linux/drivers/tty/vt
David Daney 1b45996d2e tty: vt: Fix soft lockup in fbcon cursor blink timer.
We are getting somewhat random soft lockups with this signature:

[   86.992215] [<fffffc00080935e0>] el1_irq+0xa0/0x10c
[   86.997082] [<fffffc000841822c>] cursor_timer_handler+0x30/0x54
[   87.002991] [<fffffc000810ec44>] call_timer_fn+0x54/0x1a8
[   87.008378] [<fffffc000810ef88>] run_timer_softirq+0x1c4/0x2bc
[   87.014200] [<fffffc000809077c>] __do_softirq+0x114/0x344
[   87.019590] [<fffffc00080af45c>] irq_exit+0x74/0x98
[   87.024458] [<fffffc00080fac20>] __handle_domain_irq+0x98/0xfc
[   87.030278] [<fffffc000809056c>] gic_handle_irq+0x94/0x190

This is caused by the vt visual_init() function calling into
fbcon_init() with a vc_cur_blink_ms value of zero.  This is a
transient condition, as it is later set to a non-zero value.  But, if
the timer happens to expire while the blink rate is zero, it goes into
an endless loop, and we get soft lockup.

The fix is to initialize vc_cur_blink_ms before calling the con_init()
function.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: stable@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Scot Doyle <lkml14@scotdoyle.com>
Tested-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 10:41:13 -07:00
..
.gitignore
consolemap.c tty: consolemap.c: move assignment out of if () block 2015-05-10 19:04:16 +02:00
cp437.uni
defkeymap.c_shipped
defkeymap.map
keyboard.c tty/vt/keyboard: use memdup_user to simplify code 2016-02-06 23:27:46 -08:00
Makefile tty: vt/Makefile: set the variables to static 2013-01-15 21:52:24 -08:00
selection.c tty: Replace TTY_THROTTLED bit tests with tty_throttled() 2016-04-30 09:26:55 -07:00
vc_screen.c vc: switch to fixed_size_llseek() 2013-06-29 12:57:30 +04:00
vt_ioctl.c vt: vt_ioctl: use msecs_to_jiffies for time conversion 2015-03-07 04:02:26 +01:00
vt.c tty: vt: Fix soft lockup in fbcon cursor blink timer. 2016-06-25 10:41:13 -07:00