[media] wl128x: do not call copy_to_user() while holding spinlocks
copy_to_user() must not be called with spinlocks held, but it is in
fmc_transfer_rds_from_internal_buff().
The patch copies data to tmpbuf, releases spinlock and then passes it to userspace.
By the way there is a small unification: replace a couple of hardcoded constants by a macro.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/radio/wl128x/fmdrv_common.c b/drivers/media/radio/wl128x/fmdrv_common.c
index a002234..253f307 100644
--- a/drivers/media/radio/wl128x/fmdrv_common.c
+++ b/drivers/media/radio/wl128x/fmdrv_common.c
@@ -715,7 +715,7 @@
struct fm_rdsdata_format rds_fmt;
struct fm_rds *rds = &fmdev->rx.rds;
unsigned long group_idx, flags;
- u8 *rds_data, meta_data, tmpbuf[3];
+ u8 *rds_data, meta_data, tmpbuf[FM_RDS_BLK_SIZE];
u8 type, blk_idx;
u16 cur_picode;
u32 rds_len;
@@ -1073,6 +1073,7 @@
u8 __user *buf, size_t count)
{
u32 block_count;
+ u8 tmpbuf[FM_RDS_BLK_SIZE];
unsigned long flags;
int ret;
@@ -1087,29 +1088,32 @@
}
/* Calculate block count from byte count */
- count /= 3;
+ count /= FM_RDS_BLK_SIZE;
block_count = 0;
ret = 0;
- spin_lock_irqsave(&fmdev->rds_buff_lock, flags);
-
while (block_count < count) {
- if (fmdev->rx.rds.wr_idx == fmdev->rx.rds.rd_idx)
- break;
+ spin_lock_irqsave(&fmdev->rds_buff_lock, flags);
- if (copy_to_user(buf, &fmdev->rx.rds.buff[fmdev->rx.rds.rd_idx],
- FM_RDS_BLK_SIZE))
+ if (fmdev->rx.rds.wr_idx == fmdev->rx.rds.rd_idx) {
+ spin_unlock_irqrestore(&fmdev->rds_buff_lock, flags);
break;
-
+ }
+ memcpy(tmpbuf, &fmdev->rx.rds.buff[fmdev->rx.rds.rd_idx],
+ FM_RDS_BLK_SIZE);
fmdev->rx.rds.rd_idx += FM_RDS_BLK_SIZE;
if (fmdev->rx.rds.rd_idx >= fmdev->rx.rds.buf_size)
fmdev->rx.rds.rd_idx = 0;
+ spin_unlock_irqrestore(&fmdev->rds_buff_lock, flags);
+
+ if (copy_to_user(buf, tmpbuf, FM_RDS_BLK_SIZE))
+ break;
+
block_count++;
buf += FM_RDS_BLK_SIZE;
ret += FM_RDS_BLK_SIZE;
}
- spin_unlock_irqrestore(&fmdev->rds_buff_lock, flags);
return ret;
}