[Intel-gfx] Bug while running 4.5.0-rc7-mm1

[Matthew Wilcox]

X is running, but I'm not even logged in at this point (only over ssh):

[64299.755262] general protection fault: 0000 [#1] SMP 
[64299.755303] Modules linked in: binfmt_misc snd_hda_codec_hdmi hid_generic usbhid hid iTCO_wdt iTCO_vendor_support x86_pkg_temp_thermal coretemp kvm_intel kvm irqbypass crc32_pclmul snd_hda_codec_realtek snd_hda_codec_generic ghash_clmulni_intel jitterentropy_rng hmac drbg aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd sg nd_pmem serio_raw snd_hda_intel snd_hda_codec pcspkr snd_hwdep snd_hda_core i915 snd_pcm snd_timer lpc_ich mfd_core i2c_algo_bit drm_kms_helper i2c_i801 mei_me snd drm mei soundcore evdev video button processor loop parport_pc ppdev lp parport sd_mod ehci_pci ehci_hcd ahci crc32c_intel libahci psmouse libata xhci_pci xhci_hcd scsi_mod usbcore usb_common fan thermal
[64299.755724] CPU: 7 PID: 611 Comm: cc1 Tainted: G        W       4.5.0-rc7-mm1+ #49
[64299.755761] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H, BIOS F6 08/03/2013
[64299.755805] task: ffff8800af164280 ti: ffff880097fd4000 task.ti: ffff880097fd4000
[64299.755839] RIP: 0010:[<ffffffff811bf426>]  [<ffffffff811bf426>] page_mapping+0x6/0x70
[64299.755885] RSP: 0000:ffff880097fd78c8  EFLAGS: 00010202
[64299.755911] RAX: 0000000000000000 RBX: 48c0310000441f00 RCX: 0000000000000000
[64299.755944] RDX: ffffffff81254f00 RSI: ffffffff81254f00 RDI: 48c0310000441f00
[64299.755978] RBP: ffff880097fd78e0 R08: 0000000000000000 R09: 0000000000000000
[64299.756012] R10: 0000000000000004 R11: 0000000000000000 R12: ffff8800a5f4ec80
[64299.756046] R13: 0000160000000000 R14: ffff8800a5f4ece0 R15: ffff8800a5f4ed98
[64299.756079] FS:  00002b75382b8680(0000) GS:ffff880239a00000(0000) knlGS:0000000000000000
[64299.756118] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[64299.756143] CR2: 00002b753b83c180 CR3: 0000000097f9f000 CR4: 00000000001406e0
[64299.756177] Stack:
[64299.756189]  ffff880097fd78e0 ffffffff811a72d2 48c0310000441f00 ffff880097fd7920
[64299.756232]  ffffffffa035c494 ffffffff81254f00 81254f4000000000 0000004000000001
[64299.756277]  ffff8800a5f4ec80 0000000000000000 ffff880097fd7990 ffff880097fd7940
[64299.756322] Call Trace:
[64299.756341]  [<ffffffff811a72d2>] ? set_page_dirty+0x12/0x90
[64299.756392]  [<ffffffffa035c494>] i915_gem_object_put_pages_gtt+0x164/0x200 [i915]
[64299.756432]  [<ffffffff81254f00>] ? current_chrooted+0xf0/0xf0
[64299.756477]  [<ffffffffa0359835>] i915_gem_object_put_pages+0xa5/0x110 [i915]
[64299.756527]  [<ffffffffa0362496>] i915_gem_shrink+0x1f6/0x3e0 [i915]
[64299.756575]  [<ffffffffa036270d>] i915_gem_shrinker_scan+0x8d/0xa0 [i915]
[64299.756609]  [<ffffffff811b11bb>] shrink_slab.part.40+0x1fb/0x530
[64299.756639]  [<ffffffff8121d2ad>] ? mem_cgroup_iter+0xad/0x6d0
[64299.756670]  [<ffffffff811b6655>] shrink_zone+0x2c5/0x2d0
[64299.756697]  [<ffffffff811b67a0>] do_try_to_free_pages+0x140/0x360
[64299.756729]  [<ffffffff811b6a99>] try_to_free_pages+0xd9/0x2c0
[64299.756760]  [<ffffffff811a510b>] __alloc_pages_nodemask+0x80b/0xfe0
[64299.756792]  [<ffffffff8121a9c5>] ? get_mem_cgroup_from_mm+0x5/0x370
[64299.756824]  [<ffffffff811fd8a4>] alloc_pages_vma+0xc4/0x310
[64299.756854]  [<ffffffff811d7aa8>] handle_mm_fault+0x1608/0x1870
[64299.756885]  [<ffffffff811d64e9>] ? handle_mm_fault+0x49/0x1870
[64299.756916]  [<ffffffff8106bdcf>] __do_page_fault+0x1ff/0x4f0
[64299.756946]  [<ffffffff8106c0e2>] do_page_fault+0x22/0x30
[64299.756976]  [<ffffffff816e7418>] page_fault+0x28/0x30
[64299.756997] Code: 08 48 89 d1 48 89 d0 ba 00 00 00 00 83 e1 03 48 83 e0 fc 48 83 f9 01 48 0f 45 c2 c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 <48> 8b 47 20 48 89 e5 48 8d 50 ff a8 01 48 0f 45 fa 48 8b 57 20 
[64299.757216] RIP  [<ffffffff811bf426>] page_mapping+0x6/0x70
[64299.757248]  RSP <ffff880097fd78c8>
[64299.766817] ---[ end trace 804b5f61da45645c ]---

The exact tree I'm running is
http://git.infradead.org/users/willy/linux-dax.git/shortlog/refs/heads/dax-pud-2016-03-09
which is v4.5-rc7-mmots-2016-03-08-15-59 plus the 14 DAX patches that
shouldn't affect the i915 driver in any way.