ftrace,kdb: Extend kdb to be able to dump the ftrace buffer

Add in a helper function to allow the kdb shell to dump the ftrace
buffer.

Modify trace.c to expose the capability to iterate over the ftrace
buffer in a read only capacity.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2cd96399463f..0605fc00c176 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -338,6 +338,14 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
                                           int *ent_cpu, u64 *ent_ts);
 
+int trace_empty(struct trace_iterator *iter);
+
+void *trace_find_next_entry_inc(struct trace_iterator *iter);
+
+void trace_init_global_iter(struct trace_iterator *iter);
+
+void tracing_iter_reset(struct trace_iterator *iter, int cpu);
+
 void default_wait_pipe(struct trace_iterator *iter);
 void poll_wait_pipe(struct trace_iterator *iter);
 
@@ -380,6 +388,15 @@ void tracing_start_sched_switch_record(void);
 int register_tracer(struct tracer *type);
 void unregister_tracer(struct tracer *type);
 int is_tracing_stopped(void);
+enum trace_file_type {
+        TRACE_FILE_LAT_FMT      = 1,
+        TRACE_FILE_ANNOTATE     = 2,
+};
+
+extern cpumask_var_t __read_mostly tracing_buffer_mask;
+
+#define for_each_tracing_cpu(cpu)       \
+        for_each_cpu(cpu, tracing_buffer_mask)
 
 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 
@@ -471,6 +488,8 @@ trace_array_vprintk(struct trace_array *tr,
                     unsigned long ip, const char *fmt, va_list args);
 int trace_array_printk(struct trace_array *tr,
                        unsigned long ip, const char *fmt, ...);
+void trace_printk_seq(struct trace_seq *s);
+enum print_line_t print_trace_line(struct trace_iterator *iter);
 
 extern unsigned long trace_flags;