tree 370431fbaa75e42e1c97d2dec184de46005ddd9b
parent ab5eb336411f18fd449a1fb37d36a55ec422603f
author Max Filippov <jcmvbkbc@gmail.com> 1612702678 -0800
committer Max Filippov <jcmvbkbc@gmail.com> 1617042311 -0700

xtensa: fix uaccess-related livelock in do_page_fault

If a uaccess (e.g. get_user()) triggers a fault and there's a
fault signal pending, the handler will return to the uaccess without
having performed a uaccess fault fixup, and so the CPU will immediately
execute the uaccess instruction again, whereupon it will livelock
bouncing between that instruction and the fault handler.

https://lore.kernel.org/lkml/20210121123140.GD48431@C02TD0UTHF1T.local/

Cc: stable@vger.kernel.org
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>