ARM: 8691/1: Export save_stack_trace_tsk()

The kernel watchdog is a great debugging tool for finding tasks that
consume a disproportionate amount of CPU time in contiguous chunks. One
can imagine building a similar watchdog for arbitrary driver threads
using save_stack_trace_tsk() and print_stack_trace(). However, this is
not viable for dynamically loaded driver modules on ARM platforms
because save_stack_trace_tsk() is not exported for those architectures.
Export save_stack_trace_tsk() for the ARM architecture to align with
x86 and support various debugging use cases such as arbitrary driver
thread watchdog timers.

Signed-off-by: Dustin Brown <dustinb@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/kernel/stacktrace.c

@@ -171,6 +171,7 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	__save_stack_trace(tsk, trace, 1);
 }
+EXPORT_SYMBOL(save_stack_trace_tsk);
 
 void save_stack_trace(struct stack_trace *trace)
 {