From: "Steven Rostedt (Google)" <rost...@goodmis.org> When CONFIG_DYNAMIC_FTRACE is not set, the function fgraph_update_pid_func() doesn't do anything. Currently, most of its logic is within a "#ifdef CONFIG_DYNAMIC_FTRACE" block, but its variables were declared outside that, and when DYNAMIC_FTRACE is not set, it produces unused variable warnings.
Instead, just place it (and the helper function fgraph_pid_func()) within the #ifdef block and have the header file use a empty stub function for when DYNAMIC_FTRACE is not defined. Reported-by: kernel test robot <l...@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406071806.brjac5ff-...@intel.com/ Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org> --- kernel/trace/fgraph.c | 4 ++-- kernel/trace/ftrace_internal.h | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c0e428c87ea5..0859ab112db7 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -1151,6 +1151,7 @@ void ftrace_graph_exit_task(struct task_struct *t) kfree(ret_stack); } +#ifdef CONFIG_DYNAMIC_FTRACE static int fgraph_pid_func(struct ftrace_graph_ent *trace, struct fgraph_ops *gops) { @@ -1177,7 +1178,6 @@ void fgraph_update_pid_func(void) if (!(graph_ops.flags & FTRACE_OPS_FL_INITIALIZED)) return; -#ifdef CONFIG_DYNAMIC_FTRACE list_for_each_entry(op, &graph_ops.subop_list, list) { if (op->flags & FTRACE_OPS_FL_PID) { gops = container_of(op, struct fgraph_ops, ops); @@ -1187,8 +1187,8 @@ void fgraph_update_pid_func(void) static_call_update(fgraph_func, gops->entryfunc); } } -#endif } +#endif /* Allocate a return stack for each task */ static int start_graph_tracing(void) diff --git a/kernel/trace/ftrace_internal.h b/kernel/trace/ftrace_internal.h index 4bb1e881154a..3235470e61b3 100644 --- a/kernel/trace/ftrace_internal.h +++ b/kernel/trace/ftrace_internal.h @@ -52,7 +52,11 @@ static inline int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_o #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern int ftrace_graph_active; +# ifdef CONFIG_DYNAMIC_FTRACE extern void fgraph_update_pid_func(void); +# else +static inline void fgraph_update_pid_func(void) {} +# endif #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ # define ftrace_graph_active 0 static inline void fgraph_update_pid_func(void) {} -- 2.43.0
