summaryrefslogtreecommitdiff
path: root/drivers/s390/char/vmur.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/s390/char/vmur.c')
-rw-r--r--drivers/s390/char/vmur.c75
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;
}