[RFC][PATCH 05/14 v2] ftrace/function_graph: Pass fgraph_ops to function graph callbacks

From: Steven Rostedt
Date: Mon May 20 2019 - 10:24:49 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

Pass the fgraph_ops structure to the function graph callbacks. This will
allow callbacks to add a descriptor to a fgraph_ops private field that wil
be added in the future and use it for the callbacks. This will be useful
when more than one callback can be registered to the function graph tracer.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/linux/ftrace.h | 10 +++++++---
kernel/trace/fgraph.c | 14 ++++++++------
kernel/trace/ftrace.c | 6 ++++--
kernel/trace/trace.h | 4 ++--
kernel/trace/trace_functions_graph.c | 11 +++++++----
kernel/trace/trace_irqsoff.c | 6 ++++--
kernel/trace/trace_sched_wakeup.c | 6 ++++--
kernel/trace/trace_selftest.c | 5 +++--
8 files changed, 39 insertions(+), 23 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 6fe69e0dc415..906f7c25faa6 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -737,11 +737,15 @@ struct ftrace_graph_ret {
int depth;
} __packed;

+struct fgraph_ops;
+
/* Type of the callback handlers for tracing function graph*/
-typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
-typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
+typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *,
+ struct fgraph_ops *); /* return */
+typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
+ struct fgraph_ops *); /* entry */

-extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
+extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index ce7212830207..0af9d40c4363 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -128,13 +128,13 @@ static inline int get_fgraph_array(struct task_struct *t, int offset)
}

/* ftrace_graph_entry set to this to tell some archs to run function graph */
-static int entry_run(struct ftrace_graph_ent *trace)
+static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops)
{
return 0;
}

/* ftrace_graph_return set to this to tell some archs to run function graph */
-static void return_run(struct ftrace_graph_ret *trace)
+static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops)
{
return;
}
@@ -177,12 +177,14 @@ get_ret_stack(struct task_struct *t, int offset, int *index)
/* Both enabled by default (can be cleared by function_graph tracer flags */
static bool fgraph_sleep_time = true;

-int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
return 0;
}

-static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace)
+static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
}

@@ -320,7 +322,7 @@ int function_graph_enter(unsigned long ret, unsigned long func,
atomic_inc(&current->trace_overrun);
break;
}
- if (fgraph_array[i]->entryfunc(&trace)) {
+ if (fgraph_array[i]->entryfunc(&trace, fgraph_array[i])) {
offset = current->curr_ret_stack;
/* Check the top level stored word */
type = get_fgraph_type(current, offset - 1);
@@ -487,7 +489,7 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
i = 0;
do {
idx = get_fgraph_array(current, offset - i);
- fgraph_array[idx]->retfunc(&trace);
+ fgraph_array[idx]->retfunc(&trace, fgraph_array[idx]);
i++;
} while (i < index);

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9f3282d10f47..64b60217d037 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -790,7 +790,8 @@ void ftrace_graph_graph_time_control(bool enable)
fgraph_graph_time = enable;
}

-static int profile_graph_entry(struct ftrace_graph_ent *trace)
+static int profile_graph_entry(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
struct ftrace_ret_stack *ret_stack;

@@ -807,7 +808,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace)
return 1;
}

-static void profile_graph_return(struct ftrace_graph_ret *trace)
+static void profile_graph_return(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
struct ftrace_ret_stack *ret_stack;
struct ftrace_profile_stat *stat;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1974ce818ddb..48f152ca3558 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -737,8 +737,8 @@ void trace_default_header(struct seq_file *m);
void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
int trace_empty(struct trace_iterator *iter);

-void trace_graph_return(struct ftrace_graph_ret *trace);
-int trace_graph_entry(struct ftrace_graph_ent *trace);
+void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
+int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
void set_graph_array(struct trace_array *tr);

void tracing_start_cmdline_record(void);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 69ebf3c2f1b5..2ae21788fcaf 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -124,7 +124,8 @@ static inline int ftrace_graph_ignore_irqs(void)
return in_irq();
}

-int trace_graph_entry(struct ftrace_graph_ent *trace)
+int trace_graph_entry(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = graph_array;
struct trace_array_cpu *data;
@@ -237,7 +238,8 @@ void __trace_graph_return(struct trace_array *tr,
trace_buffer_unlock_commit_nostack(buffer, event);
}

-void trace_graph_return(struct ftrace_graph_ret *trace)
+void trace_graph_return(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = graph_array;
struct trace_array_cpu *data;
@@ -274,7 +276,8 @@ void set_graph_array(struct trace_array *tr)
smp_mb();
}

-static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
+static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
ftrace_graph_addr_finish(trace);

@@ -287,7 +290,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
(trace->rettime - trace->calltime < tracing_thresh))
return;
else
- trace_graph_return(trace);
+ trace_graph_return(trace, gops);
}

static struct fgraph_ops funcgraph_thresh_ops = {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index a745b0cee5d3..55c547f6e31d 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -172,7 +172,8 @@ static int irqsoff_display_graph(struct trace_array *tr, int set)
return start_irqsoff_tracer(irqsoff_trace, set);
}

-static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
+static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
@@ -202,7 +203,8 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
return ret;
}

-static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
+static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 743b2b520d34..9da1062a8181 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -112,7 +112,8 @@ static int wakeup_display_graph(struct trace_array *tr, int set)
return start_func_tracer(tr, set);
}

-static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
+static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
@@ -142,7 +143,8 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
return ret;
}

-static void wakeup_graph_return(struct ftrace_graph_ret *trace)
+static void wakeup_graph_return(struct ftrace_graph_ret *trace,
+ struct fgraph_ops *gops)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 69ee8ef12cee..8639d278b6b2 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -724,7 +724,8 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
static unsigned int graph_hang_thresh;

/* Wrap the real function entry probe to avoid possible hanging */
-static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
+static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace,
+ struct fgraph_ops *gops)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
@@ -738,7 +739,7 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
return 0;
}

- return trace_graph_entry(trace);
+ return trace_graph_entry(trace, gops);
}

static struct fgraph_ops fgraph_ops __initdata = {
--
2.20.1