From 3bc016bb6caa15c3bb16053cd9e2e601703080ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tapani=20P=C3=A4lli?= <tapani.palli@intel.com>
Date: Wed, 2 Apr 2025 18:01:12 +0300
Subject: [PATCH] mesa: clamp texbuf query size to MAX_TEXTURE_BUFFER_SIZE
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixes upcoming CTS test checking for clamping.

Cc: mesa-stable
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34428>
---
 src/mesa/main/texparam.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/texparam.c b/src/mesa/main/texparam.c
index 747bc29355c..80a350d7ef5 100644
--- a/src/mesa/main/texparam.c
+++ b/src/mesa/main/texparam.c
@@ -1997,8 +1997,15 @@ get_tex_level_parameter_buffer(struct gl_context *ctx,
          *params = bo->Name;
          break;
       case GL_TEXTURE_WIDTH:
-         *params = ((texObj->BufferSize == -1) ? bo->Size : texObj->BufferSize)
-            / bytes;
+         /* From OpenGL 4.6 spec "8.9 Buffer Textures":
+          *
+          *    "The number of texels in the texture image is then clamped to an
+          *     implementation-dependent limit, the value of
+          *     MAX_TEXTURE_BUFFER_SIZE."
+          */
+         *params = CLAMP(((texObj->BufferSize == -1) ?
+                           bo->Size : texObj->BufferSize) / bytes,
+                         0, ctx->Const.MaxTextureBufferSize);
          break;
       case GL_TEXTURE_HEIGHT:
       case GL_TEXTURE_DEPTH: