Re: [PATCH v3 2/5] [PATCH 2/5] gdb: Improve SIGSEGV diagnostics for POE faults

Srinath Parvathaneni <[email protected]> Thu, 23 Jul 2026 09:03:50 +0000
Newsgroups gmane.comp.gdb.patches
Message-ID <AS8PR08MB1009915869FFF60CBB8DA52679BC02@AS8PR08MB10099.eurprd08.prod.outlook.com>
>
>>>> +  /* For POE SEGSEGV, show additional information.  */
>>>
>>> Is this really supposed to be POE SEGSEGV or is it a typo?
>>>
>>
>> For now, in my knowledge, AARCH64_SEGV_PKUERR is only used for POE.
>> However, it will also be used soon for another upcoming feature.
>> I would recommend to either simply eliminate the comment, or make it more clear like
>>
>> /* For memory permission faults, e.g. due to a permission overlay
>>     restriction when feature POE is enabled.  */
>>
>> Matthieu
>
>Sorry, I may not have been clear, but I was referring specifically to
>the SEGSEGV. Should it be SIGSEGV instead?

Yes Luis, that's a typo. It should be SIGSEGV instead of SEGSEGV, thanks for
spotting it, I will update in the re-spin.

Regarding the comment itself, while SIGSEGV already implies a memory fault,
AARCH64_SEGV_PKUERR is currently only generated for Permission Overlay
violations. I think something like following would be more accurate description.

/* Additional information for SIGSEGV caused by a permission overlay violation.  */

Regards,
Sri.
________________________________
From: Luis <[email protected]>
Sent: 23 July 2026 00:11
To: Matthieu Longo <[email protected]>; Srinath Parvathaneni <[email protected]>; [email protected] <[email protected]>
Cc: [email protected] <[email protected]>; [email protected] <[email protected]>; Ezra Sitorus <[email protected]>; [email protected] <[email protected]>
Subject: Re: [PATCH v3 2/5] [PATCH 2/5] gdb: Improve SIGSEGV diagnostics for POE faults

On 22/07/2026 10:41, Matthieu Longo wrote:
> On 21/07/2026 21:30, Luis wrote:
>> On 14/07/2026 21:15, [email protected] wrote:
>>> From: Srinath Parvathaneni <[email protected]>
>>>
>>> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
>>> index f11eccc1bc1..b8a02ab9972 100644
>>> --- a/gdb/aarch64-linux-tdep.c
>>> +++ b/gdb/aarch64-linux-tdep.c
>>>    @@ -2734,6 +2741,14 @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
>>>          uiout->field_string ("logical-tag", hex_string (ltag));
>>>        }
>>>        }
>>> +  /* For POE SEGSEGV, show additional information.  */
>>
>> Is this really supposed to be POE SEGSEGV or is it a typo?
>>
>
> For now, in my knowledge, AARCH64_SEGV_PKUERR is only used for POE.
> However, it will also be used soon for another upcoming feature.
> I would recommend to either simply eliminate the comment, or make it more clear like
>
> /* For memory permission faults, e.g. due to a permission overlay
>     restriction when feature POE is enabled.  */
>
> Matthieu

Sorry, I may not have been clear, but I was referring specifically to
the SEGSEGV. Should it be SIGSEGV instead?