On Tue, Dec 11, 2018 at 06:56:42PM +0530, P J P wrote:
> From: Prasad J Pandit <p...@fedoraproject.org>
>
> pvrdma_idx_ring_has_[data/space] routines also return invalid
> index PVRDMA_INVALID_IDX[=-1], if ring has no data/space. Check
> return value from these routines to avoid plausible infinite loops.
>
> Reported-by: Li Qiang <liq...@163.com>
> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org>
> ---
> hw/rdma/vmw/pvrdma_dev_ring.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.c
> index 01247fc041..61b6a0a869 100644
> --- a/hw/rdma/vmw/pvrdma_dev_ring.c
> +++ b/hw/rdma/vmw/pvrdma_dev_ring.c
> @@ -73,6 +73,7 @@ out:
>
> void *pvrdma_ring_next_elem_read(PvrdmaRing *ring)
> {
> + int e;
> unsigned int idx = 0, offset;
>
> /*
> @@ -80,7 +81,8 @@ void *pvrdma_ring_next_elem_read(PvrdmaRing *ring)
> ring->ring_state->cons_head);
> */
>
> - if (!pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx)) {
> + e = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx);
> + if (e <= 0) {
> pr_dbg("No more data in ring\n");
> return NULL;
> }
> @@ -105,20 +107,24 @@ void pvrdma_ring_read_inc(PvrdmaRing *ring)
>
> void *pvrdma_ring_next_elem_write(PvrdmaRing *ring)
> {
> - unsigned int idx, offset, tail;
> + int idx;
> + unsigned int offset, tail;
>
> /*
> pr_dbg("%s: t=%d, h=%d\n", ring->name, ring->ring_state->prod_tail,
> ring->ring_state->cons_head);
> */
> -
> - if (!pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems,
> &tail)) {
> + idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems,
> &tail);
> + if (idx <= 0) {
> pr_dbg("CQ is full\n");
> return NULL;
> }
>
> idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems);
> - /* TODO: tail == idx */
> + if (idx < 0 || tail == idx) {
> + pr_dbg("invalid idx\n");
> + return NULL;
> + }
Thanks Prasad,
Two cosmetic suggestions though:
(1) In pvrdma_ring_next_elem_read, can you stick to your convention and
replace 'e' with 'idx'?
(2) Can you delete all leftover comments?
In any case:
Reviewed-by: Yuval Shaia <yuval.sh...@oracle.com>
>
> offset = idx * ring->elem_sz;
> return ring->pages[offset / TARGET_PAGE_SIZE] + (offset %
> TARGET_PAGE_SIZE);
> --
> 2.19.2
>
