diff options
| author | Alexey Khoroshilov <khoroshilov@ispras.ru> | 2013-05-07 20:57:08 (GMT) |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2013-05-21 11:23:31 (GMT) |
| commit | 5255e4d9dfe2e33a5d68c54f6d1bee28fc5edd66 (patch) | |
| tree | 752d04c450af3b822dc65df7eaa1068586e4c51d | |
| parent | 88107675fba0b83d45744e9f2414dfea21686f87 (diff) | |
| download | linux-fsl-qoriq-5255e4d9dfe2e33a5d68c54f6d1bee28fc5edd66.tar.xz | |
[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>
| -rw-r--r-- | drivers/media/radio/wl128x/fmdrv_common.c | 24 |
1 files changed, 14 insertions, 10 deletions
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 @@ 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; } |