ARM: 7468/1: ftrace: Trace function entry before updating index

Commit 722b3c74695377d11d18a52f3da08114d37f3f37 modified x86 ftrace to
avoid tracing all functions called from irqs when function graph was
used with a filter.  Port the same fix to ARM.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 9 insertions, 8 deletions

diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index df0bf0c8cb79..34e56647dcee 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -179,19 +179,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
         old = *parent;
         *parent = return_hooker;
 
-        err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-                                       frame_pointer);
-        if (err == -EBUSY) {
-                *parent = old;
-                return;
-        }
-
         trace.func = self_addr;
+        trace.depth = current->curr_ret_stack + 1;
 
         /* Only trace if the calling function expects to */
         if (!ftrace_graph_entry(&trace)) {
-                current->curr_ret_stack--;
                 *parent = old;
+                return;
+        }
+
+        err = ftrace_push_return_trace(old, self_addr, &trace.depth,
+                                       frame_pointer);
+        if (err == -EBUSY) {
+                *parent = old;
+                return;
         }
 }