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Re: kprobes problem

From: Prasanna S Panchamukhi <prasanna at in dot ibm dot com>
To: William Cohen <wcohen at redhat dot com>
Cc: richardj_moore at uk dot ibm dot com, systemtap at sources dot redhat dot com
Date: Tue, 15 Mar 2005 20:37:19 +0530
Subject: Re: kprobes problem
References: <OF7F0DF479.BA7ED37B-ON00256FC4.005D204A-00256FC4.005D5CEB@uk.ibm.com> <4235C51B.8060302@redhat.com>
Reply-to: prasanna at in dot ibm dot com

Hi Will,

> >I was certainly intended to. As I mentioned before there is specific code
> >to deal with call, jmp etc. Probing INT should be OK, though I don't think
> >a probe on INT3 works. Need to check.
> 
> I figured that INT3 wouldn't be probed. However, there are certainly 
> some other INT instructions in the code. I saw them (and the IRET) in 
> the disassembled code. I was just figuring if we are fixing up the RET 
> that we take a moment and make sure there are no other omissions.
> 

IRET/ IRETD instructions are taken care. Probing INT n should be ok, but probe on 
int3 instruction is not handled properly. kprobe_handler() should return appropriate 
value based on the current kprobes status. I will send out a patch soon. Also there is
 one bug reported by Stas on LKML about int 3(int n type) instruction. Patch can be 
found at the URL.

	http://lkml.org/lkml/2004/12/9/43

Thanks
Prasanna

-- 

Prasanna S Panchamukhi
Linux Technology Center
India Software Labs, IBM Bangalore
Ph: 91-80-25044636
<prasanna@in.ibm.com>

References:
- Re: kprobes problem
  - From: Richard J Moore
- Re: kprobes problem
  - From: William Cohen

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