On 28/06/2022 02:18, Douglas Anderson wrote:
> Commit ac0126a01735 ("soc: qcom: cmd-db: replace strncpy() with
> strscpy_pad()") breaks booting on my sc7280-herobrine-herobrine
> device. From printouts I see that at bootup the function is called
> with an id of "lnbclka2" which is 8 bytes big.
>
> Previously all 8 bytes of this string were copied to the
> destination. Now only 7 bytes will be copied since strscpy_pad() saves
> a byte for '\0' termination.
>
> We don't need the '\0' termination in the destination. Let's go back
> to strncpy(). According to the warning:
> If a caller is using non-NUL-terminated strings, strncpy() can still
> be used, but destinations should be marked with the __nonstring
> attribute to avoid future compiler warnings.
> ...so we'll do that.
>
> While we're at it, let's change the query array to use
> "sizeof(ent->id)" so it can't possibly go out of sync with our later
> copy.
>
> Fixes: ac0126a01735 ("soc: qcom: cmd-db: replace strncpy() with strscpy_pad()")
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
>
> ---
>
> Changes in v2:
> - Size array with "sizeof(ent->id)"
>
> drivers/soc/qcom/cmd-db.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c
> index c5137c25d819..ffd2660b2890 100644
> --- a/drivers/soc/qcom/cmd-db.c
> +++ b/drivers/soc/qcom/cmd-db.c
> @@ -141,14 +141,14 @@ static int cmd_db_get_header(const char *id, const struct entry_header **eh,
> const struct rsc_hdr *rsc_hdr;
> const struct entry_header *ent;
> int ret, i, j;
> - u8 query[8];
> + u8 query[sizeof(ent->id)] __nonstring;
>
> ret = cmd_db_ready();
> if (ret)
> return ret;
>
> /* Pad out query string to same length as in DB */
I would find useful a comment that length of the ID can be equal to
sizeof(query)... so no one will need to increment the counter of wasted
time on this. :)
But beside that, thanks for the fix:
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> - strscpy_pad(query, id, sizeof(query));
> + strncpy(query, id, sizeof(query));
>
> for (i = 0; i < MAX_SLV_ID; i++) {
> rsc_hdr = &cmd_db_header->header[i];
Best regards,
Krzysztof
