x86/entry/64: Teach idtentry to use the IRQ stack
We don't specifically need IST for things like kprobes, but we do
want to avoid rare, surprising extra stack usage if a kprobe hits
with a deep stack.
Teach idtentry to use the IRQ stack for selected entries.
This implementation uses the IRQ stack even if we entered from user
mode. This disallows tricks like ist_begin_non_atomic. If we ever
need such a trick in one of these entries, we can rework this. For
now, let's keep it simple.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
1 file changed
