Merge tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Fix printf format warning for bprintf

   sunrpc uses a trace_printk() that triggers a printf warning during
   the compile. Move the __printf() attribute around for when debugging
   is not enabled the warning will go away

 - Remove redundant check for EVENT_FILE_FL_FREED in
   event_filter_write()

   The FREED flag is checked in the call to event_file_file() and then
   checked again right afterward, which is unneeded

 - Clean up event_file_file() and event_file_data() helpers

   These helper functions played a different role in the past, but now
   with eventfs, the READ_ONCE() isn't needed. Simplify the code a bit
   and also add a warning to event_file_data() if the file or its data
   is not present

 - Remove updating file->private_data in tracing open

   All access to the file private data is handled by the helper
   functions, which do not use file->private_data. Stop updating it on
   open

 - Show ENUM names in function arguments via BTF in function tracing

   When showing the function arguments when func-args option is set for
   function tracing, if one of the arguments is found to be an enum,
   show the name of the enum instead of its number

 - Add new trace_call__##name() API for tracepoints

   Tracepoints are enabled via static_branch() blocks, where when not
   enabled, there's only a nop that is in the code where the execution
   will just skip over it. When tracing is enabled, the nop is converted
   to a direct jump to the tracepoint code. Sometimes more calculations
   are required to be performed to update the parameters of the
   tracepoint. In this case, trace_##name##_enabled() is called which is
   a static_branch() that gets enabled only when the tracepoint is
   enabled. This allows the extra calculations to also be skipped by the
   nop:

	if (trace_foo_enabled()) {
		x = bar();
		trace_foo(x);
	}

   Where the x=bar() is only performed when foo is enabled. The problem
   with this approach is that there's now two static_branch() calls. One
   for checking if the tracepoint is enabled, and then again to know if
   the tracepoint should be called. The second one is redundant

   Introduce trace_call__foo() that will call the foo() tracepoint
   directly without doing a static_branch():

	if (trace_foo_enabled()) {
		x = bar();
		trace_call__foo();
	}

 - Update various locations to use the new trace_call__##name() API

 - Move snapshot code out of trace.c

   Cleaning up trace.c to not be a "dump all", move the snapshot code
   out of it and into a new trace_snapshot.c file

 - Clean up some "%*.s" to "%*s"

 - Allow boot kernel command line options to be called multiple times

   Have options like:

	ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo

   Equal to:

	ftrace_filter=foo,bar,zoo

 - Fix ipi_raise event CPU field to be a CPU field

   The ipi_raise target_cpus field is defined as a __bitmask(). There is
   now a __cpumask() field definition. Update the field to use that

 - Have hist_field_name() use a snprintf() and not a series of strcat()

   It's safer to use snprintf() that a series of strcat()

 - Fix tracepoint regfunc balancing

   A tracepoint can define a "reg" and "unreg" function that gets called
   before the tracepoint is enabled, and after it is disabled
   respectively. But on error, after the "reg" func is called and the
   tracepoint is not enabled, the "unreg" function is not called to tear
   down what the "reg" function performed

 - Fix output that shows what histograms are enabled

   Event variables are displayed incorrectly in the histogram output

   Instead of "sched.sched_wakeup.$var", it is showing
   "$sched.sched_wakeup.var" where the '$' is in the incorrect location

 - Some other simple cleanups

* tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (24 commits)
  selftests/ftrace: Add test case for fully-qualified variable references
  tracing: Fix fully-qualified variable reference printing in histograms
  tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()
  tracing: Rebuild full_name on each hist_field_name() call
  tracing: Report ipi_raise target CPUs as cpumask
  tracing: Remove duplicate latency_fsnotify() stub
  tracing: Preserve repeated trace_trigger boot parameters
  tracing: Append repeated boot-time tracing parameters
  tracing: Remove spurious default precision from show_event_trigger/filter formats
  cpufreq: Use trace_call__##name() at guarded tracepoint call sites
  tracing: Remove tracing_alloc_snapshot() when snapshot isn't defined
  tracing: Move snapshot code out of trace.c and into trace_snapshot.c
  mm: damon: Use trace_call__##name() at guarded tracepoint call sites
  btrfs: Use trace_call__##name() at guarded tracepoint call sites
  spi: Use trace_call__##name() at guarded tracepoint call sites
  i2c: Use trace_call__##name() at guarded tracepoint call sites
  kernel: Use trace_call__##name() at guarded tracepoint call sites
  tracepoint: Add trace_call__##name() API
  tracing: trace_mmap.h: fix a kernel-doc warning
  tracing: Pretty-print enum parameters in function arguments
  ...

Author: torvalds

drivers/cpufreq/amd-pstate.c

@@ -256,7 +256,7 @@ static int msr_update_perf(struct cpufreq_policy *policy, u8 min_perf,
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		union perf_cached perf = READ_ONCE(cpudata->perf);
 
-		trace_amd_pstate_epp_perf(cpudata->cpu,
+		trace_call__amd_pstate_epp_perf(cpudata->cpu,
 					  perf.highest_perf,
 					  epp,
 					  min_perf,
@@ -306,7 +306,7 @@ static int msr_set_epp(struct cpufreq_policy *policy, u8 epp)
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		union perf_cached perf = cpudata->perf;
 
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
+		trace_call__amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  epp,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
 						    cpudata->cppc_req_cached),
@@ -420,7 +420,7 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		union perf_cached perf = cpudata->perf;
 
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
+		trace_call__amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  epp,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
 						    cpudata->cppc_req_cached),
@@ -585,7 +585,7 @@ static int shmem_update_perf(struct cpufreq_policy *policy, u8 min_perf,
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		union perf_cached perf = READ_ONCE(cpudata->perf);
 
-		trace_amd_pstate_epp_perf(cpudata->cpu,
+		trace_call__amd_pstate_epp_perf(cpudata->cpu,
 					  perf.highest_perf,
 					  epp,
 					  min_perf,
@@ -663,7 +663,7 @@ static void amd_pstate_update(struct cpufreq_policy *policy, u8 min_perf,
 	}
 
 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
-		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
+		trace_call__amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
 			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
 				cpudata->cpu, fast_switch);
 	}

drivers/cpufreq/cpufreq.c

@@ -2212,7 +2212,7 @@ unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
 
 	if (trace_cpu_frequency_enabled()) {
 		for_each_cpu(cpu, policy->cpus)
-			trace_cpu_frequency(freq, cpu);
+			trace_call__cpu_frequency(freq, cpu);
 	}
 
 	return freq;

drivers/cpufreq/intel_pstate.c

@@ -3132,7 +3132,7 @@ static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, in
 		return;
 
 	sample = &cpu->sample;
-	trace_pstate_sample(trace_type,
+	trace_call__pstate_sample(trace_type,
 		0,
 		old_pstate,
 		cpu->pstate.current_pstate,

drivers/i2c/i2c-core-slave.c

@@ -89,7 +89,7 @@ int i2c_slave_event(struct i2c_client *client,
 	int ret = client->slave_cb(client, event, val);
 
 	if (trace_i2c_slave_enabled())
-		trace_i2c_slave(client, event, val, ret);
+		trace_call__i2c_slave(client, event, val, ret);
 
 	return ret;
 }

drivers/spi/spi-axi-spi-engine.c

@@ -953,7 +953,7 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
 		struct spi_transfer *xfer;
 
 		list_for_each_entry(xfer, &msg->transfers, transfer_list)
-			trace_spi_transfer_start(msg, xfer);
+			trace_call__spi_transfer_start(msg, xfer);
 	}
 
 	spin_lock_irqsave(&spi_engine->lock, flags);
@@ -987,7 +987,7 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
 		struct spi_transfer *xfer;
 
 		list_for_each_entry(xfer, &msg->transfers, transfer_list)
-			trace_spi_transfer_stop(msg, xfer);
+			trace_call__spi_transfer_stop(msg, xfer);
 	}
 
 out:

fs/btrfs/extent_map.c

@@ -1318,7 +1318,7 @@ static void btrfs_extent_map_shrinker_worker(struct work_struct *work)
 	if (trace_btrfs_extent_map_shrinker_scan_enter_enabled()) {
 		s64 nr = percpu_counter_sum_positive(&fs_info->evictable_extent_maps);
 
-		trace_btrfs_extent_map_shrinker_scan_enter(fs_info, nr);
+		trace_call__btrfs_extent_map_shrinker_scan_enter(fs_info, nr);
 	}
 
 	while (ctx.scanned < ctx.nr_to_scan && !btrfs_fs_closing(fs_info)) {
@@ -1358,7 +1358,7 @@ static void btrfs_extent_map_shrinker_worker(struct work_struct *work)
 	if (trace_btrfs_extent_map_shrinker_scan_exit_enabled()) {
 		s64 nr = percpu_counter_sum_positive(&fs_info->evictable_extent_maps);
 
-		trace_btrfs_extent_map_shrinker_scan_exit(fs_info, nr_dropped, nr);
+		trace_call__btrfs_extent_map_shrinker_scan_exit(fs_info, nr_dropped, nr);
 	}
 
 	atomic64_set(&fs_info->em_shrinker_nr_to_scan, 0);

fs/btrfs/raid56.c

@@ -1719,7 +1719,7 @@ static void submit_read_wait_bio_list(struct btrfs_raid_bio *rbio,
 			struct raid56_bio_trace_info trace_info = { 0 };
 
 			bio_get_trace_info(rbio, bio, &trace_info);
-			trace_raid56_read(rbio, bio, &trace_info);
+			trace_call__raid56_read(rbio, bio, &trace_info);
 		}
 		submit_bio(bio);
 	}
@@ -2404,7 +2404,7 @@ static void submit_write_bios(struct btrfs_raid_bio *rbio,
 			struct raid56_bio_trace_info trace_info = { 0 };
 
 			bio_get_trace_info(rbio, bio, &trace_info);
-			trace_raid56_write(rbio, bio, &trace_info);
+			trace_call__raid56_write(rbio, bio, &trace_info);
 		}
 		submit_bio(bio);
 	}

include/linux/ftrace.h

@@ -31,7 +31,7 @@
 #define ARCH_SUPPORTS_FTRACE_OPS 0
 #endif
 
-#ifdef CONFIG_TRACING
+#ifdef CONFIG_TRACER_SNAPSHOT
 extern void ftrace_boot_snapshot(void);
 #else
 static inline void ftrace_boot_snapshot(void) { }

include/linux/trace_printk.h

@@ -107,7 +107,6 @@ do {									\
 		__trace_printk(_THIS_IP_, fmt, ##args);			\
 } while (0)
 
-extern __printf(2, 3)
 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
 
 extern __printf(2, 3)

include/linux/tracepoint.h

@@ -314,6 +314,10 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 			WARN_ONCE(!rcu_is_watching(),			\
 				  "RCU not watching for tracepoint");	\
 		}							\
+	}								\
+	static inline void trace_call__##name(proto)			\
+	{								\
+		__do_trace_##name(args);				\
 	}
 
 #define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto)		\
@@ -333,6 +337,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 			WARN_ONCE(!rcu_is_watching(),			\
 				  "RCU not watching for tracepoint");	\
 		}							\
+	}								\
+	static inline void trace_call__##name(proto)			\
+	{								\
+		might_fault();						\
+		__do_trace_##name(args);				\
 	}
 
 /*
@@ -418,6 +427,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 #define __DECLARE_TRACE_COMMON(name, proto, args, data_proto)		\
 	static inline void trace_##name(proto)				\
 	{ }								\
+	static inline void trace_call__##name(proto)			\
+	{ }								\
 	static inline int						\
 	register_trace_##name(void (*probe)(data_proto),		\
 			      void *data)				\