drivers/block/virtio_blk.c:570:68: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 7

From: kernel test robot
Date: Tue Nov 14 2023 - 17:22:58 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 9bacdd8996c77c42ca004440be610692275ff9d0
commit: 4e0400525691d0e676dbe002641f9a61261f1e1b virtio-blk: support polling I/O
date: 1 year, 5 months ago
config: x86_64-sof-customedconfig-edison-defconfig (https://download.01.org/0day-ci/archive/20231115/202311150655.hb4vzaIj-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231115/202311150655.hb4vzaIj-lkp@xxxxxxxxx/reproduce)

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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311150655.hb4vzaIj-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

drivers/block/virtio_blk.c: In function 'init_vq':
>> drivers/block/virtio_blk.c:570:68: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 7 [-Werror=format-truncation=]
570 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~
drivers/block/virtio_blk.c:570:58: note: directive argument in the range [-2147483648, 65534]
570 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~~~~~~~~~~~~
drivers/block/virtio_blk.c:570:17: note: 'snprintf' output between 11 and 21 bytes into a destination of size 16
570 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors


vim +570 drivers/block/virtio_blk.c

511
512 static int init_vq(struct virtio_blk *vblk)
513 {
514 int err;
515 int i;
516 vq_callback_t **callbacks;
517 const char **names;
518 struct virtqueue **vqs;
519 unsigned short num_vqs;
520 unsigned int num_poll_vqs;
521 struct virtio_device *vdev = vblk->vdev;
522 struct irq_affinity desc = { 0, };
523
524 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
525 struct virtio_blk_config, num_queues,
526 &num_vqs);
527 if (err)
528 num_vqs = 1;
529
530 if (!err && !num_vqs) {
531 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
532 return -EINVAL;
533 }
534
535 num_vqs = min_t(unsigned int,
536 min_not_zero(num_request_queues, nr_cpu_ids),
537 num_vqs);
538
539 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
540
541 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
542 vblk->io_queues[HCTX_TYPE_READ] = 0;
543 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
544
545 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
546 vblk->io_queues[HCTX_TYPE_DEFAULT],
547 vblk->io_queues[HCTX_TYPE_READ],
548 vblk->io_queues[HCTX_TYPE_POLL]);
549
550 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
551 if (!vblk->vqs)
552 return -ENOMEM;
553
554 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
555 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
556 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
557 if (!names || !callbacks || !vqs) {
558 err = -ENOMEM;
559 goto out;
560 }
561
562 for (i = 0; i < num_vqs - num_poll_vqs; i++) {
563 callbacks[i] = virtblk_done;
564 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
565 names[i] = vblk->vqs[i].name;
566 }
567
568 for (; i < num_vqs; i++) {
569 callbacks[i] = NULL;
> 570 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
571 names[i] = vblk->vqs[i].name;
572 }
573
574 /* Discover virtqueues and write information to configuration. */
575 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
576 if (err)
577 goto out;
578
579 for (i = 0; i < num_vqs; i++) {
580 spin_lock_init(&vblk->vqs[i].lock);
581 vblk->vqs[i].vq = vqs[i];
582 }
583 vblk->num_vqs = num_vqs;
584
585 out:
586 kfree(vqs);
587 kfree(callbacks);
588 kfree(names);
589 if (err)
590 kfree(vblk->vqs);
591 return err;
592 }
593

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0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki