I'm not sure when this happened, only that it happened sometime overnight. It was left running an Xfce desktop having only logged in, but with the monitor disconnected. Fedora 23 plus xf86-video-armada.
I don't have any more information than that and the kernel messages below.
[51328.909729] ============================================ [51328.915044] WARNING: possible recursive locking detected [51328.920361] 4.20.0+ #307 Not tainted [51328.923939] -------------------------------------------- [51328.929254] Xorg/5379 is trying to acquire lock: [51328.933874] cd12d5e4 (&(&fence->lock)->rlock){-.-.}, at: dma_fence_signal+0x9c/0x1d4 [51328.941638] [51328.941638] but task is already holding lock: [51328.947474] cd12d6a4 (&(&fence->lock)->rlock){-.-.}, at: dma_fence_signal+0x9c/0x1d4 [51328.955226] [51328.955226] other info that might help us debug this: [51328.961756] Possible unsafe locking scenario: [51328.961756] [51328.967678] CPU0 [51328.970127] ---- [51328.976761] lock(&(&fence->lock)->rlock); [51328.980948] [51328.980948] *** DEADLOCK *** [51328.980948] [51328.986871] May be due to missing lock nesting notation [51328.986871] [51328.993663] 4 locks held by Xorg/5379: [51328.997414] #0: d8c6bdd0 (reservation_ww_class_acquire){+.+.}, at: drm_ioctl_kernel+0x90/0xc8 [51329.006040] #1: d879e2ac (&suballoc->lock){+.+.}, at: etnaviv_cmdbuf_init+0x5c/0x16c [etnaviv] [51329.014784] #2: d900dd88 (&(&gpu->fence_spinlock)->rlock){-.-.}, at: dma_fence_signal+0x9c/0x1d4 [51329.023668] #3: cd12d6a4 (&(&fence->lock)->rlock){-.-.}, at: dma_fence_signal+0x9c/0x1d4 [51329.031854] [51329.031854] stack backtrace: [51329.036218] CPU: 0 PID: 5379 Comm: Xorg Not tainted 4.20.0+ #307 [51329.042227] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [51329.048772] [<c0019658>] (unwind_backtrace) from [<c001489c>] (show_stack+0x10/0x14) [51329.056527] [<c001489c>] (show_stack) from [<c07fb420>] (dump_stack+0x9c/0xd4) [51329.063763] [<c07fb420>] (dump_stack) from [<c0086818>] (__lock_acquire+0x1270/0x19b8) [51329.071689] [<c0086818>] (__lock_acquire) from [<c0087848>] (lock_acquire+0xc4/0x1dc) [51329.079529] [<c0087848>] (lock_acquire) from [<c081a0a4>] (_raw_spin_lock_irqsave+0x44/0x58) [51329.087975] [<c081a0a4>] (_raw_spin_lock_irqsave) from [<c04c4dec>] (dma_fence_signal+0x9c/0x1d4) [51329.096872] [<c04c4dec>] (dma_fence_signal) from [<bf046908>] (drm_sched_entity_kill_jobs_cb+0x14/0x78 [gpu_sched]) [51329.107327] [<bf046908>] (drm_sched_entity_kill_jobs_cb [gpu_sched]) from [<c04c4e30>] (dma_fence_signal+0xe0/0x1d4) [51329.117866] [<c04c4e30>] (dma_fence_signal) from [<bf0458ec>] (drm_sched_process_job+0x60/0x1a4 [gpu_sched]) [51329.127710] [<bf0458ec>] (drm_sched_process_job [gpu_sched]) from [<c04c4e30>] (dma_fence_signal+0xe0/0x1d4) [51329.137569] [<c04c4e30>] (dma_fence_signal) from [<bf05ed58>] (irq_handler+0xc8/0x1d8 [etnaviv]) [51329.146389] [<bf05ed58>] (irq_handler [etnaviv]) from [<c009bd98>] (__handle_irq_event_percpu+0x98/0x378) [51329.155966] [<c009bd98>] (__handle_irq_event_percpu) from [<c009c094>] (handle_irq_event_percpu+0x1c/0x58) [51329.165629] [<c009c094>] (handle_irq_event_percpu) from [<c009c108>] (handle_irq_event+0x38/0x5c) [51329.174511] [<c009c108>] (handle_irq_event) from [<c009f830>] (handle_fasteoi_irq+0x94/0x124) [51329.183044] [<c009f830>] (handle_fasteoi_irq) from [<c009b4f8>] (generic_handle_irq+0x18/0x28) [51329.191665] [<c009b4f8>] (generic_handle_irq) from [<c009b5fc>] (__handle_domain_irq+0x54/0xb0) [51329.200374] [<c009b5fc>] (__handle_domain_irq) from [<c03a6afc>] (gic_handle_irq+0x48/0x98) [51329.208735] [<c03a6afc>] (gic_handle_irq) from [<c0009a10>] (__irq_svc+0x70/0x98) [51329.216221] Exception stack(0xd8c6bc28 to 0xd8c6bc70) [51329.221279] bc20: 00000001 00000011 d8c6bc78 c2005940 00000000 d879e2ac [51329.229462] bc40: 00000000 00000000 00000000 c0c2c580 600b0013 c0b98568 c13bb508 d8c6bc78 [51329.237643] bc60: c0085804 c0087860 800b0013 ffffffff [51329.242704] [<c0009a10>] (__irq_svc) from [<c0087860>] (lock_acquire+0xdc/0x1dc) [51329.250111] [<c0087860>] (lock_acquire) from [<c0815cc8>] (__mutex_lock+0x50/0x8b8) [51329.257777] [<c0815cc8>] (__mutex_lock) from [<c08165b8>] (mutex_lock_nested+0x1c/0x24) [51329.265812] [<c08165b8>] (mutex_lock_nested) from [<bf05a8e0>] (etnaviv_cmdbuf_init+0x5c/0x16c [etnaviv]) [51329.275424] [<bf05a8e0>] (etnaviv_cmdbuf_init [etnaviv]) from [<bf05c514>] (etnaviv_ioctl_gem_submit+0x61c/0x1210 [etnaviv]) [51329.286668] [<bf05c514>] (etnaviv_ioctl_gem_submit [etnaviv]) from [<c0460efc>] (drm_ioctl_kernel+0x90/0xc8) [51329.296503] [<c0460efc>] (drm_ioctl_kernel) from [<c0461114>] (drm_ioctl+0x1e0/0x3b0) [51329.304344] [<c0461114>] (drm_ioctl) from [<c01cae20>] (do_vfs_ioctl+0x90/0xa48) [51329.311750] [<c01cae20>] (do_vfs_ioctl) from [<c01cb80c>] (ksys_ioctl+0x34/0x60) [51329.319155] [<c01cb80c>] (ksys_ioctl) from [<c0009000>] (ret_fast_syscall+0x0/0x28) [51329.326813] Exception stack(0xd8c6bfa8 to 0xd8c6bff0) [51329.331870] bfa0: 00b0e120 be9f7b28 00000009 c0306446 be9f7b28 c0306400 [51329.340053] bfc0: 00b0e120 be9f7b28 c0306446 00000036 be9f7b84 be9f7b28 00e19a30 00e460c0 [51329.348234] bfe0: b6d19f18 be9f7ae4 b6d0185c b6a0be5c [51329.353376] ------------[ cut here ]------------ [51329.358004] kernel BUG at /home/rmk/git/linux-rmk/mm/vmalloc.c:1612! [51329.364365] Internal error: Oops - BUG: 0 [#1] SMP ARM [51329.369510] Modules linked in: ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter xt_tcpudp ipt_REJECT nf_reject_ipv4 xt_conntrack ip_set nfnetlink ebtable_broute ebtable_nat ip6table_raw ip6table_nat nf_nat_ipv6 ip6table_mangle iptable_raw iptable_nat nf_nat_ipv4 nf_nat nf_conntrack nf_defrag_ipv4 nf_defrag_ipv6 libcrc32c iptable_mangle ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter caam_jr error snd_soc_imx_spdif imx_thermal nvmem_imx_ocotp snd_soc_imx_audmux snd_soc_sgtl5000 caam imx_sdma virt_dma rc_cec coda snd_soc_fsl_spdif snd_soc_fsl_ssi v4l2_mem2mem imx_pcm_dma imx_vdoa videobuf2_dma_contig dw_hdmi_cec dw_hdmi_ahb_audio etnaviv gpu_sched imx6q_cpufreq sch_fq_codel nfsd ip_tables x_tables [51329.432047] CPU: 0 PID: 5379 Comm: Xorg Not tainted 4.20.0+ #307 [51329.438059] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [51329.444599] PC is at vunmap+0x48/0x4c [51329.448298] LR is at etnaviv_gem_shmem_release+0x10/0x64 [etnaviv] [51329.454486] pc : [<c0192220>] lr : [<bf05d4c8>] psr: 200b0193 [51329.460758] sp : d8c6ba90 ip : c23c4e98 fp : c0c2c314 [51329.465988] r10: 00000200 r9 : 00000100 r8 : c23c4f20 [51329.471219] r7 : c23c4e00 r6 : c9dc4600 r5 : 00000000 r4 : 00010000 [51329.477751] r3 : 00010000 r2 : d8c6ba90 r1 : c2005940 r0 : 00000000 [51329.484287] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none [51329.491514] Control: 10c5387d Table: 13340059 DAC: 00000051 [51329.497267] Process Xorg (pid: 5379, stack limit = 0xd8c6a218) [51329.503105] Stack: (0xd8c6ba90 to 0xd8c6c000) [51329.507470] ba80: bf05d4b8 c23c4e00 c23c4f8c bf05d4c8 [51329.515657] baa0: c23c4f8c bf05e258 d900e800 c23c4e00 c9c13a00 c23c4e00 c9c13a90 00000000 [51329.523843] bac0: c9c13a58 c045fab8 00000001 00000006 c9c13a38 bf05bdbc c9c13a0c cd12d940 [51329.532028] bae0: c9c13a00 cd12d650 200b0193 00000000 00000001 bf046944 d8df790c cd12d640 [51329.540214] bb00: d8df790c c04c4e30 d900d908 dba27308 cd12d640 cd12d600 bf047e84 bf0458ec [51329.548400] bb20: dba27318 dba27308 dba27318 dba27318 200b0193 00000000 00000001 c04c4e30 [51329.556586] bb40: 00000002 d900d840 00000000 d900db20 d900dd98 bf05ed58 c9f94680 da962600 [51329.564772] bb60: c0b9efd4 00000016 00000000 d8c6bbb4 c0b98568 c009bd98 da962674 c0083798 [51329.572958] bb80: da962664 da962600 c2005940 da962600 da962600 c0b9efd4 00000029 db410400 [51329.581143] bba0: f4001100 d8c6bc28 c0b98568 c009c094 db410400 00000000 da962664 da962600 [51329.589329] bbc0: da962664 c009c108 da962600 da962664 c0b9efd4 c009f830 c0b8d9e4 00000000 [51329.597515] bbe0: 00000000 c009b4f8 0000012f c009b5fc f4000100 f400010c c0b98cf8 000003eb [51329.605701] bc00: c0be9f4c c03a6afc c0087860 800b0013 ffffffff d8c6bc5c 00000000 d8c6a000 [51329.613887] bc20: 600b0013 c0009a10 00000001 00000011 d8c6bc78 c2005940 00000000 d879e2ac [51329.622073] bc40: 00000000 00000000 00000000 c0c2c580 600b0013 c0b98568 c13bb508 d8c6bc78 [51329.630258] bc60: c0085804 c0087860 800b0013 ffffffff 00000051 bf000000 00000001 00000000 [51329.638444] bc80: 00000000 bf05a8e0 00000000 00000000 00000000 00000000 d879e2d8 d879e278 [51329.646629] bca0: 00000000 00000000 c13bb508 00000003 00000002 d879e2bc d9116f74 c0815cc8 [51329.654815] bcc0: 00000001 00000000 bf05a8e0 00000004 00000006 c2005940 d879e2ac 00000000 [51329.663001] bce0: d879e2bc c0087b6c 00000001 c2005940 c081a5f4 00000001 d879e278 000009c4 [51329.671187] bd00: d879e200 d879e2c8 d879e278 00000003 00000000 d879e2bc d9116f74 c08165b8 [51329.679373] bd20: bf05a8e0 d879e200 d879e2c8 bf05a8e0 00000000 00000000 c2005940 c007b8bc [51329.687558] bd40: d8c6bd40 d8c6bd40 c0460efc c2ccb340 c716e000 00000010 d2fa8000 c9e5cc00 [51329.695743] bd60: 00000000 d900e040 d8c6be68 bf05c514 00000001 00000000 c0460efc 00000000 [51329.703929] bd80: c0bfe0f8 00000001 ffffffff 00000000 c9e5c000 00000000 d9116f00 c0087848 [51329.712115] bda0: 00000000 00000000 00000000 c0462190 c0bfaa0c c2005940 003cb56c 00000000 [51329.720300] bdc0: 00010000 00000000 c0bfe0f8 00000000 c0bfe0fc c0d97fc0 00000000 c0a3e038 [51329.728486] bde0: 00000001 0000000c c9e5cc00 d900e800 00000000 c9e5cc00 00000021 bf05bef8 [51329.736671] be00: d8c6be68 d8c6be68 d8c6be68 c0460efc be9f7b28 00000000 be9f7b28 00000030 [51329.744857] be20: c9e5cc00 be9f7b28 bf0636c0 c0306446 c307c640 c0461114 00000001 bf0649fc [51329.753043] be40: c0c2c580 60070093 c13cc100 00000051 00000046 00000030 00000048 bf05bef8 [51329.761228] be60: c2005e48 00000000 00000000 00000001 00000001 00000003 0000008e 00006a90 [51329.769413] be80: 00ec5cc0 00000000 00ec6dc0 00000000 00b22048 00000000 00000000 00000000 [51329.777598] bea0: 00000000 00000000 00000000 00000000 c2008978 00000000 c13cc144 00000000 [51329.785784] bec0: 00000000 00000002 c0c2c580 60070093 c13cc100 00000000 c13cc144 c0083798 [51329.793969] bee0: c13cc100 c13cc144 c2005940 c01cb80c c307c640 00000009 00000009 be9f7b28 [51329.802155] bf00: c9eef568 be9f7b28 00e460c0 c01cae20 c13cc100 c00c2108 00000000 c00ba828 [51329.810340] bf20: 00000001 00000000 c00c2108 c00871a4 da2cf27c 00000023 0000c881 00000000 [51329.818526] bf40: 00000000 14e4373b a38c2bbe 00000051 00206a48 00000107 c00091c4 be9f7c0c [51329.826712] bf60: 00000008 00000000 be9f7c0c c307c640 c307c640 c0306446 00000009 be9f7b28 [51329.834898] bf80: d8c6a000 00000036 00e460c0 c01cb80c 00b0e120 be9f7b28 c0306446 00000036 [51329.843084] bfa0: c00091c4 c0009000 00b0e120 be9f7b28 00000009 c0306446 be9f7b28 c0306400 [51329.851270] bfc0: 00b0e120 be9f7b28 c0306446 00000036 be9f7b84 be9f7b28 00e19a30 00e460c0 [51329.859456] bfe0: b6d19f18 be9f7ae4 b6d0185c b6a0be5c 80070010 00000009 00000000 00000000 [51329.867671] [<c0192220>] (vunmap) from [<bf05d4c8>] (etnaviv_gem_shmem_release+0x10/0x64 [etnaviv]) [51329.876770] [<bf05d4c8>] (etnaviv_gem_shmem_release [etnaviv]) from [<bf05e258>] (etnaviv_gem_free_object+0xd0/0x1c4 [etnaviv]) [51329.888279] [<bf05e258>] (etnaviv_gem_free_object [etnaviv]) from [<c045fab8>] (drm_gem_object_free+0x20/0x64) [51329.898311] [<c045fab8>] (drm_gem_object_free) from [<bf05bdbc>] (etnaviv_submit_put+0x6c/0x1a8 [etnaviv]) [51329.908007] [<bf05bdbc>] (etnaviv_submit_put [etnaviv]) from [<bf046944>] (drm_sched_entity_kill_jobs_cb+0x50/0x78 [gpu_sched]) [51329.919506] [<bf046944>] (drm_sched_entity_kill_jobs_cb [gpu_sched]) from [<c04c4e30>] (dma_fence_signal+0xe0/0x1d4) [51329.930048] [<c04c4e30>] (dma_fence_signal) from [<bf0458ec>] (drm_sched_process_job+0x60/0x1a4 [gpu_sched]) [51329.939896] [<bf0458ec>] (drm_sched_process_job [gpu_sched]) from [<c04c4e30>] (dma_fence_signal+0xe0/0x1d4) [51329.949755] [<c04c4e30>] (dma_fence_signal) from [<bf05ed58>] (irq_handler+0xc8/0x1d8 [etnaviv]) [51329.958577] [<bf05ed58>] (irq_handler [etnaviv]) from [<c009bd98>] (__handle_irq_event_percpu+0x98/0x378) [51329.968157] [<c009bd98>] (__handle_irq_event_percpu) from [<c009c094>] (handle_irq_event_percpu+0x1c/0x58) [51329.977822] [<c009c094>] (handle_irq_event_percpu) from [<c009c108>] (handle_irq_event+0x38/0x5c) [51329.986706] [<c009c108>] (handle_irq_event) from [<c009f830>] (handle_fasteoi_irq+0x94/0x124) [51329.995242] [<c009f830>] (handle_fasteoi_irq) from [<c009b4f8>] (generic_handle_irq+0x18/0x28) [51330.003866] [<c009b4f8>] (generic_handle_irq) from [<c009b5fc>] (__handle_domain_irq+0x54/0xb0) [51330.012577] [<c009b5fc>] (__handle_domain_irq) from [<c03a6afc>] (gic_handle_irq+0x48/0x98) [51330.020939] [<c03a6afc>] (gic_handle_irq) from [<c0009a10>] (__irq_svc+0x70/0x98) [51330.028427] Exception stack(0xd8c6bc28 to 0xd8c6bc70) [51330.033487] bc20: 00000001 00000011 d8c6bc78 c2005940 00000000 d879e2ac [51330.041673] bc40: 00000000 00000000 00000000 c0c2c580 600b0013 c0b98568 c13bb508 d8c6bc78 [51330.049857] bc60: c0085804 c0087860 800b0013 ffffffff [51330.054922] [<c0009a10>] (__irq_svc) from [<c0087860>] (lock_acquire+0xdc/0x1dc) [51330.062332] [<c0087860>] (lock_acquire) from [<c0815cc8>] (__mutex_lock+0x50/0x8b8) [51330.070000] [<c0815cc8>] (__mutex_lock) from [<c08165b8>] (mutex_lock_nested+0x1c/0x24) [51330.078039] [<c08165b8>] (mutex_lock_nested) from [<bf05a8e0>] (etnaviv_cmdbuf_init+0x5c/0x16c [etnaviv]) [51330.087654] [<bf05a8e0>] (etnaviv_cmdbuf_init [etnaviv]) from [<bf05c514>] (etnaviv_ioctl_gem_submit+0x61c/0x1210 [etnaviv]) [51330.098900] [<bf05c514>] (etnaviv_ioctl_gem_submit [etnaviv]) from [<c0460efc>] (drm_ioctl_kernel+0x90/0xc8) [51330.108738] [<c0460efc>] (drm_ioctl_kernel) from [<c0461114>] (drm_ioctl+0x1e0/0x3b0) [51330.116579] [<c0461114>] (drm_ioctl) from [<c01cae20>] (do_vfs_ioctl+0x90/0xa48) [51330.123986] [<c01cae20>] (do_vfs_ioctl) from [<c01cb80c>] (ksys_ioctl+0x34/0x60) [51330.131393] [<c01cb80c>] (ksys_ioctl) from [<c0009000>] (ret_fast_syscall+0x0/0x28) [51330.139055] Exception stack(0xd8c6bfa8 to 0xd8c6bff0) [51330.144116] bfa0: 00b0e120 be9f7b28 00000009 c0306446 be9f7b28 c0306400 [51330.152302] bfc0: 00b0e120 be9f7b28 c0306446 00000036 be9f7b84 be9f7b28 00e19a30 00e460c0 [51330.160486] bfe0: b6d19f18 be9f7ae4 b6d0185c b6a0be5c [51330.165548] Code: e1a00005 e1a01004 e8bd4038 eaffffb1 (e7f001f2) [51330.171657] ---[ end trace d9abb4e69be36a96 ]--- [51330.176282] Kernel panic - not syncing: Fatal exception in interrupt [51330.182654] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---