Mesa (main): util/draw: fix map size of indirect buffer in util_draw_indirect_read

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Module: Mesa
Branch: main
Commit: efca37d4154496f9318064ff40e931233a4e5748
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=efca37d4154496f9318064ff40e931233a4e5748

Author: Mike Blumenkrantz <michael.blumenkrantz at gmail.com>
Date:   Fri Apr 15 10:34:03 2022 -0400

util/draw: fix map size of indirect buffer in util_draw_indirect_read

this was incorrectly calculating too small of a map region if
the stride was less than the size of the struct

Fixes: 3eb99323172 ("aux/draw: add a util function for reading back indirect draw params")

Reviewed-by: Marek Olšák <marek.olsak at amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15963>

---

 src/gallium/auxiliary/util/u_draw.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/gallium/auxiliary/util/u_draw.c b/src/gallium/auxiliary/util/u_draw.c
index d65ac6a6497..70721586738 100644
--- a/src/gallium/auxiliary/util/u_draw.c
+++ b/src/gallium/auxiliary/util/u_draw.c
@@ -158,12 +158,11 @@ util_draw_indirect_read(struct pipe_context *pipe,
    if (!draws)
       return NULL;
 
-   if (indirect->stride)
-      num_params = MIN2(indirect->stride / 4, num_params);
+   unsigned map_size = (draw_count - 1) * indirect->stride + (num_params * sizeof(uint32_t));
    params = pipe_buffer_map_range(pipe,
                                   indirect->buffer,
                                   indirect->offset,
-                                  (num_params * indirect->draw_count) * sizeof(uint32_t),
+                                  map_size,
                                   PIPE_MAP_READ,
                                   &transfer);
    if (!transfer) {