From: Dan Callaghan Date: Tue, 21 Jan 2020 00:12:17 +0000 (+1000) Subject: gpiolib: hold gpio devices lock until ->descs array is initialised X-Git-Tag: v5.10.7~3374^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=207270dd0b2d593a8b92043c9bcdabb42111fcc3;p=platform%2Fkernel%2Flinux-rpi.git 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 Link: https://lore.kernel.org/r/20200121001216.15964-1-dan.callaghan@opengear.com Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e48461c..d5f9977 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