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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-18 17:19:26 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-27 20:29:52 -0500
commitf1f5b14afd7cce39e6a9b25c685e1ea34c231096 (patch)
tree30542e3187f519e0f56f258764123e577f654dfa /arch/arm
parent07f7175b43827640d1e69c9eded89aa089a234b4 (diff)
ARM: function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have ARM use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Russell King <linux@armlinux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/kernel/ftrace.c17
1 files changed, 1 insertions, 16 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 0142fcfcc3d3..bda949fd84e8 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -183,9 +183,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
unsigned long frame_pointer)
{
unsigned long return_hooker = (unsigned long) &return_to_handler;
- struct ftrace_graph_ent trace;
unsigned long old;
- int err;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;
@@ -193,21 +191,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
old = *parent;
*parent = return_hooker;
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace)) {
+ if (function_graph_enter(old, self_addr, frame_pointer, NULL))
*parent = old;
- return;
- }
-
- err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, NULL);
- if (err == -EBUSY) {
- *parent = old;
- return;
- }
}
#ifdef CONFIG_DYNAMIC_FTRACE