Re: [PATCH] gdb questions: fallback on maps still relevant today ?

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

Hi,

On 01/07/2026 13:17, Matthieu Longo wrote:
> I am wondering whether the fallback on maps when reading smaps is still
> relevant nowadays. /proc/$PID/smaps has been around since 2005. I doubt
> that anyone using an older Linux kernel version out there would use the
> latest version of GDB.
> I propose to remove this fallback logic in linux_find_memory_regions_full.

That´d be fine by me. We might want to do the deprecation dance and then 
drop from a future release.

> 
> Additionnally, reading from smaps file is tested against NULL. Why ?
> Is there such a valid case where the result of target_fileio_read_stralloc()
> could be null, and at the same time, GDB is attached to a process, local
> or remote via gdbserver, or while reading a coredump ?
> In my understanding, all those cases ensures that the smaps file is always
> present and so, I propose to replace this check with a gdb_assert instead.

There are error cases. And this file isn´t something static on disk but 
rather a dynamically-created file on request. Due to that, bad things 
can happen and a read may fail.

We don´t want to assert on a temporary hiccup as it will completely kill 
gdb during a debug session. If this error ever happens the user gets a 
warning or error message and can take action. That isn´t the case with 
assertions.

> 
> Why do I care about the above ?
> I would like to wrap the reading and parsing code in a class to avoid
> the duplication of all the boiler plates in different places.

Can´t you accomplish that already regardless of whether reading smaps 
fails or not?

> Please let me know your thoughts ?

I'm all for tidying things up. And I'm OK with dropping the fallback too.