Re: [PATCH] x86: replace snprintf in show functions with sysfs_emit

From: Hans de Goede
Date: Tue Oct 19 2021 - 11:12:54 EST


Hi,

On 10/15/21 08:50, Qing Wang wrote:
> show() must not use snprintf() when formatting the value to be
> returned to user space.
>
> Fix the coccicheck warnings:
> WARNING: use scnprintf or sprintf.
>
> Use sysfs_emit instead of scnprintf or sprintf makes more sense.
>
> Signed-off-by: Qing Wang <wangqing@xxxxxxxx>

Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans


> ---
> drivers/platform/x86/panasonic-laptop.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
> index d4f4444..37850d0 100644
> --- a/drivers/platform/x86/panasonic-laptop.c
> +++ b/drivers/platform/x86/panasonic-laptop.c
> @@ -470,7 +470,7 @@ static ssize_t numbatt_show(struct device *dev, struct device_attribute *attr,
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_NUM_BATTERIES]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_NUM_BATTERIES]);
> }
>
> static ssize_t lcdtype_show(struct device *dev, struct device_attribute *attr,
> @@ -482,7 +482,7 @@ static ssize_t lcdtype_show(struct device *dev, struct device_attribute *attr,
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_LCD_TYPE]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_LCD_TYPE]);
> }
>
> static ssize_t mute_show(struct device *dev, struct device_attribute *attr,
> @@ -494,7 +494,7 @@ static ssize_t mute_show(struct device *dev, struct device_attribute *attr,
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_MUTE]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_MUTE]);
> }
>
> static ssize_t mute_store(struct device *dev, struct device_attribute *attr,
> @@ -524,7 +524,7 @@ static ssize_t sticky_key_show(struct device *dev, struct device_attribute *attr
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sticky_key);
> + return sysfs_emit(buf, "%u\n", pcc->sticky_key);
> }
>
> static ssize_t sticky_key_store(struct device *dev, struct device_attribute *attr,
> @@ -566,7 +566,7 @@ static ssize_t eco_mode_show(struct device *dev, struct device_attribute *attr,
> result = -EIO;
> break;
> }
> - return snprintf(buf, PAGE_SIZE, "%u\n", result);
> + return sysfs_emit(buf, "%u\n", result);
> }
>
> static ssize_t eco_mode_store(struct device *dev, struct device_attribute *attr,
> @@ -625,7 +625,7 @@ static ssize_t ac_brightness_show(struct device *dev, struct device_attribute *a
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_AC_CUR_BRIGHT]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_AC_CUR_BRIGHT]);
> }
>
> static ssize_t ac_brightness_store(struct device *dev, struct device_attribute *attr,
> @@ -655,7 +655,7 @@ static ssize_t dc_brightness_show(struct device *dev, struct device_attribute *a
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_DC_CUR_BRIGHT]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_DC_CUR_BRIGHT]);
> }
>
> static ssize_t dc_brightness_store(struct device *dev, struct device_attribute *attr,
> @@ -685,7 +685,7 @@ static ssize_t current_brightness_show(struct device *dev, struct device_attribu
> if (!acpi_pcc_retrieve_biosdata(pcc))
> return -EIO;
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_CUR_BRIGHT]);
> + return sysfs_emit(buf, "%u\n", pcc->sinf[SINF_CUR_BRIGHT]);
> }
>
> static ssize_t current_brightness_store(struct device *dev, struct device_attribute *attr,
> @@ -710,7 +710,7 @@ static ssize_t current_brightness_store(struct device *dev, struct device_attrib
> static ssize_t cdpower_show(struct device *dev, struct device_attribute *attr,
> char *buf)
> {
> - return snprintf(buf, PAGE_SIZE, "%d\n", get_optd_power_state());
> + return sysfs_emit(buf, "%d\n", get_optd_power_state());
> }
>
> static ssize_t cdpower_store(struct device *dev, struct device_attribute *attr,
>