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@xxxxxxxxxxxx/
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
