Re: [PATCH v4 2/2] hwmon: (pmbus/d1u74t) Add Murata D1U74T PSU driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Low] Missing includes for <linux/module.h> and <linux/string.h>.
- [Low] Logging raw I2C device strings without escaping.
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commit f645f72f2f4d8cc53bec169fb4350e6231e649a4
Author: Abdurrahman Hussain <abdurrahman@nexthop.ai>

hwmon: (pmbus/d1u74t) Add Murata D1U74T PSU driver

This commit adds a PMBus client driver for the Murata D1U74T power supplies.

Closes: https://lore.kernel.org/oe-kbuild-all/202605122253.zInzmUeX-lkp@intel.com/

> diff --git a/drivers/hwmon/pmbus/d1u74t.c b/drivers/hwmon/pmbus/d1u74t.c
> new file mode 100644
> index 0000000000000..286ba492e3362
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/d1u74t.c
> @@ -0,0 +1,86 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2026 Nexthop Systems.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/of.h>
> +#include <linux/pmbus.h>
> +
> +#include "pmbus.h"

This isn't a bug, but should this file include <linux/module.h> and
<linux/string.h>? It uses module-specific macros like MODULE_DEVICE_TABLE
and MODULE_AUTHOR, as well as the strncmp function. While compilation might
succeed due to transitive includes, it could lead to build failures or
implicit declaration warnings on some architectures.

[ ... ]

> +static int d1u74t_probe(struct i2c_client *client)
> +{
> +	char buf[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
> +	struct device *dev = &client->dev;
> +	int rc;
> +
> +	rc = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
> +	if (rc < 0)
> +		return dev_err_probe(dev, rc, "Failed to read PMBUS_MFR_ID\n");
> +
> +	if (rc != 9 || strncmp(buf, "Murata-PS", 9)) {
> +		buf[rc] = '\0';
> +		return dev_err_probe(dev, -ENODEV,
> +				     "Unsupported Manufacturer ID '%s'\n",
> +				     buf);
> +	}
> +
> +	rc = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
> +	if (rc < 0)
> +		return dev_err_probe(dev, rc,
> +				     "Failed to read PMBUS_MFR_MODEL\n");
> +
> +	if (rc < 8 || strncmp(buf, "D1U74T-W", 8)) {
> +		buf[rc] = '\0';
> +		return dev_err_probe(dev, -ENODEV, "Model '%s' not supported\n",
> +				     buf);
> +	}

Does this code log potentially unescaped strings directly from the device?

Since the I2C bus can return garbage data or unprintable characters from a
malfunctioning device, using the %s format specifier could result in
corrupted log output. Would it be safer to use the %*pE specifier to safely
escape these untrusted strings?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260514-d1u74t-v4-0-1f1ee7b002ec@nexthop.ai?part=2