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[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>
This commit is contained in:
Alexey Khoroshilov 2013-05-07 17:57:08 -03:00 committed by Mauro Carvalho Chehab
parent 88107675fb
commit 5255e4d9df
1 changed files with 14 additions and 10 deletions
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24
drivers/media/radio/wl128x/fmdrv_common.c
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@ -715,7 +715,7 @@ static void fm_irq_handle_rdsdata_getcmd_resp(struct fmdev *fmdev)
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 @@ int fmc_transfer_rds_from_internal_buff(struct fmdev *fmdev, struct file *file,
u8 __user *buf, size_t count)
{
u32 block_count;
u8 tmpbuf[FM_RDS_BLK_SIZE];
unsigned long flags;
int ret;
@ -1087,29 +1088,32 @@ int fmc_transfer_rds_from_internal_buff(struct fmdev *fmdev, struct file *file,
}
/* 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;
}