Em 22/11/2025 02:50, André Almeida escreveu:
Hello,
This version is a complete rewrite of the syscall (thanks Thomas for the
suggestions!).
* Use case
The use-case for the new syscalls is detailed in the last patch version:
https://lore.kernel.org/lkml/[email protected]
* The syscall interface
Documented at patches 3/9 "futex: Create set_robust_list2() syscall" and
4/9 "futex: Create get_robust_list2() syscall".
* Testing
I expanded the current robust list selftest to use the new interface,
and also ported the original syscall to use the new syscall internals,
and everything survived the tests.
* Changelog
Changes from v5:
- Complete interface rewrite, there are so many changes but the main
ones are the following points
- Array of robust lists now has a static size, allocated once during the
first usage of the list
- Now that the list of robust lists have a fixed size, I removed the
logic of having a command for creating a new index on the list. To
simplify things for everyone, userspace just need to call
set_robust_list2(head, 32-bit/64-bit type, index).
Actually, this won't work well. The application that calls
set_robust_list2() may be using glibc, that will also want to call
set_robust_list2(), and there's no way to know which lists are being by
each library. I will re-add the create/modify logic for the next version.
