* \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
* and positive on success.
*/
-int pass_buffer_as_shm(int fd, uint8_t band, char *buf, size_t size)
+int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
{
int ret, shmid;
void *shm;