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;
 }