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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-19 01:10:15 +0300
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-27 00:18:04 +0300
commit8114865ff82e200b383e46821c25cb0625b842b5 (patch)
tree88cbfcc66e0a8013ef4a4eed6141730aee75f6ee /kernel
parent9ff01193a20d391e8dbce4403dd5ef87c7eaaca6 (diff)
downloadlinux-8114865ff82e200b383e46821c25cb0625b842b5.tar.xz
function_graph: Create function_graph_enter() to consolidate architecture code
Currently all the architectures do basically the same thing in preparing the function graph tracer on entry to a function. This code can be pulled into a generic location and then this will allow the function graph tracer to be fixed, as well as extended. Create a new function graph helper function_graph_enter() that will call the hook function (ftrace_graph_entry) and the shadow stack operation (ftrace_push_return_trace), and remove the need of the architecture code to manage the shadow stack. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. 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 'kernel')
-rw-r--r--kernel/trace/trace_functions_graph.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 169b3c44ee97..28f2602435d0 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -182,6 +182,22 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
return 0;
}
+int function_graph_enter(unsigned long ret, unsigned long func,
+ unsigned long frame_pointer, unsigned long *retp)
+{
+ struct ftrace_graph_ent trace;
+
+ trace.func = func;
+ trace.depth = current->curr_ret_stack + 1;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace))
+ return -EBUSY;
+
+ return ftrace_push_return_trace(ret, func, &trace.depth,
+ frame_pointer, retp);
+}
+
/* Retrieve a function return address to the trace stack on thread info.*/
static void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,