Re: [RFC][PATCH 0/3] ftrace: Add dynamically allocated trampolines

[Masami Hiramatsu]

(2014/07/11 6:44), Jiri Kosina wrote:
> On Thu, 10 Jul 2014, Josh Poimboeuf wrote:
> 
>> I did some testing with kpatch and I found one minor issue.  The dynamically
>> allocated trampoline seems to confuse dump_stack() somewhat.
>>
>> I added a dump_stack() call in my ftrace_ops callback function
>> (kpatch_ftrace_handler) which had a filter on meminfo_proc_show().
> 
> Interesting. Are you using dwarf2 unwinder for stack dumping by any 
> chance? It seems to get things right here. Will look into it more 
> tomorrow.

Hmm, can dwarf2 unwinder work on the trampoline method?
Since the trampoline just a copy of instructions which
will not have CFI(which is stored in dwarf section),
I guess it may not work...
Frame pointer (push bp and save sp to bp on the entry) can
work anyway.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/