linux/drivers
Daniel Vetter 621bd0f698 drm: Fix locking for sysfs dpms file
With atomic drivers we need to make sure that (at least in general)
property reads hold the right locks. But the legacy dpms property is
special and can be read locklessly. Since userspace loves to just
randomly look at that all the time (like with "status") do that.

To make it clear that we play tricks use the READ_ONCE compiler
barrier (and also for paranoia).

Note that there's not really anything bad going on since even with the
new atomic paths we eventually end up not chasing any pointers (and
hence possibly freed memory and other fun stuff). The locking WARNING
has been added in

commit 88a48e297b
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu Dec 18 16:01:50 2014 -0500

    drm: add atomic properties

but since drivers are converting not everyone will have seen this from
the start.

Jens reported this and submitted a patch to just grab the
mode_config.connection_mutex, but we can do a bit better.

v2: Remove unused variables I failed to git add for real.

Reference: http://mid.gmane.org/20150928194822.GA3930@kernel.dk
Reported-by: Jens Axboe <axboe@fb.com>
Tested-by: Jens Axboe <axboe@fb.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-10-09 10:19:14 +10:00
..
accessibility
acpi Merge branch 'acpi-ec' 2015-10-01 22:30:35 +02:00
amba
android mm: mark most vm_operations_struct const 2015-09-10 13:29:01 -07:00
ata Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-09-03 16:55:55 -07:00
atm solos-pci: Increase headroom on received packets 2015-09-17 21:29:07 -07:00
auxdisplay
base Merge branches 'pm-cpuidle', 'pm-opp' and 'pm-tools' 2015-10-01 22:30:47 +02:00
bcma
block blk-mq: fix racy updates of rq->errors 2015-10-01 10:10:55 +02:00
bluetooth Bluetooth: hci_bcm: Fix crash on suspend 2015-08-28 21:09:14 +02:00
bus regmap: Changes for v4.3 2015-09-08 16:48:55 -07:00
cdrom
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-09-26 21:05:23 -04:00
clk A few driver fixes for tegra, rockchip, and st SoCs and a two-liner 2015-09-19 20:17:40 -07:00
clocksource clocksource/drivers/keystone: Fix bad NO_IRQ usage 2015-09-29 14:33:51 +02:00
connector
cpufreq cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get() 2015-09-16 02:17:49 +02:00
cpuidle Additional power management and ACPI material for v4.3-rc1 2015-09-11 19:11:06 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-09-26 21:05:23 -04:00
dca
devfreq PM / devfreq: Fix incorrect type issue. 2015-09-11 14:23:30 +09:00
dio
dma dmaengine fixes for 4.3-rc4 2015-10-02 14:46:15 -04:00
dma-buf
edac edac updates for v4.3-rc1 2015-09-11 16:21:12 -07:00
eisa
extcon extcon: Fix attached value returned by is_extcon_changed 2015-09-21 15:07:19 +09:00
firewire
firmware arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions 2015-10-01 12:51:28 +02:00
fmc
gpio Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-18 08:11:42 -07:00
gpu drm: Fix locking for sysfs dpms file 2015-10-09 10:19:14 +10:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-09-04 12:02:11 -07:00
hsi mm: mark most vm_operations_struct const 2015-09-10 13:29:01 -07:00
hv Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc 2015-09-20 22:44:51 -07:00
hwmon hwmon: (pwm-fan) Fix module autoload for OF platform driver 2015-09-20 17:50:19 -07:00
hwspinlock
hwtracing/coresight
i2c Merge branch 'i2c/for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2015-09-08 16:16:26 -07:00
ide
idle intel_idle: Skylake Client Support - updated 2015-09-10 14:03:44 -04:00
iio This is the bulk of GPIO changes for the v4.3 kernel cycle: 2015-09-04 10:07:45 -07:00
infiniband Changes for 4.3-rc4 2015-10-01 16:38:52 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-10-02 17:53:25 -04:00
iommu Merge git://git.infradead.org/intel-iommu 2015-10-02 07:59:29 -04:00
ipack
irqchip Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-10-04 11:40:09 +01:00
isdn libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
leds leds:lp55xx: Correct Kconfig dependency for f/w user helper 2015-09-17 10:02:20 +02:00
lguest
macintosh powerpc updates for 4.3 2015-09-03 16:41:38 -07:00
mailbox Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2015-09-05 18:11:04 -07:00
mcb
md Assorted fixes for md in 4.3-rc 2015-10-04 11:47:28 +01:00
media media updates for v4.3-rc1 2015-09-11 16:42:39 -07:00
memory IOMMU Updates for Linux v4.3 2015-09-08 17:22:35 -07:00
memstick
message mptfusion: prevent some memory corruption 2015-08-26 07:11:45 -07:00
mfd genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
misc Char/Misc driver fixes for 4.3-rc3 2015-09-26 20:53:15 -04:00
mmc mmc: core: fix dead loop of mmc_retune 2015-09-30 14:54:22 +02:00
mtd UBI: return ENOSPC if no enough space available 2015-09-29 12:47:05 +02:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-01 21:55:35 -04:00
nfc This is the bulk of GPIO changes for the v4.3 kernel cycle: 2015-09-04 10:07:45 -07:00
ntb NTB: Fix range check on memory window index 2015-09-07 15:27:12 -04:00
nubus
nvdimm pmem: add proper fencing to pmem_rw_page() 2015-09-17 11:49:28 -04:00
nvmem
of Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-09-26 06:01:33 -04:00
oprofile
parisc PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
parport
pci Merge branches 'pm-pci' and 'acpi-pci' 2015-10-01 22:30:12 +02:00
pcmcia pcmcia: soc_common: remove skt_dev_info's clk pointer 2015-09-03 16:01:03 +01:00
perf
phy This is the bulk of GPIO changes for the v4.3 kernel cycle: 2015-09-04 10:07:45 -07:00
pinctrl Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-18 08:11:42 -07:00
platform platform-drivers-x86 for 4.3-2 2015-09-17 21:41:02 -07:00
pnp
power power supply and reset fixes for the v4.3 series 2015-09-17 12:25:42 -07:00
powercap powercap / RAPL: disable the 2nd power limit properly 2015-08-29 01:46:40 +02:00
pps
ps3
ptp
pwm pwm: Changes for v4.3-rc1 2015-09-09 10:55:32 -07:00
rapidio
ras
regulator Merge commit 'b8c93646fd5c' into omap-for-v4.3/fixes 2015-09-24 16:23:20 -07:00
remoteproc
reset reset: ath79: Fix missing spin_lock_init 2015-09-01 14:48:40 +02:00
rpmsg
rtc rtc: abx80x: fix RTC write bit 2015-09-05 19:37:31 +02:00
s390 virtio: fixes on top of 4.3-rc1 2015-09-18 09:28:20 -07:00
sbus
scsi blk-mq: fix racy updates of rq->errors 2015-10-01 10:10:55 +02:00
sfi
sh SH Drivers Updates for v4.3 2015-09-21 12:02:27 -07:00
sn
soc genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
spi Merge remote-tracking branches 'spi/fix/spidev' and 'spi/fix/xtfpga' into spi-linus 2015-09-22 09:48:41 -07:00
spmi genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
ssb
staging Staging driver fixes for 4.3-rc3 2015-09-26 20:56:50 -04:00
target iscsi-target: Avoid OFMarker + IFMarker negotiation 2015-09-24 23:24:46 -07:00
tc
thermal thermal: avoid division by zero in power allocator 2015-10-01 21:42:35 -04:00
thunderbolt thunderbolt: Allow loading of module on recent Apple MacBooks with thunderbolt 2 controller 2015-09-20 15:20:11 -07:00
tty tty: serial: Add missing module license for 8250_base.ko 2015-09-22 09:09:15 -07:00
uio
usb USB: whiteheat: fix potential null-deref at probe 2015-09-23 12:15:19 -07:00
uwb
vfio
vhost virtio: fixes on top of 4.3-rc1 2015-09-18 09:28:20 -07:00
video Merge branch 'akpm' (patches from Andrew) 2015-09-10 18:19:42 -07:00
virt
virtio virtio_balloon: do not change memory amount visible via /proc/meminfo 2015-09-08 13:32:11 +03:00
vlynq
vme
w1 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-09-01 18:46:42 -07:00
watchdog watchdog: iTCO: Fix dependencies on I2C 2015-09-28 10:56:10 +02:00
xen Merge branch 'akpm' (patches from Andrew) 2015-09-10 18:19:42 -07:00
zorro
Kconfig Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-09-03 16:27:01 -07:00
Makefile This is the bulk of pin control changes for the v4.3 development 2015-09-04 10:22:09 -07:00