ring-buffer: fix ring_buffer_read_page
The ring_buffer_read_page was broken if it were to only copy part
of the page. This patch fixes that up as well as adds a parameter
to allow a length field, in order to only copy part of the buffer page.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index f5e793d..79fcbc4 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -121,6 +121,9 @@
u64 ring_buffer_time_stamp(int cpu);
void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
+size_t ring_buffer_page_len(void *page);
+
+
/*
* The below functions are fine to use outside the tracing facility.
*/
@@ -138,8 +141,8 @@
void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
-int ring_buffer_read_page(struct ring_buffer *buffer,
- void **data_page, int cpu, int full);
+int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page,
+ size_t len, int cpu, int full);
enum ring_buffer_flags {
RB_FL_OVERWRITE = 1 << 0,