libplacebo349 – Segfault on NVIDIA Blackwell (RTX 5060) / Driver 580 [solved]

[nullptrdesaster]

GPU NVIDIA GeForce RTX 5060 (Blackwell GB206, SM 12.0)NVIDIA Treiber580.126.20 (Open)Vulkan API1.4.312libplacebo3497.349.0+git20241013-18-9e16c86f-1yavdr0noblevdr-plugin-softhdcuvid3.35-0yavdr0nobleOSUbuntu 24.04.4 LTS (Noble)PlattformProxmox VM with GPU-Passthrough.

dmesg alarms a segfault while vdr displaythread stops:
dmesg:

[ 1461.349433] video display[1715]: segfault at 79bcfc1b06c0
ip 000079bcfc1b06c0 sp 000079bcc53ba828 error 15 likely on CPU 0

journalctl says: vdr[1487]: delete placebo ← last log-entry before crash
kernel: video display[1715]: segfault ...

In src/vulkan/context.c, CmdBeginDebugUtilsLabelEXT and CmdEndDebugUtilsLabelEXT are loaded into the required list vk_dev_funs[]: lines 321 and 336. These functions belong to the extension VK_EXT_debug_utils, which is not requested in vkInstanceCreateInfo.

Confirmed by the Vulkan Validation Layer:
vkCmdBeginDebugUtilsLabelEXT(): function requires the extension
VK_EXT_debug_utils, which has not been enabled.

Fix:
sed -i '/PL_VK_DEV_FUN(CmdBeginDebugUtilsLabelEXT)/d' src/vulkan/context.c
sed -i '/PL_VK_DEV_FUN(CmdEndDebugUtilsLabelEXT)/d' src/vulkan/context.c

[nullptrdesaster]

libplacebo.so.338 has the same bug and should be patched the same way.

[kasper93]

vkGetDeviceProcAddr is required to return NULL for functions from disabled extensions. And this is checked.

Side note, I actually have made this patch long time ago https://code.videolan.org/kasper93/libplacebo/-/commit/9d0a1e72, but I don't think this is needed and likely won't be merged.