On Sat, Jun 29, 2024 at 12:31:57AM +0800, kernel test robot wrote: > Hi Niklas, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on linus/master] > [also build test WARNING on v6.10-rc5 next-20240627] > [cannot apply to mkp-scsi/for-next jejb-scsi/for-next] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Niklas-Cassel/ata-libata-core-Fix-null-pointer-dereference-on-error/20240627-123023 > base: linus/master > patch link: https://lore.kernel.org/r/20240626180031.4050226-26-cassel%40kernel.org > patch subject: [PATCH v2 11/13] ata: libata-core: Reuse available ata_port print_ids > config: i386-randconfig-141-20240628 (https://download.01.org/0day-ci/archive/20240629/202406290027.cdgsPQAF-lkp@xxxxxxxxx/config) > compiler: gcc-8 (Ubuntu 8.4.0-3ubuntu2) 8.4.0 > > 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/202406290027.cdgsPQAF-lkp@xxxxxxxxx/ > > smatch warnings: > drivers/ata/libata-core.c:5467 ata_port_alloc() warn: unsigned 'ap->print_id' is never less than zero. > > vim +5467 drivers/ata/libata-core.c > > 5443 > 5444 /** > 5445 * ata_port_alloc - allocate and initialize basic ATA port resources > 5446 * @host: ATA host this allocated port belongs to > 5447 * > 5448 * Allocate and initialize basic ATA port resources. > 5449 * > 5450 * RETURNS: > 5451 * Allocate ATA port on success, NULL on failure. > 5452 * > 5453 * LOCKING: > 5454 * Inherited from calling layer (may sleep). > 5455 */ > 5456 struct ata_port *ata_port_alloc(struct ata_host *host) > 5457 { > 5458 struct ata_port *ap; > 5459 > 5460 ap = kzalloc(sizeof(*ap), GFP_KERNEL); > 5461 if (!ap) > 5462 return NULL; > 5463 > 5464 ap->pflags |= ATA_PFLAG_INITIALIZING | ATA_PFLAG_FROZEN; > 5465 ap->lock = &host->lock; > 5466 ap->print_id = ida_alloc_min(&ata_ida, 1, GFP_KERNEL); > > 5467 if (ap->print_id < 0) { Well, the check is correct, but since ap->print_id is unsigned int, we will need to use a temporary (signed) variable to check for errors from ida_alloc_min(). Will fix in next revision. > 5468 kfree(ap); > 5469 return NULL; > 5470 } > 5471 ap->host = host; > 5472 ap->dev = host->dev; > 5473 > 5474 mutex_init(&ap->scsi_scan_mutex); > 5475 INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug); > 5476 INIT_DELAYED_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan); > 5477 INIT_LIST_HEAD(&ap->eh_done_q); > 5478 init_waitqueue_head(&ap->eh_wait_q); > 5479 init_completion(&ap->park_req_pending); > 5480 timer_setup(&ap->fastdrain_timer, ata_eh_fastdrain_timerfn, > 5481 TIMER_DEFERRABLE); > 5482 > 5483 ap->cbl = ATA_CBL_NONE; > 5484 > 5485 ata_link_init(ap, &ap->link, 0); > 5486 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki