1 files changed, 22 insertions, 29 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4b1122d0df37..ba14a22be4cc 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -101,10 +101,7 @@ static inline void ftrace_enable_cpu(void)
         preempt_enable();
 }
 
-static cpumask_var_t __read_mostly      tracing_buffer_mask;
-
-#define for_each_tracing_cpu(cpu)       \
-        for_each_cpu(cpu, tracing_buffer_mask)
+cpumask_var_t __read_mostly     tracing_buffer_mask;
 
 /*
  * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
@@ -744,13 +741,6 @@ __acquires(kernel_lock)
                 return -1;
         }
 
-        /*
-         * When this gets called we hold the BKL which means that
-         * preemption is disabled. Various trace selftests however
-         * need to disable and enable preemption for successful tests.
-         * So we drop the BKL here and grab it after the tests again.
-         */
-        unlock_kernel();
         mutex_lock(&trace_types_lock);
 
         tracing_selftest_running = true;
@@ -832,7 +822,6 @@ __acquires(kernel_lock)
 #endif
 
  out_unlock:
-        lock_kernel();
         return ret;
 }
 
@@ -1493,11 +1482,6 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
-enum trace_file_type {
-        TRACE_FILE_LAT_FMT      = 1,
-        TRACE_FILE_ANNOTATE     = 2,
-};
-
 static void trace_iterator_increment(struct trace_iterator *iter)
 {
         /* Don't allow ftrace to trace into the ring buffers */
@@ -1595,7 +1579,7 @@ struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 }
 
 /* Find the next real entry, and increment the iterator to the next entry */
-static void *find_next_entry_inc(struct trace_iterator *iter)
+void *trace_find_next_entry_inc(struct trace_iterator *iter)
 {
         iter->ent = __find_next_entry(iter, &iter->cpu,
                                       &iter->lost_events, &iter->ts);
@@ -1630,19 +1614,19 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
                 return NULL;
 
         if (iter->idx < 0)
-                ent = find_next_entry_inc(iter);
+                ent = trace_find_next_entry_inc(iter);
         else
                 ent = iter;
 
         while (ent && iter->idx < i)
-                ent = find_next_entry_inc(iter);
+                ent = trace_find_next_entry_inc(iter);
 
         iter->pos = *pos;
 
         return ent;
 }
 
-static void tracing_iter_reset(struct trace_iterator *iter, int cpu)
+void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 {
         struct trace_array *tr = iter->tr;
         struct ring_buffer_event *event;
@@ -2003,7 +1987,7 @@ int trace_empty(struct trace_iterator *iter)
 }
 
 /*  Called with trace_event_read_lock() held. */
-static enum print_line_t print_trace_line(struct trace_iterator *iter)
+enum print_line_t print_trace_line(struct trace_iterator *iter)
 {
         enum print_line_t ret;
 
@@ -3193,7 +3177,7 @@ waitagain:
 
         trace_event_read_lock();
         trace_access_lock(iter->cpu_file);
-        while (find_next_entry_inc(iter) != NULL) {
+        while (trace_find_next_entry_inc(iter) != NULL) {
                 enum print_line_t ret;
                 int len = iter->seq.len;
 
@@ -3276,7 +3260,7 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
                 if (ret != TRACE_TYPE_NO_CONSUME)
                         trace_consume(iter);
                 rem -= count;
-                if (!find_next_entry_inc(iter)) {
+                if (!trace_find_next_entry_inc(iter))   {
                         rem = 0;
                         iter->ent = NULL;
                         break;
@@ -3332,7 +3316,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
         if (ret <= 0)
                 goto out_err;
 
-        if (!iter->ent && !find_next_entry_inc(iter)) {
+        if (!iter->ent && !trace_find_next_entry_inc(iter)) {
                 ret = -EFAULT;
                 goto out_err;
         }
@@ -4402,7 +4386,7 @@ static struct notifier_block trace_die_notifier = {
  */
 #define KERN_TRACE              KERN_EMERG
 
-static void
+void
 trace_printk_seq(struct trace_seq *s)
 {
         /* Probably should print a warning here. */
@@ -4417,6 +4401,13 @@ trace_printk_seq(struct trace_seq *s)
         trace_seq_init(s);
 }
 
+void trace_init_global_iter(struct trace_iterator *iter)
+{
+        iter->tr = &global_trace;
+        iter->trace = current_trace;
+        iter->cpu_file = TRACE_PIPE_ALL_CPU;
+}
+
 static void
 __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
 {
@@ -4442,8 +4433,10 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
         if (disable_tracing)
                 ftrace_kill();
 
+        trace_init_global_iter(&iter);
+
         for_each_tracing_cpu(cpu) {
-                atomic_inc(&global_trace.data[cpu]->disabled);
+                atomic_inc(&iter.tr->data[cpu]->disabled);
         }
 
         old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;
@@ -4492,7 +4485,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
                 iter.iter_flags |= TRACE_FILE_LAT_FMT;
                 iter.pos = -1;
 
-                if (find_next_entry_inc(&iter) != NULL) {
+                if (trace_find_next_entry_inc(&iter) != NULL) {
                         int ret;
 
                         ret = print_trace_line(&iter);
@@ -4514,7 +4507,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
                 trace_flags |= old_userobj;
 
                 for_each_tracing_cpu(cpu) {
-                        atomic_dec(&global_trace.data[cpu]->disabled);
+                        atomic_dec(&iter.tr->data[cpu]->disabled);
                 }
                 tracing_on();
         }