tree: https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git for-next head: 5f9f982dd71b418aeba7a0b37f87312545c06df4 commit: d712c58c55d9a4b4cc88ec2e1f8cd2e3b82359b5 [5/6] ALSA: pcm: optimize and clarify stream synchronization ID API config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20240705/202407050501.o5Z3bibi-lkp@i...) compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240705/202407050501.o5Z3bibi-lkp@i...)

If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot lkp@intel.com | Closes: https://lore.kernel.org/oe-kbuild-all/202407050501.o5Z3bibi-lkp@intel.com/

All warnings (new ones prefixed by >>):

In function 'snd_pcm_set_sync_per_card', inlined from 'snd_pcm_lib_ioctl_sync_id' at sound/core/pcm_lib.c:1837:3, inlined from 'snd_pcm_lib_ioctl' at sound/core/pcm_lib.c:1863:10:

...

sound/core/pcm_lib.c:547:9: warning: 'strncpy' output truncated before terminating nul copying 12 bytes from a string of the same length [-Wstringop-truncation]

547 | strncpy(params->sync + 4, id, len); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/strncpy +547 sound/core/pcm_lib.c

517 518 /** 519 * snd_pcm_set_sync_per_card - set the PCM sync id with card number 520 * @substream: the pcm substream 521 * @params: modified hardware parameters 522 * @id: identifier (max 12 bytes) 523 * @len: identifier length (max 12 bytes) 524 * 525 * Sets the PCM sync identifier for the card with zero padding. 526 * 527 * User space or any user should use this 16-byte identifier for a comparison only 528 * to check if two IDs are similar or different. Special case is the identifier 529 * containing only zeros. Interpretation for this combination is - empty (not set). 530 * The contents of the identifier should not be interpreted in any other way. 531 * 532 * The synchronization ID must be unique per clock source (usually one sound card, 533 * but multiple soundcard may use one PCM word clock source which means that they 534 * are fully synchronized). 535 * 536 * This routine composes this ID using card number in first four bytes and 537 * 12-byte additional ID. When other ID composition is used (e.g. for multiple 538 * sound cards), make sure that the composition does not clash with this 539 * composition scheme. 540 */ 541 void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream, 542 struct snd_pcm_hw_params *params, 543 const unsigned char *id, unsigned int len) 544 { 545 *(__u32 *)params->sync = cpu_to_le32(substream->pcm->card->number); 546 len = max(12, len);

547 strncpy(params->sync + 4, id, len);

548 memset(params->sync + 4 + len, 0, 12 - len); 549 } 550