diff options
| -rw-r--r-- | drivers/iio/kfifo_buf.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c index ce51092695ab..c95b61f60919 100644 --- a/drivers/iio/kfifo_buf.c +++ b/drivers/iio/kfifo_buf.c @@ -12,6 +12,7 @@ struct iio_kfifo { struct iio_buffer buffer; struct kfifo kf; + struct mutex user_lock; int update_needed; }; @@ -34,10 +35,12 @@ static int iio_request_update_kfifo(struct iio_buffer *r) if (!buf->update_needed) goto error_ret; + mutex_lock(&buf->user_lock); kfifo_free(&buf->kf); ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, buf->buffer.length); r->stufftoread = false; + mutex_unlock(&buf->user_lock); error_ret: return ret; } @@ -114,12 +117,13 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r, int ret, copied; struct iio_kfifo *kf = iio_to_kfifo(r); - if (n < r->bytes_per_datum || r->bytes_per_datum == 0) - return -EINVAL; + if (mutex_lock_interruptible(&kf->user_lock)) + return -ERESTARTSYS; - ret = kfifo_to_user(&kf->kf, buf, n, &copied); - if (ret < 0) - return ret; + if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) + ret = -EINVAL; + else + ret = kfifo_to_user(&kf->kf, buf, n, &copied); if (kfifo_is_empty(&kf->kf)) r->stufftoread = false; @@ -127,6 +131,10 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r, if (!kfifo_is_empty(&kf->kf)) r->stufftoread = true; + mutex_unlock(&kf->user_lock); + if (ret < 0) + return ret; + return copied; } @@ -134,6 +142,7 @@ static void iio_kfifo_buffer_release(struct iio_buffer *buffer) { struct iio_kfifo *kf = iio_to_kfifo(buffer); + mutex_destroy(&kf->user_lock); kfifo_free(&kf->kf); kfree(kf); } @@ -161,6 +170,7 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) kf->buffer.attrs = &iio_kfifo_attribute_group; kf->buffer.access = &kfifo_access_funcs; kf->buffer.length = 2; + mutex_init(&kf->user_lock); return &kf->buffer; } EXPORT_SYMBOL(iio_kfifo_allocate); |