[PATCH] misc: mic: fix passing the current time

From: Arnd Bergmann
Date: Mon Jun 18 2018 - 10:26:44 EST


I noticed that the mic driver passes a 'struct timespec64' as part of
a message into an attached device, where it is used to set the current
system time.

This won't actually work if one of the two sides runs a 32-bit kernel and
the other runs a 64-bit kernel, since the structure layout is different
between the two.

I found this while replacing calls to the deprecated do_settimeofday64()
interface with the modern ktime_get_real_ts() variant, but it seems
appropriate to address both at the same time here.

To make sure we have a sane structure, let's define our own structure
using the layout of the 64-bit kernel.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/misc/mic/cosm/cosm_main.h | 5 ++++-
drivers/misc/mic/cosm/cosm_scif_server.c | 6 +++++-
drivers/misc/mic/cosm_client/cosm_scif_client.c | 6 +++++-
3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/mic/cosm/cosm_main.h b/drivers/misc/mic/cosm/cosm_main.h
index f01156fca881..aa78cdf25e40 100644
--- a/drivers/misc/mic/cosm/cosm_main.h
+++ b/drivers/misc/mic/cosm/cosm_main.h
@@ -45,7 +45,10 @@ struct cosm_msg {
u64 id;
union {
u64 shutdown_status;
- struct timespec64 timespec;
+ struct {
+ u64 tv_sec;
+ u64 tv_nsec;
+ } timespec;
};
};

diff --git a/drivers/misc/mic/cosm/cosm_scif_server.c b/drivers/misc/mic/cosm/cosm_scif_server.c
index 05a63286741c..e94b7eac4a06 100644
--- a/drivers/misc/mic/cosm/cosm_scif_server.c
+++ b/drivers/misc/mic/cosm/cosm_scif_server.c
@@ -179,9 +179,13 @@ static void cosm_set_crashed(struct cosm_device *cdev)
static void cosm_send_time(struct cosm_device *cdev)
{
struct cosm_msg msg = { .id = COSM_MSG_SYNC_TIME };
+ struct timespec64 ts;
int rc;

- getnstimeofday64(&msg.timespec);
+ ktime_get_real_ts64(&ts);
+ msg.timespec.tv_sec = ts.tv_sec;
+ msg.timespec.tv_nsec = ts.tv_nsec;
+
rc = scif_send(cdev->epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
if (rc < 0)
dev_err(&cdev->dev, "%s %d scif_send failed rc %d\n",
diff --git a/drivers/misc/mic/cosm_client/cosm_scif_client.c b/drivers/misc/mic/cosm_client/cosm_scif_client.c
index beafc0da4027..225078cb51fd 100644
--- a/drivers/misc/mic/cosm_client/cosm_scif_client.c
+++ b/drivers/misc/mic/cosm_client/cosm_scif_client.c
@@ -63,7 +63,11 @@ static struct notifier_block cosm_reboot = {
/* Set system time from timespec value received from the host */
static void cosm_set_time(struct cosm_msg *msg)
{
- int rc = do_settimeofday64(&msg->timespec);
+ struct timespec64 ts = {
+ .tv_sec = msg->timespec.tv_sec,
+ .tv_nsec = msg->timespec.tv_nsec,
+ };
+ int rc = do_settimeofday64(&ts);

if (rc)
dev_err(&client_spdev->dev, "%s: %d settimeofday rc %d\n",
--
2.9.0