Hi Nathan, kernel test robot noticed the following build warnings: url: https://github.com/intel-lab-lkp/linux/commits/Nathan-Chancellor/media-dvbdev-Avoid-using-uninitialized-ret-in-dvb_register_device/20241022-000519 base: ba9cf6b430433e57bfc8072364e944b7c0eca2a4 patch link: https://lore.kernel.org/r/20241021-dvbdev-fix-uninitialized-return-v1-1-a704945f20e5%40kernel.org patch subject: [PATCH] media: dvbdev: Avoid using uninitialized ret in dvb_register_device() config: i386-randconfig-141-20241022 (https://download.01.org/0day-ci/archive/20241022/202410222222.usQ05jBM-lkp@xxxxxxxxx/config) compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) 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> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202410222222.usQ05jBM-lkp@xxxxxxxxx/ smatch warnings: drivers/media/dvb-core/dvbdev.c:600 dvb_register_device() warn: inconsistent returns '&minor_rwsem'. vim +600 drivers/media/dvb-core/dvbdev.c ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 454 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev, 6bbf7a855d200d drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2017-09-19 455 const struct dvb_device *template, void *priv, 6bbf7a855d200d drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2017-09-19 456 enum dvb_device_type type, int demux_sink_pads) ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 457 { ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 458 struct dvb_device *dvbdev; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 459 struct file_operations *dvbdevfops = NULL; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 460 struct dvbdevfops_node *node = NULL, *new_node = NULL; 5f553388b06532 drivers/media/dvb/dvb-core/dvbdev.c Kay Sievers 2007-08-15 461 struct device *clsdev; 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 462 int minor; f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 463 int id, ret; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 464 c278850206fd9d drivers/media/dvb/dvb-core/dvbdev.c Simon Arlott 2007-03-10 465 mutex_lock(&dvbdev_register_lock); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 466 f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 467 id = dvbdev_get_free_id(adap, type); f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 468 if (id < 0) { 1e4baed379a2bf drivers/media/dvb/dvb-core/dvbdev.c Ingo Molnar 2006-01-15 469 mutex_unlock(&dvbdev_register_lock); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 470 *pdvbdev = NULL; b3ad24d2e0b039 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2016-10-13 471 pr_err("%s: couldn't find free device id\n", __func__); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 472 return -ENFILE; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 473 } ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 474 f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 475 *pdvbdev = dvbdev = kzalloc(sizeof(*dvbdev), GFP_KERNEL); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 476 if (!dvbdev) { 1e4baed379a2bf drivers/media/dvb/dvb-core/dvbdev.c Ingo Molnar 2006-01-15 477 mutex_unlock(&dvbdev_register_lock); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 478 return -ENOMEM; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 479 } ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 480 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 481 /* 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 482 * When a device of the same type is probe()d more than once, 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 483 * the first allocated fops are used. This prevents memory leaks 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 484 * that can occur when the same device is probe()d repeatedly. 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 485 */ 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 486 list_for_each_entry(node, &dvbdevfops_list, list_head) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 487 if (node->fops->owner == adap->module && f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 488 node->type == type && node->template == template) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 489 dvbdevfops = node->fops; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 490 break; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 491 } 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 492 } b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 493 f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 494 if (!dvbdevfops) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 495 dvbdevfops = kmemdup(template->fops, sizeof(*dvbdevfops), GFP_KERNEL); b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 496 if (!dvbdevfops) { b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 497 kfree(dvbdev); 8c64f4cdf4e6cc drivers/media/dvb-core/dvbdev.c Zhipeng Lu 2024-02-03 498 *pdvbdev = NULL; b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 499 mutex_unlock(&dvbdev_register_lock); b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 500 return -ENOMEM; b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 501 } b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 502 f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 503 new_node = kzalloc(sizeof(*new_node), GFP_KERNEL); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 504 if (!new_node) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 505 kfree(dvbdevfops); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 506 kfree(dvbdev); 8c64f4cdf4e6cc drivers/media/dvb-core/dvbdev.c Zhipeng Lu 2024-02-03 507 *pdvbdev = NULL; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 508 mutex_unlock(&dvbdev_register_lock); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 509 return -ENOMEM; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 510 } 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 511 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 512 new_node->fops = dvbdevfops; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 513 new_node->type = type; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 514 new_node->template = template; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 515 list_add_tail(&new_node->list_head, &dvbdevfops_list); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 516 } 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 517 ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 518 memcpy(dvbdev, template, sizeof(struct dvb_device)); 3a664569b71b0a drivers/media/dvb-core/dvbdev.c Lin Ma 2022-11-28 519 kref_init(&dvbdev->ref); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 520 dvbdev->type = type; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 521 dvbdev->id = id; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 522 dvbdev->adapter = adap; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 523 dvbdev->priv = priv; b61901024776b2 drivers/media/dvb/dvb-core/dvbdev.c Marcel Siegert 2007-02-13 524 dvbdev->fops = dvbdevfops; ca5be9cd051662 drivers/media/dvb/dvb-core/dvbdev.c Markus Rechberger 2007-04-14 525 init_waitqueue_head(&dvbdev->wait_queue); 784e29d2031b53 drivers/media/dvb/dvb-core/dvbdev.c Jan Engelhardt 2009-01-11 526 dvbdevfops->owner = adap->module; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 527 list_add_tail(&dvbdev->list_head, &adap->device_list); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 528 down_write(&minor_rwsem); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 529 #ifdef CONFIG_DVB_DYNAMIC_MINORS 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 530 for (minor = 0; minor < MAX_DVB_MINORS; minor++) f28701cc24fcfd drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2023-05-13 531 if (!dvb_minors[minor]) 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 532 break; 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 533 if (minor >= MAX_DVB_MINORS) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 534 if (new_node) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 535 list_del(&new_node->list_head); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 536 kfree(dvbdevfops); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 537 kfree(new_node); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 538 } 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 539 list_del(&dvbdev->list_head); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 540 kfree(dvbdev); 8c64f4cdf4e6cc drivers/media/dvb-core/dvbdev.c Zhipeng Lu 2024-02-03 541 *pdvbdev = NULL; 82163edcdfa4eb drivers/media/dvb/dvb-core/dvbdev.c Santosh Nayak 2012-06-23 542 up_write(&minor_rwsem); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 543 mutex_unlock(&dvbdev_register_lock); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 544 return -EINVAL; 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 545 } 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 546 #else 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 547 minor = nums2minor(adap->num, type, id); 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 548 if (minor >= MAX_DVB_MINORS) { 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 549 dvb_media_device_free(dvbdev); 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 550 list_del(&dvbdev->list_head); 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 551 kfree(dvbdev); 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 552 *pdvbdev = NULL; up_write(&minor_rwsem); Heh. Obviously you didn't introduce this bug but your commit triggers the warning because now Smatch knows it's an error path. 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 553 mutex_unlock(&dvbdev_register_lock); 922fbcc41a2134 drivers/media/dvb-core/dvbdev.c Nathan Chancellor 2024-10-21 554 return -EINVAL; 972e63e895abbe drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2024-10-15 555 } 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 556 #endif 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 557 dvbdev->minor = minor; 0fc044b2b5e2d0 drivers/media/dvb-core/dvbdev.c Lin Ma 2022-08-07 558 dvb_minors[minor] = dvb_device_get(dvbdev); 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 559 up_write(&minor_rwsem); f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 560 ret = dvb_register_media_device(dvbdev, type, minor, demux_sink_pads); f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 561 if (ret) { b3ad24d2e0b039 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2016-10-13 562 pr_err("%s: dvb_register_media_device failed to create the mediagraph\n", f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 563 __func__); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 564 if (new_node) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 565 list_del(&new_node->list_head); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 566 kfree(dvbdevfops); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 567 kfree(new_node); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 568 } f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 569 dvb_media_device_free(dvbdev); 1fec2ecc252301 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2021-06-09 570 list_del(&dvbdev->list_head); f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 571 kfree(dvbdev); 8c64f4cdf4e6cc drivers/media/dvb-core/dvbdev.c Zhipeng Lu 2024-02-03 572 *pdvbdev = NULL; f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 573 mutex_unlock(&dvbdev_register_lock); f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 574 return ret; f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 575 } f50d51661af375 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2015-09-04 576 a9b12619f7b6f1 drivers/media/dvb/dvb-core/dvbdev.c Greg Kroah-Hartman 2008-07-21 577 clsdev = device_create(dvb_class, adap->device, b7496780e80006 drivers/media/dvb/dvb-core/dvbdev.c Hans Verkuil 2008-11-03 578 MKDEV(DVB_MAJOR, minor), a5f4c0ce682efa drivers/media/dvb/dvb-core/dvbdev.c Kay Sievers 2008-10-27 579 dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id); 4abdcf933f6477 drivers/media/dvb/dvb-core/dvbdev.c Simon Arlott 2007-05-06 580 if (IS_ERR(clsdev)) { b3ad24d2e0b039 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2016-10-13 581 pr_err("%s: failed to create device dvb%d.%s%d (%ld)\n", 46b4f7c176a2dd drivers/media/dvb/dvb-core/dvbdev.c Harvey Harrison 2008-04-08 582 __func__, adap->num, dnames[type], id, PTR_ERR(clsdev)); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 583 if (new_node) { 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 584 list_del(&new_node->list_head); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 585 kfree(dvbdevfops); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 586 kfree(new_node); 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 587 } 167faadfcf9339 drivers/media/dvb-core/dvbdev.c Dinghao Liu 2020-08-24 588 dvb_media_device_free(dvbdev); 1fec2ecc252301 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2021-06-09 589 list_del(&dvbdev->list_head); 167faadfcf9339 drivers/media/dvb-core/dvbdev.c Dinghao Liu 2020-08-24 590 kfree(dvbdev); 8c64f4cdf4e6cc drivers/media/dvb-core/dvbdev.c Zhipeng Lu 2024-02-03 591 *pdvbdev = NULL; 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 592 mutex_unlock(&dvbdev_register_lock); 4abdcf933f6477 drivers/media/dvb/dvb-core/dvbdev.c Simon Arlott 2007-05-06 593 return PTR_ERR(clsdev); 4abdcf933f6477 drivers/media/dvb/dvb-core/dvbdev.c Simon Arlott 2007-05-06 594 } 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 595 b3ad24d2e0b039 drivers/media/dvb-core/dvbdev.c Mauro Carvalho Chehab 2016-10-13 596 dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n", 5dd3f3071070f5 drivers/media/dvb/dvb-core/dvbdev.c Andreas Oberritter 2008-10-23 597 adap->num, dnames[type], id, minor, minor); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 598 627bb528b086b4 drivers/media/dvb-core/dvbdev.c Hyunwoo Kim 2022-11-17 599 mutex_unlock(&dvbdev_register_lock); ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 @600 return 0; ^1da177e4c3f41 drivers/media/dvb/dvb-core/dvbdev.c Linus Torvalds 2005-04-16 601 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
