Hi John, url: https://github.com/intel-lab-lkp/linux/commits/John-Garry/DMA-mapping-changes-for-SCSI-core/20220520-163049 base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next config: s390-randconfig-m031-20220519 (https://download.01.org/0day-ci/archive/20220521/202205210545.gkS834ds-lkp@xxxxxxxxx/config) compiler: s390-linux-gcc (GCC) 11.3.0 If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> smatch warnings: drivers/scsi/hosts.c:243 scsi_add_host_with_dma() warn: variable dereferenced before check 'dma_dev' (see line 228) vim +/dma_dev +243 drivers/scsi/hosts.c d139b9bd0e52dd James Bottomley 2009-11-05 209 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, d139b9bd0e52dd James Bottomley 2009-11-05 210 struct device *dma_dev) ^1da177e4c3f41 Linus Torvalds 2005-04-16 211 { ^1da177e4c3f41 Linus Torvalds 2005-04-16 212 struct scsi_host_template *sht = shost->hostt; ^1da177e4c3f41 Linus Torvalds 2005-04-16 213 int error = -EINVAL; ^1da177e4c3f41 Linus Torvalds 2005-04-16 214 91921e016a2199 Hannes Reinecke 2014-06-25 215 shost_printk(KERN_INFO, shost, "%s\n", ^1da177e4c3f41 Linus Torvalds 2005-04-16 216 sht->info ? sht->info(shost) : sht->name); ^1da177e4c3f41 Linus Torvalds 2005-04-16 217 ^1da177e4c3f41 Linus Torvalds 2005-04-16 218 if (!shost->can_queue) { 91921e016a2199 Hannes Reinecke 2014-06-25 219 shost_printk(KERN_ERR, shost, 91921e016a2199 Hannes Reinecke 2014-06-25 220 "can_queue = 0 no longer supported\n"); 542bd1377a9630 James Bottomley 2008-04-21 221 goto fail; ^1da177e4c3f41 Linus Torvalds 2005-04-16 222 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 223 50b6cb3516365c Dexuan Cui 2021-10-07 224 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */ 50b6cb3516365c Dexuan Cui 2021-10-07 225 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun, ea2f0f77538c50 John Garry 2021-05-19 226 shost->can_queue); ea2f0f77538c50 John Garry 2021-05-19 227 2ad7ba6ca08593 John Garry 2022-05-20 @228 if (dma_dev->dma_mask) { ^^^^^^^^^^^^^^^^^ The patch adds a new unchecked dereference 2ad7ba6ca08593 John Garry 2022-05-20 229 shost->max_sectors = min_t(unsigned int, shost->max_sectors, 2ad7ba6ca08593 John Garry 2022-05-20 230 dma_opt_mapping_size(dma_dev) >> SECTOR_SHIFT); 2ad7ba6ca08593 John Garry 2022-05-20 231 } 2ad7ba6ca08593 John Garry 2022-05-20 232 0a6ac4ee7c2109 Christoph Hellwig 2017-01-03 233 error = scsi_init_sense_cache(shost); 0a6ac4ee7c2109 Christoph Hellwig 2017-01-03 234 if (error) 0a6ac4ee7c2109 Christoph Hellwig 2017-01-03 235 goto fail; 0a6ac4ee7c2109 Christoph Hellwig 2017-01-03 236 d285203cf647d7 Christoph Hellwig 2014-01-17 237 error = scsi_mq_setup_tags(shost); 542bd1377a9630 James Bottomley 2008-04-21 238 if (error) 542bd1377a9630 James Bottomley 2008-04-21 239 goto fail; d285203cf647d7 Christoph Hellwig 2014-01-17 240 ^1da177e4c3f41 Linus Torvalds 2005-04-16 241 if (!shost->shost_gendev.parent) ^1da177e4c3f41 Linus Torvalds 2005-04-16 242 shost->shost_gendev.parent = dev ? dev : &platform_bus; 3c8d9a957d0ae6 James Bottomley 2012-05-04 @243 if (!dma_dev) ^^^^^^^^ The old code checked for NULL 3c8d9a957d0ae6 James Bottomley 2012-05-04 244 dma_dev = shost->shost_gendev.parent; 3c8d9a957d0ae6 James Bottomley 2012-05-04 245 d139b9bd0e52dd James Bottomley 2009-11-05 246 shost->dma_dev = dma_dev; ^1da177e4c3f41 Linus Torvalds 2005-04-16 247 5c6fab9d558470 Mika Westerberg 2016-02-18 248 /* 5c6fab9d558470 Mika Westerberg 2016-02-18 249 * Increase usage count temporarily here so that calling 5c6fab9d558470 Mika Westerberg 2016-02-18 250 * scsi_autopm_put_host() will trigger runtime idle if there is 5c6fab9d558470 Mika Westerberg 2016-02-18 251 * nothing else preventing suspending the device. 5c6fab9d558470 Mika Westerberg 2016-02-18 252 */ 5c6fab9d558470 Mika Westerberg 2016-02-18 253 pm_runtime_get_noresume(&shost->shost_gendev); bc4f24014de58f Alan Stern 2010-06-17 254 pm_runtime_set_active(&shost->shost_gendev); bc4f24014de58f Alan Stern 2010-06-17 255 pm_runtime_enable(&shost->shost_gendev); bc4f24014de58f Alan Stern 2010-06-17 256 device_enable_async_suspend(&shost->shost_gendev); bc4f24014de58f Alan Stern 2010-06-17 257 -- 0-DAY CI Kernel Test Service https://01.org/lkp