tracing: Have trace_array keep track if snapshot buffer is allocated

[firefly-linux-kernel-4.4.55.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9bb0b52cbd32ed4f8274864efea3f4f61a1e9424..bcc9460c2d653302c25926dcae7089a450233832 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -667,7 +667,7 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 
        WARN_ON_ONCE(!irqs_disabled());
 
-       if (!tr->current_trace->allocated_snapshot) {
+       if (!tr->allocated_snapshot) {
                /* Only the nop tracer should hit this when disabling */
                WARN_ON_ONCE(tr->current_trace != &nop_trace);
                return;
@@ -700,7 +700,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
                return;
 
        WARN_ON_ONCE(!irqs_disabled());
-       if (WARN_ON_ONCE(!tr->current_trace->allocated_snapshot))
+       if (WARN_ON_ONCE(!tr->allocated_snapshot))
                return;
 
        arch_spin_lock(&ftrace_max_lock);
@@ -802,7 +802,7 @@ int register_tracer(struct tracer *type)
                        if (ring_buffer_expanded)
                                ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
                                                   RING_BUFFER_ALL_CPUS);
-                       type->allocated_snapshot = true;
+                       tr->allocated_snapshot = true;
                }
 #endif
 
@@ -822,7 +822,7 @@ int register_tracer(struct tracer *type)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
                if (type->use_max_tr) {
-                       type->allocated_snapshot = false;
+                       tr->allocated_snapshot = false;
 
                        /* Shrink the max buffer again */
                        if (ring_buffer_expanded)
@@ -2463,7 +2463,7 @@ static void show_snapshot_percpu_help(struct seq_file *m)
 
 static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
 {
-       if (iter->trace->allocated_snapshot)
+       if (iter->tr->allocated_snapshot)
                seq_printf(m, "#\n# * Snapshot is allocated *\n#\n");
        else
                seq_printf(m, "#\n# * Snapshot is freed *\n#\n");
@@ -3364,12 +3364,12 @@ static int tracing_set_tracer(const char *buf)
        if (tr->current_trace->reset)
                tr->current_trace->reset(tr);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-       had_max_tr = tr->current_trace->allocated_snapshot;
-
        /* Current trace needs to be nop_trace before synchronize_sched */
        tr->current_trace = &nop_trace;
 
+#ifdef CONFIG_TRACER_MAX_TRACE
+       had_max_tr = tr->allocated_snapshot;
+
        if (had_max_tr && !t->use_max_tr) {
                /*
                 * We need to make sure that the update_max_tr sees that
@@ -3387,10 +3387,8 @@ static int tracing_set_tracer(const char *buf)
                ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
                set_buffer_entries(&tr->max_buffer, 1);
                tracing_reset_online_cpus(&tr->max_buffer);
-               tr->current_trace->allocated_snapshot = false;
+               tr->allocated_snapshot = false;
        }
-#else
-       tr->current_trace = &nop_trace;
 #endif
        destroy_trace_option_files(topts);
 
@@ -3403,7 +3401,7 @@ static int tracing_set_tracer(const char *buf)
                                                   RING_BUFFER_ALL_CPUS);
                if (ret < 0)
                        goto out;
-               t->allocated_snapshot = true;
+               tr->allocated_snapshot = true;
        }
 #endif
 
@@ -4275,13 +4273,13 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
                        ret = -EINVAL;
                        break;
                }
-               if (tr->current_trace->allocated_snapshot) {
+               if (tr->allocated_snapshot) {
                        /* free spare buffer */
                        ring_buffer_resize(tr->max_buffer.buffer, 1,
                                           RING_BUFFER_ALL_CPUS);
                        set_buffer_entries(&tr->max_buffer, 1);
                        tracing_reset_online_cpus(&tr->max_buffer);
-                       tr->current_trace->allocated_snapshot = false;
+                       tr->allocated_snapshot = false;
                }
                break;
        case 1:
@@ -4292,13 +4290,13 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
                        break;
                }
 #endif
-               if (!tr->current_trace->allocated_snapshot) {
+               if (!tr->allocated_snapshot) {
                        /* allocate spare buffer */
                        ret = resize_buffer_duplicate_size(&tr->max_buffer,
                                        &tr->trace_buffer, RING_BUFFER_ALL_CPUS);
                        if (ret < 0)
                                break;
-                       tr->current_trace->allocated_snapshot = true;
+                       tr->allocated_snapshot = true;
                }
                local_irq_disable();
                /* Now, we're going to swap */
@@ -4309,7 +4307,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
                local_irq_enable();
                break;
        default:
-               if (tr->current_trace->allocated_snapshot) {
+               if (tr->allocated_snapshot) {
                        if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
                                tracing_reset_online_cpus(&tr->max_buffer);
                        else