ftrace: insert in the ftrace_preempt_disable()/enable() functions

Impact: use new, consolidated APIs in ftrace plugins

This patch replaces the schedule safe preempt disable code with the
ftrace_preempt_disable() and ftrace_preempt_enable() safe functions.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 15 insertions, 41 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index cedf4e268285..151f6a748676 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -16,6 +16,8 @@
 #include <linux/list.h>
 #include <linux/fs.h>
 
+#include "trace.h"
+
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
@@ -1122,8 +1124,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
                 return NULL;
 
         /* If we are tracing schedule, we don't want to recurse */
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
 
         cpu = raw_smp_processor_id();
 
@@ -1154,10 +1155,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
         return event;
 
  out:
-        if (resched)
-                preempt_enable_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
         return NULL;
 }
 
@@ -1199,12 +1197,9 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
         /*
          * Only the last preempt count needs to restore preemption.
          */
-        if (preempt_count() == 1) {
-                if (per_cpu(rb_need_resched, cpu))
-                        preempt_enable_no_resched_notrace();
-                else
-                        preempt_enable_notrace();
-        } else
+        if (preempt_count() == 1)
+                ftrace_preempt_enable(per_cpu(rb_need_resched, cpu));
+        else
                 preempt_enable_no_resched_notrace();
 
         return 0;
@@ -1237,8 +1232,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
         if (atomic_read(&buffer->record_disabled))
                 return -EBUSY;
 
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
 
         cpu = raw_smp_processor_id();
 
@@ -1264,10 +1258,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
 
         ret = 0;
  out:
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
 
         return ret;
 }
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e4c40c868d67..3e7bf5eb9007 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -904,8 +904,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
                 return;
 
         pc = preempt_count();
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
         local_save_flags(flags);
         cpu = raw_smp_processor_id();
         data = tr->data[cpu];
@@ -915,10 +914,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
                 trace_function(tr, data, ip, parent_ip, flags, pc);
 
         atomic_dec(&data->disabled);
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 3ae93f16b565..7bc4abf6fca8 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -50,8 +50,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
                 return;
 
         pc = preempt_count();
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
 
         cpu = raw_smp_processor_id();
         data = tr->data[cpu];
@@ -81,15 +80,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
  out:
         atomic_dec(&data->disabled);
 
-        /*
-         * To prevent recursion from the scheduler, if the
-         * resched flag was set before we entered, then
-         * don't reschedule.
-         */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index be682b62fe58..d39e8b7de6a2 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -107,8 +107,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
         if (unlikely(!ftrace_enabled || stack_trace_disabled))
                 return;
 
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
 
         cpu = raw_smp_processor_id();
         /* no atomic needed, we only modify this variable by this cpu */
@@ -120,10 +119,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
  out:
         per_cpu(trace_active, cpu)--;
         /* prevent recursion in schedule */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =