linux/drivers
Chris Wilson 007c80a549 drm: Hold the mode mutex whilst probing for sysfs status
As detect will use hw registers and may modify structures, it needs to be
serialised by use of the dev->mode_config.mutex. Make it so.

Otherwise, we may cause random crashes as the sysfs file is queried
whilst a concurrent hotplug poll is being run. For example:

[ 1189.189626] BUG: unable to handle kernel NULL pointer dereference at 00000100
[ 1189.189821] IP: [<e0c22019>] intel_tv_detect_type+0xa2/0x203 [i915]
[ 1189.190020] *pde = 00000000
[ 1189.190104] Oops: 0000 [#1] SMP
[ 1189.190209] last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-SVIDEO-1/status
[ 1189.190412] Modules linked in: mperf cpufreq_conservative cpufreq_userspace cpufreq_powersave cpufreq_stats decnet uinput fuse loop joydev snd_hd a_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm i915 snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq drm_kms_helper snd_timer uvcvideo d rm snd_seq_device eeepc_laptop tpm_tis usbhid videodev i2c_algo_bit v4l1_compat snd sparse_keymap i2c_core hid serio_raw tpm psmouse evdev tpm_bios rfkill shpchp ac processor rng_c ore battery video power_supply soundcore pci_hotplug button output snd_page_alloc usb_storage uas ext3 jbd mbcache sd_mod crc_t10dif ata_generic ahci libahci ata_piix libata uhci_h cd ehci_hcd scsi_mod usbcore thermal atl2 thermal_sys nls_base [last unloaded: scsi_wait_scan]
[ 1189.192007]
[ 1189.192007] Pid: 1464, comm: upowerd Not tainted 2.6.37-2-686 #1 ASUSTeK Computer INC. 701/701
[ 1189.192007] EIP: 0060:[<e0c22019>] EFLAGS: 00010246 CPU: 0
[ 1189.192007] EIP is at intel_tv_detect_type+0xa2/0x203 [i915]
[ 1189.192007] EAX: 00000000 EBX: dca74000 ECX: e0f68004 EDX: 00068004
[ 1189.192007] ESI: dd110c00 EDI: 400c0c37 EBP: dca7429c ESP: de365e2c
[ 1189.192007]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1189.192007] Process upowerd (pid: 1464, ti=de364000 task=dcc8acb0 task.ti=de364000)
[ 1189.192007] Stack: Mar 15 03:43:23 hostname kernel: [ 1189.192007]  e0c2cda4 70000000 400c0c30 00000000 dd111000 de365e54 de365f24 dd110c00
[ 1189.192007]  e0c22203 01000000 00000003 00000000 00000000 00000000 00000000 4353544e
[ 1189.192007]  30383420 00000069 00000000 00000000 00000000 00000000 00000000 00000000
[ 1189.192007] Call Trace: Mar 15 03:43:23 hostname kernel: [ 1189.192007]  [<e0c22203>] ?  intel_tv_detect+0x89/0x12d [i915]
[ 1189.192007]  [<e0a9dcef>] ?  status_show+0x0/0x2f [drm]
[ 1189.192007]  [<e0a9dd03>] ?  status_show+0x14/0x2f [drm]

[Digression: what is upowerd doing reading those power hungry files?]

Reported-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-03-16 11:23:04 +10:00
..
accessibility
acpi Merge branch 'iomem' into release 2011-02-15 15:25:48 -05:00
amba
ata libata: set queue DMA alignment to sector size for ATAPI too 2011-01-28 03:16:20 -05:00
atm ATM, Solos PCI ADSL2+: Don't deref NULL pointer if net_ratelimit() and alloc_skb() interact badly. 2011-02-13 16:55:46 -08:00
auxdisplay
base PM / Runtime: Don't enable interrupts while running in_interrupt 2011-01-25 20:50:07 +01:00
block Merge branch 'for-linus' of git://neil.brown.name/md 2011-02-25 11:13:26 -08:00
bluetooth Revert "Bluetooth: Enable USB autosuspend by default on btusb" 2011-02-23 19:42:03 -08:00
cdrom cdrom: support devices that have check_events but not media_changed 2011-02-09 14:22:37 +01:00
char Revert "TPM: Long default timeout fix" 2011-03-01 13:23:27 -08:00
clk
clocksource drivers/clocksource/tcb_clksrc.c: fix init sequence 2011-01-26 10:50:04 +10:00
connector
cpufreq kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
cpuidle
crypto
dca
dio
dma Merge branch 'imx' into dmaengine-fixes 2011-02-14 02:40:46 -08:00
edac amd64_edac: Fix DIMMs per DCTs output 2011-02-10 14:41:49 +01:00
eisa
firewire Merge branches 'fixes' and 'fwnet' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2011-01-21 13:34:39 -08:00
firmware x86, dmi, debug: Log board name (when present) in dmesg/oops output 2011-02-15 04:20:57 +01:00
gpio drivers/gpio/pca953x.c: add a mutex to fix race condition 2011-02-11 16:12:20 -08:00
gpu drm: Hold the mode mutex whilst probing for sysfs status 2011-03-16 11:23:04 +10:00
hid kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
hwmon hwmon: (adt7411) add MODULE_DEVICE_TABLE 2011-02-26 08:59:32 -08:00
i2c i2c-omap: fixup commit cb527ede1b whitespace 2011-02-23 00:43:55 +00:00
ide kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
idle fix a shutdown regression in intel_idle 2011-01-25 05:57:34 +10:00
ieee802154
infiniband Merge branches 'nes' and 'qib' into for-next 2011-02-17 14:04:59 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2011-02-23 14:44:25 -08:00
isdn isdn: hisax: Use l2headersize() instead of dup (and buggy) func. 2011-02-15 12:18:09 -08:00
leds leds: leds-pwm: return proper error if pwm_request failed 2011-01-26 10:49:58 +10:00
lguest lguest: compile fixes 2011-01-20 21:37:29 +10:30
macintosh powerpc/macintosh: Fix wrong test in fan_{read,write}_reg() 2011-01-21 14:08:34 +11:00
mca
md md: Fix - again - partition detection when array becomes active 2011-02-24 17:26:41 +11:00
media Merge branch 'media_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2011-02-02 17:52:19 -08:00
memstick workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable' 2011-02-16 17:48:59 +01:00
message [SCSI] mptfusion: Bump version 03.04.18 2011-02-12 12:51:21 -06:00
mfd mfd: ab8500-core chip version cut 2.0 support 2011-01-14 12:38:18 +01:00
misc workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable' 2011-02-16 17:48:59 +01:00
mmc ARM: mmci: round down the bytes transferred on error 2011-01-31 10:53:37 +00:00
mtd workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable' 2011-02-16 17:48:59 +01:00
net Merge branch 'r8169-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/romieu/netdev-2.6 2011-02-23 15:03:11 -08:00
nfc drivers/nfc/pn544.c: add missing regulator 2011-02-25 15:07:36 -08:00
nubus
of dt/flattree: Return virtual address from early_init_dt_alloc_memory_arch() 2011-01-15 22:01:58 -07:00
oprofile
parisc
parport parport: make lockdep happy with waitlist_lock 2011-01-26 10:49:59 +10:00
pci pci: use security_capable() when checking capablities during config space read 2011-02-15 19:06:31 +11:00
pcmcia pcmcia: re-enable Zoomed Video support 2011-02-20 12:47:34 +01:00
platform dell-laptop: Toggle the unsupported hardware killswitch 2011-02-21 17:06:21 -05:00
pnp
power Merge git://git.infradead.org/battery-2.6 2011-01-14 09:25:59 -08:00
pps pps: initialize ts_real properly 2011-02-25 15:07:37 -08:00
ps3
rapidio rapidio: fix sysfs config attribute to access 16MB of maint space 2011-02-25 15:07:37 -08:00
regulator regulator, mc13xxx: Remove pointless test for unsigned less than zero 2011-02-25 08:51:07 +00:00
rtc drivers/rtc/rtc-ds3232.c: fix time range difference between linux and RTC chip 2011-02-25 15:07:37 -08:00
s390 [S390] dasd: correct device table 2011-02-17 13:13:58 +01:00
sbus
scsi [SCSI] qla2xxx: Return DID_NO_CONNECT when FC device is lost. 2011-02-15 11:12:17 -06:00
sfi
sh sh: update INTC to clear IRQ sense valid flag 2011-01-19 19:02:35 +09:00
sn
spi spi/pxa2xx pci: fix the release - remove race 2011-02-15 13:25:36 -07:00
ssb Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2011-02-08 12:03:54 -08:00
staging Merge branch 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 2011-02-10 12:19:23 -08:00
target [SCSI] target: fix use after free detected by SLUB poison 2011-02-12 12:32:41 -06:00
tc
telephony
thermal ACPI: Fix build for CONFIG_NET unset 2011-02-28 18:00:31 -08:00
tty Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-02-18 12:36:06 -08:00
uio
usb usb: musb: core: set has_tt flag 2011-02-24 11:16:24 -08:00
uwb
vhost vhost: rcu annotation fixup 2011-02-01 16:48:46 +02:00
video console: rename acquire/release_console_sem() to console_lock/unlock() 2011-01-26 10:50:06 +10:00
virtio virtio: remove virtio-pci root device 2011-01-20 21:37:30 +10:30
vlynq
w1 drivers/w1/masters/omap_hdq.c: add missing clk_put 2011-02-11 16:12:20 -08:00
watchdog m68knommu: Rename m548x_wdt.c to m54xx_wdt.c 2011-02-08 15:07:45 +10:00
xen xen: suspend and resume system devices when running PVHVM 2011-02-17 10:31:20 +00:00
zorro
Kconfig [SCSI] target: Add LIO target core v4.0.0-rc6 2011-01-14 10:12:29 -06:00
Makefile Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 2011-01-20 16:39:23 -08:00