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authorDan Callaghan <dan.callaghan@opengear.com>2020-01-21 10:12:17 +1000
committerLinus Walleij <linus.walleij@linaro.org>2020-01-23 16:25:03 +0100
commit207270dd0b2d593a8b92043c9bcdabb42111fcc3 (patch)
tree1196d6684b765b0b2e8a3d17b02181174443393d /drivers/gpio
parent0d311d8b93cfc8ab36aa11f09e15a5fe87147c02 (diff)
downloadlinux-207270dd0b2d593a8b92043c9bcdabb42111fcc3.tar.bz2
gpiolib: hold gpio devices lock until ->descs array is initialised
If a driver consuming the GPIO chip is being probed at the same time as the GPIO driver is registering the chip, it is possible for the consuming driver to see the ->descs array in an uninitialised state. For example, the gpio-keys-polled driver can fail like this: kernel: gpiod_request: invalid GPIO (no device) kernel: gpio-keys-polled PRP0001:07: failed to get gpio: -22 kernel: gpio-keys-polled: probe of PRP0001:07 failed with error -22 This patch makes gpiochip_add() hold the lock protecting gpio_devices until it has finished setting desc->gdev on the newly inserted list entry. Signed-off-by: Dan Callaghan <dan.callaghan@opengear.com> Link: https://lore.kernel.org/r/20200121001216.15964-1-dan.callaghan@opengear.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e48461ced552..d5f997761d3e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1486,11 +1486,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
goto err_free_label;
}
- spin_unlock_irqrestore(&gpio_lock, flags);
-
for (i = 0; i < chip->ngpio; i++)
gdev->descs[i].gdev = gdev;
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif