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>

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index b55b4a7fbefd365b76813e86e71259f799bfdb59..db24c2278be04c7400f6f5057904d49642fa75e9 100644 (file)
--- 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 6b1f6f6f866172b41b4b64e1590bb40f2de19315..c0852291b6231520c0b8583b3dca1a34c332d453 100644 (file)
--- 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 231bdd3c5b1c710131dbdb2624f3f84cb8eeb6c8..76f7141e0f91ff9c4a55469b11c52146ea924c6a 100644 (file)
--- 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;

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 677432b9cb7e6e45dc98c400b304689d0cb4ca13..a7f8134c594ee5570008440980f349abbcb1944a 100644 (file)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -379,6 +379,30 @@ struct ftrace_graph_ret {
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
+/*
+ * 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);
+
+extern int
+ftrace_push_return_trace(unsigned long ret, unsigned long long time,
+                        unsigned long func, int *depth);
+extern void
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
+
 /*
  * Sometimes we don't want to trace a function with the function
  * graph tracer but we want them to keep traced by the usual function

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 930c08e5b38e0d35ab93b79896b0150907d31e50..dce71a5b51bce5a953b5000628bbf1c58dc37cff 100644 (file)
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -42,6 +42,81 @@ static struct tracer_flags tracer_flags = {
 /* pid on the last trace processed */
 static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
 
+/* Add a function return address to the trace stack on thread info.*/
+int
+ftrace_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.*/
+void
+ftrace_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;
+
+       ftrace_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;
+}
+
 static int graph_trace_init(struct trace_array *tr)
 {
        int cpu, ret;