module function probe

[Zhang, Yanmin]

The module reference count is not correct. The module ref count should be increased with 1 when a kprobe is registered at the module exec text, and vice versa.

Yanmin

>>-----Original Message-----
>>From: Mao, Bibo
>>Sent: 2005年11月25日 13:50
>>To: systemtap@sources.redhat.com
>>Cc: 'Frank Ch. Eigler'; Keshavamurthy, Anil S; Zhang, Yanmin
>>Subject: module function probe
>>
>>Hi,
>>	I wrote one module named probed.ko after compiled, and the other is kprobe
>>module named probing.ko which is to probe some function defined in probed.ko
>>module.
>>	And then I executed the follow command so that some function can be probed.
>>		#insmod probed.ko
>>		#insmod probing.ko
>>But when I undelete module in such order kernel will crash
>>		#rmmod probed.ko		(system is ok)
>>		#rmmod probing.ko		(system will crash)
>>The reason is that when unregister kprobe it will restore original instruction,
>>but when probed module exits, its instruction address space is freed, so when
>>restore original instruction it will crash.
>>
>>Regards
>>Bibo,mao