QXL driver doesn't use any device for DMA mappings or allocations so dev_to_node() will panic inside ttm_device_init() on NUMA systems: general protection fault, probably for non-canonical address 0xdffffc000000007a: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000003d0-0x00000000000003d7] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.7.0+ #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 RIP: 0010:ttm_device_init+0x10e/0x340 Call Trace: <TASK> qxl_ttm_init+0xaa/0x310 qxl_device_init+0x1071/0x2000 qxl_pci_probe+0x167/0x3f0 local_pci_probe+0xe1/0x1b0 pci_device_probe+0x29d/0x790 really_probe+0x251/0x910 __driver_probe_device+0x1ea/0x390 driver_probe_device+0x4e/0x2e0 __driver_attach+0x1e3/0x600 bus_for_each_dev+0x12d/0x1c0 bus_add_driver+0x25a/0x590 driver_register+0x15c/0x4b0 qxl_pci_driver_init+0x67/0x80 do_one_initcall+0xf5/0x5d0 kernel_init_freeable+0x637/0xb10 kernel_init+0x1c/0x2e0 ret_from_fork+0x48/0x80 ret_from_fork_asm+0x1b/0x30 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ttm_device_init+0x10e/0x340 Fall back to NUMA_NO_NODE if there is no device for DMA. Found by Linux Verification Center (linuxtesting.org). Fixes: b0a7ce53d494 ("drm/ttm: Schedule delayed_delete worker closer") Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx> --- drivers/gpu/drm/ttm/ttm_device.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index f5187b384ae9..4130945052ed 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -195,7 +195,7 @@ int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *func bool use_dma_alloc, bool use_dma32) { struct ttm_global *glob = &ttm_glob; - int ret; + int ret, nid; if (WARN_ON(vma_manager == NULL)) return -EINVAL; @@ -215,7 +215,12 @@ int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *func ttm_sys_man_init(bdev); - ttm_pool_init(&bdev->pool, dev, dev_to_node(dev), use_dma_alloc, use_dma32); + if (dev) + nid = dev_to_node(dev); + else + nid = NUMA_NO_NODE; + + ttm_pool_init(&bdev->pool, dev, nid, use_dma_alloc, use_dma32); bdev->vma_manager = vma_manager; spin_lock_init(&bdev->lru_lock); -- 2.43.0