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linux/drivers/char
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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 mwave: fix read buffer overflow 2009-09-24 07:21:03 -07:00
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 const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
applicom.c tree-wide: Assorted spelling fixes 2010-02-09 11:13:56 +01:00
applicom.h
bfin-otp.c const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
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 drivers: Remove BKL from cs5535_gpio 2009-10-14 17:36:48 +02:00
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 headers: remove sched.h from poll.h 2009-10-04 15:05:10 -07:00
efirtc.c efirtc: explicitly set llseek to no_llseek 2009-12-16 07:19:59 -08:00
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 nvram: Drop the bkl from nvram_llseek() 2009-10-14 17:36:49 +02:00
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 headers: Fix build after <linux/sched.h> removal 2009-10-13 10:20:16 -07:00
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 Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-02-25 15:38:37 -08:00
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_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
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_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_udbg.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_vio.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_xen.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
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 tty: istallion: tty port open/close methods 2009-12-11 15:18:06 -08:00
Kconfig virtio: console: Associate each port with a char device 2010-02-24 14:22:53 +10:30
keyboard.c Input: add match() method to input hanlders 2010-02-04 00:25:19 -08:00
lp.c lp: move compat_ioctl handling into lp.c 2009-12-10 22:55:36 +01:00
Makefile tty: esp: remove broken driver 2009-12-11 15:18:03 -08:00
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 tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
mxser.c mxser: spin_lock() => spin_lock_irq() 2010-04-07 08:38:03 -07:00
mxser.h
n_hdlc.c
n_r3964.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
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 ARM: add missing include to nwflash.c 2009-12-19 23:36:00 +00:00
pc8736x_gpio.c drivers: Remove BKL from pc8736x_gpio 2009-10-14 17:36:52 +02:00
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 Fix misspellings of "truly" in comments. 2010-02-04 11:55:45 +01:00
raw.c vfs: rename block_fsync() to blkdev_fsync() 2010-04-07 08:38:04 -07:00
riscom8.c tty: riscom8: switch to the tty_port_open API 2009-12-11 15:18:06 -08:00
riscom8.h
riscom8_reg.h
rocket.c
rocket.h
rocket_int.h
rtc.c sysctl: Drop & in front of every proc_handler. 2009-11-18 08:37:40 -08:00
scc.h
scx200_gpio.c drivers: Remove BKL from scx200_gpio 2009-10-14 17:36:53 +02:00
selection.c
ser_a2232.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
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 tty: stallion: Convert to the tty_port_open/close methods 2009-12-11 15:18:06 -08:00
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 mips: Remove BKL from tb0219 2009-10-14 17:36:53 +02:00
tlclk.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
toshiba.c tosh: Use non bkl ioctl 2010-01-04 12:31:21 -08:00
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 tree-wide: fix a very frequent spelling mistake 2009-11-09 09:40:54 +01:00
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 x86, UV: Fix RTC latency bug by reading replicated cachelines 2010-01-27 11:33:53 +01:00
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 tree-wide: Assorted spelling fixes 2010-02-09 11:13:56 +01:00
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