If GuC firmware is not available on the system and we load i915 with enable
GuC, then we hit this null pointer dereference issue:
[ 71.098873] BUG: unable to handle kernel NULL pointer dereference at
0000000000000008
[ 71.098938] IP: intel_uc_fw_upload+0x1f/0x360 [i915]
[ 71.098947] PGD 0 P4D 0
[ 71.098956] Oops: 0000 [#1] PREEMPT SMP PTI
[ 71.098965] Modules linked in: i915(O+) netconsole x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel mei_me i2c_i801 prime_numbers mei [last unloaded: i915]
[ 71.099005] CPU: 2 PID: 1167 Comm: insmod Tainted: G U W O 4.16.0-rc1+ #337
[ 71.099018] Hardware name: /NUC6i5SYB, BIOS SYSKLi35.86A.0065.2018.0103.1000 01/03/2018
[ 71.099077] RIP: 0010:intel_uc_fw_upload+0x1f/0x360 [i915]
[ 71.099087] RSP: 0018:
ffffc90000417aa0 EFLAGS:
00010282
[ 71.099097] RAX:
0000000000000000 RBX:
ffff88084cad12f8 RCX:
ffffffffa03e9357
[ 71.099108] RDX:
0000000000000002 RSI:
ffffffffa034dba0 RDI:
ffff88084cad12f8
[ 71.099118] RBP:
0000000000000002 R08:
ffff88085344ca90 R09:
0000000000000001
[ 71.099128] R10:
0000000000000000 R11:
0000000000000000 R12:
ffff88084cad0000
[ 71.099139] R13:
ffffffffa034dba0 R14:
00000000fffffff5 R15:
ffff88084cad12b0
[ 71.099151] FS:
00007f7f24ae2740(0000) GS:
ffff88085e200000(0000) knlGS:
0000000000000000
[ 71.099162] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 71.099171] CR2:
0000000000000008 CR3:
0000000855f48001 CR4:
00000000003606e0
[ 71.099182] Call Trace:
[ 71.099246] intel_uc_init_hw+0xc8/0x520 [i915]
[ 71.099303] i915_gem_init_hw+0x11f/0x2d0 [i915]
[ 71.099364] i915_gem_init+0x2b9/0x640 [i915]
[ 71.099413] i915_driver_load+0xb74/0x1110 [i915]
[ 71.099462] i915_pci_probe+0x2e/0x90 [i915]
[ 71.099476] pci_device_probe+0xa1/0x130
[ 71.099488] driver_probe_device+0x302/0x470
[ 71.099502] __driver_attach+0xb9/0xe0
[ 71.099513] ? driver_probe_device+0x470/0x470
[ 71.099525] ? driver_probe_device+0x470/0x470
[ 71.099538] bus_for_each_dev+0x64/0x90
[ 71.099550] bus_add_driver+0x164/0x260
[ 71.099561] ? 0xffffffffa04d6000
[ 71.099572] driver_register+0x57/0xc0
[ 71.099582] ? 0xffffffffa04d6000
[ 71.099593] do_one_initcall+0x3b/0x160
[ 71.099606] ? kmem_cache_alloc_trace+0x1c3/0x2a0
[ 71.099621] do_init_module+0x5b/0x1f9
[ 71.099635] load_module+0x2467/0x2a70
[ 71.099654] ? SyS_finit_module+0xbd/0xe0
[ 71.099668] SyS_finit_module+0xbd/0xe0
[ 71.099682] do_syscall_64+0x73/0x1c0
[ 71.099694] entry_SYSCALL_64_after_hwframe+0x26/0x9b
[ 71.099706] RIP: 0033:0x7f7f23fb40d9
[ 71.099717] RSP: 002b:
00007ffda7d67ed8 EFLAGS:
00000246 ORIG_RAX:
0000000000000139
[ 71.099734] RAX:
ffffffffffffffda RBX:
000055f96e2a8870 RCX:
00007f7f23fb40d9
[ 71.099748] RDX:
0000000000000000 RSI:
000055f96e2a8260 RDI:
0000000000000003
[ 71.099763] RBP:
000055f96e2a8260 R08:
0000000000000000 R09:
00007ffda7d68088
[ 71.099777] R10:
0000000000000003 R11:
0000000000000246 R12:
0000000000000000
[ 71.099791] R13:
000055f96e2a8830 R14:
0000000000000000 R15:
000055f96e2a8260
[ 71.099810] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 41 54 49 89 f5 55 53 48 c7 c1 57 93 3e a0 48 8b 47 10 48 89 fb 4c 8b 07 <48> 8b 68 08 8b 47 28 85 c0 74 15 83 f8 01 48 c7 c1 5b 93 3e a0
[ 71.100004] RIP: intel_uc_fw_upload+0x1f/0x360 [i915] RSP:
ffffc90000417aa0
[ 71.100020] CR2:
0000000000000008
[ 71.100031] ---[ end trace
d8ac93c30ceff5b2 ]--
Fixes: 6b0478fb722a ("drm/i915: Implement dynamic GuC WOPCM offset and size calculation")
v2: don't assume it is always GuC FW (Michal)
v3: added a new variable to avoid exceeding the number of characters in the
line (Michal)
Signed-off-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reported-by: Radoslaw Szwichtenberg <radoslaw.szwichtenberg@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jackie Li <yaodong.li@intel.com>
Cc: Radoslaw Szwichtenberg <radoslaw.szwichtenberg@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Jackie Li <yaodong.li@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180323112319.16293-1-piotr.piorkowski@intel.com