ftrace: build fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 66 insertions, 45 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d74c039305ad..71b25b79b3de 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -432,47 +432,6 @@ notrace void tracing_reset(struct trace_array_cpu *data)
         data->trace_tail_idx = 0;
 }
 
-#ifdef CONFIG_FTRACE
-static notrace void
-function_trace_call(unsigned long ip, unsigned long parent_ip)
-{
-        struct trace_array *tr = &global_trace;
-        struct trace_array_cpu *data;
-        unsigned long flags;
-        long disabled;
-        int cpu;
-
-        if (unlikely(!tracer_enabled))
-                return;
-
-        local_irq_save(flags);
-        cpu = raw_smp_processor_id();
-        data = tr->data[cpu];
-        disabled = atomic_inc_return(&data->disabled);
-
-        if (likely(disabled == 1))
-                ftrace(tr, data, ip, parent_ip, flags);
-
-        atomic_dec(&data->disabled);
-        local_irq_restore(flags);
-}
-
-static struct ftrace_ops trace_ops __read_mostly =
-{
-        .func = function_trace_call,
-};
-#endif
-
-notrace void tracing_start_function_trace(void)
-{
-        register_ftrace_function(&trace_ops);
-}
-
-notrace void tracing_stop_function_trace(void)
-{
-        unregister_ftrace_function(&trace_ops);
-}
-
 #define SAVED_CMDLINES 128
 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
@@ -635,8 +594,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 }
 
 notrace void
-ftrace(struct trace_array *tr, struct trace_array_cpu *data,
-       unsigned long ip, unsigned long parent_ip, unsigned long flags)
+__ftrace(struct trace_array *tr, struct trace_array_cpu *data,
+         unsigned long ip, unsigned long parent_ip, unsigned long flags)
 {
         struct trace_entry *entry;
         unsigned long irq_flags;
@@ -651,6 +610,14 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
 }
 
 notrace void
+ftrace(struct trace_array *tr, struct trace_array_cpu *data,
+       unsigned long ip, unsigned long parent_ip, unsigned long flags)
+{
+        if (likely(!atomic_read(&data->disabled)))
+                __ftrace(tr, data, ip, parent_ip, flags);
+}
+
+notrace void
 trace_special(struct trace_array *tr, struct trace_array_cpu *data,
               unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
@@ -688,6 +655,47 @@ tracing_sched_switch_trace(struct trace_array *tr,
         spin_unlock_irqrestore(&data->lock, irq_flags);
 }
 
+#ifdef CONFIG_FTRACE
+static notrace void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+        struct trace_array *tr = &global_trace;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int cpu;
+
+        if (unlikely(!tracer_enabled))
+                return;
+
+        local_irq_save(flags);
+        cpu = raw_smp_processor_id();
+        data = tr->data[cpu];
+        disabled = atomic_inc_return(&data->disabled);
+
+        if (likely(disabled == 1))
+                __ftrace(tr, data, ip, parent_ip, flags);
+
+        atomic_dec(&data->disabled);
+        local_irq_restore(flags);
+}
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+        .func = function_trace_call,
+};
+
+notrace void tracing_start_function_trace(void)
+{
+        register_ftrace_function(&trace_ops);
+}
+
+notrace void tracing_stop_function_trace(void)
+{
+        unregister_ftrace_function(&trace_ops);
+}
+#endif
+
 enum trace_file_type {
         TRACE_FILE_LAT_FMT      = 1,
 };
@@ -722,7 +730,7 @@ trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
         return &array[iter->next_page_idx[cpu]];
 }
 
-static struct notrace trace_entry *
+static struct trace_entry * notrace
 find_next_entry(struct trace_iterator *iter, int *ent_cpu)
 {
         struct trace_array *tr = iter->tr;
@@ -1866,6 +1874,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
         static cpumask_t mask;
         static int start;
         unsigned long flags;
+        int ftrace_save;
         int read = 0;
         int cpu;
         int len;
@@ -1944,6 +1953,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 
         cpus_clear(mask);
         local_irq_save(flags);
+        ftrace_save = ftrace_enabled;
+        ftrace_enabled = 0;
+        smp_wmb();
         for_each_possible_cpu(cpu) {
                 data = iter->tr->data[cpu];
 
@@ -1951,10 +1963,14 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                         continue;
 
                 atomic_inc(&data->disabled);
-                spin_lock(&data->lock);
                 cpu_set(cpu, mask);
         }
 
+        for_each_cpu_mask(cpu, mask) {
+                data = iter->tr->data[cpu];
+                spin_lock(&data->lock);
+        }
+
         while (find_next_entry_inc(iter) != NULL) {
                 int len = iter->seq.len;
 
@@ -1974,8 +1990,13 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
         for_each_cpu_mask(cpu, mask) {
                 data = iter->tr->data[cpu];
                 spin_unlock(&data->lock);
+        }
+
+        for_each_cpu_mask(cpu, mask) {
+                data = iter->tr->data[cpu];
                 atomic_dec(&data->disabled);
         }
+        ftrace_enabled = ftrace_save;
         local_irq_restore(flags);
 
         /* Now copy what we have to the user */