[Nouveau] 5.9-rc7 oops in nvkm_udevice_info() w/ GA100

[dann frazier]

hey,
  I'm seeing an Oops when nouveau loads (see below). I've verified
that this is because both device->chip and device->name are NULL prior
to the strncpy()s at the end of nvkm_udevice_info(). Bisect shows that
this started happening after:

commit 24d5ff40a732633dceab68c6559ba723784f4a68
Author: Karol Herbst <kherbst at redhat.com>
Date: Tue Apr 28 18:54:02 2020 +0200

    drm/nouveau/device: rework mmio mapping code to get rid of second map

    Fixes warnings on GPUs with smaller a smaller mmio region like vGPUs.

    Signed-off-by: Karol Herbst <kherbst at redhat.com>
    Signed-off-by: Ben Skeggs <bskeggs at redhat.com>

[ 213.131657] nouveau 0000:07:00.0: unknown chipset (170000a1)
[ 213.138547] nouveau 0000:07:00.0: unknown chipset (170000a1)
[ 213.144938] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 213.152704] #PF: supervisor read access in kernel mode
[ 213.158433] #PF: error_code(0x0000) - not-present page
[ 213.164162] PGD 0 P4D 0
[ 213.166985] Oops: 0000 [#1] SMP NOPTI
[ 213.171068] CPU: 32 PID: 206 Comm: kworker/32:0 Not tainted 5.9.0-rc7+ #1
[ 213.178639] Hardware name: NVIDIA DGXA100
920-23687-2530-000/DGXA100, BIOS 0.25 06/30/2020
[ 213.187866] Workqueue: events work_for_cpu_fn
[ 213.192761] RIP: 0010:nvkm_udevice_mthd+0x1ed/0x7d0 [nouveau]
[ 213.199170] Code: 10 49 89 47 08 4d 85 c9 74 10 48 85 c0 74 0b 41 8b
51 70 48 29 d0 49 89 47 10 49 8b 86 c0 00 00 00 49 8d 7f 18 ba 10 00
00 00 <48> 8b 30 e8 6b 91 89 c0 49 8b 76 28 49 8d 7f 28 ba 40 00 00 00
e8
[ 213.220121] RSP: 0018:ffffae0619d47b48 EFLAGS: 00010246
[ 213.225948] RAX: 0000000000000000 RBX: ffff9cefab819580 RCX: 00000000000000c6
[ 213.233907] RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff9cef988f0578
[ 213.241864] RBP: ffffae0619d47b80 R08: 0000000000000000 R09: 0000000000000000
[ 213.249813] R10: 0000000000000088 R11: 0000000001320122 R12: 0000000000000000
[ 213.257762] R13: 0000000000000068 R14: ffff9cef6107c400 R15: ffff9cef988f0560
[ 213.265721] FS: 0000000000000000(0000) GS:ffff9cefce000000(0000)
knlGS:0000000000000000
[ 213.274747] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 213.281153] CR2: 0000000000000000 CR3: 0000007f3019c000 CR4: 0000000000350ee0
[ 213.289104] Call Trace:
[ 213.291854] ? nvkm_object_insert+0x6f/0x80 [nouveau]
[ 213.297509] nvkm_object_mthd+0x1a/0x30 [nouveau]
[ 213.302773] nvkm_ioctl_mthd+0x65/0x70 [nouveau]
[ 213.307940] nvkm_ioctl+0xf0/0x190 [nouveau]
[ 213.312735] nvkm_client_ioctl+0x12/0x20 [nouveau]
[ 213.318097] nvif_object_ioctl+0x4f/0x60 [nouveau]
[ 213.323460] nvif_object_mthd+0x9f/0x150 [nouveau]
[ 213.328822] ? nvif_object_ctor+0x14b/0x1d0 [nouveau]
[ 213.334473] nvif_device_ctor+0x61/0x70 [nouveau]
[ 213.339749] nouveau_cli_init+0x1a3/0x460 [nouveau]
[ 213.345215] ? nouveau_drm_device_init+0x3e/0x780 [nouveau]
[ 213.351454] nouveau_drm_device_init+0x77/0x780 [nouveau]
[ 213.357479] ? pci_read_config_word+0x27/0x40
[ 213.362337] ? pci_enable_device_flags+0x14f/0x170
[ 213.367705] nouveau_drm_probe+0x132/0x1f0 [nouveau]
[ 213.373241] local_pci_probe+0x48/0x80
[ 213.377419] work_for_cpu_fn+0x1a/0x30
[ 213.381598] process_one_work+0x1e8/0x3b0
[ 213.386068] worker_thread+0x53/0x420
[ 213.390149] kthread+0x12f/0x150
[ 213.393745] ? process_one_work+0x3b0/0x3b0
[ 213.398406] ? __kthread_bind_mask+0x70/0x70
[ 213.403169] ret_from_fork+0x22/0x30
[ 213.407153] Modules linked in: nouveau(+) mxm_wmi wmi video
nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua
amd64_edac_mod edac_mce_amd amd_energy kvm_amd kvm rapl efi_pstore
ipmi_ssif input_leds cdc_ether usbnet mii ccp k10temp acpi_ipmi
ipmi_si ipmi_devintf ipmi_msghandler mac_hid sch_fq_codel ip_tables
x_tables autofs4 btrfs blake2b_generic raid10 raid456
async_raid6_recov async_memcpy async_pq async_xor async_tx xor
raid6_pq libcrc32c raid1 raid0 multipath linear mlx5_ib ses enclosure
hid_generic usbhid uas hid usb_storage ib_uverbs ib_core
crct10dif_pclmul crc32_pclmul ast ghash_clmulni_intel drm_vram_helper
aesni_intel drm_ttm_helper crypto_simd ttm cryptd drm_kms_helper
glue_helper syscopyarea sysfillrect sysimgblt mlx5_core fb_sys_fops
pci_hyperv_intf igb cec mpt3sas dca rc_core raid_class nvme tls
i2c_algo_bit scsi_transport_sas drm mlxfw xhci_pci nvme_core
xhci_pci_renesas i2c_piix4
[ 213.497060] CR2: 0000000000000000
[ 213.500755] ---[ end trace eed3a19f1f25ca74 ]---