[for-next][PATCH 15/33] tracing: Have the snapshot trigger use the mapping helper functions

[Steven Rostedt <rostedt@goodmis.org>]

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From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

As the data pointer for individual ips will soon be removed and no longer
passed to the callback function probe handlers, convert the snapshot
trigger counter over to the new ftrace_func_mapper helper functions.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 52 ++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 41e9a20f91f0..7febeb823c62 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6745,13 +6745,19 @@ static void
 ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
 		      struct ftrace_probe_ops *ops, void **data)
 {
-	unsigned long *count = (long *)data;
+	struct ftrace_func_mapper *mapper = ops->private_data;
+	long *count = NULL;
 
-	if (!*count)
-		return;
+	if (mapper)
+		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+	if (count) {
+
+		if (*count <= 0)
+			return;
 
-	if (*count != -1)
 		(*count)--;
+	}
 
 	tracing_snapshot();
 }
@@ -6760,20 +6766,42 @@ static int
 ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
 		      struct ftrace_probe_ops *ops, void *data)
 {
-	long count = (long)data;
+	struct ftrace_func_mapper *mapper = ops->private_data;
+	long *count = NULL;
 
 	seq_printf(m, "%ps:", (void *)ip);
 
 	seq_puts(m, "snapshot");
 
-	if (count == -1)
-		seq_puts(m, ":unlimited\n");
+	if (mapper)
+		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+	if (count)
+		seq_printf(m, ":count=%ld\n", *count);
 	else
-		seq_printf(m, ":count=%ld\n", count);
+		seq_puts(m, ":unlimited\n");
 
 	return 0;
 }
 
+static int
+ftrace_snapshot_init(struct ftrace_probe_ops *ops, unsigned long ip,
+		     void **data)
+{
+	struct ftrace_func_mapper *mapper = ops->private_data;
+
+	return ftrace_func_mapper_add_ip(mapper, ip, *data);
+}
+
+static void
+ftrace_snapshot_free(struct ftrace_probe_ops *ops, unsigned long ip,
+		     void **_data)
+{
+	struct ftrace_func_mapper *mapper = ops->private_data;
+
+	ftrace_func_mapper_remove_ip(mapper, ip);
+}
+
 static struct ftrace_probe_ops snapshot_probe_ops = {
 	.func			= ftrace_snapshot,
 	.print			= ftrace_snapshot_print,
@@ -6782,6 +6810,8 @@ static struct ftrace_probe_ops snapshot_probe_ops = {
 static struct ftrace_probe_ops snapshot_count_probe_ops = {
 	.func			= ftrace_count_snapshot,
 	.print			= ftrace_snapshot_print,
+	.init			= ftrace_snapshot_init,
+	.free			= ftrace_snapshot_free,
 };
 
 static int
@@ -6812,6 +6842,12 @@ ftrace_trace_snapshot_callback(struct ftrace_hash *hash,
 	if (!strlen(number))
 		goto out_reg;
 
+	if (!ops->private_data) {
+		ops->private_data = allocate_ftrace_func_mapper();
+		if (!ops->private_data)
+			return -ENOMEM;
+	}
+
 	/*
 	 * We use the callback data field (which is a pointer)
 	 * as our counter.
-- 
2.10.2