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From: Arnd Bergmann <arnd@arndb.de>
To: David Howells <dhowells@redhat.com>
Cc: Tina Ruchandani <ruchandani.tina@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] afs: correctly use 64-bit time for UUID
Date: Wed, 11 Jan 2017 14:44:25 +0100	[thread overview]
Message-ID: <20170111134436.3877048-1-arnd@arndb.de> (raw)

From: Tina Ruchandani <ruchandani.tina@gmail.com>

UUID calculation uses 'struct timespec' whose seconds will overflow
in year 2038 and beyond for 32-bit systems. This patch removes the
dependency on 'struct timespec' by using ktime_get_real().
While the patch does not fix a 'bug' as such, it is part of a larger
effort to remove instances of 'struct timespec' and other data-structures
suffering from y2038 problem from the kernel.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/afs/main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/afs/main.c b/fs/afs/main.c
index f8188feb03ad..59e7ef38e541 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -13,6 +13,7 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/completion.h>
+#include <linux/ktime.h>
 #include <linux/sched.h>
 #include <linux/random.h>
 #define CREATE_TRACE_POINTS
@@ -39,7 +40,6 @@ struct workqueue_struct *afs_wq;
  */
 static int __init afs_get_client_UUID(void)
 {
-	struct timespec ts;
 	u64 uuidtime;
 	u16 clockseq;
 	int ret;
@@ -50,9 +50,7 @@ static int __init afs_get_client_UUID(void)
 	if (ret < 0)
 		return ret;
 
-	getnstimeofday(&ts);
-	uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10;
-	uuidtime += ts.tv_nsec / 100;
+	uuidtime = ktime_divns(ktime_get_real(), 100);
 	uuidtime += AFS_UUID_TO_UNIX_TIME;
 	afs_uuid.time_low = uuidtime;
 	afs_uuid.time_mid = uuidtime >> 32;
-- 
2.9.0

             reply	other threads:[~2017-01-11 13:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-11 13:44 Arnd Bergmann [this message]
2017-01-11 13:51 ` [PATCH] afs: correctly use 64-bit time for UUID David Howells
2017-01-11 14:03   ` Arnd Bergmann
2017-01-11 14:47   ` David Howells
2017-01-11 15:55     ` Arnd Bergmann
2017-01-12  9:27       ` [PATCH] afs: use random UUID kbuild test robot
  -- strict thread matches above, loose matches on Subject: below --
2015-10-30  8:51 [PATCH] AFS: Correctly use 64-bit time for UUID Tina Ruchandani
2015-11-05 16:25 ` Arnd Bergmann
2015-01-29  5:53 Tina Ruchandani
2015-02-11 13:52 ` David Howells

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