pps: fix padding issue with PPS_FETCH for ioctl_compat

Issue is that x86 32-bit aligns to 4-bytes instead of 8-bytes
so this patchset works around the issue and corrects the data
returned in pps_fdata_compat.

Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 452ead5..6eb0db3 100644 (file)
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -64,6 +64,43 @@ static int pps_cdev_fasync(int fd, struct file *file, int on)
        return fasync_helper(fd, file, on, &pps->async_queue);
 }
 
+static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)
+{
+       unsigned int ev = pps->last_ev;
+       int err = 0;
+
+       /* Manage the timeout */
+       if (fdata->timeout.flags & PPS_TIME_INVALID)
+               err = wait_event_interruptible(pps->queue,
+                               ev != pps->last_ev);
+       else {
+               unsigned long ticks;
+
+               dev_dbg(pps->dev, "timeout %lld.%09d\n",
+                               (long long) fdata->timeout.sec,
+                               fdata->timeout.nsec);
+               ticks = fdata->timeout.sec * HZ;
+               ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ);
+
+               if (ticks != 0) {
+                       err = wait_event_interruptible_timeout(
+                                       pps->queue,
+                                       ev != pps->last_ev,
+                                       ticks);
+                       if (err == 0)
+                               return -ETIMEDOUT;
+               }
+       }
+
+       /* Check for pending signals */
+       if (err == -ERESTARTSYS) {
+               dev_dbg(pps->dev, "pending signal caught\n");
+               return -EINTR;
+       }
+
+       return 0;
+}
+
 static long pps_cdev_ioctl(struct file *file,
                unsigned int cmd, unsigned long arg)
 {
@@ -144,7 +181,6 @@ static long pps_cdev_ioctl(struct file *file,
 
        case PPS_FETCH: {
                struct pps_fdata fdata;
-               unsigned int ev;
 
                dev_dbg(pps->dev, "PPS_FETCH\n");
 
@@ -152,36 +188,9 @@ static long pps_cdev_ioctl(struct file *file,
                if (err)
                        return -EFAULT;
 
-               ev = pps->last_ev;
-
-               /* Manage the timeout */
-               if (fdata.timeout.flags & PPS_TIME_INVALID)
-                       err = wait_event_interruptible(pps->queue,
-                                       ev != pps->last_ev);
-               else {
-                       unsigned long ticks;
-
-                       dev_dbg(pps->dev, "timeout %lld.%09d\n",
-                                       (long long) fdata.timeout.sec,
-                                       fdata.timeout.nsec);
-                       ticks = fdata.timeout.sec * HZ;
-                       ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
-
-                       if (ticks != 0) {
-                               err = wait_event_interruptible_timeout(
-                                               pps->queue,
-                                               ev != pps->last_ev,
-                                               ticks);
-                               if (err == 0)
-                                       return -ETIMEDOUT;
-                       }
-               }
-
-               /* Check for pending signals */
-               if (err == -ERESTARTSYS) {
-                       dev_dbg(pps->dev, "pending signal caught\n");
-                       return -EINTR;
-               }
+               err = pps_cdev_pps_fetch(pps, &fdata);
+               if (err)
+                       return err;
 
                /* Return the fetched timestamp */
                spin_lock_irq(&pps->lock);
@@ -246,8 +255,47 @@ static long pps_cdev_ioctl(struct file *file,
 static long pps_cdev_compat_ioctl(struct file *file,
                unsigned int cmd, unsigned long arg)
 {
+       struct pps_device *pps = file->private_data;
+       void __user *uarg = (void __user *) arg;
+
        cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
 
+       if (cmd == PPS_FETCH) {
+               struct pps_fdata_compat compat;
+               struct pps_fdata fdata;
+               int err;
+
+               dev_dbg(pps->dev, "PPS_FETCH\n");
+
+               err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
+               if (err)
+                       return -EFAULT;
+
+               memcpy(&fdata.timeout, &compat.timeout,
+                                       sizeof(struct pps_ktime_compat));
+
+               err = pps_cdev_pps_fetch(pps, &fdata);
+               if (err)
+                       return err;
+
+               /* Return the fetched timestamp */
+               spin_lock_irq(&pps->lock);
+
+               compat.info.assert_sequence = pps->assert_sequence;
+               compat.info.clear_sequence = pps->clear_sequence;
+               compat.info.current_mode = pps->current_mode;
+
+               memcpy(&compat.info.assert_tu, &pps->assert_tu,
+                               sizeof(struct pps_ktime_compat));
+               memcpy(&compat.info.clear_tu, &pps->clear_tu,
+                               sizeof(struct pps_ktime_compat));
+
+               spin_unlock_irq(&pps->lock);
+
+               return copy_to_user(uarg, &compat,
+                               sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
+       }
+
        return pps_cdev_ioctl(file, cmd, arg);
 }
 #else

diff --git a/include/uapi/linux/pps.h b/include/uapi/linux/pps.h
index a9bb1d9..c1cb382 100644 (file)
--- a/include/uapi/linux/pps.h
+++ b/include/uapi/linux/pps.h
@@ -55,6 +55,12 @@ struct pps_ktime {
        __s32 nsec;
        __u32 flags;
 };
+
+struct pps_ktime_compat {
+       __s64 sec;
+       __s32 nsec;
+       __u32 flags;
+} __attribute__((packed, aligned(4)));
 #define PPS_TIME_INVALID       (1<<0)  /* used to specify timeout==NULL */
 
 struct pps_kinfo {
@@ -65,6 +71,14 @@ struct pps_kinfo {
        int current_mode;               /* current mode bits */
 };
 
+struct pps_kinfo_compat {
+       __u32 assert_sequence;                  /* seq. num. of assert event */
+       __u32 clear_sequence;                   /* seq. num. of clear event */
+       struct pps_ktime_compat assert_tu;      /* time of assert event */
+       struct pps_ktime_compat clear_tu;       /* time of clear event */
+       int current_mode;                       /* current mode bits */
+};
+
 struct pps_kparams {
        int api_version;                /* API version # */
        int mode;                       /* mode bits */
@@ -114,6 +128,11 @@ struct pps_fdata {
        struct pps_ktime timeout;
 };
 
+struct pps_fdata_compat {
+       struct pps_kinfo_compat info;
+       struct pps_ktime_compat timeout;
+};
+
 struct pps_bind_args {
        int tsformat;   /* format of time stamps */
        int edge;       /* selected event type */