diff options
Diffstat (limited to 'drivers/iommu/iommufd/pages.c')
| -rw-r--r-- | drivers/iommu/iommufd/pages.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 3427749bc5ce..c3433b845561 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -1287,8 +1287,7 @@ static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages, } static struct iopt_pages *iopt_alloc_pages(unsigned long start_byte, - unsigned long length, - bool writable) + unsigned long length, bool writable) { struct iopt_pages *pages; @@ -1328,7 +1327,7 @@ struct iopt_pages *iopt_alloc_user_pages(void __user *uptr, struct iopt_pages *pages; unsigned long end; void __user *uptr_down = - (void __user *) ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE); + (void __user *)ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE); if (check_add_overflow((unsigned long)uptr, length, &end)) return ERR_PTR(-EOVERFLOW); @@ -2104,6 +2103,7 @@ iopt_pages_get_exact_access(struct iopt_pages *pages, unsigned long index, * @last_index: Inclusive last page index * @out_pages: Output list of struct page's representing the PFNs * @flags: IOMMUFD_ACCESS_RW_* flags + * @lock_area: Fail userspace munmap on this area * * Record that an in-kernel access will be accessing the pages, ensure they are * pinned, and return the PFNs as a simple list of 'struct page *'. @@ -2111,8 +2111,8 @@ iopt_pages_get_exact_access(struct iopt_pages *pages, unsigned long index, * This should be undone through a matching call to iopt_area_remove_access() */ int iopt_area_add_access(struct iopt_area *area, unsigned long start_index, - unsigned long last_index, struct page **out_pages, - unsigned int flags) + unsigned long last_index, struct page **out_pages, + unsigned int flags, bool lock_area) { struct iopt_pages *pages = area->pages; struct iopt_pages_access *access; @@ -2125,6 +2125,8 @@ int iopt_area_add_access(struct iopt_area *area, unsigned long start_index, access = iopt_pages_get_exact_access(pages, start_index, last_index); if (access) { area->num_accesses++; + if (lock_area) + area->num_locks++; access->users++; iopt_pages_fill_from_xarray(pages, start_index, last_index, out_pages); @@ -2146,6 +2148,8 @@ int iopt_area_add_access(struct iopt_area *area, unsigned long start_index, access->node.last = last_index; access->users = 1; area->num_accesses++; + if (lock_area) + area->num_locks++; interval_tree_insert(&access->node, &pages->access_itree); mutex_unlock(&pages->mutex); return 0; @@ -2162,12 +2166,13 @@ err_unlock: * @area: The source of PFNs * @start_index: First page index * @last_index: Inclusive last page index + * @unlock_area: Must match the matching iopt_area_add_access()'s lock_area * * Undo iopt_area_add_access() and unpin the pages if necessary. The caller * must stop using the PFNs before calling this. */ void iopt_area_remove_access(struct iopt_area *area, unsigned long start_index, - unsigned long last_index) + unsigned long last_index, bool unlock_area) { struct iopt_pages *pages = area->pages; struct iopt_pages_access *access; @@ -2178,6 +2183,10 @@ void iopt_area_remove_access(struct iopt_area *area, unsigned long start_index, goto out_unlock; WARN_ON(area->num_accesses == 0 || access->users == 0); + if (unlock_area) { + WARN_ON(area->num_locks == 0); + area->num_locks--; + } area->num_accesses--; access->users--; if (access->users) |