From: Steven Rostedt <[email protected]>
The function graph infrastructure uses subops of the function tracer.
These are not shown in enabled_functions. Add a "subops:" section to the
enabled_functions line to show what functions are attached via subops. If
the subops is from the function_graph infrastructure, then show the entry
and return callbacks that are attached.
Here's an example of the output:
schedule_on_each_cpu (1) tramp: 0xffffffffc03ef000
(ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops:
{ent:trace_graph_entry+0x0/0x20 ret:trace_graph_return+0x0/0x150}
Signed-off-by: Steven Rostedt (Google) <[email protected]>
---
include/linux/ftrace.h | 2 ++
kernel/trace/fgraph.c | 2 ++
kernel/trace/ftrace.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 40 insertions(+)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index fbabc3d848b3..fc939ca2ff66 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -328,6 +328,7 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
* DIRECT - Used by the direct ftrace_ops helper for direct functions
* (internal ftrace only, should not be used by others)
* SUBOP - Is controlled by another op in field managed.
+ * GRAPH - Is a component of the fgraph_ops structure
*/
enum {
FTRACE_OPS_FL_ENABLED = BIT(0),
@@ -349,6 +350,7 @@ enum {
FTRACE_OPS_FL_PERMANENT = BIT(16),
FTRACE_OPS_FL_DIRECT = BIT(17),
FTRACE_OPS_FL_SUBOP = BIT(18),
+ FTRACE_OPS_FL_GRAPH = BIT(19),
};
#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 8d925cbdce3a..c5b207992fb4 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1382,6 +1382,8 @@ int register_ftrace_graph(struct fgraph_ops *gops)
/* Always save the function, and reset at unregistering */
gops->saved_func = gops->entryfunc;
+ gops->ops.flags |= FTRACE_OPS_FL_GRAPH;
+
ret = ftrace_startup_subops(&graph_ops, &gops->ops, command);
if (!ret)
fgraph_array[i] = gops;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a48aedb5255..cd62f5ab3dfe 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4323,6 +4323,40 @@ static inline int print_rec(struct seq_file *m, unsigned
long ip)
}
#endif
+static void print_subops(struct seq_file *m, struct ftrace_ops *ops, struct
dyn_ftrace *rec)
+{
+ struct ftrace_ops *subops;
+ bool first = true;
+
+ list_for_each_entry(subops, &ops->subop_list, list) {
+ if (!((subops->flags & FTRACE_OPS_FL_ENABLED) &&
+ hash_contains_ip(rec->ip, subops->func_hash)))
+ continue;
+ if (first) {
+ seq_printf(m, "\tsubops:");
+ first = false;
+ }
+ if (subops->flags & FTRACE_OPS_FL_GRAPH) {
+ struct fgraph_ops *gops;
+
+ gops = container_of(subops, struct fgraph_ops, ops);
+ seq_printf(m, " {ent:%pS ret:%pS}",
+ (void *)gops->entryfunc,
+ (void *)gops->retfunc);
+ continue;
+ }
+ if (subops->trampoline) {
+ seq_printf(m, " {%pS (%pS)}",
+ (void *)subops->trampoline,
+ (void *)subops->func);
+ add_trampoline_func(m, subops, rec);
+ } else {
+ seq_printf(m, " {%pS}",
+ (void *)subops->func);
+ }
+ }
+}
+
static int t_show(struct seq_file *m, void *v)
{
struct ftrace_iterator *iter = m->private;
@@ -4375,6 +4409,7 @@ static int t_show(struct seq_file *m, void *v)
(void *)ops->trampoline,
(void *)ops->func);
add_trampoline_func(m, ops, rec);
+ print_subops(m, ops, rec);
ops = ftrace_find_tramp_ops_next(rec,
ops);
} while (ops);
} else
@@ -4387,6 +4422,7 @@ static int t_show(struct seq_file *m, void *v)
if (ops) {
seq_printf(m, "\tops: %pS (%pS)",
ops, ops->func);
+ print_subops(m, ops, rec);
} else {
seq_puts(m, "\tops: ERROR!");
}
--
2.47.2
