From 07ffd4ce80b9a452d8c8eb154924e19499302d00 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 10 Nov 2017 16:58:27 +0100 Subject: [PATCH] scsi: 3w-9xxx: rework lock timeouts 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 Acked-by: Adam Radford Signed-off-by: Martin K. Petersen --- 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 b1c9bd9..b42c9c4 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(¤t_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 b6c208c..d88cd34 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; -- 2.7.4