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Anton Blanchard 320718ee07 hvc_console: Fix race between hvc_close and hvc_remove 
I don't claim to understand the tty layer, but it seems like hvc_open and
hvc_close should be balanced in their kref reference counting.

Right now we get a kref every call to hvc_open:

        if (hp->count++ > 0) {
                tty_kref_get(tty); <----- here
                spin_unlock_irqrestore(&hp->lock, flags);
                hvc_kick();
                return 0;
        } /* else count == 0 */

        tty->driver_data = hp;

        hp->tty = tty_kref_get(tty); <------ or here if hp->count was 0

But hvc_close has:

        tty_kref_get(tty);

        if (--hp->count == 0) {
...
                /* Put the ref obtained in hvc_open() */
                tty_kref_put(tty);
...
        }

        tty_kref_put(tty);

Since the outside kref get/put balance we only do a single kref_put when
count reaches 0.

The patch below changes things to call tty_kref_put once for every
hvc_close call, and with that my machine boots fine.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-04-08 09:46:20 +09:30
..
agp include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hw_random include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ip2 Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
ipmi sysfs: fix sysfs lockdep warning in ipmi code 2010-03-19 07:12:12 -07:00
mwave
pcmcia include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rio include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tpm include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
xilinx_hwicap include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
.gitignore
amiserial.c drivers/char/amiserial.c: add missing local_irq_restore 2010-04-07 08:38:02 -07:00
apm-emulation.c
applicom.c
applicom.h
bfin-otp.c
bfin_jtag_comm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
briq_panel.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bsr.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
cd1865.h
consolemap.c
cp437.uni
cs5535_gpio.c
cyclades.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
defkeymap.c_shipped
defkeymap.map
digi1.h
digiFep1.h
digiPCI.h
ds1302.c
ds1620.c
dsp56k.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dtlk.c
efirtc.c
epca.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
epca.h
epcaconfig.h
generic_nvram.c
generic_serial.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
genrtc.c
hangcheck-timer.c
hpet.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvc_beat.c
hvc_console.c hvc_console: Fix race between hvc_close and hvc_remove 2010-04-08 09:46:20 +09:30
hvc_console.h
hvc_irq.c
hvc_iseries.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
hvc_iucv.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvc_rtas.c
hvc_udbg.c
hvc_vio.c
hvc_xen.c
hvcs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvsi.c
i8k.c
isicom.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
istallion.c
Kconfig
keyboard.c
lp.c
Makefile
mbcs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mbcs.h
mem.c frv: hide uncached_access() when pgprot_noncached is not #defined 2010-04-07 08:38:05 -07:00
misc.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mmtimer.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
moxa.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
moxa.h
mspec.c
mxser.c mxser: spin_lock() => spin_lock_irq() 2010-04-07 08:38:03 -07:00
mxser.h
n_hdlc.c
n_r3964.c
n_tty.c ldisc n_tty: add new method n_tty_inherit_ops() 2010-03-12 15:52:43 -08:00
nozomi.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nsc_gpio.c
nvram.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nwbutton.c
nwbutton.h
nwflash.c
pc8736x_gpio.c
ppdev.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ps3flash.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pty.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
random.c
raw.c vfs: rename block_fsync() to blkdev_fsync() 2010-04-07 08:38:04 -07:00
riscom8.c
riscom8.h
riscom8_reg.h
rocket.c
rocket.h
rocket_int.h
rtc.c
scc.h
scx200_gpio.c
selection.c
ser_a2232.c
ser_a2232.h
ser_a2232fw.ax
ser_a2232fw.h
serial167.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
snsc.c
snsc.h
snsc_event.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sonypi.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
specialix.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
specialix_io8.h
stallion.c
sx.c
sx.h
sxboards.h
sxwindow.h
synclink.c Char: synclink, remove unnecessary checks 2010-03-02 14:43:16 -08:00
synclink_gt.c serial: synclink_gt: dropped transmit data bugfix 2010-03-02 14:43:08 -08:00
synclinkmp.c
sysrq.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tb0219.c
tlclk.c
toshiba.c
tty_audit.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tty_buffer.c tty_buffer: Fix distinct type warning 2010-03-19 07:17:55 -07:00
tty_io.c tty: release_one_tty() forgets to put pids 2010-04-02 19:44:09 -07:00
tty_ioctl.c
tty_ldisc.c tty: Fix the ldisc hangup race 2010-03-02 14:43:22 -08:00
tty_port.c tty_port,usb-console: Fix usb serial console open/close regression 2010-03-19 07:17:57 -07:00
uv_mmtimer.c
vc_screen.c
viotape.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
virtio_console.c virtio: disable multiport console support. 2010-04-08 09:46:19 +09:30
vme_scc.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
vt.c
vt_ioctl.c Revert "tty: Add a new VT mode which is like VT_PROCESS but doesn't require a VT_RELDISP ioctl call" 2010-03-19 07:17:52 -07:00