[PATCH 1/3] scsi: 3ware: fix 32-bit time calculations

[PATCH 1/3] scsi: 3ware: fix 32-bit time calculations

[Arnd Bergmann]

twl_aen_queue_event/twa_aen_queue_event, we use do_gettimeofday()
to read the lower 32 bits of the current time in seconds, to pass
them to the TW_IOCTL_GET_NEXT_EVENT ioctl or the 3ware_aen_read
sysfs file.

This will overflow on all architectures in year 2106, there is
not much we can do about that without breaking the ABI. User
space has 90 years to learn to deal with it, so it's probably ok.

I'm changing it to use ktime_get_real_seconds() with a comment
to document what happens when.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/3w-9xxx.c | 5 ++---
 drivers/scsi/3w-sas.c  | 5 ++---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 00e7968a1d70..cb9af3f7b653 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -369,7 +369,6 @@ static int twa_aen_drain_queue(TW_Device_Extension *tw_dev, int no_check_reset)
 static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
 {
 	u32 local_time;
-	struct timeval time;
 	TW_Event *event;
 	unsigned short aen;
 	char host[16];
@@ -392,8 +391,8 @@ static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_H
 	memset(event, 0, sizeof(TW_Event));
 
 	event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
-	do_gettimeofday(&time);
-	local_time = (u32)(time.tv_sec - (sys_tz.tz_minuteswest * 60));
+	/* event->time_stamp_sec overflows in y2106 */
+	local_time = (u32)(ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
 	event->time_stamp_sec = local_time;
 	event->aen_code = aen;
 	event->retrieved = TW_AEN_NOT_RETRIEVED;
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index b150e131b2e7..c283fdb3cb24 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -221,7 +221,6 @@ static char *twl_aen_severity_lookup(unsigned char severity_code)
 static void twl_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
 {
 	u32 local_time;
-	struct timeval time;
 	TW_Event *event;
 	unsigned short aen;
 	char host[16];
@@ -240,8 +239,8 @@ static void twl_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_H
 	memset(event, 0, sizeof(TW_Event));
 
 	event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
-	do_gettimeofday(&time);
-	local_time = (u32)(time.tv_sec - (sys_tz.tz_minuteswest * 60));
+	/* event->time_stamp_sec overflows in y2106 */
+	local_time = (u32)(ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
 	event->time_stamp_sec = local_time;
 	event->aen_code = aen;
 	event->retrieved = TW_AEN_NOT_RETRIEVED;
-- 
2.9.0

[PATCH 2/3] scsi: 3ware: use 64-bit times for FW time sync

[Arnd Bergmann]

The calculation of the number of seconds since Sunday 00:00:00 overflows
in 2106, meaning that we instead will return the seconds since Wednesday
06:28:16 afterwards.

Using 64-bit time stamps avoids this slight inconsistency, and the
deprecated do_gettimeofday(), replacing it with the simpler
ktime_get_real_seconds().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/3w-9xxx.c |  8 +++-----
 drivers/scsi/3w-sas.c  | 10 ++++------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index cb9af3f7b653..b1c9bd9c1bfd 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -472,11 +472,10 @@ static char *twa_aen_severity_lookup(unsigned char severity_code)
 static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
 {
 	u32 schedulertime;
-	struct timeval utc;
 	TW_Command_Full *full_command_packet;
 	TW_Command *command_packet;
 	TW_Param_Apache *param;
-	u32 local_time;
+	time64_t local_time;
 
 	/* Fill out the command packet */
 	full_command_packet = tw_dev->command_packet_virt[request_id];
@@ -498,9 +497,8 @@ static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
 
 	/* Convert system time in UTC to local time seconds since last 
            Sunday 12:00AM */
-	do_gettimeofday(&utc);
-	local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
-	schedulertime = local_time - (3 * 86400);
+	local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
+	div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
 	schedulertime = cpu_to_le32(schedulertime % 604800);
 
 	memcpy(param->data, &schedulertime, sizeof(u32));
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index c283fdb3cb24..cf9f2a09b47d 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -407,11 +407,10 @@ static int twl_aen_read_queue(TW_Device_Extension *tw_dev, int request_id)
 static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
 {
 	u32 schedulertime;
-	struct timeval utc;
 	TW_Command_Full *full_command_packet;
 	TW_Command *command_packet;
 	TW_Param_Apache *param;
-	u32 local_time;
+	time64_t local_time;
 
 	/* Fill out the command packet */
 	full_command_packet = tw_dev->command_packet_virt[request_id];
@@ -433,10 +432,9 @@ static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
 
 	/* Convert system time in UTC to local time seconds since last 
            Sunday 12:00AM */
-	do_gettimeofday(&utc);
-	local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
-	schedulertime = local_time - (3 * 86400);
-	schedulertime = cpu_to_le32(schedulertime % 604800);
+	local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
+	div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
+	schedulertime = cpu_to_le32(schedulertime);
 
 	memcpy(param->data, &schedulertime, sizeof(u32));
 
-- 
2.9.0

[PATCH 3/3] scsi: 3w-9xxx: rework lock timeouts

[Arnd Bergmann]

The TW_IOCTL_GET_LOCK ioctl uses do_gettimeofday() to check whether
a lock has expired. This can misbehave due to a concurrent
settimeofday() call, as it is based on 'real' time, and it
will overflow in y2038 on 32-bit architectures, producing
unexpected results when used across the overflow time.

This changes it to using monotonic time, using ktime_get()
to simplify the code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/3w-9xxx.c | 13 ++++++-------
 drivers/scsi/3w-9xxx.h |  2 +-
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index b1c9bd9c1bfd..b42c9c479d4b 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -645,8 +645,7 @@ static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
 	TW_Command_Full *full_command_packet;
 	TW_Compatibility_Info *tw_compat_info;
 	TW_Event *event;
-	struct timeval current_time;
-	u32 current_time_ms;
+	ktime_t current_time;
 	TW_Device_Extension *tw_dev = twa_device_extension_list[iminor(inode)];
 	int retval = TW_IOCTL_ERROR_OS_EFAULT;
 	void __user *argp = (void __user *)arg;
@@ -837,17 +836,17 @@ static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
 		break;
 	case TW_IOCTL_GET_LOCK:
 		tw_lock = (TW_Lock *)tw_ioctl->data_buffer;
-		do_gettimeofday(&current_time);
-		current_time_ms = (current_time.tv_sec * 1000) + (current_time.tv_usec / 1000);
+		current_time = ktime_get();
 
-		if ((tw_lock->force_flag == 1) || (tw_dev->ioctl_sem_lock == 0) || (current_time_ms >= tw_dev->ioctl_msec)) {
+		if ((tw_lock->force_flag == 1) || (tw_dev->ioctl_sem_lock == 0) ||
+		    ktime_after(current_time, tw_dev->ioctl_time)) {
 			tw_dev->ioctl_sem_lock = 1;
-			tw_dev->ioctl_msec = current_time_ms + tw_lock->timeout_msec;
+			tw_dev->ioctl_time = ktime_add_ms(current_time, tw_lock->timeout_msec);
 			tw_ioctl->driver_command.status = 0;
 			tw_lock->time_remaining_msec = tw_lock->timeout_msec;
 		} else {
 			tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_LOCKED;
-			tw_lock->time_remaining_msec = tw_dev->ioctl_msec - current_time_ms;
+			tw_lock->time_remaining_msec = ktime_ms_delta(tw_dev->ioctl_time, current_time);
 		}
 		break;
 	case TW_IOCTL_RELEASE_LOCK:
diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h
index b6c208cc474f..d88cd3499bd5 100644
--- a/drivers/scsi/3w-9xxx.h
+++ b/drivers/scsi/3w-9xxx.h
@@ -666,7 +666,7 @@ typedef struct TAG_TW_Device_Extension {
 	unsigned char		event_queue_wrapped;
 	unsigned int            error_sequence_id;
 	int                     ioctl_sem_lock;
-	u32                     ioctl_msec;
+	ktime_t                 ioctl_time;
 	int			chrdev_request_id;
 	wait_queue_head_t	ioctl_wqueue;
 	struct mutex		ioctl_lock;
-- 
2.9.0

Re: [PATCH 3/3] scsi: 3w-9xxx: rework lock timeouts

[adam radford]

On Fri, Nov 10, 2017 at 7:58 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> The TW_IOCTL_GET_LOCK ioctl uses do_gettimeofday() to check whether
> a lock has expired. This can misbehave due to a concurrent
> settimeofday() call, as it is based on 'real' time, and it
> will overflow in y2038 on 32-bit architectures, producing
> unexpected results when used across the overflow time.
>
> This changes it to using monotonic time, using ktime_get()
> to simplify the code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/scsi/3w-9xxx.c | 13 ++++++-------
>  drivers/scsi/3w-9xxx.h |  2 +-
>  2 files changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
> index b1c9bd9c1bfd..b42c9c479d4b 100644
> --- a/drivers/scsi/3w-9xxx.c
> +++ b/drivers/scsi/3w-9xxx.c
> @@ -645,8 +645,7 @@ static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
>         TW_Command_Full *full_command_packet;
>         TW_Compatibility_Info *tw_compat_info;
>         TW_Event *event;
> -       struct timeval current_time;
> -       u32 current_time_ms;
> +       ktime_t current_time;
>         TW_Device_Extension *tw_dev = twa_device_extension_list[iminor(inode)];
>         int retval = TW_IOCTL_ERROR_OS_EFAULT;
>         void __user *argp = (void __user *)arg;
> @@ -837,17 +836,17 @@ static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
>                 break;
>         case TW_IOCTL_GET_LOCK:
>                 tw_lock = (TW_Lock *)tw_ioctl->data_buffer;
> -               do_gettimeofday(&current_time);
> -               current_time_ms = (current_time.tv_sec * 1000) + (current_time.tv_usec / 1000);
> +               current_time = ktime_get();
>
> -               if ((tw_lock->force_flag == 1) || (tw_dev->ioctl_sem_lock == 0) || (current_time_ms >= tw_dev->ioctl_msec)) {
> +               if ((tw_lock->force_flag == 1) || (tw_dev->ioctl_sem_lock == 0) ||
> +                   ktime_after(current_time, tw_dev->ioctl_time)) {
>                         tw_dev->ioctl_sem_lock = 1;
> -                       tw_dev->ioctl_msec = current_time_ms + tw_lock->timeout_msec;
> +                       tw_dev->ioctl_time = ktime_add_ms(current_time, tw_lock->timeout_msec);
>                         tw_ioctl->driver_command.status = 0;
>                         tw_lock->time_remaining_msec = tw_lock->timeout_msec;
>                 } else {
>                         tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_LOCKED;
> -                       tw_lock->time_remaining_msec = tw_dev->ioctl_msec - current_time_ms;
> +                       tw_lock->time_remaining_msec = ktime_ms_delta(tw_dev->ioctl_time, current_time);
>                 }
>                 break;
>         case TW_IOCTL_RELEASE_LOCK:
> diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h
> index b6c208cc474f..d88cd3499bd5 100644
> --- a/drivers/scsi/3w-9xxx.h
> +++ b/drivers/scsi/3w-9xxx.h
> @@ -666,7 +666,7 @@ typedef struct TAG_TW_Device_Extension {
>         unsigned char           event_queue_wrapped;
>         unsigned int            error_sequence_id;
>         int                     ioctl_sem_lock;
> -       u32                     ioctl_msec;
> +       ktime_t                 ioctl_time;
>         int                     chrdev_request_id;
>         wait_queue_head_t       ioctl_wqueue;
>         struct mutex            ioctl_lock;
> --
> 2.9.0
>

Looks good...  Thanks for this fix!

Acked-by: Adam Radford <aradford@gmail.com>

Re: [PATCH 1/3] scsi: 3ware: fix 32-bit time calculations

[adam radford]

On Fri, Nov 10, 2017 at 7:58 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> twl_aen_queue_event/twa_aen_queue_event, we use do_gettimeofday()
> to read the lower 32 bits of the current time in seconds, to pass
> them to the TW_IOCTL_GET_NEXT_EVENT ioctl or the 3ware_aen_read
> sysfs file.
>
> This will overflow on all architectures in year 2106, there is
> not much we can do about that without breaking the ABI. User
> space has 90 years to learn to deal with it, so it's probably ok.
>
> I'm changing it to use ktime_get_real_seconds() with a comment
> to document what happens when.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/scsi/3w-9xxx.c | 5 ++---
>  drivers/scsi/3w-sas.c  | 5 ++---
>  2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
> index 00e7968a1d70..cb9af3f7b653 100644
> --- a/drivers/scsi/3w-9xxx.c
> +++ b/drivers/scsi/3w-9xxx.c
> @@ -369,7 +369,6 @@ static int twa_aen_drain_queue(TW_Device_Extension *tw_dev, int no_check_reset)
>  static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
>  {
>         u32 local_time;
> -       struct timeval time;
>         TW_Event *event;
>         unsigned short aen;
>         char host[16];
> @@ -392,8 +391,8 @@ static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_H
>         memset(event, 0, sizeof(TW_Event));
>
>         event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
> -       do_gettimeofday(&time);
> -       local_time = (u32)(time.tv_sec - (sys_tz.tz_minuteswest * 60));
> +       /* event->time_stamp_sec overflows in y2106 */
> +       local_time = (u32)(ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
>         event->time_stamp_sec = local_time;
>         event->aen_code = aen;
>         event->retrieved = TW_AEN_NOT_RETRIEVED;
> diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
> index b150e131b2e7..c283fdb3cb24 100644
> --- a/drivers/scsi/3w-sas.c
> +++ b/drivers/scsi/3w-sas.c
> @@ -221,7 +221,6 @@ static char *twl_aen_severity_lookup(unsigned char severity_code)
>  static void twl_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
>  {
>         u32 local_time;
> -       struct timeval time;
>         TW_Event *event;
>         unsigned short aen;
>         char host[16];
> @@ -240,8 +239,8 @@ static void twl_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_H
>         memset(event, 0, sizeof(TW_Event));
>
>         event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
> -       do_gettimeofday(&time);
> -       local_time = (u32)(time.tv_sec - (sys_tz.tz_minuteswest * 60));
> +       /* event->time_stamp_sec overflows in y2106 */
> +       local_time = (u32)(ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
>         event->time_stamp_sec = local_time;
>         event->aen_code = aen;
>         event->retrieved = TW_AEN_NOT_RETRIEVED;
> --
> 2.9.0
>

Acked-by: Adam Radford <aradford@gmail.com>

Re: [PATCH 2/3] scsi: 3ware: use 64-bit times for FW time sync

[adam radford]

On Fri, Nov 10, 2017 at 7:58 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> The calculation of the number of seconds since Sunday 00:00:00 overflows
> in 2106, meaning that we instead will return the seconds since Wednesday
> 06:28:16 afterwards.
>
> Using 64-bit time stamps avoids this slight inconsistency, and the
> deprecated do_gettimeofday(), replacing it with the simpler
> ktime_get_real_seconds().
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/scsi/3w-9xxx.c |  8 +++-----
>  drivers/scsi/3w-sas.c  | 10 ++++------
>  2 files changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
> index cb9af3f7b653..b1c9bd9c1bfd 100644
> --- a/drivers/scsi/3w-9xxx.c
> +++ b/drivers/scsi/3w-9xxx.c
> @@ -472,11 +472,10 @@ static char *twa_aen_severity_lookup(unsigned char severity_code)
>  static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>  {
>         u32 schedulertime;
> -       struct timeval utc;
>         TW_Command_Full *full_command_packet;
>         TW_Command *command_packet;
>         TW_Param_Apache *param;
> -       u32 local_time;
> +       time64_t local_time;
>
>         /* Fill out the command packet */
>         full_command_packet = tw_dev->command_packet_virt[request_id];
> @@ -498,9 +497,8 @@ static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>
>         /* Convert system time in UTC to local time seconds since last
>             Sunday 12:00AM */
> -       do_gettimeofday(&utc);
> -       local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
> -       schedulertime = local_time - (3 * 86400);
> +       local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
> +       div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
>         schedulertime = cpu_to_le32(schedulertime % 604800);
>
>         memcpy(param->data, &schedulertime, sizeof(u32));
> diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
> index c283fdb3cb24..cf9f2a09b47d 100644
> --- a/drivers/scsi/3w-sas.c
> +++ b/drivers/scsi/3w-sas.c
> @@ -407,11 +407,10 @@ static int twl_aen_read_queue(TW_Device_Extension *tw_dev, int request_id)
>  static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>  {
>         u32 schedulertime;
> -       struct timeval utc;
>         TW_Command_Full *full_command_packet;
>         TW_Command *command_packet;
>         TW_Param_Apache *param;
> -       u32 local_time;
> +       time64_t local_time;
>
>         /* Fill out the command packet */
>         full_command_packet = tw_dev->command_packet_virt[request_id];
> @@ -433,10 +432,9 @@ static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>
>         /* Convert system time in UTC to local time seconds since last
>             Sunday 12:00AM */
> -       do_gettimeofday(&utc);
> -       local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
> -       schedulertime = local_time - (3 * 86400);
> -       schedulertime = cpu_to_le32(schedulertime % 604800);
> +       local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
> +       div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
> +       schedulertime = cpu_to_le32(schedulertime);
>
>         memcpy(param->data, &schedulertime, sizeof(u32));
>
> --
> 2.9.0
>

Acked-by: Adam Radford <aradford@gmail.com>

Re: [PATCH 1/3] scsi: 3ware: fix 32-bit time calculations

[Martin K. Petersen]

Arnd,

> twl_aen_queue_event/twa_aen_queue_event, we use do_gettimeofday()
> to read the lower 32 bits of the current time in seconds, to pass
> them to the TW_IOCTL_GET_NEXT_EVENT ioctl or the 3ware_aen_read
> sysfs file.
>
> This will overflow on all architectures in year 2106, there is
> not much we can do about that without breaking the ABI. User
> space has 90 years to learn to deal with it, so it's probably ok.
>
> I'm changing it to use ktime_get_real_seconds() with a comment
> to document what happens when.

Applied to 4.16/scsi-queue.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 2/3] scsi: 3ware: use 64-bit times for FW time sync

[Martin K. Petersen]

Arnd,

> The calculation of the number of seconds since Sunday 00:00:00
> overflows in 2106, meaning that we instead will return the seconds
> since Wednesday 06:28:16 afterwards.
>
> Using 64-bit time stamps avoids this slight inconsistency, and the
> deprecated do_gettimeofday(), replacing it with the simpler
> ktime_get_real_seconds().

Applied to 4.16/scsi-queue.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 3/3] scsi: 3w-9xxx: rework lock timeouts

[Martin K. Petersen]

Arnd,

> The TW_IOCTL_GET_LOCK ioctl uses do_gettimeofday() to check whether a
> lock has expired. This can misbehave due to a concurrent
> settimeofday() call, as it is based on 'real' time, and it will
> overflow in y2038 on 32-bit architectures, producing unexpected
> results when used across the overflow time.
>
> This changes it to using monotonic time, using ktime_get() to simplify
> the code.

Applied to 4.16/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering