Hitachi djprobe mechanism

[Masami Hiramatsu]

Hi, Roland

Roland McGrath wrote:
>>  I think Kerninst is similar in effect to djprobe. both of them copy
>>original code to a buffer and jump to the buffer.
>>  However I think that the most unique feature of djprobe is use of
>>"bypass" route to safely insert code on SMP.
>>  I cannot find SMP safety mechanism like "bypass" in kerninst papers
>>yet.
> 
> 
> If by this you mean inserting an int3 while writing the rest of the jmp
> instruction and then overwriting the first byte when the rest is in place,
> I recall reading about that in some kerninst paper to be sure.

Thanks a lot.
Finally, I found it in page.9 of the OSDI paper:
"Fine-Grained Dynamic Instrumentation of Commodity Operating System Kernels",
Ariel Tamches and Barton P. Miller, OSDI, Feb 1999.

Actually, it seems to describe a similar thing.

-- 
Masami HIRAMATSU
2nd Research Dept.
Hitachi, Ltd., Systems Development Laboratory
E-mail: hiramatu@sdl.hitachi.co.jp