On 19/07/2021 08:58, Dan Carpenter wrote:
Hi John,
url:
https://github.com/0day-ci/linux/commits/John-Garry/iommu-Allow-IOVA-rcache-range-be-configured/20210714-184328
base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: ia64-randconfig-m031-20210714 (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
smatch warnings:
drivers/iommu/dma-iommu.c:384 iommu_dma_init_domain() warn: variable
dereferenced before check 'dev' (see line 374)
thanks for the notice
vim +/dev +384 drivers/iommu/dma-iommu.c
06d60728ff5c01 Christoph Hellwig 2019-05-20 332 static int
iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
ac6d704679d343 Jean-Philippe Brucker 2021-06-18 333
dma_addr_t limit, struct device *dev)
0db2e5d18f76a6 Robin Murphy 2015-10-01 334 {
fdbe574eb69312 Robin Murphy 2017-01-19 335 struct iommu_dma_cookie
*cookie = domain->iova_cookie;
c61a4633a56aaa Shaokun Zhang 2019-01-24 336 unsigned long order,
base_pfn;
6b0c54e7f27159 Yunsheng Lin 2019-08-24 337 struct iova_domain
*iovad;
de4ba360c3e4ed John Garry 2021-07-14 338 size_t max_opt_dma_size;
de4ba360c3e4ed John Garry 2021-07-14 339 unsigned long iova_len
= 0;
0db2e5d18f76a6 Robin Murphy 2015-10-01 340
fdbe574eb69312 Robin Murphy 2017-01-19 341 if (!cookie ||
cookie->type != IOMMU_DMA_IOVA_COOKIE)
fdbe574eb69312 Robin Murphy 2017-01-19 342 return -EINVAL;
0db2e5d18f76a6 Robin Murphy 2015-10-01 343
6b0c54e7f27159 Yunsheng Lin 2019-08-24 344 iovad = &cookie->iovad;
6b0c54e7f27159 Yunsheng Lin 2019-08-24 345
0db2e5d18f76a6 Robin Murphy 2015-10-01 346 /* Use the smallest
supported page size for IOVA granularity */
d16e0faab911cc Robin Murphy 2016-04-07 347 order =
__ffs(domain->pgsize_bitmap);
0db2e5d18f76a6 Robin Murphy 2015-10-01 348 base_pfn = max_t(unsigned
long, 1, base >> order);
0db2e5d18f76a6 Robin Murphy 2015-10-01 349
0db2e5d18f76a6 Robin Murphy 2015-10-01 350 /* Check the domain
allows at least some access to the device... */
0db2e5d18f76a6 Robin Murphy 2015-10-01 351 if
(domain->geometry.force_aperture) {
0db2e5d18f76a6 Robin Murphy 2015-10-01 352 if (base >
domain->geometry.aperture_end ||
ac6d704679d343 Jean-Philippe Brucker 2021-06-18 353 limit <
domain->geometry.aperture_start) {
0db2e5d18f76a6 Robin Murphy 2015-10-01 354
pr_warn("specified DMA range outside IOMMU capability\n");
0db2e5d18f76a6 Robin Murphy 2015-10-01 355 return
-EFAULT;
0db2e5d18f76a6 Robin Murphy 2015-10-01 356 }
0db2e5d18f76a6 Robin Murphy 2015-10-01 357 /* ...then
finally give it a kicking to make sure it fits */
0db2e5d18f76a6 Robin Murphy 2015-10-01 358 base_pfn =
max_t(unsigned long, base_pfn,
0db2e5d18f76a6 Robin Murphy 2015-10-01 359
domain->geometry.aperture_start >> order);
0db2e5d18f76a6 Robin Murphy 2015-10-01 360 }
0db2e5d18f76a6 Robin Murphy 2015-10-01 361
f51d7bb79c1124 Robin Murphy 2017-01-16 362 /* start_pfn is always
nonzero for an already-initialised domain */
0db2e5d18f76a6 Robin Murphy 2015-10-01 363 if (iovad->start_pfn) {
0db2e5d18f76a6 Robin Murphy 2015-10-01 364 if (1UL << order
!= iovad->granule ||
f51d7bb79c1124 Robin Murphy 2017-01-16 365 base_pfn !=
iovad->start_pfn) {
0db2e5d18f76a6 Robin Murphy 2015-10-01 366
pr_warn("Incompatible range for DMA domain\n");
0db2e5d18f76a6 Robin Murphy 2015-10-01 367 return
-EFAULT;
0db2e5d18f76a6 Robin Murphy 2015-10-01 368 }
7c1b058c8b5a31 Robin Murphy 2017-03-16 369
7c1b058c8b5a31 Robin Murphy 2017-03-16 370 return 0;
0db2e5d18f76a6 Robin Murphy 2015-10-01 371 }
7c1b058c8b5a31 Robin Murphy 2017-03-16 372
de4ba360c3e4ed John Garry 2021-07-14 373
de4ba360c3e4ed John Garry 2021-07-14 @374 max_opt_dma_size =
iommu_group_get_max_opt_dma_size(dev->iommu_group);
^^^^^^^^^^^^^^^^
New unchecked dereference
de4ba360c3e4ed John Garry 2021-07-14 375 if (max_opt_dma_size) {
de4ba360c3e4ed John Garry 2021-07-14 376 unsigned long shift =
__ffs(1UL << order);
de4ba360c3e4ed John Garry 2021-07-14 377
de4ba360c3e4ed John Garry 2021-07-14 378 iova_len =
max_opt_dma_size >> shift;
de4ba360c3e4ed John Garry 2021-07-14 379 iova_len =
roundup_pow_of_two(iova_len);
de4ba360c3e4ed John Garry 2021-07-14 380 }
de4ba360c3e4ed John Garry 2021-07-14 381
de4ba360c3e4ed John Garry 2021-07-14 382 init_iova_domain(iovad, 1UL
<< order, base_pfn, iova_len);
2da274cdf998a1 Zhen Lei 2018-09-20 383
82c3cefb9f1652 Lu Baolu 2021-02-25 @384 if (!cookie->fq_domain && (!dev
|| !dev_is_untrusted(dev)) &&
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
a250c23f15c21c Robin Murphy 2021-04-01 385
domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) {
b34e9b0de3c411 Tom Murphy 2020-09-10 386 if
(init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
2a2b8eaa5b2566 Tom Murphy 2020-11-24 387
iommu_dma_entry_dtor))
b34e9b0de3c411 Tom Murphy 2020-09-10 388
pr_warn("iova flush queue initialization failed\n");
b34e9b0de3c411 Tom Murphy 2020-09-10 389 else
2da274cdf998a1 Zhen Lei 2018-09-20 390
cookie->fq_domain = domain;
2da274cdf998a1 Zhen Lei 2018-09-20 391 }
2da274cdf998a1 Zhen Lei 2018-09-20 392
7c1b058c8b5a31 Robin Murphy 2017-03-16 393 if (!dev)
^^^^
Old code has checks for NULL
I doubt that in practice we need this check.
Function iommu_dma_init_domain() is only called by
iommu_setup_dma_ops(). Furthermore, iommu_setup_dma_ops() calls
iommu_get_domain_for_dev(dev), which cannot safely handle dev == NULL
for when we call iommu_dma_init_domain() there. As such, the dev == NULL
checks in iommu_dma_init_domain() are effectively redundant.
0db2e5d18f76a6 Robin Murphy 2015-10-01 394 return 0;
7c1b058c8b5a31 Robin Murphy 2017-03-16 395
7c1b058c8b5a31 Robin Murphy 2017-03-16 396 return
iova_reserve_iommu_regions(dev, domain);
0db2e5d18f76a6 Robin Murphy 2015-10-01 397 }
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
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