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

Cc: stable@vger.kernel.org
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>
2016-12-07 15:23:39 +01:00
..
devres.c gpio: Propagate all errors in devm_get_gpiod_from_child() 2016-02-25 10:04:25 +01:00
gpio-74x164.c gpio: 74x164: Use spi_write() helper instead of open coding 2016-06-23 11:07:12 +02:00
gpio-74xx-mmio.c gpio: 74xx-mmio: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:19:42 +05:30
gpio-104-dio-48e.c gpio: 104-dio-48e: Fix control port offset computation off-by-one error 2016-06-08 10:08:12 +02:00
gpio-104-idi-48.c gpio: 104-idi-48: Fix missing spin_lock_init for ack_lock 2016-06-13 14:48:10 +02:00
gpio-104-idio-16.c gpio: 104-idio-16: Utilize the ISA bus driver 2016-05-02 09:32:04 -07:00
gpio-adnp.c gpio: adnp: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:19:46 +05:30
gpio-adp5520.c gpio: adp5520: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:34:06 +05:30
gpio-adp5588.c gpio: adp5588: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:34:24 +05:30
gpio-altera-a10sr.c gpio: altera-a10sr: Drop unnecessary gpiochip_remove 2016-10-25 13:58:42 +02:00
gpio-altera.c gpio: altera: fix implicit assumption module.h is present 2016-09-15 14:00:47 +02:00
gpio-amd8111.c gpio: amd8111: Use devm_request_region 2016-02-16 00:19:52 +01:00
gpio-amdpt.c gpio: amdpt: Add a new ACPI HID 2016-03-30 10:38:51 +02:00
gpio-arizona.c gpio: arizona: Tidy up probe error path 2016-12-07 15:23:38 +01:00
gpio-aspeed.c gpio: aspeed: remove redundant return value check 2016-09-23 15:11:09 +02:00
gpio-ath79.c gpio: ath79: fix implicit assumption module.h is present 2016-09-15 14:01:36 +02:00
gpio-axp209.c gpio: axp209: use correct register for GPIO input status 2016-11-24 16:19:02 +01:00
gpio-bcm-kona.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-brcmstb.c gpio: brcmstb: Return proper error if bank width is invalid 2016-04-15 10:09:48 +02:00
gpio-bt8xx.c gpio: bt8xx: use gpiochip data pointer 2016-01-05 11:21:03 +01:00
gpio-clps711x.c gpio: clps711x: Remove board support 2016-06-08 10:49:58 +02:00
gpio-crystalcove.c gpio: crystalcove: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:27 +05:30
gpio-cs5535.c gpio: cs5535: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:28 +05:30
gpio-da9052.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-da9055.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-davinci.c gpio: davinci: Use unique labels for each gpio chip 2016-11-09 09:13:35 +01:00
gpio-dln2.c gpio: dln2: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:30 +05:30
gpio-dwapb.c gpio: dwapb: add missing fwnode_handle_put() in dwapb_gpio_get_pdata() 2016-07-22 15:30:42 +02:00
gpio-em.c gpio: em: use gpiochip data pointer 2016-01-05 11:21:05 +01:00
gpio-ep93xx.c gpio: ep93xx: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:30 +05:30
gpio-etraxfs.c gpio: etraxfs: use builtin_platform_driver 2016-11-22 10:14:22 +01:00
gpio-f7188x.c gpio: f7188x: use gpiochip_get_data instead of container_of 2016-09-18 13:35:06 +02:00
gpio-ge.c gpio: ge: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:31 +05:30
gpio-gpio-mm.c gpio: Add GPIO support for the Diamond Systems GPIO-MM 2016-08-11 13:37:25 +02:00
gpio-grgpio.c gpio: generic: factor into gpio_chip struct 2016-01-05 11:21:00 +01:00
gpio-htc-egpio.c gpio: htc-egpio: read output value from cache 2016-11-13 11:50:22 +01:00
gpio-ich.c gpio: ich: Use devm_request_region 2016-02-16 00:19:53 +01:00
gpio-intel-mid.c gpio: intel-mid: use builtin_pci_driver 2016-11-15 10:34:47 +01:00
gpio-iop.c gpio: iop: Use generic GPIO MMIO functions for driver 2016-09-12 15:28:18 +02:00
gpio-it87.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-janz-ttl.c gpio: janz-ttl: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:33 +05:30
gpio-kempld.c gpio: kempld: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:34 +05:30
gpio-ks8695.c gpio: ks8695: remove irq_to_gpio function 2016-02-19 00:20:30 +01:00
gpio-loongson1.c gpio: loongson1: remove redundant return value check 2016-09-23 15:10:00 +02:00
gpio-loongson.c gpio: convert remaining users to gpiochip_add_data() 2016-01-05 11:21:20 +01:00
gpio-lp873x.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-lp3943.c Revert "gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free" 2016-03-09 22:00:27 +07:00
gpio-lpc18xx.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-lpc32xx.c gpio: lpc32xx: remove unused platform data file 2016-09-12 14:23:37 +02:00
gpio-lynxpoint.c gpio: lynxpoint: avoid potential warning on error path 2016-06-23 11:07:14 +02:00
gpio-max730x.c gpio: max730x: set gpiochip data pointer before using it 2016-08-10 15:40:44 +02:00
gpio-max732x.c gpio: max732x: use gpiochip data pointer 2016-01-05 11:21:07 +01:00
gpio-max7300.c gpio: Drop owner assignment from i2c_driver 2015-11-30 09:31:00 +01:00
gpio-max7301.c spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
gpio-max77620.c gpio: max77620: add compatible string to device id list 2016-11-16 20:52:13 +01:00
gpio-mb86s7x.c gpio: mb86s7x: use builtin_platform_driver 2016-11-22 10:16:17 +01:00
gpio-mc9s08dz60.c gpio: mc9s08dz60: make explicitly non-modular 2016-03-31 15:02:09 +02:00
gpio-mc33880.c gpio: mc33880: use gpiochip data pointer 2016-01-05 11:21:07 +01:00
gpio-mcp23s08.c gpio: mcp23s08: make driver depend on OF_GPIO 2016-09-08 00:42:57 +02:00
gpio-menz127.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-merrifield.c gpio: merrifield: set default handler to be handle_bad_irq() 2016-10-24 16:33:11 +02:00
gpio-ml-ioh.c gpio: ml-ioh: use gpiochip data pointer 2016-01-05 11:21:08 +01:00
gpio-mm-lantiq.c gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs() 2016-01-13 10:21:06 +01:00
gpio-mmio.c gpio: mmio: add brcm,bcm6345 support 2016-08-11 16:17:05 +02:00
gpio-mockup.c gpio/mockup: add virtual gpio device 2016-09-26 11:47:14 -07:00
gpio-moxart.c gpio: moxart: make explicitly non-modular 2016-03-31 15:03:13 +02:00
gpio-mpc8xxx.c gpio: mpc8xxx: Slightly update the code for better readability 2016-03-09 10:44:13 +07:00
gpio-mpc5200.c gpio: Include linux/gpio.h instead of asm/gpio.h 2016-02-16 00:20:03 +01:00
gpio-msic.c gpio: msic: drop unused MODULE_ tags from non-modular code 2016-08-23 11:22:09 +02:00
gpio-mvebu.c gpio: mvebu: make explicitly non-modular 2016-03-31 15:05:44 +02:00
gpio-mxc.c This is the bulk of GPIO changes for the v4.9 series: 2016-10-05 11:49:09 -07:00
gpio-mxs.c gpio: mxs: fix duplicate level interrupts 2016-10-24 16:33:11 +02:00
gpio-octeon.c gpio: octeon: Constify octeon_gpio_match table 2016-03-30 10:38:51 +02:00
gpio-omap.c gpio: omap: fix irq triggering in smart-idle wakeup mode 2016-04-26 15:56:47 +02:00
gpio-palmas.c gpio: palmas: fix implicit assumption module.h is present 2016-09-15 13:57:43 +02:00
gpio-pca953x.c gpio: pca953x: Add MAX7318 compatible 2016-10-24 16:33:11 +02:00
gpio-pcf857x.c gpio: pcf857x: restore the initial line state of all pcf lines 2016-06-07 09:35:16 +02:00
gpio-pch.c gpio: pch: Optimize pch_gpio_get() 2016-01-05 15:46:34 +01:00
gpio-pisosr.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-pl061.c gpio: pl061: implement .get_direction() 2016-04-28 14:36:37 +02:00
gpio-pxa.c gpio: pxa: fix legacy non pinctrl aware builds 2016-04-08 10:10:08 +02:00
gpio-rc5t583.c gpio: rc5t583: make explicitly non-modular 2016-04-05 17:02:35 +02:00
gpio-rcar.c gpio: rcar: Add r8a7796 (R-Car M3-W) support 2016-09-08 01:15:46 +02:00
gpio-rdc321x.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-sa1100.c gpio: sa1100: fix irq probing for ucb1x00 2016-09-08 00:42:57 +02:00
gpio-sch311x.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-sch.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-sodaville.c gpio: sodaville: make it explicitly non-modular 2016-05-11 13:46:49 +02:00
gpio-spear-spics.c gpio: spear-spics: drop unused MODULE_ tags from non-modular code 2016-08-23 11:23:41 +02:00
gpio-sta2x11.c gpio: sta2x11: make explicitly non-modular 2016-03-31 15:07:40 +02:00
gpio-stmpe.c gpio: stmpe: fix interrupt handling bug 2016-11-24 16:19:01 +01:00
gpio-stp-xway.c gpio: stp-xway: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:43 +05:30
gpio-syscon.c gpio: syscon: Change the compatibility string 2016-06-08 10:48:17 +02:00
gpio-tb10x.c gpio: tb10x: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:44 +05:30
gpio-tc3589x.c gpio: tc3589x: fix up complaints on unsigned 2016-09-19 10:14:29 +02:00
gpio-tegra.c gpio: tegra: Make lockdep class file-scoped 2016-06-22 17:58:07 +02:00
gpio-timberdale.c gpio: timberdale: make it explicitly non-modular 2016-05-11 13:49:11 +02:00
gpio-tpic2810.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-tps6586x.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-tps65086.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-tps65218.c gpio: tps65218: use devm_gpiochip_add_data() for gpio registration 2016-09-18 13:18:13 +02:00
gpio-tps65910.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-tps65912.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-ts4800.c gpio: ts4800: fix implicit assumption module.h is present 2016-09-15 13:59:52 +02:00
gpio-ts4900.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-ts5500.c gpio: ts5500: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:49 +05:30
gpio-twl4030.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-twl6040.c gpio: twl6040: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:50 +05:30
gpio-tz1090-pdc.c gpio: tz1090-pdc: use gpiochip data pointer 2016-01-05 11:21:16 +01:00
gpio-tz1090.c gpio: tz1090: use gpiochip data pointer 2016-01-05 11:21:16 +01:00
gpio-ucb1400.c gpio: ucb1400: Use devm_gpiochip_add_data() for gpio registration 2016-02-23 20:35:50 +05:30
gpio-vf610.c gpio: vf610: use builtin_platform_driver 2016-11-24 16:19:02 +01:00
gpio-viperboard.c gpio: remove redundant owner assignments of drivers 2016-06-07 09:35:16 +02:00
gpio-vr41xx.c gpio: convert remaining users to gpiochip_add_data() 2016-01-05 11:21:20 +01:00
gpio-vx855.c gpio: vx855: use the new open drain callback 2016-04-14 14:03:28 +02:00
gpio-wcove.c gpio: wcove: fix implicit assumption module.h is present 2016-09-15 14:03:33 +02:00
gpio-wm831x.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-wm8350.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-wm8994.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-ws16c48.c gpio: ws16c48: Utilize the ISA bus driver 2016-05-02 09:32:04 -07:00
gpio-xgene-sb.c gpio: xgene-sb: Use irq_domain_free_irqs_common() 2016-03-31 10:22:53 +02:00
gpio-xgene.c This is the bulk of GPIO changes for kernel cycle v4.7: 2016-05-17 17:39:42 -07:00
gpio-xilinx.c gpio: xilinx: Add support to set multiple GPIO at once 2016-06-08 10:33:45 +02:00
gpio-xlp.c gpio: Add ACPI support for XLP GPIO controller 2016-06-08 10:54:13 +02:00
gpio-xtensa.c gpio: convert remaining users to gpiochip_add_data() 2016-01-05 11:21:20 +01:00
gpio-zevio.c gpio: zevio: make it explicitly non-modular 2016-05-11 13:50:01 +02:00
gpio-zx.c gpio: zx: make explicitly non-modular 2016-03-31 15:10:25 +02:00
gpio-zynq.c gpio: Added zynq specific check for special pins on bank zero 2016-09-23 15:26:20 +02:00
gpiolib-acpi.c ACPI / gpio: avoid warning for gpio hogging code 2016-11-09 09:43:55 +01:00
gpiolib-devprop.c gpio: gpiolib-devprop: Check chip->parent pointer before dereferencing 2016-10-25 20:23:19 +02:00
gpiolib-legacy.c Revert "gpiolib: Split GPIO flags parsing and GPIO configuration" 2016-07-04 16:51:29 +02:00
gpiolib-of.c gpio: of: add missing of_node_put() in of_gpiochip_scan_gpios() 2016-10-31 09:23:45 +01:00
gpiolib-sysfs.c gpio: fix documentation for gpiod_unexport 2016-09-12 14:53:33 +02:00
gpiolib.c gpio: chardev: Return error for seek operations 2016-12-07 15:23:39 +01:00
gpiolib.h gpio: Rework of_gpiochip_set_names() to use device property accessors 2016-10-24 16:33:11 +02:00
Kconfig gpio: em: depnd on ARCH_SHMOBILE 2016-11-24 16:18:42 +01:00
Makefile Merge branch 'ib-sx150x' of /home/linus/linux-pinctrl into devel 2016-10-24 16:33:34 +02:00