From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
As of v6.10, ring buffer user space mapping is now supported by the Linux
kernel. This also means that it is an official API. Copy the latest API from
that kernel into the trace_mmap.h file and make it accessible to user space
programs.
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
src/tracefs-mmap.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/src/tracefs-mmap.c b/src/tracefs-mmap.c
index a0130bbc1cbe..44d1597f1ba5 100644
--- a/src/tracefs-mmap.c
+++ b/src/tracefs-mmap.c
@@ -22,8 +22,8 @@
* @entries: Number of entries in the ring-buffer.
* @overrun: Number of entries lost in the ring-buffer.
* @read: Number of entries that have been read.
- * @Reserved1: Reserved for future use.
- * @Reserved2: Reserved for future use.
+ * @Reserved1: Internal use only.
+ * @Reserved2: Internal use only.
*/
struct trace_buffer_meta {
__u32 meta_page_size;
@@ -48,7 +48,7 @@ struct trace_buffer_meta {
__u64 Reserved2;
};
-#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1)
+#define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20)
struct trace_mmap {
struct trace_buffer_meta *map;
@@ -78,10 +78,6 @@ __hidden void *trace_mmap(int fd, struct kbuffer *kbuf)
void *meta;
void *data;
-#ifndef FORCE_MMAP_ENABLE
- return NULL;
-#endif
-
page_size = getpagesize();
meta = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
if (meta == MAP_FAILED)
--
2.43.0
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