sparc/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 sparc 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: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
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 17:37:40 -05:00
parent bc715ee4db
commit 9c4bf5e0db

View File

@ -126,20 +126,11 @@ unsigned long prepare_ftrace_return(unsigned long parent,
unsigned long frame_pointer)
{
unsigned long return_hooker = (unsigned long) &return_to_handler;
struct ftrace_graph_ent trace;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return parent + 8UL;
trace.func = self_addr;
trace.depth = current->curr_ret_stack + 1;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace))
return parent + 8UL;
if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
frame_pointer, NULL) == -EBUSY)
if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
return parent + 8UL;
return return_hooker;