Comment 0 for bug 1735842

Occurred whilst using Firefox Nightly 59.0a1 (2017-11-22) - session had been active for several days. No crash report or other useful info in other logs than shown here.

Firefox stopped responding then I realised the entire desktop had likewise although touchpad/mouse movement was fine. Keyboard input was also unavailable (including Ctrl+Alt+Fx).

SSHed in and after seeing the entries in kern.log did "pkill firefox" upon which full control was regained.

This is on 16.04 amd64 with linux-lowlatency-hwe-16.04-edge

lsb_release -a

LSB Version: core-9.20160110ubuntu0.2-amd64:core-9.20160110ubuntu0.2-noarch:security-9.20160110ubuntu0.2-amd64:security-9.20160110ubuntu0.2-noarch
Distributor ID: Ubuntu
Description: Ubuntu 16.04.3 LTS
Release: 16.04
Codename: xenial

uname -a
4.13.0-17-lowlatency #20~16.04.1-Ubuntu SMP PREEMPT Mon Nov 6 15:10:44 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Extract from /var/log/kern.log
Dec 1 20:53:31 hephaestion kernel: [776251.301376] nouveau 0000:01:00.0: fb: trapped write at 0020012054 on channel 5 [0f7c8000 firefox[14820]] engine 05 [PFIFO] client 08 [PFIFO_READ] subclient 01 [SEMAPHORE]
reason 00000006 [NULL_DMAOBJ]
Dec 1 20:53:31 hephaestion kernel: [776251.306835] nouveau 0000:01:00.0: fb: trapped read at 0020012050 on channel 5 [0f7c8000 firefox[14820]] engine 05 [PFIFO] client 08 [PFIFO_READ] subclient 01 [SEMAPHORE] r
eason 00000006 [NULL_DMAOBJ]
Dec 1 20:53:31 hephaestion kernel: [776251.306865] nouveau 0000:01:00.0: fifo: CACHE_ERROR - ch 5 [firefox[14820]] subc 2 mthd 0230 data 000000cf
Dec 1 20:53:31 hephaestion kernel: [776251.306897] nouveau 0000:01:00.0: fifo: CACHE_ERROR - ch 5 [firefox[14820]] subc 2 mthd 0234 data 00000000
Dec 1 20:53:31 hephaestion kernel: [776251.306927] nouveau 0000:01:00.0: fifo: CACHE_ERROR - ch 5 [firefox[14820]] subc 2 mthd 0238 data 00000040
Dec 1 20:53:31 hephaestion kernel: [776251.306961] nouveau 0000:01:00.0: fifo: CACHE_ERROR - ch 5 [firefox[14820]] subc 2 mthd 023c data 00000001
...
Dec 1 21:02:53 hephaestion kernel: [776813.709207] nouveau 0000:01:00.0: gr: DATA_ERROR 00000023 [XY_OUT_OF_BOUNDS]
Dec 1 21:02:53 hephaestion kernel: [776813.709215] nouveau 0000:01:00.0: gr: 00100000 [] ch 5 [000f7c8000 firefox[14820]] subc 5 class 5039 mthd 0328 data 00000000
Dec 1 21:02:53 hephaestion kernel: [776813.709232] nouveau 0000:01:00.0: fb: trapped read at 002001a050 on channel 5 [0f7c8000 firefox[14820]] engine 0c [SEMAPHORE_BG] client 08 [PFIFO_READ] subclient 00 [] reason 00000002 [PAGE_NOT_PRESENT]
Dec 1 21:02:53 hephaestion kernel: [776813.739326] Chrome_~dThread[19418]: segfault at 0 ip 00007fe6bee4d7c0 sp 00007fe6bd372b10 error 6 in libxul.so[7fe6beb9b000+4778000]
Dec 1 21:02:53 hephaestion kernel: [776813.739553] Chrome_~dThread[8961]: segfault at 0 ip 00007fead3b4d7c0 sp 00007fead2072b10 error 6 in libxul.so[7fead389b000+4778000]
Dec 1 21:02:53 hephaestion kernel: [776813.739734] Chrome_~dThread[16471]: segfault at 0 ip 00007f6cd444d7c0 sp 00007f6cd2972b10 error 6 in libxul.so[7f6cd419b000+4778000]
Dec 1 21:02:53 hephaestion kernel: [776813.739915] Chrome_~dThread[15142]: segfault at 0 ip 00007f714354d7c0 sp 00007f7141a72b10 error 6 in libxul.so[7f714329b000+4778000]
Dec 1 21:02:53 hephaestion kernel: [776813.740441] Chrome_~dThread[30269]: segfault at 0 ip 00007f38a2f4d7c0 sp 00007f38a1472b10 error 6 in libxul.so[7f38a2c9b000+4778000]