Re: [PATCH v17 01/12] power: reset: reboot-mode: Remove devres based allocations

Mukesh Ojha
2025-11-10T13:02:34Z

On Sun, Nov 09, 2025 at 08:07:14PM +0530, Shivendra Pratap wrote:
> Devres APIs are intended for use in drivers, and they should be
> avoided in shared subsystem code which is being used by multiple
> drivers. Avoid using devres based allocations in the reboot-mode
> subsystem and manually free the resources.
>
> Replace devm_kzalloc with kzalloc and handle memory cleanup
> explicitly.
>
> Fixes: 4fcd504edbf7 ("power: reset: add reboot mode driver")
> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
> ---
> drivers/power/reset/reboot-mode.c | 30 ++++++++++++++++++++----------
> 1 file changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
> index fba53f638da04655e756b5f8b7d2d666d1379535..ac4223794083f36960b2bd37a601b7e1f1872de5 100644
> --- a/drivers/power/reset/reboot-mode.c
> +++ b/drivers/power/reset/reboot-mode.c
> @@ -3,6 +3,8 @@
> * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
> */
>
> +#define pr_fmt(fmt) "reboot-mode: " fmt
> +
> #include <linux/device.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> @@ -71,6 +73,7 @@ static int reboot_mode_notify(struct notifier_block *this,
> int reboot_mode_register(struct reboot_mode_driver *reboot)
> {
> struct mode_info *info;
> + struct mode_info *next;
> struct property *prop;
> struct device_node *np = reboot->dev->of_node;
> size_t len = strlen(PREFIX);
> @@ -82,29 +85,27 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
> if (strncmp(prop->name, PREFIX, len))
> continue;
>
> - info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
> if (!info) {
> ret = -ENOMEM;
> goto error;
> }
>
> if (of_property_read_u32(np, prop->name, &info->magic)) {
> - dev_err(reboot->dev, "reboot mode %s without magic number\n",
> - info->mode);
> - devm_kfree(reboot->dev, info);
> + pr_err("reboot mode %s without magic number\n", info->mode);
> + kfree(info);

This as well could be avoided if we move the above memory allocation
after of_property_read_u32()

> continue;
> }
>
> info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
> if (!info->mode) {
> ret = -ENOMEM;
> - goto error;
> + goto err_info;
> } else if (info->mode[0] == '\0') {
> kfree_const(info->mode);
> ret = -EINVAL;
> - dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
> - prop->name);
> - goto error;
> + pr_err("invalid mode name(%s): too short!\n", prop->name);
> + goto err_info;
> }
>
> list_add_tail(&info->list, &reboot->head);
> @@ -115,9 +116,14 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
>
> return 0;
>
> +err_info:

free_info ?

> + kfree(info);
> error:
> - list_for_each_entry(info, &reboot->head, list)
> + list_for_each_entry_safe(info, next, &reboot->head, list) {
> + list_del(&info->list);
> kfree_const(info->mode);
> + kfree(info);
> + }
>
> return ret;
> }
> @@ -130,11 +136,15 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
> int reboot_mode_unregister(struct reboot_mode_driver *reboot)
> {
> struct mode_info *info;
> + struct mode_info *next;
>
> unregister_reboot_notifier(&reboot->reboot_notifier);
>
> - list_for_each_entry(info, &reboot->head, list)
> + list_for_each_entry_safe(info, next, &reboot->head, list) {
> + list_del(&info->list);
> kfree_const(info->mode);
> + kfree(info);
> + }
>
> return 0;
> }
>
> --
> 2.34.1
>

--
-Mukesh Ojha