diff options
| author | Eric Anholt <[email protected]> | 2018-03-20 10:42:12 -0700 |
|---|---|---|
| committer | Eric Anholt <[email protected]> | 2018-03-26 17:33:37 -0700 |
| commit | 0356db022da819176d9d0eacab63d4c2c852f876 (patch) | |
| tree | e0ff9bd91ab5bd52f5dc565263cc9424b3b2708f | |
| parent | d491ad1d364afa60eef5cf7b45f69f7007ab3dfd (diff) | |
gallium/u_vbuf: Protect against overflow with large instance divisors.
GTF-GLES3.gtf.GL3Tests.instanced_arrays.instanced_arrays_divisor uses -1
as a divisor, so we would overflow to count=0 and upload no data,
triggering the assert below. We want to upload 1 element in this case,
fixing the test on VC5.
v2: Use some more obvious logic, and explain why we don't use the normal
round_up().
Reviewed-by: Brian Paul <[email protected]>
| -rw-r--r-- | src/gallium/auxiliary/util/u_vbuf.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/gallium/auxiliary/util/u_vbuf.c b/src/gallium/auxiliary/util/u_vbuf.c index 95d7990c6ca..8a680d60a68 100644 --- a/src/gallium/auxiliary/util/u_vbuf.c +++ b/src/gallium/auxiliary/util/u_vbuf.c @@ -936,7 +936,16 @@ u_vbuf_upload_buffers(struct u_vbuf *mgr, size = mgr->ve->src_format_size[i]; } else if (instance_div) { /* Per-instance attrib. */ - unsigned count = (num_instances + instance_div - 1) / instance_div; + + /* Figure out how many instances we'll render given instance_div. We + * can't use the typical div_round_up() pattern because the CTS uses + * instance_div = ~0 for a test, which overflows div_round_up()'s + * addition. + */ + unsigned count = num_instances / instance_div; + if (count * instance_div != num_instances) + count++; + first += vb->stride * start_instance; size = vb->stride * (count - 1) + mgr->ve->src_format_size[i]; } else { |