This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed- bionic'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-bionic -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1768630 Title: arm64 SDEI support needs trampoline code for KPTI Status in linux package in Ubuntu: In Progress Status in linux source package in Bionic: Fix Committed Bug description: [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). This may lead to a crash. [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. I'm unaware of any production firmware that expose the SDEI ACPI table, which means this code isn't actively used yet anyway. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768630/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
