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microblaze: function_graph: Simplify with function_graph_enter()

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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 microblaze 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: Michal Simek <monstr@monstr.eu>
Cc: stable@kernel.org
Fixes: 03274a3ffb ("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>
This commit is contained in:
Steven Rostedt (VMware) 2018-11-18 17:23:30 -05:00
parent 01e0ab2c4f
commit 556763e5a5
1 changed files with 2 additions and 13 deletions
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15
arch/microblaze/kernel/ftrace.c
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@ -22,8 +22,7 @@
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;
@ -63,18 +62,8 @@ 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))
*parent = old;
return;
}
trace.func = self_addr;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace)) {
current->curr_ret_stack--;
*parent = old;
}
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */