tracing/function-graph-tracer: make arch generic push pop functions

There is nothing really arch specific of the push and pop functions
used by the function graph tracer. This patch moves them to generic
code.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

3 files changed, 2 insertions, 99 deletions

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index b55b4a7..db24c22 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -55,29 +55,4 @@ struct dyn_arch_ftrace {
 #endif /* __ASSEMBLY__ */
 #endif /* CONFIG_FUNCTION_TRACER */
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-
-#ifndef __ASSEMBLY__
-
-/*
- * Stack of return addresses for functions
- * of a thread.
- * Used in struct thread_info
- */
-struct ftrace_ret_stack {
-	unsigned long ret;
-	unsigned long func;
-	unsigned long long calltime;
-};
-
-/*
- * Primary handler of a function return.
- * It relays on ftrace_return_to_handler.
- * Defined in entry_32/64.S
- */
-extern void return_to_handler(void);
-
-#endif /* __ASSEMBLY__ */
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-
 #endif /* _ASM_X86_FTRACE_H */
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 6b1f6f6..c085229 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -10,6 +10,7 @@
 #include <linux/kdebug.h>
 #include <linux/module.h>
 #include <linux/ptrace.h>
+#include <linux/ftrace.h>
 #include <linux/kexec.h>
 #include <linux/bug.h>
 #include <linux/nmi.h>
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 231bdd3..76f7141 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -389,79 +389,6 @@ void ftrace_nmi_exit(void)
 
 #endif /* !CONFIG_DYNAMIC_FTRACE */
 
-/* Add a function return address to the trace stack on thread info.*/
-static int push_return_trace(unsigned long ret, unsigned long long time,
-				unsigned long func, int *depth)
-{
-	int index;
-
-	if (!current->ret_stack)
-		return -EBUSY;
-
-	/* The return trace stack is full */
-	if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
-		atomic_inc(&current->trace_overrun);
-		return -EBUSY;
-	}
-
-	index = ++current->curr_ret_stack;
-	barrier();
-	current->ret_stack[index].ret = ret;
-	current->ret_stack[index].func = func;
-	current->ret_stack[index].calltime = time;
-	*depth = index;
-
-	return 0;
-}
-
-/* Retrieve a function return address to the trace stack on thread info.*/
-static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
-{
-	int index;
-
-	index = current->curr_ret_stack;
-
-	if (unlikely(index < 0)) {
-		ftrace_graph_stop();
-		WARN_ON(1);
-		/* Might as well panic, otherwise we have no where to go */
-		*ret = (unsigned long)panic;
-		return;
-	}
-
-	*ret = current->ret_stack[index].ret;
-	trace->func = current->ret_stack[index].func;
-	trace->calltime = current->ret_stack[index].calltime;
-	trace->overrun = atomic_read(&current->trace_overrun);
-	trace->depth = index;
-	barrier();
-	current->curr_ret_stack--;
-
-}
-
-/*
- * Send the trace to the ring-buffer.
- * @return the original return address.
- */
-unsigned long ftrace_return_to_handler(void)
-{
-	struct ftrace_graph_ret trace;
-	unsigned long ret;
-
-	pop_return_trace(&trace, &ret);
-	trace.rettime = cpu_clock(raw_smp_processor_id());
-	ftrace_graph_return(&trace);
-
-	if (unlikely(!ret)) {
-		ftrace_graph_stop();
-		WARN_ON(1);
-		/* Might as well panic. What else to do? */
-		ret = (unsigned long)panic;
-	}
-
-	return ret;
-}
-
 /*
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
@@ -521,7 +448,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 
 	calltime = cpu_clock(raw_smp_processor_id());
 
-	if (push_return_trace(old, calltime,
+	if (ftrace_push_return_trace(old, calltime,
 				self_addr, &trace.depth) == -EBUSY) {
 		*parent = old;
 		return;