Public bug reported: [Impact] In bug 1756096, we backported SDEI (Software Delegated Exception Interface) support for arm64. However, this backport missed 2 changes that make the SDEI entry point a trampoline which make sure the kernel is mapped before processing. (The kernel may not be mapped if KPTI is enabled and the exception comes in while e.g. executing in usermode).
[Test Case] I haven't yet found a way to inject/simulate an SDEI, so I can only regression test by boot testing. [Regression Risk] The code is restricted to arm64, and should only run on systems that support SDEI. ** Affects: linux (Ubuntu) Importance: Undecided Assignee: dann frazier (dannf) Status: In Progress ** Affects: linux (Ubuntu Bionic) Importance: Undecided Assignee: dann frazier (dannf) Status: In Progress ** Also affects: linux (Ubuntu Bionic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu) Status: New => In Progress ** Changed in: linux (Ubuntu Bionic) Status: New => In Progress ** Changed in: linux (Ubuntu) Assignee: (unassigned) => dann frazier (dannf) ** Changed in: linux (Ubuntu Bionic) Assignee: (unassigned) => dann frazier (dannf) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1768630 Title: arm64 SDEI support needs trampoline code for KPTI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768630/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs