Re: [alsa-devel] [Y2038] [PATCH v7 6/9] ALSA: Avoid using timespec for struct snd_timer_tread

On Wed, 2019-12-11 at 22:20 +0100, Arnd Bergmann wrote: [...]

+static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,

• 		unsigned int cmd, bool compat)
  

+{

• int __user *p = argp;
• int xarg, old_tread;
• if (tu->timeri) /* too late */

• return -EBUSY;
  

• if (get_user(xarg, p))

• return -EFAULT;
  

• old_tread = tu->tread;
• if (!xarg)

• tu->tread = TREAD_FORMAT_NONE;
  

• else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||

•  (IS_ENABLED(CONFIG_64BITS) && !compat))
  

This needs to check for CONFIG_64BIT not CONFIG_64BITS.

[...]

@@ -2145,14 +2202,34 @@ static ssize_t snd_timer_user_read(struct file *file, char __user *buffer, tu->qused--; spin_unlock_irq(&tu->qlock);

• if (tu->tread) {
  

• 	if (copy_to_user(buffer, &tu->tqueue[qhead],
  

• 			 sizeof(struct snd_timer_tread)))
  

• tread = &tu->tqueue[qhead];
  

• switch (tu->tread) {
  

• case TREAD_FORMAT_TIME64:
  

• 	if (copy_to_user(buffer, tread,
  

• 			 sizeof(struct snd_timer_tread64)))
  	err = -EFAULT;
  

• } else {
  

• 	break;
  

• case TREAD_FORMAT_TIME32:
  

• 	memset(&tread32, 0, sizeof(tread32));
  

• 	tread32 = (struct snd_timer_tread32) {
  

• 		.event = tread->event,
  

• 		.tstamp_sec = tread->tstamp_sec,
  

• 		.tstamp_sec = tread->tstamp_nsec,
  

• 		.val = tread->val,
  

• 	};
  

• 	if (copy_to_user(buffer, &tread32, sizeof(tread32)))
  

• 		err = -EFAULT;
  

• 	break;
  

• case TREAD_FORMAT_NONE:
  if (copy_to_user(buffer, &tu->queue[qhead],
  		 sizeof(struct snd_timer_read)))
  	err = -EFAULT;
  

• 	break;
  

• default:
  

• 	err = -ENOTSUPP;
  

[...]

This is not a valid error code for returning to user-space, but this case should be impossible so I don't think it matters.

Ben.