From e5006dc6ae984def3dbdaa0848a906b2ee398e0b Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Date: Tue, 15 Apr 2025 10:53:19 -0400
Subject: [PATCH] hk: fill sparse.write with nonzero values

fuzz for bugs.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34585>
---
 src/asahi/vulkan/hk_device.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/asahi/vulkan/hk_device.c b/src/asahi/vulkan/hk_device.c
index 6d05e597f1d..efd3ada4099 100644
--- a/src/asahi/vulkan/hk_device.c
+++ b/src/asahi/vulkan/hk_device.c
@@ -65,6 +65,11 @@ hk_upload_rodata(struct hk_device *dev)
    if (!dev->rodata.bo || !dev->sparse.write)
       return VK_ERROR_OUT_OF_HOST_MEMORY;
 
+   /* The contents of sparse.write are undefined, but making them nonzero helps
+    * fuzz for bugs where we incorrectly read from the write section.
+    */
+   memset(agx_bo_map(dev->sparse.write), 0xCA, AIL_PAGESIZE);
+
    uint8_t *map = agx_bo_map(dev->rodata.bo);
    uint32_t offs = 0;