From fbbee0cfba5fb0985a6d22cc5ab246bcd7bd5888 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Sun, 18 Nov 2018 17:19:26 -0500 Subject: [PATCH] ARM: function_graph: Simplify with function_graph_enter() commit f1f5b14afd7cce39e6a9b25c685e1ea34c231096 upstream. 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 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 Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- arch/arm/kernel/ftrace.c | 17 +---------------- 1 file changed, 1 insertion(+), 16 deletions(-) diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 5617932..ee673c0 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -227,9 +227,7 @@ 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(¤t->tracing_graph_pause))) return; @@ -237,21 +235,8 @@ 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 -- 2.7.4