[GIT PULL v2] tracing: Fixes and clean ups for v5.14

[Steven Rostedt]

Linus,

[
  Note. This version was only tested with one config and it passed the
  ftracetests in the selftests directory. I didn't run my full test
  suite as that takes forever to run, and the only thing that's
  different from the version that went through that test suite is that
  I dropped the "main" variable "fix" patch.
]

Fixes and clean ups to tracing:

- Fix header alignment when PREEMPT_RT is enabled for osnoise tracer

- Inject "stop" event to see where osnoise stopped the trace

- Define DYNAMIC_FTRACE_WITH_ARGS as some code had an #ifdef for it

- Fix erroneous message for bootconfig cmdline parameter

- Fix crash caused by not found variable in histograms


Please pull the latest trace-v5.14-rc5-2 tree, which can be found at:


  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.14-rc5-2

Tag SHA1: 26ba5d9bdfa88208677132efa9e64b488420b461
Head SHA1: 5acce0bff2a0420ce87d4591daeb867f47d552c2


Daniel Bristot de Oliveira (3):
      trace/osnoise: Add a header with PREEMPT_RT additional fields
      trace/timerlat: Add a header with PREEMPT_RT additional fields
      trace/osnoise: Print a stop tracing message

Lukas Bulwahn (1):
      tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS

Masami Hiramatsu (1):
      init: Suppress wrong warning for bootconfig cmdline parameter

Steven Rostedt (VMware) (1):
      tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name

----
 init/main.c                      |  9 +++++--
 kernel/trace/Kconfig             |  5 ++++
 kernel/trace/trace_events_hist.c |  2 ++
 kernel/trace/trace_osnoise.c     | 56 +++++++++++++++++++++++++++++++++++++++-
 4 files changed, 69 insertions(+), 3 deletions(-)
---------------------------
diff --git a/init/main.c b/init/main.c
index f5b8246e8aa1..8d97aba78c3a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -397,6 +397,12 @@ static int __init bootconfig_params(char *param, char *val,
 	return 0;
 }
 
+static int __init warn_bootconfig(char *str)
+{
+	/* The 'bootconfig' has been handled by bootconfig_params(). */
+	return 0;
+}
+
 static void __init setup_boot_config(void)
 {
 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
@@ -475,9 +481,8 @@ static int __init warn_bootconfig(char *str)
 	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 	return 0;
 }
-early_param("bootconfig", warn_bootconfig);
-
 #endif
+early_param("bootconfig", warn_bootconfig);
 
 /* Change NUL term back to "=", to make "param" the whole string. */
 static void __init repair_env_string(char *param, char *val)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index d567b1717c4c..3ee23f4d437f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -219,6 +219,11 @@ config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 	depends on DYNAMIC_FTRACE_WITH_REGS
 	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 
+config DYNAMIC_FTRACE_WITH_ARGS
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_DYNAMIC_FTRACE_WITH_ARGS
+
 config FUNCTION_PROFILER
 	bool "Kernel function profiler"
 	depends on FUNCTION_TRACER
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 949ef09dc537..a48aa2a2875b 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3430,6 +3430,8 @@ trace_action_create_field_var(struct hist_trigger_data *hist_data,
 			event = data->match_data.event;
 		}
 
+		if (!event)
+			goto free;
 		/*
 		 * At this point, we're looking at a field on another
 		 * event.  Because we can't modify a hist trigger on
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index a7e3c24dee13..b61eefe5ccf5 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -253,10 +253,40 @@ static struct osnoise_data {
  */
 static bool osnoise_busy;
 
+#ifdef CONFIG_PREEMPT_RT
 /*
  * Print the osnoise header info.
  */
 static void print_osnoise_headers(struct seq_file *s)
+{
+	if (osnoise_data.tainted)
+		seq_puts(s, "# osnoise is tainted!\n");
+
+	seq_puts(s, "#                                _-------=> irqs-off\n");
+	seq_puts(s, "#                               / _------=> need-resched\n");
+	seq_puts(s, "#                              | / _-----=> need-resched-lazy\n");
+	seq_puts(s, "#                              || / _----=> hardirq/softirq\n");
+	seq_puts(s, "#                              ||| / _---=> preempt-depth\n");
+	seq_puts(s, "#                              |||| / _--=> preempt-lazy-depth\n");
+	seq_puts(s, "#                              ||||| / _-=> migrate-disable\n");
+
+	seq_puts(s, "#                              |||||| /          ");
+	seq_puts(s, "                                     MAX\n");
+
+	seq_puts(s, "#                              ||||| /                         ");
+	seq_puts(s, "                    SINGLE      Interference counters:\n");
+
+	seq_puts(s, "#                              |||||||               RUNTIME   ");
+	seq_puts(s, "   NOISE  %% OF CPU  NOISE    +-----------------------------+\n");
+
+	seq_puts(s, "#           TASK-PID      CPU# |||||||   TIMESTAMP    IN US    ");
+	seq_puts(s, "   IN US  AVAILABLE  IN US     HW    NMI    IRQ   SIRQ THREAD\n");
+
+	seq_puts(s, "#              | |         |   |||||||      |           |      ");
+	seq_puts(s, "       |    |            |      |      |      |      |      |\n");
+}
+#else /* CONFIG_PREEMPT_RT */
+static void print_osnoise_headers(struct seq_file *s)
 {
 	if (osnoise_data.tainted)
 		seq_puts(s, "# osnoise is tainted!\n");
@@ -279,6 +309,7 @@ static void print_osnoise_headers(struct seq_file *s)
 	seq_puts(s, "#              | |         |   ||||      |           |      ");
 	seq_puts(s, "       |    |            |      |      |      |      |      |\n");
 }
+#endif /* CONFIG_PREEMPT_RT */
 
 /*
  * osnoise_taint - report an osnoise error.
@@ -323,6 +354,24 @@ static void trace_osnoise_sample(struct osnoise_sample *sample)
 /*
  * Print the timerlat header info.
  */
+#ifdef CONFIG_PREEMPT_RT
+static void print_timerlat_headers(struct seq_file *s)
+{
+	seq_puts(s, "#                                _-------=> irqs-off\n");
+	seq_puts(s, "#                               / _------=> need-resched\n");
+	seq_puts(s, "#                              | / _-----=> need-resched-lazy\n");
+	seq_puts(s, "#                              || / _----=> hardirq/softirq\n");
+	seq_puts(s, "#                              ||| / _---=> preempt-depth\n");
+	seq_puts(s, "#                              |||| / _--=> preempt-lazy-depth\n");
+	seq_puts(s, "#                              ||||| / _-=> migrate-disable\n");
+	seq_puts(s, "#                              |||||| /\n");
+	seq_puts(s, "#                              |||||||             ACTIVATION\n");
+	seq_puts(s, "#           TASK-PID      CPU# |||||||   TIMESTAMP    ID     ");
+	seq_puts(s, "       CONTEXT                LATENCY\n");
+	seq_puts(s, "#              | |         |   |||||||      |         |      ");
+	seq_puts(s, "            |                       |\n");
+}
+#else /* CONFIG_PREEMPT_RT */
 static void print_timerlat_headers(struct seq_file *s)
 {
 	seq_puts(s, "#                                _-----=> irqs-off\n");
@@ -336,6 +385,7 @@ static void print_timerlat_headers(struct seq_file *s)
 	seq_puts(s, "#              | |         |   ||||      |         |      ");
 	seq_puts(s, "            |                       |\n");
 }
+#endif /* CONFIG_PREEMPT_RT */
 
 /*
  * Record an timerlat_sample into the tracer buffer.
@@ -1025,9 +1075,13 @@ diff_osn_sample_stats(struct osnoise_variables *osn_var, struct osnoise_sample *
 /*
  * osnoise_stop_tracing - Stop tracing and the tracer.
  */
-static void osnoise_stop_tracing(void)
+static __always_inline void osnoise_stop_tracing(void)
 {
 	struct trace_array *tr = osnoise_trace;
+
+	trace_array_printk_buf(tr->array_buffer.buffer, _THIS_IP_,
+			"stop tracing hit on cpu %d\n", smp_processor_id());
+
 	tracer_tracing_off(tr);
 }