Add following function-graph tracer related options
- ftrace.fgraph.filters = FILTER[, FILTER2...];
Add fgraph tracing function filters.
- ftrace.fgraph.notraces = FILTER[, FILTER2...];
Add fgraph non tracing function filters.
- ftrace.fgraph.max_depth = MAX_DEPTH;
Set MAX_DEPTH to maximum depth of fgraph tracer.
Note that these properties are available on ftrace global node
only, because these filters are globally applied.
Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
---
kernel/trace/ftrace.c | 85 +++++++++++++++++++++++++++++----------------
kernel/trace/trace_boot.c | 71 ++++++++++++++++++++++++++++++++++++++
2 files changed, 126 insertions(+), 30 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca34503f178..e016ce12e60a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1241,7 +1241,7 @@ static void clear_ftrace_mod_list(struct list_head *head)
mutex_unlock(&ftrace_lock);
}
-static void free_ftrace_hash(struct ftrace_hash *hash)
+void free_ftrace_hash(struct ftrace_hash *hash)
{
if (!hash || hash == EMPTY_HASH)
return;
@@ -4897,7 +4897,7 @@ __setup("ftrace_filter=", set_ftrace_filter);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
-static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
+int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
static int __init set_graph_function(char *str)
{
@@ -5226,6 +5226,26 @@ __ftrace_graph_open(struct inode *inode, struct file
*file,
return ret;
}
+struct ftrace_hash *ftrace_graph_copy_hash(bool enable)
+{
+ struct ftrace_hash *hash;
+
+ mutex_lock(&graph_lock);
+
+ if (enable)
+ hash = rcu_dereference_protected(ftrace_graph_hash,
+ lockdep_is_held(&graph_lock));
+ else
+ hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+ lockdep_is_held(&graph_lock));
+
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
+
+ mutex_unlock(&graph_lock);
+
+ return hash;
+}
+
static int
ftrace_graph_open(struct inode *inode, struct file *file)
{
@@ -5282,11 +5302,40 @@ ftrace_graph_notrace_open(struct inode *inode, struct
file *file)
return ret;
}
+int ftrace_graph_apply_hash(struct ftrace_hash *hash, bool enable)
+{
+ struct ftrace_hash *old_hash, *new_hash;
+
+ new_hash = __ftrace_hash_move(hash);
+ if (!new_hash)
+ return -ENOMEM;
+
+ mutex_lock(&graph_lock);
+
+ if (enable) {
+ old_hash = rcu_dereference_protected(ftrace_graph_hash,
+ lockdep_is_held(&graph_lock));
+ rcu_assign_pointer(ftrace_graph_hash, new_hash);
+ } else {
+ old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+ lockdep_is_held(&graph_lock));
+ rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
+ }
+
+ mutex_unlock(&graph_lock);
+
+ /* Wait till all users are no longer using the old hash */
+ synchronize_rcu();
+
+ free_ftrace_hash(old_hash);
+
+ return 0;
+}
+
static int
ftrace_graph_release(struct inode *inode, struct file *file)
{
struct ftrace_graph_data *fgd;
- struct ftrace_hash *old_hash, *new_hash;
struct trace_parser *parser;
int ret = 0;
@@ -5311,41 +5360,17 @@ ftrace_graph_release(struct inode *inode, struct file
*file)
trace_parser_put(parser);
- new_hash = __ftrace_hash_move(fgd->new_hash);
- if (!new_hash) {
- ret = -ENOMEM;
- goto out;
- }
-
- mutex_lock(&graph_lock);
-
- if (fgd->type == GRAPH_FILTER_FUNCTION) {
- old_hash = rcu_dereference_protected(ftrace_graph_hash,
- lockdep_is_held(&graph_lock));
- rcu_assign_pointer(ftrace_graph_hash, new_hash);
- } else {
- old_hash =
rcu_dereference_protected(ftrace_graph_notrace_hash,
- lockdep_is_held(&graph_lock));
- rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
- }
-
- mutex_unlock(&graph_lock);
-
- /* Wait till all users are no longer using the old hash */
- synchronize_rcu();
-
- free_ftrace_hash(old_hash);
+ ret = ftrace_graph_apply_hash(fgd->new_hash,
+ fgd->type == GRAPH_FILTER_FUNCTION);
}
- out:
free_ftrace_hash(fgd->new_hash);
kfree(fgd);
return ret;
}
-static int
-ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
+int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
{
struct ftrace_glob func_g;
struct dyn_ftrace *rec;
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 942ca8d3fcc8..b32688032d36 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -72,6 +72,75 @@ trace_boot_set_instance_options(struct trace_array *tr,
struct skc_node *node)
}
}
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern unsigned int fgraph_max_depth;
+extern struct ftrace_hash *ftrace_graph_copy_hash(bool enable);
+extern int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
+extern int ftrace_graph_apply_hash(struct ftrace_hash *hash, bool enable);
+extern void free_ftrace_hash(struct ftrace_hash *hash);
+
+static void __init
+trace_boot_set_fgraph_filter(struct skc_node *node, const char *option,
+ bool enable)
+{
+ struct ftrace_hash *hash;
+ struct skc_node *anode;
+ const char *p;
+ char *q;
+ int err;
+ bool updated = false;
+
+ hash = ftrace_graph_copy_hash(enable);
+ if (!hash) {
+ pr_err("Failed to copy fgraph hash\n");
+ return;
+ }
+ skc_node_for_each_array_value(node, option, anode, p) {
+ q = kstrdup(p, GFP_KERNEL);
+ if (!q)
+ goto free_hash;
+ err = ftrace_graph_set_hash(hash, q);
+ kfree(q);
+ if (err)
+ pr_err("Failed to add %s: %s\n", option, p);
+ else
+ updated = true;
+ }
+ if (!updated)
+ goto free_hash;
+
+ if (ftrace_graph_apply_hash(hash, enable) < 0)
+ pr_err("Failed to apply new fgraph hash\n");
+ else {
+ /* If succeeded to apply new hash, old hash is released */
+ return;
+ }
+
+free_hash:
+ free_ftrace_hash(hash);
+}
+
+static void __init
+trace_boot_set_fgraph_options(struct skc_node *node)
+{
+ const char *p;
+ unsigned long v;
+
+ node = skc_node_find_child(node, "fgraph");
+ if (!node)
+ return;
+
+ trace_boot_set_fgraph_filter(node, "filters", true);
+ trace_boot_set_fgraph_filter(node, "notraces", false);
+
+ p = skc_node_find_value(node, "max_depth", NULL);
+ if (p && *p != '\0' && !kstrtoul(p, 0, &v))
+ fgraph_max_depth = (unsigned int)v;
+}
+#else
+#define trace_boot_set_fgraph_options(node) do {} while (0)
+#endif
+
static void __init
trace_boot_set_global_options(struct trace_array *tr, struct skc_node *node)
{
@@ -98,6 +167,8 @@ trace_boot_set_global_options(struct trace_array *tr, struct
skc_node *node)
if (skc_node_find_value(node, "alloc_snapshot", NULL))
if (tracing_alloc_snapshot() < 0)
pr_err("Failed to allocate snapshot buffer\n");
+
+ trace_boot_set_fgraph_options(node);
}
#ifdef CONFIG_EVENT_TRACING
