diff options
| author | Dan Callaghan <dan.callaghan@opengear.com> | 2020-01-21 10:12:17 +1000 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2020-01-23 16:25:03 +0100 |
| commit | 207270dd0b2d593a8b92043c9bcdabb42111fcc3 (patch) | |
| tree | 1196d6684b765b0b2e8a3d17b02181174443393d /drivers/gpio | |
| parent | 0d311d8b93cfc8ab36aa11f09e15a5fe87147c02 (diff) | |
| download | linux-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.c | 4 |
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 |