Commit d1e521ad authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:
 "No new features this release. Mostly clean ups, restructuring and
  documentation.

   - Have ftrace_bug() show ftrace errors before the WARN, as the WARN
     will reboot the box before the error messages are printed if
     panic_on_warn is set.

   - Have traceoff_on_warn disable tracing sooner (before prints)

   - Write a message to the trace buffer that its being disabled when
     disable_trace_on_warning() is set.

   - Separate out synthetic events from histogram code to let it be used
     by other parts of the kernel.

   - More documentation on histogram design.

   - Other small fixes and clean ups"

* tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option
  tracing/doc: Fix ascii-art in histogram-design.rst
  tracing: Add a trace print when traceoff_on_warning is triggered
  ftrace,bug: Improve traceoff_on_warn
  selftests/ftrace: Distinguish between hist and synthetic event checks
  tracing: Move synthetic events to a separate file
  tracing: Fix events.rst section numbering
  tracing/doc: Fix typos in histogram-design.rst
  tracing: Add hist_debug trace event files for histogram debugging
  tracing: Add histogram-design document
  tracing: Check state.disabled in synth event trace functions
  tracing/probe: reverse arguments to list_add
  tools/bootconfig: Add a summary of test cases and return error
  ftrace: show debugging information when panic_on_warn set
parents 595a56ac 388d8bdb

Documentation/trace/histogram-design.rst

0 → 100644
+2115 −0

File added.

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kernel/trace/Kconfig

+42 −10
Original line number Diff line number Diff line
@@ -249,15 +249,6 @@ config TRACE_PREEMPT_TOGGLE 
	  Enables hooks which will be called when preemption is first disabled,

	  and last enabled.



config PREEMPTIRQ_EVENTS

	bool "Enable trace events for preempt and irq disable/enable"

	select TRACE_IRQFLAGS

	select TRACE_PREEMPT_TOGGLE if PREEMPTION

	select GENERIC_TRACER

	default n

	help

	  Enable tracing of disable and enable events for preemption and irqs.



config IRQSOFF_TRACER

	bool "Interrupts-off Latency Tracer"

	default n
@@ -614,12 +605,30 @@ config TRACING_MAP 
	  generally used outside of that context, and is normally

	  selected by tracers that use it.



config SYNTH_EVENTS

	bool "Synthetic trace events"

	select TRACING

	select DYNAMIC_EVENTS

	default n

	help

	  Synthetic events are user-defined trace events that can be

	  used to combine data from other trace events or in fact any

	  data source.  Synthetic events can be generated indirectly

	  via the trace() action of histogram triggers or directly

	  by way of an in-kernel API.



	  See Documentation/trace/events.rst or

	  Documentation/trace/histogram.rst for details and examples.



	  If in doubt, say N.



config HIST_TRIGGERS

	bool "Histogram triggers"

	depends on ARCH_HAVE_NMI_SAFE_CMPXCHG

	select TRACING_MAP

	select TRACING

	select DYNAMIC_EVENTS

	select SYNTH_EVENTS

	default n

	help

	  Hist triggers allow one or more arbitrary trace event fields
@@ -815,7 +824,7 @@ config PREEMPTIRQ_DELAY_TEST 


config SYNTH_EVENT_GEN_TEST

	tristate "Test module for in-kernel synthetic event generation"

	depends on HIST_TRIGGERS

	depends on SYNTH_EVENTS

	help

          This option creates a test module to check the base

          functionality of in-kernel synthetic event definition and
@@ -838,6 +847,29 @@ config KPROBE_EVENT_GEN_TEST 


	  If unsure, say N.



config HIST_TRIGGERS_DEBUG

	bool "Hist trigger debug support"

	depends on HIST_TRIGGERS

	help

          Add "hist_debug" file for each event, which when read will

          dump out a bunch of internal details about the hist triggers

          defined on that event.



          The hist_debug file serves a couple of purposes:



            - Helps developers verify that nothing is broken.



            - Provides educational information to support the details

              of the hist trigger internals as described by

              Documentation/trace/histogram-design.rst.



          The hist_debug output only covers the data structures

          related to the histogram definitions themselves and doesn't

          display the internals of map buckets or variable values of

          running histograms.



          If unsure, say N.



endif # FTRACE



endif # TRACING_SUPPORT

kernel/trace/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ endif 
obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o

obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o

obj-$(CONFIG_TRACE_EVENT_INJECT) += trace_events_inject.o

obj-$(CONFIG_SYNTH_EVENTS) += trace_events_synth.o

obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o

obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o

obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe.o

kernel/trace/ftrace.c

+4 −4
Original line number Diff line number Diff line
@@ -2016,14 +2016,14 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec) 
{

	unsigned long ip = rec ? rec->ip : 0;



	pr_info("------------[ ftrace bug ]------------\n");



	switch (failed) {

	case -EFAULT:

		FTRACE_WARN_ON_ONCE(1);

		pr_info("ftrace faulted on modifying ");

		print_ip_sym(KERN_INFO, ip);

		break;

	case -EINVAL:

		FTRACE_WARN_ON_ONCE(1);

		pr_info("ftrace failed to modify ");

		print_ip_sym(KERN_INFO, ip);

		print_ip_ins(" actual:   ", (unsigned char *)ip);
@@ -2034,12 +2034,10 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec) 
		}

		break;

	case -EPERM:

		FTRACE_WARN_ON_ONCE(1);

		pr_info("ftrace faulted on writing ");

		print_ip_sym(KERN_INFO, ip);

		break;

	default:

		FTRACE_WARN_ON_ONCE(1);

		pr_info("ftrace faulted on unknown error ");

		print_ip_sym(KERN_INFO, ip);

	}
@@ -2066,6 +2064,8 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec) 
		ip = ftrace_get_addr_curr(rec);

		pr_cont("\n expected tramp: %lx\n", ip);

	}



	FTRACE_WARN_ON_ONCE(1);

}



static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)

kernel/trace/trace.c

+4 −1
Original line number Diff line number Diff line
@@ -1299,9 +1299,12 @@ EXPORT_SYMBOL_GPL(tracing_off); 


void disable_trace_on_warning(void)

{

	if (__disable_trace_on_warning)

	if (__disable_trace_on_warning) {

		trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_,

			"Disabling tracing due to warning\n");

		tracing_off();

	}

}



/**

 * tracer_tracing_is_on - show real state of ring buffer enabled

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