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

The use of the task->trace_recursion for the logic used for the function
graph no-trace was a bit of an abuse of that variable. Now that there
exists global vars that are per stack for registered graph traces, use
that instead.

Link: 
https://lore.kernel.org/linux-trace-kernel/171509107907.162236.6564679266777519065.stgit@devnote2

Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
---
 include/linux/trace_recursion.h      |  7 -------
 kernel/trace/trace.h                 |  9 +++++++++
 kernel/trace/trace_functions_graph.c | 10 ++++++----
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h
index fdfb6f66718a..ae04054a1be3 100644
--- a/include/linux/trace_recursion.h
+++ b/include/linux/trace_recursion.h
@@ -44,13 +44,6 @@ enum {
  */
        TRACE_IRQ_BIT,
 
-       /*
-        * To implement set_graph_notrace, if this bit is set, we ignore
-        * function graph tracing of called functions, until the return
-        * function is called to clear it.
-        */
-       TRACE_GRAPH_NOTRACE_BIT,
-
        /* Used to prevent recursion recording from recursing. */
        TRACE_RECORD_RECURSION_BIT,
 };
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 82d879dc63ff..b37402e3f0c9 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -919,8 +919,17 @@ enum {
 
        TRACE_GRAPH_DEPTH_START_BIT,
        TRACE_GRAPH_DEPTH_END_BIT,
+
+       /*
+        * To implement set_graph_notrace, if this bit is set, we ignore
+        * function graph tracing of called functions, until the return
+        * function is called to clear it.
+        */
+       TRACE_GRAPH_NOTRACE_BIT,
 };
 
+#define TRACE_GRAPH_NOTRACE            (1 << TRACE_GRAPH_NOTRACE_BIT)
+
 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
 {
        return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
diff --git a/kernel/trace/trace_functions_graph.c 
b/kernel/trace/trace_functions_graph.c
index 66cce73e94f8..13d0387ac6a6 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -130,6 +130,7 @@ static inline int ftrace_graph_ignore_irqs(void)
 int trace_graph_entry(struct ftrace_graph_ent *trace,
                      struct fgraph_ops *gops)
 {
+       unsigned long *task_var = fgraph_get_task_var(gops);
        struct trace_array *tr = gops->private;
        struct trace_array_cpu *data;
        unsigned long flags;
@@ -138,7 +139,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
        int ret;
        int cpu;
 
-       if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT))
+       if (*task_var & TRACE_GRAPH_NOTRACE)
                return 0;
 
        /*
@@ -149,7 +150,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
         * returning from the function.
         */
        if (ftrace_graph_notrace_addr(trace->func)) {
-               trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT);
+               *task_var |= TRACE_GRAPH_NOTRACE_BIT;
                /*
                 * Need to return 1 to have the return called
                 * that will clear the NOTRACE bit.
@@ -240,6 +241,7 @@ void __trace_graph_return(struct trace_array *tr,
 void trace_graph_return(struct ftrace_graph_ret *trace,
                        struct fgraph_ops *gops)
 {
+       unsigned long *task_var = fgraph_get_task_var(gops);
        struct trace_array *tr = gops->private;
        struct trace_array_cpu *data;
        unsigned long flags;
@@ -249,8 +251,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
 
        ftrace_graph_addr_finish(gops, trace);
 
-       if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
-               trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
+       if (*task_var & TRACE_GRAPH_NOTRACE) {
+               *task_var &= ~TRACE_GRAPH_NOTRACE;
                return;
        }
 
-- 
2.43.0



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