ftrace: add readpos to struct trace_seq; add trace_seq_to_user()
Refactor code from tracing_read_pipe() and create trace_seq_to_user().
Moved trace_seq_reset() call before iter->trace->read() call so that
when all leftover data is returned, trace_seq is reset automatically.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index ee53d70..8845033 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -155,6 +155,7 @@
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
+ unsigned int readpos;
};
/*
@@ -301,6 +302,8 @@
extern void *head_page(struct trace_array_cpu *data);
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
+extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
+ size_t cnt);
extern long ns2usecs(cycle_t nsec);
extern unsigned long trace_flags;