`strncpy` is deprecated for use on NUL-terminated destination strings [1].

We should prefer more robust and less ambiguous string interfaces.

We expect adc->chan_name[val] to be NUL-terminated based on ch_name's
use within functions that expect NUL-terminated strings like strncmp and
printf-likes:
|       if (!strncmp(stm32_adc_ic[i].name, ch_name, STM32_ADC_CH_SZ)) {
|               /* Check internal channel availability */
|               switch (i) {
|               case STM32_ADC_INT_CH_VDDCORE:
|                       if (!adc->cfg->regs->or_vddcore.reg)
|                               dev_warn(&indio_dev->dev,
|                                        "%s channel not available\n", ch_name);
...

There is no evidence that NUL-padding is needed either.

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding. If, for any reason, NUL-padding _is_
required we should go for `strscpy_pad`.

Link: 
https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
 [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinst...@google.com>
---
Note: build-tested
---
 drivers/iio/adc/stm32-adc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index f7613efb870d..9cdcf396d901 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -2209,7 +2209,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev 
*indio_dev,
                                ret = -EINVAL;
                                goto err;
                        }
-                       strncpy(adc->chan_name[val], name, STM32_ADC_CH_SZ);
+                       strscpy(adc->chan_name[val], name, STM32_ADC_CH_SZ);
                        ret = stm32_adc_populate_int_ch(indio_dev, name, val);
                        if (ret == -ENOENT)
                                continue;

---
base-commit: 2cf0f715623872823a72e451243bbf555d10d032
change-id: 20230921-strncpy-drivers-iio-adc-stm32-adc-c-1bf936a4ffbb

Best regards,
--
Justin Stitt <justinst...@google.com>


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