Paul Gortmaker f76a1cbed1 hvc: ensure hvc_init is only ever called once in hvc_console.c ... Commit 3e6c6f630a ("Delay creation of khcvd thread") moved the call of hvc_init from being a device_initcall into hvc_alloc, and used a non-null hvc_driver as indication of whether hvc_init had already been called. The problem with this is that hvc_driver is only assigned a value at the bottom of hvc_init, and so there is a window where multiple hvc_alloc calls can be in progress at the same time and hence try and call hvc_init multiple times. Previously the use of device_init guaranteed that hvc_init was only called once. This manifests itself as sporadic instances of two hvc_init calls racing each other, and with the loser of the race getting -EBUSY from tty_register_driver() and hence that virtual console fails: Couldn't register hvc console driver virtio-ports vport0p1: error -16 allocating hvc for port Here we add an atomic_t to guarantee we'll never run hvc_init twice. Cc: stable@vger.kernel.org # v2.6.24+ Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 3e6c6f630a ("Delay creation of khcvd thread") Reported-by: Jim Somerville <Jim.Somerville@windriver.com> Tested-by: Jim Somerville <Jim.Somerville@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-02-13 10:41:47 -08:00
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hvc_beat.c
hvc_bfin_jtag.c
hvc_console.c	hvc: ensure hvc_init is only ever called once in hvc_console.c	2014-02-13 10:41:47 -08:00
hvc_console.h	tty/hvc_console: Add DTR/RTS callback to handle HUPCL control	2013-07-24 15:21:13 -07:00
hvc_dcc.c	TTY: hvc_dcc: probe for a JTAG connection before registering	2013-09-25 18:10:56 -07:00
hvc_irq.c
hvc_iucv.c	s390/hvc_iucv: Automatically assign free HVC terminal devices	2014-01-22 14:02:13 +01:00
hvc_opal.c	drivers/tty/hvc: don't use module_init in non-modular hyp. console code	2014-02-07 08:40:54 -08:00
hvc_rtas.c	drivers/tty/hvc: don't use module_init in non-modular hyp. console code	2014-02-07 08:40:54 -08:00
hvc_tile.c	tile: various console improvements	2013-08-12 14:46:18 -04:00
hvc_udbg.c	drivers/tty/hvc: don't use module_init in non-modular hyp. console code	2014-02-07 08:40:54 -08:00
hvc_vio.c	hvc_vio: Do not override preferred console set by kernel parameter	2013-09-26 15:56:15 -07:00
hvc_xen.c	drivers/tty/hvc: don't use module_init in non-modular hyp. console code	2014-02-07 08:40:54 -08:00
hvcs.c	drivers/tty/hvc: Use strlcpy instead of strncpy	2013-03-05 16:56:27 +11:00
hvsi.c	TTY: add tty_port_tty_wakeup helper	2013-03-18 16:19:45 -07:00
hvsi_lib.c	tty: delete non-required instances of include <linux/init.h>	2014-01-07 17:05:21 -08:00
Kconfig	tty: Added a CONFIG_TTY option to allow removal of TTY	2013-01-18 16:15:27 -08:00
Makefile