linux/drivers
Lars-Peter Clausen 5f654078b7 gpio: chardev: Return error for seek operations
commit f4e81c5297 upstream.

The GPIO chardev is used for management tasks (allocating line and event
handles) and does neither support read() nor write() operations. Hence it
does not make much sense to allow seek operations.

Currently the chardev uses noop_llseek() for its seek implementation. This
function does not move the pointer and simply returns the current position
(always 0 for the GPIO chardev). noop_llseek() is primarily meant for
devices that can not support seek, but where there might be a user that
depends on the seek() operation succeeding. For newly added devices that
can not support seek operations it is recommended to use no_llseek(), which
will return an error. For more information see commit 6038f373a3
("llseek: automatically add .llseek fop").

Unfortunately this was overlooked when the GPIO chardev ABI was introduced.
But it is highly unlikely that since then userspace applications have
appeared that rely on being able to perform non-failing seek operations on
a GPIO chardev file descriptor. So it should be safe to change from
noop_llseel() to no_seek(). Also use nonseekable_open() in the chardev
open() callback to clear the FMODE_SEEK, FMODE_PREAD and FMODE_PWRITE flags
from the file. Neither of these should be set on a file that does not
support seek operations.

Fixes: 3c702e9987 ("gpio: add a userspace chardev ABI for GPIOs")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-09 08:32:18 +01:00
..
accessibility
acpi tools/testing/nvdimm: unit test acpi_nfit_ctl() 2016-12-06 17:42:36 -08:00
amba
android ANDROID: binder: Clear binder and cookie when setting handle in flat binder struct 2016-10-24 19:37:48 +02:00
ata libata-scsi: disable SCT Write Same for the moment 2016-12-07 16:29:09 -05:00
atm atm: fix improper return value 2016-12-05 14:53:46 -05:00
auxdisplay auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays 2016-10-06 17:03:41 +02:00
base PM / OPP: Don't use OPP structure outside of rcu protected section 2017-01-06 10:40:15 +01:00
bcma
block loop: return proper error from loop_queue_rq() 2017-01-06 10:40:14 +01:00
bluetooth Bluetooth: btwilink: Fix probe return value 2016-10-20 10:14:49 +02:00
bus bus: qcom-ebi2: depend on ARCH_QCOM or COMPILE_TEST 2016-10-17 13:46:09 -07:00
cdrom
char tpm xen: Remove bogus tpm_chip_unregister 2017-01-06 10:40:17 +01:00
clk clk: ti: omap36xx: Work around sprz319 advisory 2.1 2017-01-06 10:40:12 +01:00
clocksource Revert "clocksource/drivers/timer_sun5i: Replace code by clocksource_mmio_init" 2016-10-20 21:58:58 +02:00
connector
cpufreq PM / OPP: Pass opp_table to dev_pm_opp_put_regulator() 2017-01-06 10:40:15 +01:00
cpuidle Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
crypto crypto: caam - fix AEAD givenc descriptors 2017-01-06 10:40:13 +01:00
dax device-dax: fix private mapping restriction, permit read-only 2016-12-06 17:42:37 -08:00
dca
devfreq PM / devfreq: Skip status update on uninitialized previous_freq 2016-10-11 00:01:20 +02:00
dio
dma dmaengine: cppi41: More PM runtime fixes 2016-11-17 16:09:23 +05:30
dma-buf Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux 2016-10-11 18:12:22 -07:00
edac * Altera Arria10 enablement of NAND, DMA, USB, QSPI and SD-MMC FIFO 2016-10-04 12:06:26 -07:00
eisa
extcon extcon: qcom-spmi-misc: Sync the extcon state on interrupt 2016-10-26 16:04:29 +09:00
firewire firewire: net: fix fragmented datagram_size off-by-one 2016-11-03 14:46:39 +01:00
firmware efi/arm: Fix absolute relocation detection for older toolchains 2016-10-19 14:49:44 +02:00
fmc
fpga
gpio gpio: chardev: Return error for seek operations 2017-01-09 08:32:18 +01:00
gpu drm/amdgpu: just suspend the hw on pci shutdown 2016-12-07 11:17:21 -05:00
hid HID: hid-sensor-hub: clear memory to avoid random data 2016-11-23 17:54:58 +01:00
hsi
hv vmbus: make sysfs names consistent with PCI 2016-11-01 09:07:13 -06:00
hwmon hwmon: (core) fix resource leak on devm_kcalloc failure 2016-10-24 06:05:13 -07:00
hwspinlock
hwtracing
i2c Revert "i2c: octeon: thunderx: Limit register access retries" 2016-11-29 20:04:21 +01:00
ide
idle nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
iio iio: maxim_thermocouple: detect invalid storage size in read() 2016-11-13 10:08:32 +01:00
infiniband First round of -rc fixes 2016-11-17 13:53:02 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-12-01 10:29:41 -08:00
iommu Merge git://git.infradead.org/intel-iommu 2016-11-27 08:24:46 -08:00
ipack ipack: print a hex number after a 0x prefix 2016-10-27 18:43:43 -07:00
irqchip GIC updates for Linux 4.9-rc2 2016-10-21 21:40:29 +02:00
isdn ser_gigaset: return -ENOMEM on error instead of success 2016-12-08 14:19:17 -05:00
leds
lguest
lightnvm Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-block 2016-10-07 14:42:05 -07:00
macintosh
mailbox mailbox: PCC: Fix lockdep warning when request PCC channel 2016-11-14 22:07:38 +01:00
mcb mcb: Add a dma_device to mcb_device 2016-09-27 12:33:47 +02:00
md dm space map metadata: fix 'struct sm_metadata' leak on failed create 2017-01-06 10:40:16 +01:00
media xc2028: Fix use-after-free bug properly 2016-11-23 21:04:26 -02:00
memory ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
memstick memstick: rtsx_usb_ms: Manage runtime PM when accessing the device 2016-10-17 15:43:05 +02:00
message
mfd mfd: wm8994-core: Don't use managed regulator bulk get API 2016-11-25 11:10:55 +00:00
misc mei: bus: fix received data size check in NFC fixup 2016-10-31 10:25:22 -06:00
mmc mmc: sd: Meet alignment requirements for raw_ssr DMA 2017-01-09 08:32:17 +01:00
mtd MTD updates for 4.9-rc4: 2016-11-05 10:52:29 -07:00
net ath9k: do not return early to fix rcu unlocking 2017-01-09 08:32:17 +01:00
nfc mei: bus: fix received data size check in NFC fixup 2016-10-31 10:25:22 -06:00
ntb ntb_perf: potential info leak in debugfs 2016-11-13 16:48:30 -05:00
nubus
nvdimm acpi, nfit, libnvdimm: fix / harden ars_status output length handling 2016-12-06 16:08:10 -08:00
nvme nvmet: Fix possible infinite loop triggered on hot namespace removal 2017-01-06 10:40:14 +01:00
nvmem ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
of of_mdio: add helper to deregister fixed-link PHYs 2016-11-29 23:17:02 -05:00
oprofile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
parisc
parport
pci pci-v4.9-fixes-4 2016-12-01 16:44:42 -08:00
pcmcia pcmcia: fix return value of soc_pcmcia_regulator_set 2016-11-11 08:45:08 -08:00
perf perf: xgene: Remove bogus IS_ERR() check 2016-10-17 15:50:07 +01:00
phy phy: twl4030-usb: Fix for musb session bit based PM 2016-11-17 16:25:40 +01:00
pinctrl pinctrl-aspeed-g5: Never set SCU90[6] 2016-11-07 10:31:33 +01:00
platform ACPI fix for v4.9-rc5 2016-11-11 17:02:01 -08:00
pnp
power power supply and reset changes for the v4.9 series 2016-10-06 18:21:15 -07:00
powercap
pps pps: kc: fix non-tickless system config dependency 2016-10-11 15:06:32 -07:00
ps3
ptp drivers/ptp: Fix kernel memory disclosure 2016-10-13 10:20:06 -04:00
pwm pwm: Fix device reference leak 2016-11-29 16:43:24 +01:00
rapidio mm: replace get_user_pages() write/force parameters with gup_flags 2016-10-19 08:11:43 -07:00
ras
regulator regulator: stw481x-vmmc: fix ages old enable error 2017-01-09 08:32:17 +01:00
remoteproc rpmsg updates for v4.9 2016-10-06 17:03:49 -07:00
reset reset: uniphier: rename MIO reset to SD reset for Pro5, PXs2, LD20 SoCs 2016-10-22 18:31:42 +09:00
rpmsg
rtc rtc: omap: prevent disabling of clock/module during suspend 2016-11-04 23:11:39 +01:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2016-10-27 14:16:30 -07:00
sbus
scsi SCSI fixes on 20161208 2016-12-08 12:04:41 -08:00
sfi
sh
sn
soc powerpc updates for 4.9 #2 2016-10-14 11:07:42 -07:00
spi Merge remote-tracking branches 'spi/fix/dt', 'spi/fix/fsl-dspi' and 'spi/fix/fsl-espi' into spi-linus 2016-10-29 12:51:55 -06:00
spmi spmi: pmic-arb: Return an error code if sanity check fails 2016-09-27 12:43:34 +02:00
ssb ssb: Fix error routine when fallback SPROM fails 2017-01-09 08:32:16 +01:00
staging Staging/IIO fixes for 4.9-rc5 2016-11-13 10:13:33 -08:00
target target/tcm_fc: use CPU affinity for responses 2016-10-21 01:19:44 -07:00
tc
thermal thermal/powerclamp: add back module device table 2016-11-21 20:54:40 +08:00
thunderbolt
tty tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeup 2016-10-28 08:13:07 -04:00
uio
usb usb: gadget: composite: always set ep->mult to a sensible value 2017-01-06 10:40:15 +01:00
uwb uwb: fix device reference leaks 2016-11-01 09:04:04 -06:00
vfio vfio/pci: Fix integer overflows, bitmask check 2016-10-26 13:49:29 -06:00
vhost vhost-vsock: fix orphan connection reset 2016-12-08 21:24:30 -05:00
video video: ARM CLCD: fix Vexpress regression 2016-11-03 12:20:14 +02:00
virt mm: replace get_user_pages() write/force parameters with gup_flags 2016-10-19 08:11:43 -07:00
virtio virtio_ring: mark vring_dma_dev inline 2016-10-31 00:40:08 +02:00
vlynq
vme vme: vme_get_size potentially returning incorrect value on failure 2016-10-28 08:25:18 -04:00
w1
watchdog watchdog: qcom: fix kernel panic due to external abort on non-linefetch 2017-01-06 10:40:16 +01:00
xen xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing 2017-01-06 10:40:17 +01:00
zorro
Kconfig
Makefile A small bug fix and a new driver for acting as an IPMI device. 2016-10-23 15:56:23 -07:00