspace, if there is a crash, we can get the line numbers printed when there is a crash. Can the kernel crash/oops handler similarly not print the filenames and linenumbers automatically ? Is there a configuration or hack for getting it that way ? -- Sankar P http://psankar.blogspot.com -- Sankar P http://psankar.blogspot.com