hulk inclusion
category: feature
bugzilla: 12268
CVE: NA
-------------------------------------------------

Currently arm64 has no implementation of arch_trigger_cpumask_backtrace.
The patch provides one using library code recently added by Russell King
for for the majority of the implementation. Currently this is realized
using regular irqs but could, in the future, be implemented using
NMI-like mechanisms.

Note: There is a small (and nasty) change to the generic code to ensure
      good stack traces. The generic code currently assumes that
      show_regs() will include a stack trace but arch/arm64 does not do
      this so we must add extra code here. Ideas on a better approach
      here would be very welcome (is there any appetite to change arm64
      show_regs() or should we just tease out the dump code into a
      callback?).
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>