[PATCH] kbuffer: Handle 64 bit timestamp event

[PATCH] kbuffer: Handle 64 bit timestamp event

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

With the new TAI clock, the clock source can use all 64 bits for the time
stamp. The TIME_STAMP event only saves 59 bits of the clock, it is
expected that the 5 MSBs will be extracted from the buffer page 64 bit
timestamp.

Link: https://lore.kernel.org/all/20220427153339.16c33f75@gandalf.local.home/

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 src/kbuffer-parse.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/kbuffer-parse.c b/src/kbuffer-parse.c
index 74999501f5bf..d174e7276df2 100644
--- a/src/kbuffer-parse.c
+++ b/src/kbuffer-parse.c
@@ -14,6 +14,9 @@
 
 #define COMMIT_MASK ((1 << 27) - 1)
 
+/* Absolute time stamps do not have the 5 MSB, take from the real time stamp */
+#define TS_MSB		(0xf8ULL << 56)
+
 enum {
 	KBUFFER_FL_HOST_BIG_ENDIAN	= (1<<0),
 	KBUFFER_FL_BIG_ENDIAN		= (1<<1),
@@ -347,7 +350,7 @@ static unsigned int
 translate_data(struct kbuffer *kbuf, void *data, void **rptr,
 	       unsigned long long *delta, int *length)
 {
-	unsigned long long extend;
+	unsigned long long extend, msb = 0;
 	unsigned int type_len_ts;
 	unsigned int type_len;
 
@@ -362,13 +365,15 @@ translate_data(struct kbuffer *kbuf, void *data, void **rptr,
 		*length = read_4(kbuf, data);
 		break;
 
-	case KBUFFER_TYPE_TIME_EXTEND:
 	case KBUFFER_TYPE_TIME_STAMP:
+		msb = kbuf->timestamp & TS_MSB;
+		/* fall through */
+	case KBUFFER_TYPE_TIME_EXTEND:
 		extend = read_4(kbuf, data);
 		data += 4;
 		extend <<= TS_SHIFT;
 		extend += *delta;
-		*delta = extend;
+		*delta = extend | msb;
 		*length = 0;
 		break;
 
-- 
2.35.1