ftrace fixes for v6.19:

- Fix regression of pid filtering of function graph tracer
 
   When the function graph tracer allowed multiple instances of
   graph tracing using subops, the filtering by pid broke.
 
   The ftrace_ops->private that was used for pid filtering wasn't
   updated on creation.
 
   The wrong function entry callback was used when pid filtering was
   enabled when the function graph tracer started, which meant that
   the pid filtering wasn't happening.
 
 - Remove no longer needed ftrace_trace_task()
 
   With PID filtering working via ftrace_pids_enabled() and fgraph_pid_func(),
   the coarse-grained ftrace_trace_task() check in graph_entry() is obsolete.
 
   It was only a fallback for uninitialized op->private (now fixed), and its
   removal ensures consistent PID filtering with standard function tracing.
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Merge tag 'ftrace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

 - Fix regression of pid filtering of function graph tracer

   When the function graph tracer allowed multiple instances of graph
   tracing using subops, the filtering by pid broke.

   The ftrace_ops->private that was used for pid filtering wasn't
   updated on creation.

   The wrong function entry callback was used when pid filtering was
   enabled when the function graph tracer started, which meant that
   the pid filtering wasn't happening.

 - Remove no longer needed ftrace_trace_task()

   With PID filtering working via ftrace_pids_enabled() and
   fgraph_pid_func(), the coarse-grained ftrace_trace_task()
   check in graph_entry() is obsolete.

   It was only a fallback for uninitialized op->private (now fixed),
   and its removal ensures consistent PID filtering with standard
   function tracing.

* tag 'ftrace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fgraph: Remove coarse PID filtering from graph_entry()
  fgraph: Check ftrace_pids_enabled on registration for early filtering
  fgraph: Initialize ftrace_ops->private for function graph ops

kernel/trace/fgraph.c

@@ -1016,6 +1016,7 @@ void fgraph_init_ops(struct ftrace_ops *dst_ops,
 		mutex_init(&dst_ops->local_hash.regex_lock);
 		INIT_LIST_HEAD(&dst_ops->subop_list);
 		dst_ops->flags |= FTRACE_OPS_FL_INITIALIZED;
+		dst_ops->private = src_ops->private;
 	}
 #endif
 }
@@ -1368,6 +1369,13 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 
 	ftrace_graph_active++;
 
+	/* Always save the function, and reset at unregistering */
+	gops->saved_func = gops->entryfunc;
+#ifdef CONFIG_DYNAMIC_FTRACE
+	if (ftrace_pids_enabled(&gops->ops))
+		gops->entryfunc = fgraph_pid_func;
+#endif
+
 	if (ftrace_graph_active == 2)
 		ftrace_graph_disable_direct(true);
 
@@ -1387,8 +1395,6 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 	} else {
 		init_task_vars(gops->idx);
 	}
-	/* Always save the function, and reset at unregistering */
-	gops->saved_func = gops->entryfunc;
 
 	gops->ops.flags |= FTRACE_OPS_FL_GRAPH;
 

kernel/trace/trace.h

@@ -1162,11 +1162,6 @@ struct ftrace_func_command {
 					char *params, int enable);
 };
 extern bool ftrace_filter_param __initdata;
-static inline int ftrace_trace_task(struct trace_array *tr)
-{
-	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
-		FTRACE_PID_IGNORE;
-}
 extern int ftrace_is_dead(void);
 int ftrace_create_function_files(struct trace_array *tr,
 				 struct dentry *parent);
@@ -1184,10 +1179,6 @@ void ftrace_clear_pids(struct trace_array *tr);
 int init_function_trace(void);
 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
 #else
-static inline int ftrace_trace_task(struct trace_array *tr)
-{
-	return 1;
-}
 static inline int ftrace_is_dead(void) { return 0; }
 static inline int
 ftrace_create_function_files(struct trace_array *tr,

kernel/trace/trace_functions_graph.c

@@ -251,9 +251,6 @@ static int graph_entry(struct ftrace_graph_ent *trace,
 		return 1;
 	}
 
-	if (!ftrace_trace_task(tr))
-		return 0;
-
 	if (ftrace_graph_ignore_func(gops, trace))
 		return 0;