Re: [PATCH v2] gdb/arm: Terminate frame unwinding in M-profile lockup state

[Tomas Vanek <vanekt@fbl.cz>]

Hi Luis,

On 17/10/2022 13:06, Luis Machado wrote:
>
>> With the change:
>> ----------------
>>    (gdb) c
>>    Continuing.
>>
>>    Program received signal SIGINT, Interrupt.
>>    warning: ARM M in lockup state, stack unwinding terminated.
>>    <signal handler called>
>>    (gdb) bt
>>    #0  <signal handler called>
>>    (gdb)
>> ----------------
>>
>> There is a visible drawback of emitting a warning in a cache buildnig 
>> routine
>> as introduced in Torbjörn SVENSSON's
>
> True. We might need to move it somewhere else. Though it is not 
> something we will have to repeat over and over.

Just an idea: What about a text message (describing something odd during 
unwind)
which an unwinder can associate with the frame and  gets printed later 
by 'backtrace' command?
It may also replace not too informative <signal handler called> for 
SIGTRAMP_FRAMEs.

Anyway the message about the CPU in lockup is useful even just after 
stopping the running target.

>
> There is also the issue of communicating these warnings in a better 
> way through the MI to IDE's.
>
>> [PATCH v4] gdb/arm: Stop unwinding on error, but do not assert
>> The warning is printed just once and not repeated on each backtrace 
>> command.
>>

Tomas