Re: [PATCH 09/12] mm/sparse: remove SECTION_MARKED_PRESENT

[Seongjun Hong]

Hi David,

I'm sorry for the delayed response.

On Thu, Sep 10, 2026 at 05:11:36PM +0200, David Hildenbrand (Arm) wrote:
> >> +++ b/scripts/gdb/linux/mm.py
> >> @@ -76,7 +76,7 @@ class x86_page_ops():
> >>              self.SECTION_IS_EARLY = 1 << int(gdb.parse_and_eval('SECTION_IS_EARLY_BIT'))
> >>          except:
> >>              self.SECTION_HAS_MEM_MAP = 1 << 0
> >> -            self.SECTION_IS_EARLY = 1 << 3
> >> +            self.SECTION_IS_EARLY = 1 << 2
> > 
> > Seems a bit strage given the code is:
> > 
> >         try:
> >             self.SECTION_HAS_MEM_MAP = 1 << int(gdb.parse_and_eval('SECTION_HAS_MEM_MAP_BIT'))
> >             self.SECTION_IS_EARLY = 1 << int(gdb.parse_and_eval('SECTION_IS_EARLY_BIT'))
> >         except:
> >             self.SECTION_HAS_MEM_MAP = 1 << 0
> >             self.SECTION_IS_EARLY = 1 << 2
> > 
> > Whereas other variables must be available with no try, e.g.:
> > 
> >         self.PAGE_OFFSET = int(gdb.parse_and_eval("page_offset_base"))
> >         self.VMEMMAP_START = int(gdb.parse_and_eval("vmemmap_base"))
> >         self.PHYS_BASE = int(gdb.parse_and_eval("(unsigned long) phys_base"))
> > 
> > etc.
> > 
> > Is there some weirdness with gdb? Or is it maybe because there are some configs
> > without these symbols maybe?
> 
> TBH, I have absolutely no idea and I was asking myself the same thing (but
> decided that I couldn't care less about a python gdb script).
> 
> This code was added in February:
> 
> commit 55f8b4518d14b7436f70defe27faba4eca0cd4e1
> Author: Seongjun Hong <hsj0512@xxxxxxxxx>
> Date:   Mon Feb 2 12:42:41 2026 +0900
> 
>     scripts/gdb: implement x86_page_ops in mm.py
> 
>     Implement all member functions of x86_page_ops strictly following the
>     logic of aarch64_page_ops.
> 
>     This includes full support for SPARSEMEM and standard page translation
>     functions.
> 
>     This fixes compatibility with 'lx-' commands on x86_64, preventing
>     AttributeErrors when using lx-pfn_to_page and others.
> 
> @Seongjun, why are these conditional and the others not? Trying to support older
> kernels?

No. TBH I didn't look at the gdb script carefully at that time and just 
wanted to avoid a symbol lookup failure. 

It would be better if we remove the try statement.

Thanks! :)

--
Best regards,
Seongjun Hong