1 files changed, 37 insertions, 38 deletions

diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c
index 161867cebd8c..1b758b51d7ed 100644
--- a/drivers/s390/char/vmur.c
+++ b/drivers/s390/char/vmur.c
@@ -119,10 +119,12 @@ static void urdev_put(struct urdev *urd)
 /*
  * Low-level functions to do I/O to a ur device.
  *     alloc_chan_prog
+ *     free_chan_prog
  *     do_ur_io
  *     ur_int_handler
  *
  * alloc_chan_prog allocates and builds the channel program
+ * free_chan_prog frees memory of the channel program
  *
  * do_ur_io issues the channel program to the device and blocks waiting
  * on a completion event it publishes at urd->io_done. The function
@@ -137,6 +139,16 @@ static void urdev_put(struct urdev *urd)
  * address pointer that alloc_chan_prog returned.
  */
 
+static void free_chan_prog(struct ccw1 *cpa)
+{
+        struct ccw1 *ptr = cpa;
+
+        while (ptr->cda) {
+                kfree((void *)(addr_t) ptr->cda);
+                ptr++;
+        }
+        kfree(cpa);
+}
 
 /*
  * alloc_chan_prog
@@ -144,44 +156,45 @@ static void urdev_put(struct urdev *urd)
  * with a final NOP CCW command-chained on (which ensures that CE and DE
  * are presented together in a single interrupt instead of as separate
  * interrupts unless an incorrect length indication kicks in first). The
- * data length in each CCW is reclen. The caller must ensure that count
- * is an integral multiple of reclen.
- * The channel program pointer returned by this function must be freed
- * with kfree. The caller is responsible for checking that
- * count/reclen is not ridiculously large.
+ * data length in each CCW is reclen.
  */
-static struct ccw1 *alloc_chan_prog(char *buf, size_t count, size_t reclen)
+static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
+                                    int reclen)
 {
-        size_t num_ccws;
         struct ccw1 *cpa;
+        void *kbuf;
         int i;
 
-        TRACE("alloc_chan_prog(%p, %zu, %zu)\n", buf, count, reclen);
+        TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
 
         /*
          * We chain a NOP onto the writes to force CE+DE together.
          * That means we allocate room for CCWs to cover count/reclen
          * records plus a NOP.
          */
-        num_ccws = count / reclen + 1;
-        cpa = kmalloc(num_ccws * sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
+        cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
+                      GFP_KERNEL | GFP_DMA);
         if (!cpa)
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
-        for (i = 0; count; i++) {
+        for (i = 0; i < rec_count; i++) {
                 cpa[i].cmd_code = WRITE_CCW_CMD;
                 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
                 cpa[i].count = reclen;
-                cpa[i].cda = __pa(buf);
-                buf += reclen;
-                count -= reclen;
+                kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
+                if (!kbuf) {
+                        free_chan_prog(cpa);
+                        return ERR_PTR(-ENOMEM);
+                }
+                cpa[i].cda = (u32)(addr_t) kbuf;
+                if (copy_from_user(kbuf, ubuf, reclen)) {
+                        free_chan_prog(cpa);
+                        return ERR_PTR(-EFAULT);
+                }
+                ubuf += reclen;
         }
         /* The following NOP CCW forces CE+DE to be presented together */
         cpa[i].cmd_code = CCW_CMD_NOOP;
-        cpa[i].flags = 0;
-        cpa[i].count = 0;
-        cpa[i].cda = 0;
-
         return cpa;
 }
 
@@ -325,24 +338,11 @@ static ssize_t do_write(struct urdev *urd, const char __user *udata,
                         size_t count, size_t reclen, loff_t *ppos)
 {
         struct ccw1 *cpa;
-        char *buf;
         int rc;
 
-        /* Data buffer must be under 2GB line for fmt1 CCWs: hence GFP_DMA */
-        buf = kmalloc(count, GFP_KERNEL | GFP_DMA);
-        if (!buf)
-                return -ENOMEM;
-
-        if (copy_from_user(buf, udata, count)) {
-                rc = -EFAULT;
-                goto fail_kfree_buf;
-        }
-
-        cpa = alloc_chan_prog(buf, count, reclen);
-        if (!cpa) {
-                rc = -ENOMEM;
-                goto fail_kfree_buf;
-        }
+        cpa = alloc_chan_prog(udata, count / reclen, reclen);
+        if (IS_ERR(cpa))
+                return PTR_ERR(cpa);
 
         rc = do_ur_io(urd, cpa);
         if (rc)
@@ -354,10 +354,9 @@ static ssize_t do_write(struct urdev *urd, const char __user *udata,
         }
         *ppos += count;
         rc = count;
+
 fail_kfree_cpa:
-        kfree(cpa);
-fail_kfree_buf:
-        kfree(buf);
+        free_chan_prog(cpa);
         return rc;
 }