Re: [PATCH v5 07/12] gdb: amd64 linux coredump support with shadow stack.

[Luis <luis.machado.foss@gmail.com>]

On 8/5/25 05:29, Thiago Jung Bauermann wrote:
> Hello,
> 
> "Schimpe, Christina" <christina.schimpe@intel.com> writes:
> 
>>>>>> +
>>>>>> +    # At this point we have a couple of core files, the gcore one
>>>>>> + generated by
>>>>>> +    # GDB and the one generated by the operating system.  Make
>>>>>> + sure GDB can
>>>>>> +    # read both correctly.
>>>>>> +
>>>>>> +    if {$gcore_generated} {
>>>>>> +	clean_restart $binfile
>>>>>> +
>>>>>> +	with_test_prefix "gcore corefile" {
>>>>>> +	    check_core_file $gcore_filename $ssp_in_gcore
>>>>>> +	}
>>>>>> +    } else {
>>>>>> +	fail "gcore corefile not generated"
>>>>>
>>>>> It's better, where possible, to avoid having pass/fail results that
>>>>> only show up down some code paths.
>>>>>
>>>>> In this case it's easy to avoid having a stray 'fail' by
>>>>> restructuring the code too:
>>>>>
>>>>>    gdb_assert { $gcore_generated } "gcore corefile created"
>>>>>    if { $gcore_generated } {
>>>>>      ... etc ...
>>>>>    }
>>>>>
>>>>> Now you'll always have either a pass or fail based on the gcore
>>>>> being generated.
>>>>
>>>> Good idea. I did that for aarch64-gcs-core.exp.
>>
>> If no OS corefile is found we will see a FAIL here.
>> The usual coredump testing doesn't fail in case the coredump file is not found.
>> So all gdb.base/corefile*.exp tests have sth. like:
>>
>> set corefile [core_find $binfile {}]
>> if {$corefile == ""} {
>>      return
>> }
>>
>> This can happen in case corefiles are managed, for instance, by apport on ubuntu.
>> Do we want a different behaviour ?
> 
> Interesting point. Perhaps a FAIL Isn't the best result to report in
> this case, but IMHO it would be worth reporting an UNTESTED or perhaps
> UNSUPPORTED result rather than silently returning.
> 
> I don't have a strong opinion on this matter though.
> 

When testing core files, I usually change the core_pattern in 
/proc/sys/kernel/core_pattern so the files are properly generated and 
saved. Personally I find it useful to have a FAIL output when the core 
file generation didn't work.