diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 94903fc1c145..2fa3756c9073 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -101,6 +101,7 @@ static bool gpiolib_initialized; const char *gpiod_get_label(struct gpio_desc *desc) { + struct gpio_desc_label *label; unsigned long flags; flags = READ_ONCE(desc->flags); @@ -108,23 +109,36 @@ const char *gpiod_get_label(struct gpio_desc *desc) !test_bit(FLAG_REQUESTED, &flags)) return "interrupt"; - return test_bit(FLAG_REQUESTED, &flags) ? - srcu_dereference(desc->label, &desc->srcu) : NULL; + if (!test_bit(FLAG_REQUESTED, &flags)) + return NULL; + + label = srcu_dereference_check(desc->label, &desc->srcu, + srcu_read_lock_held(&desc->srcu)); + + return label->str; +} + +static void desc_free_label(struct rcu_head *rh) +{ + kfree(container_of(rh, struct gpio_desc_label, rh)); } static int desc_set_label(struct gpio_desc *desc, const char *label) { - const char *new = NULL, *old; + struct gpio_desc_label *new = NULL, *old; if (label) { - new = kstrdup_const(label, GFP_KERNEL); + new = kzalloc(struct_size(new, str, strlen(label) + 1), + GFP_KERNEL); if (!new) return -ENOMEM; + + strcpy(new->str, label); } old = rcu_replace_pointer(desc->label, new, 1); - synchronize_srcu(&desc->srcu); - kfree_const(old); + if (old) + call_srcu(&desc->srcu, &old->rh, desc_free_label); return 0; } @@ -697,8 +711,11 @@ static void gpiodev_release(struct device *dev) struct gpio_device *gdev = to_gpio_device(dev); unsigned int i; - for (i = 0; i < gdev->ngpio; i++) + for (i = 0; i < gdev->ngpio; i++) { + /* Free pending label. */ + synchronize_srcu(&gdev->descs[i].srcu); cleanup_srcu_struct(&gdev->descs[i].srcu); + } ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); |