Re: [PATCH] dump_stack() based on prologue code analysis

[David Daney <ddaney@avtrex.com>]

Thiemo Seufer wrote:
> David Daney wrote:
> 
>>Atsushi Nemoto wrote:
>>
>>>Instead of dump all possible address in the stack, unwind the stack
>>>frame based on prologue code analysis, as like as get_chan() does.
>>>While the code analysis might fail for some reason, there is a new
>>>kernel option "raw_show_trace" to disable this feature.
>>>
>>>Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
>>
>>Let me start by saying I have not analyzed how all this code works, but 
>>I have done something similar in user space.
>>
>>Since the kernel ABI does not use gp, many functions may not have a 
>>prolog (especially when compiled with newer versions of GCC).  In the 
>>user space case, most leaf functions have no prolog.  For the kernel I 
>>would imagine that many non-leaf functions (simple non-leaf functions 
>>that do only a tail call) would also not have a prolog.
> 
> 
> Non-leaves have to save/restore $31 somewhere, so there should be a
> prologue.

OK, good point.

But there is still the leaf function problem.

David Daney.