Re: Stack segments for Aarch64

[Phil Phil via Gdb <gdb@sourceware.org>]

Would you suggest that the output of maintenance info sections is more "complete" if you want to see all mapped memory regions?
________________________________
From: Luis Machado <luis.machado@arm.com>
Sent: Thursday, June 6, 2024 10:15 AM
To: Phil Phil <heidegg@hotmail.com>; gdb@sourceware.org <gdb@sourceware.org>
Subject: Re: Stack segments for Aarch64

On 6/6/24 10:57, Phil Phil wrote:
> Should the stack segment still be there though? I compared a stackpointer to the memory areas from info proc mappings and I can't find a match.

You'll likely find it in a core file section instead: maint info sections.

For me:

 [28]     0xfffffffdf000->0x1000000000000 at 0x00191350: load13 ALLOC LOAD HAS_CONTENTS

Does that help? GDB will look things up in the core file instead of memory, which is probably
why the way it displays things is slightly different.

It could be improved I suppose.

> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *From:* Luis Machado <luis.machado@arm.com>
> *Sent:* Thursday, June 6, 2024 9:41 AM
> *To:* Phil Phil <heidegg@hotmail.com>; gdb@sourceware.org <gdb@sourceware.org>
> *Subject:* Re: Stack segments for Aarch64
>
> Hi,
>
> On 6/6/24 10:33, Phil Phil wrote:
>> GDB 12.1 coredump post mortem coredump debugging on an x64 Linux desktop.  I do not see a perms column in info proc mappings.
>>
>
> Ah, so it is corefile debugging. Checking on my end, I don't see the permissions column either. Now it escapes me if we have any
> special reason for that or if it is just an oversight somewhere. As for the stack marker, I suppose we lose that reference
> when the corefile is generated. That reference comes from /proc/<pid>/maps when we do "info proc mapping".
>
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>> *From:* Luis Machado <luis.machado@arm.com>
>> *Sent:* Thursday, June 6, 2024 9:23 AM
>> *To:* Phil Phil <heidegg@hotmail.com>; gdb@sourceware.org <gdb@sourceware.org>
>> *Subject:* Re: Stack segments for Aarch64
>>
>> Hi,
>>
>> On 6/6/24 10:17, Phil Phil via Gdb wrote:
>>> Greetings,
>>>
>>> I'm trying get some memory info on an Aarch64 for a coredump. The aarch64 gdb produces this output for info proc mappings
>>>
>>>           Start Addr           End Addr       Size     Offset objfile
>>>         0x557ead9000       0x5582dee000  0x4315000        0x0 /usr/bin/myproc
>>>         0x5582dfe000       0x5582f0a000   0x10c000  0x4315000 /usr/bin/myproc
>>>         0x5582f0a000       0x5582f24000    0x1a000  0x4421000 /usr/bin/myproc
>>>
>>> I'm missing at least two things here compared to the x64 output:
>>>
>>>
>>>   *
>>> No read/write permissions
>>>   *
>>> Stack segments are not shown.
>>>
>>> Any ideas on how to make these two things visible on Aarch64?
>>>
>>> Regards
>>
>> What aarch64 debugging setup do you have? Versions etc? Remote?
>>
>> For me, running native gdb on aarch64:
>>
>> process 1681741
>> Mapped address spaces:
>>
>>           Start Addr           End Addr       Size     Offset  Perms  objfile
>>       0xaaaaaaaa0000     0xaaaaac3c6000  0x1926000        0x0  r-xp   /home/ubuntu/work/build/binutils-gdb-master/gdb/gdb
>>       0xaaaaac3d5000     0xaaaaacd2a000   0x955000  0x1925000  r--p   /home/ubuntu/work/build/binutils-gdb-master/gdb/gdb
>>       0xaaaaacfc6000     0xaaaaad069000    0xa3000        0x0  rw-p   [heap]
>> ...
>>       0xfffffffdf000    0x1000000000000    0x21000        0x0  rw-p   [stack]
>