arm64: Export save_stack_trace_tsk()

Dustin Brown · wildea01 · commit e27c7fa015d6 · 2017-06-15T11:52:35.000+01:00
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 ARM64 architecture to align with
x86 and support various debugging use cases such as arbitrary driver
thread watchdog timers.

Signed-off-by: Dustin Brown &lt;dustinb@codeaurora.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
@@ -210,6 +210,7 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 
 	put_task_stack(tsk);
 }
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
 
 void save_stack_trace(struct stack_trace *trace)
 {

Original file line number	Diff line number	Diff line change
`@@ -210,6 +210,7 @@ void save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)`
`210`	`210`
`211`	`211`	`put_task_stack(tsk);`
`212`	`212`	`}`
	`213`	`+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);`
`213`	`214`
`214`	`215`	`void save_stack_trace(struct stack_trace *trace)`
`215`	`216`	`{`