[bug report] iommufd: Add a selftest

[bug report] iommufd: Add a selftest

[Dan Carpenter]

Hello Jason Gunthorpe,

The patch 147393321d65: "iommufd: Add a selftest" from Nov 19, 2021,
leads to the following Smatch static checker warning:

	drivers/iommu/iommufd/selftest.c:160 mock_domain_map_pages()
	warn: use 'gfp' here instead of GFP_XXX?

drivers/iommu/iommufd/selftest.c
   133  static int mock_domain_map_pages(struct iommu_domain *domain,
   134                                   unsigned long iova, phys_addr_t paddr,
   135                                   size_t pgsize, size_t pgcount, int prot,
   136                                   gfp_t gfp, size_t *mapped)
   137  {
   138          struct mock_iommu_domain *mock =
   139                  container_of(domain, struct mock_iommu_domain, domain);
   140          unsigned long flags = MOCK_PFN_START_IOVA;
   141          unsigned long start_iova = iova;
   142  
   143          /*
   144           * xarray does not reliably work with fault injection because it does a
   145           * retry allocation, so put our own failure point.
   146           */
   147          if (iommufd_should_fail())
   148                  return -ENOENT;
   149  
   150          WARN_ON(iova % MOCK_IO_PAGE_SIZE);
   151          WARN_ON(pgsize % MOCK_IO_PAGE_SIZE);
   152          for (; pgcount; pgcount--) {
   153                  size_t cur;
   154  
   155                  for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) {
   156                          void *old;
   157  
   158                          if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize)
   159                                  flags = MOCK_PFN_LAST_IOVA;
   160                          old = xa_store(&mock->pfns, iova / MOCK_IO_PAGE_SIZE,
   161                                         xa_mk_value((paddr / MOCK_IO_PAGE_SIZE) |
   162                                                     flags),
   163                                         GFP_KERNEL);
                                               ^^^^^^^^^^
"gfp" isn't used anywhere so maybe it was intended here?



   164                          if (xa_is_err(old)) {
   165                                  for (; start_iova != iova;
   166                                       start_iova += MOCK_IO_PAGE_SIZE)
   167                                          xa_erase(&mock->pfns,
   168                                                   start_iova /
   169                                                           MOCK_IO_PAGE_SIZE);
   170                                  return xa_err(old);
   171                          }
   172                          WARN_ON(old);
   173                          iova += MOCK_IO_PAGE_SIZE;
   174                          paddr += MOCK_IO_PAGE_SIZE;

regards,
dan carpenter

Re: [bug report] iommufd: Add a selftest

[Jason Gunthorpe]

On Tue, Nov 15, 2022 at 03:49:44PM +0300, Dan Carpenter wrote:
> Hello Jason Gunthorpe,
> 
> The patch 147393321d65: "iommufd: Add a selftest" from Nov 19, 2021,
> leads to the following Smatch static checker warning:
> 
> 	drivers/iommu/iommufd/selftest.c:160 mock_domain_map_pages()
> 	warn: use 'gfp' here instead of GFP_XXX?
> 
> drivers/iommu/iommufd/selftest.c
>    133  static int mock_domain_map_pages(struct iommu_domain *domain,
>    134                                   unsigned long iova, phys_addr_t paddr,
>    135                                   size_t pgsize, size_t pgcount, int prot,
>    136                                   gfp_t gfp, size_t *mapped)
>    137  {
>    138          struct mock_iommu_domain *mock =
>    139                  container_of(domain, struct mock_iommu_domain, domain);
>    140          unsigned long flags = MOCK_PFN_START_IOVA;
>    141          unsigned long start_iova = iova;
>    142  
>    143          /*
>    144           * xarray does not reliably work with fault injection because it does a
>    145           * retry allocation, so put our own failure point.
>    146           */
>    147          if (iommufd_should_fail())
>    148                  return -ENOENT;
>    149  
>    150          WARN_ON(iova % MOCK_IO_PAGE_SIZE);
>    151          WARN_ON(pgsize % MOCK_IO_PAGE_SIZE);
>    152          for (; pgcount; pgcount--) {
>    153                  size_t cur;
>    154  
>    155                  for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) {
>    156                          void *old;
>    157  
>    158                          if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize)
>    159                                  flags = MOCK_PFN_LAST_IOVA;
>    160                          old = xa_store(&mock->pfns, iova / MOCK_IO_PAGE_SIZE,
>    161                                         xa_mk_value((paddr / MOCK_IO_PAGE_SIZE) |
>    162                                                     flags),
>    163                                         GFP_KERNEL);
>                                                ^^^^^^^^^^
> "gfp" isn't used anywhere so maybe it was intended here?

It is always GFP_KERNEL, but yes it can use that. I fixed it

Jason