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

Allow for instances to have their own ftrace_ops part of the fgraph_ops that
makes the funtion_graph tracer filter on the set_ftrace_filter file of the
instance and not the top instance.

Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
---
 include/linux/ftrace.h               |    1 +
 kernel/trace/fgraph.c                |   60 +++++++++++++++++++++-------------
 kernel/trace/ftrace.c                |    6 ++-
 kernel/trace/trace.h                 |   16 +++++----
 kernel/trace/trace_functions.c       |    2 +
 kernel/trace/trace_functions_graph.c |    8 +++--
 6 files changed, 58 insertions(+), 35 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7fd044ae3da5..9dab365c6023 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -1044,6 +1044,7 @@ extern int ftrace_graph_entry_stub(struct 
ftrace_graph_ent *trace, struct fgraph
 struct fgraph_ops {
        trace_func_graph_ent_t          entryfunc;
        trace_func_graph_ret_t          retfunc;
+       struct ftrace_ops               ops; /* for the hash lists */
        void                            *private;
 };
 
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 1e8c17f70b84..0642f3281b64 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -17,14 +17,6 @@
 #include "ftrace_internal.h"
 #include "trace.h"
 
-#ifdef CONFIG_DYNAMIC_FTRACE
-#define ASSIGN_OPS_HASH(opsname, val) \
-       .func_hash              = val, \
-       .local_hash.regex_lock  = 
__MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
-#else
-#define ASSIGN_OPS_HASH(opsname, val)
-#endif
-
 #define FGRAPH_RET_SIZE sizeof(struct ftrace_ret_stack)
 #define FGRAPH_RET_INDEX (FGRAPH_RET_SIZE / sizeof(long))
 
@@ -338,9 +330,6 @@ int function_graph_enter(unsigned long ret, unsigned long 
func,
                return -EBUSY;
 #endif
 
-       if (!ftrace_ops_test(&global_ops, func, NULL))
-               return -EBUSY;
-
        trace.func = func;
        trace.depth = ++current->curr_ret_depth;
 
@@ -361,7 +350,8 @@ int function_graph_enter(unsigned long ret, unsigned long 
func,
                        atomic_inc(&current->trace_overrun);
                        break;
                }
-               if (fgraph_array[i]->entryfunc(&trace, fgraph_array[i])) {
+               if (ftrace_ops_test(&gops->ops, func, NULL) &&
+                   gops->entryfunc(&trace, gops)) {
                        offset = current->curr_ret_stack;
                        /* Check the top level stored word */
                        type = get_fgraph_type(current, offset - 1);
@@ -656,17 +646,25 @@ unsigned long ftrace_graph_ret_addr(struct task_struct 
*task, int *idx,
 }
 #endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
 
-static struct ftrace_ops graph_ops = {
-       .func                   = ftrace_graph_func,
-       .flags                  = FTRACE_OPS_FL_INITIALIZED |
-                                  FTRACE_OPS_FL_PID |
-                                  FTRACE_OPS_GRAPH_STUB,
+void fgraph_init_ops(struct ftrace_ops *dst_ops,
+                    struct ftrace_ops *src_ops)
+{
+       dst_ops->func = ftrace_stub;
+       dst_ops->flags = FTRACE_OPS_FL_PID | FTRACE_OPS_FL_STUB;
+
 #ifdef FTRACE_GRAPH_TRAMP_ADDR
-       .trampoline             = FTRACE_GRAPH_TRAMP_ADDR,
+       dst_ops->trampoline = FTRACE_GRAPH_TRAMP_ADDR;
        /* trampoline_size is only needed for dynamically allocated tramps */
 #endif
-       ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
-};
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+       if (src_ops) {
+               dst_ops->func_hash = &src_ops->local_hash;
+               mutex_init(&dst_ops->local_hash.regex_lock);
+               dst_ops->flags |= FTRACE_OPS_FL_INITIALIZED;
+       }
+#endif
+}
 
 void ftrace_graph_sleep_time_control(bool enable)
 {
@@ -871,11 +869,20 @@ static int start_graph_tracing(void)
 
 int register_ftrace_graph(struct fgraph_ops *gops)
 {
+       int command = 0;
        int ret = 0;
        int i;
 
        mutex_lock(&ftrace_lock);
 
+       if (!gops->ops.func) {
+               gops->ops.flags |= FTRACE_OPS_FL_STUB;
+               gops->ops.func = ftrace_stub;
+#ifdef FTRACE_GRAPH_TRAMP_ADDR
+               gops->ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR;
+#endif
+       }
+
        if (!fgraph_array[0]) {
                /* The array must always have real data on it */
                for (i = 0; i < FGRAPH_ARRAY_SIZE; i++) {
@@ -912,9 +919,10 @@ int register_ftrace_graph(struct fgraph_ops *gops)
                 */
                ftrace_graph_return = return_run;
                ftrace_graph_entry = entry_run;
-
-               ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
+               command = FTRACE_START_FUNC_RET;
        }
+
+       ret = ftrace_startup(&gops->ops, command);
 out:
        mutex_unlock(&ftrace_lock);
        return ret;
@@ -922,6 +930,7 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 
 void unregister_ftrace_graph(struct fgraph_ops *gops)
 {
+       int command = 0;
        int i;
 
        mutex_lock(&ftrace_lock);
@@ -944,10 +953,15 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
        }
 
        ftrace_graph_active--;
+
+       if (!ftrace_graph_active)
+               command = FTRACE_STOP_FUNC_RET;
+
+       ftrace_shutdown(&gops->ops, command);
+
        if (!ftrace_graph_active) {
                ftrace_graph_return = ftrace_stub_graph;
                ftrace_graph_entry = ftrace_graph_entry_stub;
-               ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
                unregister_pm_notifier(&ftrace_suspend_notifier);
                unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, 
NULL);
        }
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 83fbfb7b48f8..c4cc2a9d0047 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3050,6 +3050,8 @@ int ftrace_startup(struct ftrace_ops *ops, int command)
        if (unlikely(ftrace_disabled))
                return -ENODEV;
 
+       ftrace_ops_init(ops);
+
        ret = __register_ftrace_function(ops);
        if (ret)
                return ret;
@@ -7319,7 +7321,7 @@ __init void ftrace_init_global_array_ops(struct 
trace_array *tr)
        tr->ops = &global_ops;
        tr->ops->private = tr;
        ftrace_init_trace_array(tr);
-       init_array_fgraph_ops(tr);
+       init_array_fgraph_ops(tr, tr->ops);
 }
 
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
@@ -8051,7 +8053,7 @@ static int register_ftrace_function_nolock(struct 
ftrace_ops *ops)
  */
 int register_ftrace_function(struct ftrace_ops *ops)
 {
-       int ret;
+       int ret = -1;
 
        lock_direct_mutex();
        ret = prepare_direct_functions_for_ipmodify(ops);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 73fe789ba143..531cfdb44911 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -886,8 +886,8 @@ extern int __trace_graph_entry(struct trace_array *tr,
 extern void __trace_graph_return(struct trace_array *tr,
                                 struct ftrace_graph_ret *trace,
                                 unsigned int trace_ctx);
-extern void init_array_fgraph_ops(struct trace_array *tr);
-extern int allocate_fgraph_ops(struct trace_array *tr);
+extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops 
*ops);
+extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
 extern void free_fgraph_ops(struct trace_array *tr);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -970,6 +970,7 @@ static inline int ftrace_graph_notrace_addr(unsigned long 
addr)
        preempt_enable_notrace();
        return ret;
 }
+
 #else
 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
 {
@@ -995,18 +996,19 @@ static inline bool ftrace_graph_ignore_func(struct 
ftrace_graph_ent *trace)
                (fgraph_max_depth && trace->depth >= fgraph_max_depth);
 }
 
+void fgraph_init_ops(struct ftrace_ops *dst_ops,
+                    struct ftrace_ops *src_ops);
+
 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 static inline enum print_line_t
 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 {
        return TRACE_TYPE_UNHANDLED;
 }
-static inline void init_array_fgraph_ops(struct trace_array *tr) { }
-static inline int allocate_fgraph_ops(struct trace_array *tr)
-{
-       return 0;
-}
 static inline void free_fgraph_ops(struct trace_array *tr) { }
+/* ftrace_ops may not be defined */
+#define init_array_fgraph_ops(tr, ops) do { } while (0)
+#define allocate_fgraph_ops(tr, ops) ({ 0; })
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 extern struct list_head ftrace_pids;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8e8da0d0ee52..13bf2415245d 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -91,7 +91,7 @@ int ftrace_create_function_files(struct trace_array *tr,
        if (!tr->ops)
                return -EINVAL;
 
-       ret = allocate_fgraph_ops(tr);
+       ret = allocate_fgraph_ops(tr, tr->ops);
        if (ret) {
                kfree(tr->ops);
                return ret;
diff --git a/kernel/trace/trace_functions_graph.c 
b/kernel/trace/trace_functions_graph.c
index 9ccc904a7703..7f30652f0e97 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -288,7 +288,7 @@ static struct fgraph_ops funcgraph_ops = {
        .retfunc = &trace_graph_return,
 };
 
-int allocate_fgraph_ops(struct trace_array *tr)
+int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops)
 {
        struct fgraph_ops *gops;
 
@@ -301,6 +301,9 @@ int allocate_fgraph_ops(struct trace_array *tr)
 
        tr->gops = gops;
        gops->private = tr;
+
+       fgraph_init_ops(&gops->ops, ops);
+
        return 0;
 }
 
@@ -309,10 +312,11 @@ void free_fgraph_ops(struct trace_array *tr)
        kfree(tr->gops);
 }
 
-__init void init_array_fgraph_ops(struct trace_array *tr)
+__init void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops 
*ops)
 {
        tr->gops = &funcgraph_ops;
        funcgraph_ops.private = tr;
+       fgraph_init_ops(&tr->gops->ops, ops);
 }
 
 static int graph_trace_init(struct trace_array *tr)


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