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gpiolib: fix memory leak in gpiochip_setup_dev()
[ Upstream commitec851b2308
] Here is a backtrace report about memory leak detected in gpiochip_setup_dev(): unreferenced object 0xffff88810b406400 (size 512): comm "python3", pid 1682, jiffies 4295346908 (age 24.090s) backtrace: kmalloc_trace device_add device_private_init at drivers/base/core.c:3361 (inlined by) device_add at drivers/base/core.c:3411 cdev_device_add gpiolib_cdev_register gpiochip_setup_dev gpiochip_add_data_with_key gcdev_register() & gcdev_unregister() would call device_add() & device_del() (no matter CONFIG_GPIO_CDEV is enabled or not) to register/unregister device. However, if device_add() succeeds, some resource (like struct device_private allocated by device_private_init()) is not released by device_del(). Therefore, after device_add() succeeds by gcdev_register(), it needs to call put_device() to release resource in the error handle path. Here we move forward the register of release function, and let it release every piece of resource by put_device() instead of kfree(). While at it, fix another subtle issue, i.e. when gc->ngpio is equal to 0, we still call kcalloc() and, in case of further error, kfree() on the ZERO_PTR pointer, which is not NULL. It's not a bug per se, but rather waste of the resources and potentially wrong expectation about contents of the gdev->descs variable. Fixes:159f3cd92f
("gpiolib: Defer gpio device setup until after gpiolib initialization") Signed-off-by: Zeng Heng <zengheng4@huawei.com> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
16eb37b565
commit
3713637163
1 changed files with 26 additions and 16 deletions
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@ -526,12 +526,13 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
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if (ret)
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return ret;
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/* From this point, the .release() function cleans up gpio_device */
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gdev->dev.release = gpiodevice_release;
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ret = gpiochip_sysfs_register(gdev);
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if (ret)
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goto err_remove_device;
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/* From this point, the .release() function cleans up gpio_device */
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gdev->dev.release = gpiodevice_release;
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dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
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gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
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@ -597,10 +598,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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struct fwnode_handle *fwnode = NULL;
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struct gpio_device *gdev;
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unsigned long flags;
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int base = gc->base;
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unsigned int i;
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u32 ngpios = 0;
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int base = 0;
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int ret = 0;
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u32 ngpios;
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if (gc->fwnode)
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fwnode = gc->fwnode;
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@ -647,17 +648,12 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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else
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gdev->owner = THIS_MODULE;
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gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
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if (!gdev->descs) {
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ret = -ENOMEM;
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goto err_free_dev_name;
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}
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/*
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* Try the device properties if the driver didn't supply the number
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* of GPIO lines.
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*/
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if (gc->ngpio == 0) {
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ngpios = gc->ngpio;
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if (ngpios == 0) {
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ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
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if (ret == -ENODATA)
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/*
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@ -668,7 +664,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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*/
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ngpios = 0;
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else if (ret)
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goto err_free_descs;
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goto err_free_dev_name;
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gc->ngpio = ngpios;
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}
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@ -676,13 +672,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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if (gc->ngpio == 0) {
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chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
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ret = -EINVAL;
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goto err_free_descs;
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goto err_free_dev_name;
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}
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if (gc->ngpio > FASTPATH_NGPIO)
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chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
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gc->ngpio, FASTPATH_NGPIO);
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gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
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if (!gdev->descs) {
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ret = -ENOMEM;
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goto err_free_dev_name;
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}
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gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
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if (!gdev->label) {
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ret = -ENOMEM;
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@ -701,11 +703,13 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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* it may be a pipe dream. It will not happen before we get rid
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* of the sysfs interface anyways.
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*/
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base = gc->base;
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if (base < 0) {
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base = gpiochip_find_base(gc->ngpio);
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if (base < 0) {
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ret = base;
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spin_unlock_irqrestore(&gpio_lock, flags);
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ret = base;
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base = 0;
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goto err_free_label;
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}
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/*
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@ -816,6 +820,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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err_free_gpiochip_mask:
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gpiochip_remove_pin_ranges(gc);
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gpiochip_free_valid_mask(gc);
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if (gdev->dev.release) {
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/* release() has been registered by gpiochip_setup_dev() */
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put_device(&gdev->dev);
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goto err_print_message;
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}
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err_remove_from_list:
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spin_lock_irqsave(&gpio_lock, flags);
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list_del(&gdev->list);
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@ -829,13 +838,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
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err_free_ida:
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ida_free(&gpio_ida, gdev->id);
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err_free_gdev:
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kfree(gdev);
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err_print_message:
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/* failures here can mean systems won't boot... */
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if (ret != -EPROBE_DEFER) {
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pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
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gdev->base, gdev->base + gdev->ngpio - 1,
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base, base + (int)ngpios - 1,
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gc->label ? : "generic", ret);
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}
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kfree(gdev);
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return ret;
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}
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EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
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