Tobias Klausmann e94c55b8e0 nouveau: Skip unvailable ttm page entries ... Starting with commit f295c8cfec ("drm/nouveau: fix dma syncing warning with debugging on.") the following oops occures: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 1013 Comm: Xorg.bin Tainted: G E 5.11.0-desktop-rc0+ #2 Hardware name: Acer Aspire VN7-593G/Pluto_KLS, BIOS V1.11 08/01/2018 RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau] Call Trace: nouveau_bo_validate+0x5d/0x80 [nouveau] nouveau_gem_ioctl_pushbuf+0x662/0x1120 [nouveau] ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau] drm_ioctl_kernel+0xa6/0xf0 [drm] drm_ioctl+0x1f4/0x3a0 [drm] ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau] nouveau_drm_ioctl+0x50/0xa0 [nouveau] __x64_sys_ioctl+0x7e/0xb0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae ---[ end trace ccfb1e7f4064374f ]--- RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau] The underlying problem is not introduced by the commit, yet it uncovered the underlying issue. The cited commit relies on valid pages. This is not given for due to some bugs. For now, just warn and work around the issue by just ignoring the bad ttm objects. Below is some debug info gathered while debugging this issue: nouveau 0000:01:00.0: DRM: ttm_dma->num_pages: 2048 nouveau 0000:01:00.0: DRM: ttm_dma->pages is NULL nouveau 0000:01:00.0: DRM: ttm_dma: 00000000e96058e7 nouveau 0000:01:00.0: DRM: ttm_dma->page_flags: nouveau 0000:01:00.0: DRM: ttm_dma: Populated: 1 nouveau 0000:01:00.0: DRM: ttm_dma: No Retry: 0 nouveau 0000:01:00.0: DRM: ttm_dma: SG: 256 nouveau 0000:01:00.0: DRM: ttm_dma: Zero Alloc: 0 nouveau 0000:01:00.0: DRM: ttm_dma: Swapped: 0 Signed-off-by: Tobias Klausmann <tobias.klausmann@freenet.de> Signed-off-by: Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210313222159.3346-1-tobias.klausmann@freenet.de		2021-03-19 10:38:31 +10:00
..
drm	nouveau: Skip unvailable ttm page entries	2021-03-19 10:38:31 +10:00
host1x	gpu/host1x: bus: Add missing description for 'driver'	2020-11-05 22:12:55 +01:00
ipu-v3	gpu/ipu-v3/ipu-di: Strip out 2 unused 'di_sync_config' entries	2021-01-04 12:54:18 +01:00
trace
vga	pci-v5.11-changes	2020-12-15 16:49:59 -08:00
Makefile