Merge tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Rework of the kprobe/uprobe and synthetic events to consolidate all
   the dynamic event code. This will make changes in the future easier.

 - Partial rewrite of the function graph tracing infrastructure. This
   will allow for multiple users of hooking onto functions to get the
   callback (return) of the function. This is the ground work for having
   kprobes and function graph tracer using one code base.

 - Clean up of the histogram code that will facilitate adding more
   features to the histograms in the future.

 - Addition of str_has_prefix() and a few use cases. There currently is
   a similar function strstart() that is used in a few places, but only
   returns a bool and not a length. These instances will be removed in
   the future to use str_has_prefix() instead.

 - A few other various clean ups as well.

* tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  tracing: Use the return of str_has_prefix() to remove open coded numbers
  tracing: Have the historgram use the result of str_has_prefix() for len of prefix
  tracing: Use str_has_prefix() instead of using fixed sizes
  tracing: Use str_has_prefix() helper for histogram code
  string.h: Add str_has_prefix() helper function
  tracing: Make function ‘ftrace_exports’ static
  tracing: Simplify printf'ing in seq_print_sym
  tracing: Avoid -Wformat-nonliteral warning
  tracing: Merge seq_print_sym_short() and seq_print_sym_offset()
  tracing: Add hist trigger comments for variable-related fields
  tracing: Remove hist trigger synth_var_refs
  tracing: Use hist trigger's var_ref array to destroy var_refs
  tracing: Remove open-coding of hist trigger var_ref management
  tracing: Use var_refs[] for hist trigger reference checking
  tracing: Change strlen to sizeof for hist trigger static strings
  tracing: Remove unnecessary hist trigger struct field
  tracing: Fix ftrace_graph_get_ret_stack() to use task and not current
  seq_buf: Use size_t for len in seq_buf_puts()
  seq_buf: Make seq_buf_puts() null-terminate the buffer
  arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack
  ...

1 files changed, 128 insertions, 142 deletions

diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 7d04b9890755..4ea7e6845efb 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -35,26 +35,19 @@ static arch_spinlock_t wakeup_lock =
 
 static void wakeup_reset(struct trace_array *tr);
 static void __wakeup_reset(struct trace_array *tr);
+static int start_func_tracer(struct trace_array *tr, int graph);
+static void stop_func_tracer(struct trace_array *tr, int graph);
 
 static int save_flags;
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static int wakeup_display_graph(struct trace_array *tr, int set);
 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
 #else
-static inline int wakeup_display_graph(struct trace_array *tr, int set)
-{
-        return 0;
-}
 # define is_graph(tr) false
 #endif
 
-
 #ifdef CONFIG_FUNCTION_TRACER
 
-static int wakeup_graph_entry(struct ftrace_graph_ent *trace);
-static void wakeup_graph_return(struct ftrace_graph_ret *trace);
-
 static bool function_enabled;
 
 /*
@@ -104,122 +97,8 @@ out_enable:
         return 0;
 }
 
-/*
- * wakeup uses its own tracer function to keep the overhead down:
- */
-static void
-wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
-                   struct ftrace_ops *op, struct pt_regs *pt_regs)
-{
-        struct trace_array *tr = wakeup_trace;
-        struct trace_array_cpu *data;
-        unsigned long flags;
-        int pc;
-
-        if (!func_prolog_preempt_disable(tr, &data, &pc))
-                return;
-
-        local_irq_save(flags);
-        trace_function(tr, ip, parent_ip, flags, pc);
-        local_irq_restore(flags);
-
-        atomic_dec(&data->disabled);
-        preempt_enable_notrace();
-}
-
-static int register_wakeup_function(struct trace_array *tr, int graph, int set)
-{
-        int ret;
-
-        /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
-        if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
-                return 0;
-
-        if (graph)
-                ret = register_ftrace_graph(&wakeup_graph_return,
-                                            &wakeup_graph_entry);
-        else
-                ret = register_ftrace_function(tr->ops);
-
-        if (!ret)
-                function_enabled = true;
-
-        return ret;
-}
-
-static void unregister_wakeup_function(struct trace_array *tr, int graph)
-{
-        if (!function_enabled)
-                return;
-
-        if (graph)
-                unregister_ftrace_graph();
-        else
-                unregister_ftrace_function(tr->ops);
-
-        function_enabled = false;
-}
-
-static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
-{
-        if (!(mask & TRACE_ITER_FUNCTION))
-                return 0;
-
-        if (set)
-                register_wakeup_function(tr, is_graph(tr), 1);
-        else
-                unregister_wakeup_function(tr, is_graph(tr));
-        return 1;
-}
-#else
-static int register_wakeup_function(struct trace_array *tr, int graph, int set)
-{
-        return 0;
-}
-static void unregister_wakeup_function(struct trace_array *tr, int graph) { }
-static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
-{
-        return 0;
-}
-#endif /* CONFIG_FUNCTION_TRACER */
-
-static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
-{
-        struct tracer *tracer = tr->current_trace;
-
-        if (wakeup_function_set(tr, mask, set))
-                return 0;
-
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-        if (mask & TRACE_ITER_DISPLAY_GRAPH)
-                return wakeup_display_graph(tr, set);
-#endif
 
-        return trace_keep_overwrite(tracer, mask, set);
-}
-
-static int start_func_tracer(struct trace_array *tr, int graph)
-{
-        int ret;
-
-        ret = register_wakeup_function(tr, graph, 0);
-
-        if (!ret && tracing_is_enabled())
-                tracer_enabled = 1;
-        else
-                tracer_enabled = 0;
-
-        return ret;
-}
-
-static void stop_func_tracer(struct trace_array *tr, int graph)
-{
-        tracer_enabled = 0;
-
-        unregister_wakeup_function(tr, graph);
-}
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 static int wakeup_display_graph(struct trace_array *tr, int set)
 {
         if (!(is_graph(tr) ^ set))
@@ -283,6 +162,11 @@ static void wakeup_graph_return(struct ftrace_graph_ret *trace)
         return;
 }
 
+static struct fgraph_ops fgraph_wakeup_ops = {
+        .entryfunc = &wakeup_graph_entry,
+        .retfunc = &wakeup_graph_return,
+};
+
 static void wakeup_trace_open(struct trace_iterator *iter)
 {
         if (is_graph(iter->tr))
@@ -318,20 +202,87 @@ static void wakeup_print_header(struct seq_file *s)
         else
                 trace_default_header(s);
 }
+#endif /* else CONFIG_FUNCTION_GRAPH_TRACER */
 
+/*
+ * wakeup uses its own tracer function to keep the overhead down:
+ */
 static void
-__trace_function(struct trace_array *tr,
-                 unsigned long ip, unsigned long parent_ip,
-                 unsigned long flags, int pc)
+wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
+                   struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
-        if (is_graph(tr))
-                trace_graph_function(tr, ip, parent_ip, flags, pc);
+        struct trace_array *tr = wakeup_trace;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        int pc;
+
+        if (!func_prolog_preempt_disable(tr, &data, &pc))
+                return;
+
+        local_irq_save(flags);
+        trace_function(tr, ip, parent_ip, flags, pc);
+        local_irq_restore(flags);
+
+        atomic_dec(&data->disabled);
+        preempt_enable_notrace();
+}
+
+static int register_wakeup_function(struct trace_array *tr, int graph, int set)
+{
+        int ret;
+
+        /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
+        if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
+                return 0;
+
+        if (graph)
+                ret = register_ftrace_graph(&fgraph_wakeup_ops);
         else
-                trace_function(tr, ip, parent_ip, flags, pc);
+                ret = register_ftrace_function(tr->ops);
+
+        if (!ret)
+                function_enabled = true;
+
+        return ret;
 }
-#else
-#define __trace_function trace_function
 
+static void unregister_wakeup_function(struct trace_array *tr, int graph)
+{
+        if (!function_enabled)
+                return;
+
+        if (graph)
+                unregister_ftrace_graph(&fgraph_wakeup_ops);
+        else
+                unregister_ftrace_function(tr->ops);
+
+        function_enabled = false;
+}
+
+static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
+{
+        if (!(mask & TRACE_ITER_FUNCTION))
+                return 0;
+
+        if (set)
+                register_wakeup_function(tr, is_graph(tr), 1);
+        else
+                unregister_wakeup_function(tr, is_graph(tr));
+        return 1;
+}
+#else /* CONFIG_FUNCTION_TRACER */
+static int register_wakeup_function(struct trace_array *tr, int graph, int set)
+{
+        return 0;
+}
+static void unregister_wakeup_function(struct trace_array *tr, int graph) { }
+static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
+{
+        return 0;
+}
+#endif /* else CONFIG_FUNCTION_TRACER */
+
+#ifndef CONFIG_FUNCTION_GRAPH_TRACER
 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 {
         return TRACE_TYPE_UNHANDLED;
@@ -340,23 +291,58 @@ static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 static void wakeup_trace_open(struct trace_iterator *iter) { }
 static void wakeup_trace_close(struct trace_iterator *iter) { }
 
-#ifdef CONFIG_FUNCTION_TRACER
-static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
-{
-        return -1;
-}
-static void wakeup_graph_return(struct ftrace_graph_ret *trace) { }
 static void wakeup_print_header(struct seq_file *s)
 {
         trace_default_header(s);
 }
-#else
-static void wakeup_print_header(struct seq_file *s)
+#endif /* !CONFIG_FUNCTION_GRAPH_TRACER */
+
+static void
+__trace_function(struct trace_array *tr,
+                 unsigned long ip, unsigned long parent_ip,
+                 unsigned long flags, int pc)
 {
-        trace_latency_header(s);
+        if (is_graph(tr))
+                trace_graph_function(tr, ip, parent_ip, flags, pc);
+        else
+                trace_function(tr, ip, parent_ip, flags, pc);
+}
+
+static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
+{
+        struct tracer *tracer = tr->current_trace;
+
+        if (wakeup_function_set(tr, mask, set))
+                return 0;
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        if (mask & TRACE_ITER_DISPLAY_GRAPH)
+                return wakeup_display_graph(tr, set);
+#endif
+
+        return trace_keep_overwrite(tracer, mask, set);
+}
+
+static int start_func_tracer(struct trace_array *tr, int graph)
+{
+        int ret;
+
+        ret = register_wakeup_function(tr, graph, 0);
+
+        if (!ret && tracing_is_enabled())
+                tracer_enabled = 1;
+        else
+                tracer_enabled = 0;
+
+        return ret;
+}
+
+static void stop_func_tracer(struct trace_array *tr, int graph)
+{
+        tracer_enabled = 0;
+
+        unregister_wakeup_function(tr, graph);
 }
-#endif /* CONFIG_FUNCTION_TRACER */
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 /*
  * Should this new latency be reported/recorded?