fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-02-13 17:50:31 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

gallium/u_vbuf: Protect against overflow with large instance divisors.

Browse source 
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 <brianp@vmware.com>
This commit is contained in:
Eric Anholt 2018-03-20 10:42:12 -07:00
parent d491ad1d36
commit 0356db022d
1 changed files with 10 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
src/gallium/auxiliary/util/u_vbuf.c
View file

@ -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 {