Re: MPS codegen

[Helmut Eller]

On Sat, Jun 15 2024, Gerd Möllmann wrote:

> Helmut Eller <eller.helmut@gmail.com> writes:
>
>> On Sat, Jun 15 2024, Gerd Möllmann wrote:
>>
>>> I can't munmap because that
>>> would write back the changes done by the reloc phase back to the .pdmp
>>> file.
>>
>> I think that's a misunderstanding.  dump_map_file_posix sets MAP_PRIVATE
>> for DUMP_MEMORY_ACCESS_READWRITE.  So whatever changes the reloc phase
>> makes, they are written to copy-on-write pages and never to disk.
>
> Hm, I can try that a bit later. So, the theory would be that mprotect
> PROT_NONE does not work somehow on madvice'd not needed memory?  

It looks like dump_discard_mem doesn't properly check error codes.
Maybe the region it want's to discard is not at page boundaries or
something like that.