[PATCH 11/19] perf ftrace: add option '-u/--userstacktrace' to show userspace stacktrace

[Changbin Du]

This adds an option ''-u/--userstacktrace' for function tracer to display
userspace back trace.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
 tools/perf/builtin-ftrace.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 2ef5d1c4b23c..ab76ba66bd9e 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -40,6 +40,7 @@ struct perf_ftrace {
 	struct list_head	nograph_funcs;
 	int			graph_depth;
 	bool			func_stack_trace;
+	bool			userstacktrace;
 	bool			nosleep_time;
 	bool			nofuncgraph_irqs;
 	bool			funcgraph_tail;
@@ -197,6 +198,8 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
 	write_tracing_option_file("funcgraph-proc", "0");
 	write_tracing_option_file("funcgraph-abstime", "0");
 	write_tracing_option_file("irq-info", "0");
+	write_tracing_option_file("userstacktrace", "0");
+	write_tracing_option_file("sym-userobj", "0");
 }
 
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -287,6 +290,20 @@ static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_userstacktrace(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->userstacktrace)
+		return 0;
+
+	if (write_tracing_option_file("userstacktrace", "1") < 0)
+		return -1;
+
+	if (write_tracing_option_file("sym-userobj", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int reset_tracing_cpu(void)
 {
 	struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@@ -482,6 +499,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_userstacktrace(ftrace) < 0) {
+		pr_err("failed to set tracing option userstacktrace\n");
+		goto out_reset;
+	}
+
 	if (set_tracing_filters(ftrace) < 0) {
 		pr_err("failed to set tracing filters\n");
 		goto out_reset;
@@ -644,6 +666,8 @@ int cmd_ftrace(int argc, const char **argv)
 		     "do not trace given functions", parse_filter_func),
 	OPT_BOOLEAN('s', "func-stack-trace", &ftrace.func_stack_trace,
 		    "Show kernel stack trace for function tracer"),
+	OPT_BOOLEAN('u', "userstacktrace", &ftrace.userstacktrace,
+		    "Show stacktrace of the current user space thread"),
 	OPT_CALLBACK_DEFAULT('G', "graph-funcs", &ftrace.graph_funcs, "func",
 		     "Set graph filter on given functions (imply to use function_graph tracer)",
 		     parse_filter_func, "*"),
-- 
2.25.1