Merge tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Updates for tracing and bootconfig:

   - Add support for "bool" type in synthetic events

   - Add per instance tracing for bootconfig

   - Support perf-style return probe ("SYMBOL%return") in kprobes and
     uprobes

   - Allow for kprobes to be enabled earlier in boot up

   - Added tracepoint helper function to allow testing if tracepoints
     are enabled in headers

   - Synthetic events can now have dynamic strings (variable length)

   - Various fixes and cleanups"

* tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (58 commits)
  tracing: support "bool" type in synthetic trace events
  selftests/ftrace: Add test case for synthetic event syntax errors
  tracing: Handle synthetic event array field type checking correctly
  selftests/ftrace: Change synthetic event name for inter-event-combined test
  tracing: Add synthetic event error logging
  tracing: Check that the synthetic event and field names are legal
  tracing: Move is_good_name() from trace_probe.h to trace.h
  tracing: Don't show dynamic string internals in synthetic event description
  tracing: Fix some typos in comments
  tracing/boot: Add ftrace.instance.*.alloc_snapshot option
  tracing: Fix race in trace_open and buffer resize call
  tracing: Check return value of __create_val_fields() before using its result
  tracing: Fix synthetic print fmt check for use of __get_str()
  tracing: Remove a pointless assignment
  ftrace: ftrace_global_list is renamed to ftrace_ops_list
  ftrace: Format variable declarations of ftrace_allocate_records
  ftrace: Simplify the calculation of page number for ftrace_page->records
  ftrace: Simplify the dyn_ftrace->flags macro
  ftrace: Simplify the hash calculation
  ftrace: Use fls() to get the bits for dup_hash()
  ...

1 files changed, 21 insertions, 2 deletions

diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index fa0fc08c6ef8..c22a152ef0b4 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -40,6 +40,16 @@ trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
 			pr_err("Failed to set option: %s\n", buf);
 	}
 
+	p = xbc_node_find_value(node, "tracing_on", NULL);
+	if (p && *p != '\0') {
+		if (kstrtoul(p, 10, &v))
+			pr_err("Failed to set tracing on: %s\n", p);
+		if (v)
+			tracer_tracing_on(tr);
+		else
+			tracer_tracing_off(tr);
+	}
+
 	p = xbc_node_find_value(node, "trace_clock", NULL);
 	if (p && *p != '\0') {
 		if (tracing_set_clock(tr, p) < 0)
@@ -274,6 +284,12 @@ trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
 		if (tracing_set_tracer(tr, p) < 0)
 			pr_err("Failed to set given tracer: %s\n", p);
 	}
+
+	/* Since tracer can free snapshot buffer, allocate snapshot here.*/
+	if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
+		if (tracing_alloc_snapshot_instance(tr) < 0)
+			pr_err("Failed to allocate snapshot buffer\n");
+	}
 }
 
 static void __init
@@ -330,5 +346,8 @@ static int __init trace_boot_init(void)
 
 	return 0;
 }
-
-fs_initcall(trace_boot_init);
+/*
+ * Start tracing at the end of core-initcall, so that it starts tracing
+ * from the beginning of postcore_initcall.
+ */
+core_initcall_sync(trace_boot_init);