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Commit bc715ee4 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

sh/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 superh 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: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Cc: stable@kernel.org
Fixes: 03274a3f ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 18588e14

arch/sh/kernel/ftrace.c

+2 −14
Original line number Diff line number Diff line
@@ -321,8 +321,7 @@ int ftrace_disable_ftrace_graph_caller(void) 
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)

{

	unsigned long old;

	int faulted, err;

	struct ftrace_graph_ent trace;

	int faulted;

	unsigned long return_hooker = (unsigned long)&return_to_handler;



	if (unlikely(ftrace_graph_is_dead()))
@@ -365,18 +364,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) 
		return;

	}



	err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL);

	if (err == -EBUSY) {

	if (function_graph_enter(old, self_addr, 0, NULL))

		__raw_writel(old, parent);

		return;

	}



	trace.func = self_addr;



	/* Only trace if the calling function expects to */

	if (!ftrace_graph_entry(&trace)) {

		current->curr_ret_stack--;

		__raw_writel(old, parent);

	}

}

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */