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[Qemu-devel] [PATCH v1 5/6] pvrdma: check return value from pvrdma_idx_r
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH v1 5/6] pvrdma: check return value from pvrdma_idx_ring_has_ routines |
Date: |
Wed, 12 Dec 2018 17:17:25 +0530 |
From: Prasad J Pandit <address@hidden>
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 <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
hw/rdma/vmw/pvrdma_dev_ring.c | 37 +++++++++++++++++------------------
1 file changed, 18 insertions(+), 19 deletions(-)
Update v1: receive error code in idx variable, remove comments
-> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02342.html
diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.c
index 01247fc041..2dccac8442 100644
--- a/hw/rdma/vmw/pvrdma_dev_ring.c
+++ b/hw/rdma/vmw/pvrdma_dev_ring.c
@@ -73,23 +73,22 @@ out:
void *pvrdma_ring_next_elem_read(PvrdmaRing *ring)
{
- unsigned int idx = 0, offset;
+ int idx;
+ unsigned int offset, head;
- /*
- 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_data(ring->ring_state, ring->max_elems, &idx)) {
+ idx = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &head);
+ if (idx <= 0) {
pr_dbg("No more data in ring\n");
return NULL;
}
+ idx = pvrdma_idx(&ring->ring_state->cons_head, ring->max_elems);
+ if (idx < 0 || head != idx) {
+ pr_dbg("invalid idx\n");
+ return NULL;
+ }
+
offset = idx * ring->elem_sz;
- /*
- pr_dbg("idx=%d\n", idx);
- pr_dbg("offset=%d\n", offset);
- */
return ring->pages[offset / TARGET_PAGE_SIZE] + (offset %
TARGET_PAGE_SIZE);
}
@@ -105,20 +104,20 @@ 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;
+ }
offset = idx * ring->elem_sz;
return ring->pages[offset / TARGET_PAGE_SIZE] + (offset %
TARGET_PAGE_SIZE);
--
2.19.2
- Re: [Qemu-devel] [PATCH v1 3/6] pvrdma: check number of pages when creating rings, (continued)