Re: [PATCH] kernel/fork: stop playing lockless games for exe_file replacement

David Hildenbrand
2023-08-14T07:55:12Z

On 13.08.23 14:33, Mateusz Guzik wrote:
> xchg originated in 6e399cd144d8 ("prctl: avoid using mmap_sem for
> exe_file serialization"). While the commit message does not explain
> *why* the change, clearly the intent was to use mmap_sem less in this
> codepath. I found the original submission [1] which ultimately claims it
> cleans things up.

More details are apparently in v1 of that patch:

https://lore.kernel.org/lkml/1424979417.10344.14.camel@stgolabs.net/

Regarding your patch: adding more mmap_write_lock() where avoidable, I'm
not so sure.

Your patch doesn't look (to me) like it is removing a lot of complexity.

--
Cheers,

David / dhildenb