[PATCH v2] trace: Make trace_hwlat timestamp y2038 safe

[PATCH v2] trace: Make trace_hwlat timestamp y2038 safe

[Deepa Dinamani]

struct timespec is not y2038 safe on 32 bit machines
and needs to be replaced by struct timespec64
in order to represent times beyond year 2038 on such
machines.

Fix all the timestamp representation in struct trace_hwlat
and all the corresponding implementations.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
---
-Changes from v1
* Added long long casts to fix kbuild warning

kernel/trace/trace_entries.h | 6 +++---
 kernel/trace/trace_hwlat.c   | 4 ++--
 kernel/trace/trace_output.c  | 9 ++++-----
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index c203ac4..adcdbbe 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -348,14 +348,14 @@ FTRACE_ENTRY(hwlat, hwlat_entry,
 		__field(	u64,			duration	)
 		__field(	u64,			outer_duration	)
 		__field(	u64,			nmi_total_ts	)
-		__field_struct( struct timespec,	timestamp	)
-		__field_desc(	long,	timestamp,	tv_sec		)
+		__field_struct( struct timespec64,	timestamp	)
+		__field_desc(	s64,	timestamp,	tv_sec		)
 		__field_desc(	long,	timestamp,	tv_nsec		)
 		__field(	unsigned int,		nmi_count	)
 		__field(	unsigned int,		seqnum		)
 	),
 
-	F_printk("cnt:%u\tts:%010lu.%010lu\tinner:%llu\touter:%llunmi-ts:%llu\tnmi-count:%u\n",
+	F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llunmi-ts:%llu\tnmi-count:%u\n",
 		 __entry->seqnum,
 		 __entry->tv_sec,
 		 __entry->tv_nsec,
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 21ea6ae..2257ff1 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -83,7 +83,7 @@ struct hwlat_sample {
 	u64		duration;	/* delta */
 	u64		outer_duration;	/* delta (outer loop) */
 	u64		nmi_total_ts;	/* Total time spent in NMIs */
-	struct timespec	timestamp;	/* wall time */
+	struct timespec64	timestamp;	/* wall time */
 	int		nmi_count;	/* # NMIs during this sample */
 };
 
@@ -250,7 +250,7 @@ static int get_sample(void)
 		s.seqnum = hwlat_data.count;
 		s.duration = sample;
 		s.outer_duration = outer_sample;
-		s.timestamp = CURRENT_TIME;
+		ktime_get_real_ts64(&s.timestamp);
 		s.nmi_total_ts = nmi_total_ts;
 		s.nmi_count = nmi_count;
 		trace_hwlat_sample(&s);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 02a4aeb..08f9bab 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -4,7 +4,6 @@
  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
  *
  */
-
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/ftrace.h>
@@ -1161,11 +1160,11 @@ trace_hwlat_print(struct trace_iterator *iter, int flags,
 
 	trace_assign_type(field, entry);
 
-	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
+	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
 			 field->seqnum,
 			 field->duration,
 			 field->outer_duration,
-			 field->timestamp.tv_sec,
+			 (long long)field->timestamp.tv_sec,
 			 field->timestamp.tv_nsec);
 
 	if (field->nmi_count) {
@@ -1195,10 +1194,10 @@ trace_hwlat_raw(struct trace_iterator *iter, int flags,
 
 	trace_assign_type(field, iter->ent);
 
-	trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
+	trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
 			 field->duration,
 			 field->outer_duration,
-			 field->timestamp.tv_sec,
+			 (long long)field->timestamp.tv_sec,
 			 field->timestamp.tv_nsec,
 			 field->seqnum);
 
-- 
2.7.4

Re: [PATCH v2] trace: Make trace_hwlat timestamp y2038 safe

[Steven Rostedt]

On Tue, 28 Mar 2017 07:50:17 -0700
Deepa Dinamani <deepa.kernel@gmail.com> wrote:

> diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
> index 21ea6ae..2257ff1 100644
> --- a/kernel/trace/trace_hwlat.c
> +++ b/kernel/trace/trace_hwlat.c
> @@ -83,7 +83,7 @@ struct hwlat_sample {
>  	u64		duration;	/* delta */
>  	u64		outer_duration;	/* delta (outer loop) */
>  	u64		nmi_total_ts;	/* Total time spent in NMIs */
> -	struct timespec	timestamp;	/* wall time */
> +	struct timespec64	timestamp;	/* wall time */
>  	int		nmi_count;	/* # NMIs during this sample */
>  };
>  

This is a nit, but please make all the fields line up nicely again.
That is, add a tab to each line.

Thanks,

-- Steve