On Thu, 23 May 2024, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> On Thu, May 23, 2024 at 06:51:08PM +0300, Jani Nikula wrote:
>> Enabling -Wformat-truncation yields the following warning:
>>
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c: In function ‘imx_ldb_probe’:
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:57: error: ‘_sel’ directive output may be truncated writing 4 bytes into a region of size between 3 and 13 [-Werror=format-truncation=]
>> 658 | snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>> | ^~~~
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:17: note: ‘snprintf’ output between 8 and 18 bytes into a destination of size 16
>> 658 | snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> If only the compiler could count to three...
I did not try, but apparently using %hhd would hide the issue too:
snprintf(clkname, sizeof(clkname), "di%hhd_sel", i);
BR,
Jani.
>
>>
>> Silence the warning by checking the snprintf() return value.
>>
>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>>
>> ---
>>
>> Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
>> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
>> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
>> Cc: Fabio Estevam <festevam@xxxxxxxxx>
>> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
>> Cc: imx@xxxxxxxxxxxxxxx
>> ---
>> drivers/gpu/drm/imx/ipuv3/imx-ldb.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> index 71d70194fcbd..46f779fe60ee 100644
>> --- a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> +++ b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> @@ -654,8 +654,12 @@ static int imx_ldb_probe(struct platform_device *pdev)
>> */
>> for (i = 0; i < 4; i++) {
>> char clkname[16];
>> + int len;
>> +
>> + len = snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>> + if (len >= sizeof(clkname))
>> + dev_err(dev, "clkname truncated\n");
>>
>> - snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>> imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
>> if (IS_ERR(imx_ldb->clk_sel[i])) {
>> ret = PTR_ERR(imx_ldb->clk_sel[i]);
>> --
>> 2.39.2
--
Jani Nikula, Intel
