On 03/21/2017 04:36 AM, lixiubo@xxxxxxxxxxxxxxxxxxxx wrote:
> From: Xiubo Li <lixiubo@xxxxxxxxxxxxxxxxxxxx>
>
> If there has BIDI data, its first iov[] will overwrite the last
> iov[] for se_cmd->t_data_sg.
>
> To fix this, we can just increase the iov pointer, but this may
> introuduce a new memory leakage bug: If the se_cmd->data_length
> and se_cmd->t_bidi_data_sg->length are all not aligned up to the
> DATA_BLOCK_SIZE, the actual length needed maybe larger than just
> sum of them.
>
> So, this could be avoided by rounding all the data lengthes up
> to DATA_BLOCK_SIZE.
>
> Signed-off-by: Xiubo Li <lixiubo@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Bryant G. Ly <bryantly@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/target/target_core_user.c | 34 +++++++++++++++++++++++-----------
> 1 file changed, 23 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
> index 57defc3..65d475f 100644
> --- a/drivers/target/target_core_user.c
> +++ b/drivers/target/target_core_user.c
> @@ -394,6 +394,20 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
> return true;
> }
>
> +static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
> +{
> + struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
> + size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
> +
> + if (se_cmd->se_cmd_flags & SCF_BIDI) {
> + BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
> + data_length += round_up(se_cmd->t_bidi_data_sg->length,
> + DATA_BLOCK_SIZE);
> + }
> +
> + return data_length;
> +}
> +
> static sense_reason_t
> tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
> {
> @@ -407,7 +421,7 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
> uint32_t cmd_head;
> uint64_t cdb_off;
> bool copy_to_data_area;
> - size_t data_length;
> + size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
> DECLARE_BITMAP(old_bitmap, DATA_BLOCK_BITS);
>
> if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
> @@ -433,11 +447,6 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
>
> mb = udev->mb_addr;
> cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
> - data_length = se_cmd->data_length;
> - if (se_cmd->se_cmd_flags & SCF_BIDI) {
> - BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
> - data_length += se_cmd->t_bidi_data_sg->length;
> - }
> if ((command_size > (udev->cmdr_size / 2)) ||
> data_length > udev->data_size) {
> pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
> @@ -511,11 +520,14 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
> entry->req.iov_dif_cnt = 0;
>
> /* Handle BIDI commands */
> - iov_cnt = 0;
> - alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg,
> - se_cmd->t_bidi_data_nents, &iov, &iov_cnt, false);
> - entry->req.iov_bidi_cnt = iov_cnt;
> -
> + if (se_cmd->se_cmd_flags & SCF_BIDI) {
> + iov_cnt = 0;
> + iov++;
> + alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg,
> + se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
> + false);
> + entry->req.iov_bidi_cnt = iov_cnt;
> + }
> /* cmd's data_bitmap is what changed in process */
> bitmap_xor(tcmu_cmd->data_bitmap, old_bitmap, udev->data_bitmap,
> DATA_BLOCK_BITS);
>
Patch looks ok to me.
Reviewed-by: Mike Christie <mchristi@xxxxxxxxxx>
