diff options
Diffstat (limited to 'drivers/iommu/iommufd/selftest.c')
| -rw-r--r-- | drivers/iommu/iommufd/selftest.c | 1107 |
1 files changed, 1107 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c new file mode 100644 index 0000000000..56506d5753 --- /dev/null +++ b/drivers/iommu/iommufd/selftest.c @@ -0,0 +1,1107 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + * + * Kernel side components to support tools/testing/selftests/iommu + */ +#include <linux/slab.h> +#include <linux/iommu.h> +#include <linux/xarray.h> +#include <linux/file.h> +#include <linux/anon_inodes.h> +#include <linux/fault-inject.h> +#include <linux/platform_device.h> +#include <uapi/linux/iommufd.h> + +#include "../iommu-priv.h" +#include "io_pagetable.h" +#include "iommufd_private.h" +#include "iommufd_test.h" + +static DECLARE_FAULT_ATTR(fail_iommufd); +static struct dentry *dbgfs_root; +static struct platform_device *selftest_iommu_dev; + +size_t iommufd_test_memory_limit = 65536; + +enum { + MOCK_IO_PAGE_SIZE = PAGE_SIZE / 2, + + /* + * Like a real page table alignment requires the low bits of the address + * to be zero. xarray also requires the high bit to be zero, so we store + * the pfns shifted. The upper bits are used for metadata. + */ + MOCK_PFN_MASK = ULONG_MAX / MOCK_IO_PAGE_SIZE, + + _MOCK_PFN_START = MOCK_PFN_MASK + 1, + MOCK_PFN_START_IOVA = _MOCK_PFN_START, + MOCK_PFN_LAST_IOVA = _MOCK_PFN_START, +}; + +/* + * Syzkaller has trouble randomizing the correct iova to use since it is linked + * to the map ioctl's output, and it has no ide about that. So, simplify things. + * In syzkaller mode the 64 bit IOVA is converted into an nth area and offset + * value. This has a much smaller randomization space and syzkaller can hit it. + */ +static unsigned long iommufd_test_syz_conv_iova(struct io_pagetable *iopt, + u64 *iova) +{ + struct syz_layout { + __u32 nth_area; + __u32 offset; + }; + struct syz_layout *syz = (void *)iova; + unsigned int nth = syz->nth_area; + struct iopt_area *area; + + down_read(&iopt->iova_rwsem); + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + if (nth == 0) { + up_read(&iopt->iova_rwsem); + return iopt_area_iova(area) + syz->offset; + } + nth--; + } + up_read(&iopt->iova_rwsem); + + return 0; +} + +void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, u64 *iova, u32 *flags) +{ + struct iommufd_ioas *ioas; + + if (!(*flags & MOCK_FLAGS_ACCESS_SYZ)) + return; + *flags &= ~(u32)MOCK_FLAGS_ACCESS_SYZ; + + ioas = iommufd_get_ioas(ucmd->ictx, ioas_id); + if (IS_ERR(ioas)) + return; + *iova = iommufd_test_syz_conv_iova(&ioas->iopt, iova); + iommufd_put_object(&ioas->obj); +} + +struct mock_iommu_domain { + struct iommu_domain domain; + struct xarray pfns; +}; + +enum selftest_obj_type { + TYPE_IDEV, +}; + +struct mock_dev { + struct device dev; +}; + +struct selftest_obj { + struct iommufd_object obj; + enum selftest_obj_type type; + + union { + struct { + struct iommufd_device *idev; + struct iommufd_ctx *ictx; + struct mock_dev *mock_dev; + } idev; + }; +}; + +static void mock_domain_blocking_free(struct iommu_domain *domain) +{ +} + +static int mock_domain_nop_attach(struct iommu_domain *domain, + struct device *dev) +{ + return 0; +} + +static const struct iommu_domain_ops mock_blocking_ops = { + .free = mock_domain_blocking_free, + .attach_dev = mock_domain_nop_attach, +}; + +static struct iommu_domain mock_blocking_domain = { + .type = IOMMU_DOMAIN_BLOCKED, + .ops = &mock_blocking_ops, +}; + +static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type) +{ + struct iommu_test_hw_info *info; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return ERR_PTR(-ENOMEM); + + info->test_reg = IOMMU_HW_INFO_SELFTEST_REGVAL; + *length = sizeof(*info); + *type = IOMMU_HW_INFO_TYPE_SELFTEST; + + return info; +} + +static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type) +{ + struct mock_iommu_domain *mock; + + if (iommu_domain_type == IOMMU_DOMAIN_BLOCKED) + return &mock_blocking_domain; + + if (iommu_domain_type != IOMMU_DOMAIN_UNMANAGED) + return NULL; + + mock = kzalloc(sizeof(*mock), GFP_KERNEL); + if (!mock) + return NULL; + mock->domain.geometry.aperture_start = MOCK_APERTURE_START; + mock->domain.geometry.aperture_end = MOCK_APERTURE_LAST; + mock->domain.pgsize_bitmap = MOCK_IO_PAGE_SIZE; + xa_init(&mock->pfns); + return &mock->domain; +} + +static void mock_domain_free(struct iommu_domain *domain) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + + WARN_ON(!xa_empty(&mock->pfns)); + kfree(mock); +} + +static int mock_domain_map_pages(struct iommu_domain *domain, + unsigned long iova, phys_addr_t paddr, + size_t pgsize, size_t pgcount, int prot, + gfp_t gfp, size_t *mapped) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + unsigned long flags = MOCK_PFN_START_IOVA; + unsigned long start_iova = iova; + + /* + * xarray does not reliably work with fault injection because it does a + * retry allocation, so put our own failure point. + */ + if (iommufd_should_fail()) + return -ENOENT; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + WARN_ON(pgsize % MOCK_IO_PAGE_SIZE); + for (; pgcount; pgcount--) { + size_t cur; + + for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) { + void *old; + + if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize) + flags = MOCK_PFN_LAST_IOVA; + old = xa_store(&mock->pfns, iova / MOCK_IO_PAGE_SIZE, + xa_mk_value((paddr / MOCK_IO_PAGE_SIZE) | + flags), + gfp); + if (xa_is_err(old)) { + for (; start_iova != iova; + start_iova += MOCK_IO_PAGE_SIZE) + xa_erase(&mock->pfns, + start_iova / + MOCK_IO_PAGE_SIZE); + return xa_err(old); + } + WARN_ON(old); + iova += MOCK_IO_PAGE_SIZE; + paddr += MOCK_IO_PAGE_SIZE; + *mapped += MOCK_IO_PAGE_SIZE; + flags = 0; + } + } + return 0; +} + +static size_t mock_domain_unmap_pages(struct iommu_domain *domain, + unsigned long iova, size_t pgsize, + size_t pgcount, + struct iommu_iotlb_gather *iotlb_gather) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + bool first = true; + size_t ret = 0; + void *ent; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + WARN_ON(pgsize % MOCK_IO_PAGE_SIZE); + + for (; pgcount; pgcount--) { + size_t cur; + + for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) { + ent = xa_erase(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + WARN_ON(!ent); + /* + * iommufd generates unmaps that must be a strict + * superset of the map's performend So every starting + * IOVA should have been an iova passed to map, and the + * + * First IOVA must be present and have been a first IOVA + * passed to map_pages + */ + if (first) { + WARN_ON(!(xa_to_value(ent) & + MOCK_PFN_START_IOVA)); + first = false; + } + if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize) + WARN_ON(!(xa_to_value(ent) & + MOCK_PFN_LAST_IOVA)); + + iova += MOCK_IO_PAGE_SIZE; + ret += MOCK_IO_PAGE_SIZE; + } + } + return ret; +} + +static phys_addr_t mock_domain_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + void *ent; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + ent = xa_load(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + WARN_ON(!ent); + return (xa_to_value(ent) & MOCK_PFN_MASK) * MOCK_IO_PAGE_SIZE; +} + +static bool mock_domain_capable(struct device *dev, enum iommu_cap cap) +{ + return cap == IOMMU_CAP_CACHE_COHERENCY; +} + +static void mock_domain_set_plaform_dma_ops(struct device *dev) +{ + /* + * mock doesn't setup default domains because we can't hook into the + * normal probe path + */ +} + +static struct iommu_device mock_iommu_device = { +}; + +static struct iommu_device *mock_probe_device(struct device *dev) +{ + return &mock_iommu_device; +} + +static const struct iommu_ops mock_ops = { + .owner = THIS_MODULE, + .pgsize_bitmap = MOCK_IO_PAGE_SIZE, + .hw_info = mock_domain_hw_info, + .domain_alloc = mock_domain_alloc, + .capable = mock_domain_capable, + .set_platform_dma_ops = mock_domain_set_plaform_dma_ops, + .device_group = generic_device_group, + .probe_device = mock_probe_device, + .default_domain_ops = + &(struct iommu_domain_ops){ + .free = mock_domain_free, + .attach_dev = mock_domain_nop_attach, + .map_pages = mock_domain_map_pages, + .unmap_pages = mock_domain_unmap_pages, + .iova_to_phys = mock_domain_iova_to_phys, + }, +}; + +static inline struct iommufd_hw_pagetable * +get_md_pagetable(struct iommufd_ucmd *ucmd, u32 mockpt_id, + struct mock_iommu_domain **mock) +{ + struct iommufd_hw_pagetable *hwpt; + struct iommufd_object *obj; + + obj = iommufd_get_object(ucmd->ictx, mockpt_id, + IOMMUFD_OBJ_HW_PAGETABLE); + if (IS_ERR(obj)) + return ERR_CAST(obj); + hwpt = container_of(obj, struct iommufd_hw_pagetable, obj); + if (hwpt->domain->ops != mock_ops.default_domain_ops) { + iommufd_put_object(&hwpt->obj); + return ERR_PTR(-EINVAL); + } + *mock = container_of(hwpt->domain, struct mock_iommu_domain, domain); + return hwpt; +} + +struct mock_bus_type { + struct bus_type bus; + struct notifier_block nb; +}; + +static struct mock_bus_type iommufd_mock_bus_type = { + .bus = { + .name = "iommufd_mock", + }, +}; + +static atomic_t mock_dev_num; + +static void mock_dev_release(struct device *dev) +{ + struct mock_dev *mdev = container_of(dev, struct mock_dev, dev); + + atomic_dec(&mock_dev_num); + kfree(mdev); +} + +static struct mock_dev *mock_dev_create(void) +{ + struct mock_dev *mdev; + int rc; + + mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); + if (!mdev) + return ERR_PTR(-ENOMEM); + + device_initialize(&mdev->dev); + mdev->dev.release = mock_dev_release; + mdev->dev.bus = &iommufd_mock_bus_type.bus; + + rc = dev_set_name(&mdev->dev, "iommufd_mock%u", + atomic_inc_return(&mock_dev_num)); + if (rc) + goto err_put; + + rc = device_add(&mdev->dev); + if (rc) + goto err_put; + return mdev; + +err_put: + put_device(&mdev->dev); + return ERR_PTR(rc); +} + +static void mock_dev_destroy(struct mock_dev *mdev) +{ + device_unregister(&mdev->dev); +} + +bool iommufd_selftest_is_mock_dev(struct device *dev) +{ + return dev->release == mock_dev_release; +} + +/* Create an hw_pagetable with the mock domain so we can test the domain ops */ +static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd, + struct iommu_test_cmd *cmd) +{ + struct iommufd_device *idev; + struct selftest_obj *sobj; + u32 pt_id = cmd->id; + u32 idev_id; + int rc; + + sobj = iommufd_object_alloc(ucmd->ictx, sobj, IOMMUFD_OBJ_SELFTEST); + if (IS_ERR(sobj)) + return PTR_ERR(sobj); + + sobj->idev.ictx = ucmd->ictx; + sobj->type = TYPE_IDEV; + + sobj->idev.mock_dev = mock_dev_create(); + if (IS_ERR(sobj->idev.mock_dev)) { + rc = PTR_ERR(sobj->idev.mock_dev); + goto out_sobj; + } + + idev = iommufd_device_bind(ucmd->ictx, &sobj->idev.mock_dev->dev, + &idev_id); + if (IS_ERR(idev)) { + rc = PTR_ERR(idev); + goto out_mdev; + } + sobj->idev.idev = idev; + + rc = iommufd_device_attach(idev, &pt_id); + if (rc) + goto out_unbind; + + /* Userspace must destroy the device_id to destroy the object */ + cmd->mock_domain.out_hwpt_id = pt_id; + cmd->mock_domain.out_stdev_id = sobj->obj.id; + cmd->mock_domain.out_idev_id = idev_id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_detach; + iommufd_object_finalize(ucmd->ictx, &sobj->obj); + return 0; + +out_detach: + iommufd_device_detach(idev); +out_unbind: + iommufd_device_unbind(idev); +out_mdev: + mock_dev_destroy(sobj->idev.mock_dev); +out_sobj: + iommufd_object_abort(ucmd->ictx, &sobj->obj); + return rc; +} + +/* Replace the mock domain with a manually allocated hw_pagetable */ +static int iommufd_test_mock_domain_replace(struct iommufd_ucmd *ucmd, + unsigned int device_id, u32 pt_id, + struct iommu_test_cmd *cmd) +{ + struct iommufd_object *dev_obj; + struct selftest_obj *sobj; + int rc; + + /* + * Prefer to use the OBJ_SELFTEST because the destroy_rwsem will ensure + * it doesn't race with detach, which is not allowed. + */ + dev_obj = + iommufd_get_object(ucmd->ictx, device_id, IOMMUFD_OBJ_SELFTEST); + if (IS_ERR(dev_obj)) + return PTR_ERR(dev_obj); + + sobj = container_of(dev_obj, struct selftest_obj, obj); + if (sobj->type != TYPE_IDEV) { + rc = -EINVAL; + goto out_dev_obj; + } + + rc = iommufd_device_replace(sobj->idev.idev, &pt_id); + if (rc) + goto out_dev_obj; + + cmd->mock_domain_replace.pt_id = pt_id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +out_dev_obj: + iommufd_put_object(dev_obj); + return rc; +} + +/* Add an additional reserved IOVA to the IOAS */ +static int iommufd_test_add_reserved(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, + unsigned long start, size_t length) +{ + struct iommufd_ioas *ioas; + int rc; + + ioas = iommufd_get_ioas(ucmd->ictx, mockpt_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + down_write(&ioas->iopt.iova_rwsem); + rc = iopt_reserve_iova(&ioas->iopt, start, start + length - 1, NULL); + up_write(&ioas->iopt.iova_rwsem); + iommufd_put_object(&ioas->obj); + return rc; +} + +/* Check that every pfn under each iova matches the pfn under a user VA */ +static int iommufd_test_md_check_pa(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, unsigned long iova, + size_t length, void __user *uptr) +{ + struct iommufd_hw_pagetable *hwpt; + struct mock_iommu_domain *mock; + uintptr_t end; + int rc; + + if (iova % MOCK_IO_PAGE_SIZE || length % MOCK_IO_PAGE_SIZE || + (uintptr_t)uptr % MOCK_IO_PAGE_SIZE || + check_add_overflow((uintptr_t)uptr, (uintptr_t)length, &end)) + return -EINVAL; + + hwpt = get_md_pagetable(ucmd, mockpt_id, &mock); + if (IS_ERR(hwpt)) + return PTR_ERR(hwpt); + + for (; length; length -= MOCK_IO_PAGE_SIZE) { + struct page *pages[1]; + unsigned long pfn; + long npages; + void *ent; + + npages = get_user_pages_fast((uintptr_t)uptr & PAGE_MASK, 1, 0, + pages); + if (npages < 0) { + rc = npages; + goto out_put; + } + if (WARN_ON(npages != 1)) { + rc = -EFAULT; + goto out_put; + } + pfn = page_to_pfn(pages[0]); + put_page(pages[0]); + + ent = xa_load(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + if (!ent || + (xa_to_value(ent) & MOCK_PFN_MASK) * MOCK_IO_PAGE_SIZE != + pfn * PAGE_SIZE + ((uintptr_t)uptr % PAGE_SIZE)) { + rc = -EINVAL; + goto out_put; + } + iova += MOCK_IO_PAGE_SIZE; + uptr += MOCK_IO_PAGE_SIZE; + } + rc = 0; + +out_put: + iommufd_put_object(&hwpt->obj); + return rc; +} + +/* Check that the page ref count matches, to look for missing pin/unpins */ +static int iommufd_test_md_check_refs(struct iommufd_ucmd *ucmd, + void __user *uptr, size_t length, + unsigned int refs) +{ + uintptr_t end; + + if (length % PAGE_SIZE || (uintptr_t)uptr % PAGE_SIZE || + check_add_overflow((uintptr_t)uptr, (uintptr_t)length, &end)) + return -EINVAL; + + for (; length; length -= PAGE_SIZE) { + struct page *pages[1]; + long npages; + + npages = get_user_pages_fast((uintptr_t)uptr, 1, 0, pages); + if (npages < 0) + return npages; + if (WARN_ON(npages != 1)) + return -EFAULT; + if (!PageCompound(pages[0])) { + unsigned int count; + + count = page_ref_count(pages[0]); + if (count / GUP_PIN_COUNTING_BIAS != refs) { + put_page(pages[0]); + return -EIO; + } + } + put_page(pages[0]); + uptr += PAGE_SIZE; + } + return 0; +} + +struct selftest_access { + struct iommufd_access *access; + struct file *file; + struct mutex lock; + struct list_head items; + unsigned int next_id; + bool destroying; +}; + +struct selftest_access_item { + struct list_head items_elm; + unsigned long iova; + size_t length; + unsigned int id; +}; + +static const struct file_operations iommfd_test_staccess_fops; + +static struct selftest_access *iommufd_access_get(int fd) +{ + struct file *file; + + file = fget(fd); + if (!file) + return ERR_PTR(-EBADFD); + + if (file->f_op != &iommfd_test_staccess_fops) { + fput(file); + return ERR_PTR(-EBADFD); + } + return file->private_data; +} + +static void iommufd_test_access_unmap(void *data, unsigned long iova, + unsigned long length) +{ + unsigned long iova_last = iova + length - 1; + struct selftest_access *staccess = data; + struct selftest_access_item *item; + struct selftest_access_item *tmp; + + mutex_lock(&staccess->lock); + list_for_each_entry_safe(item, tmp, &staccess->items, items_elm) { + if (iova > item->iova + item->length - 1 || + iova_last < item->iova) + continue; + list_del(&item->items_elm); + iommufd_access_unpin_pages(staccess->access, item->iova, + item->length); + kfree(item); + } + mutex_unlock(&staccess->lock); +} + +static int iommufd_test_access_item_destroy(struct iommufd_ucmd *ucmd, + unsigned int access_id, + unsigned int item_id) +{ + struct selftest_access_item *item; + struct selftest_access *staccess; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + mutex_lock(&staccess->lock); + list_for_each_entry(item, &staccess->items, items_elm) { + if (item->id == item_id) { + list_del(&item->items_elm); + iommufd_access_unpin_pages(staccess->access, item->iova, + item->length); + mutex_unlock(&staccess->lock); + kfree(item); + fput(staccess->file); + return 0; + } + } + mutex_unlock(&staccess->lock); + fput(staccess->file); + return -ENOENT; +} + +static int iommufd_test_staccess_release(struct inode *inode, + struct file *filep) +{ + struct selftest_access *staccess = filep->private_data; + + if (staccess->access) { + iommufd_test_access_unmap(staccess, 0, ULONG_MAX); + iommufd_access_destroy(staccess->access); + } + mutex_destroy(&staccess->lock); + kfree(staccess); + return 0; +} + +static const struct iommufd_access_ops selftest_access_ops_pin = { + .needs_pin_pages = 1, + .unmap = iommufd_test_access_unmap, +}; + +static const struct iommufd_access_ops selftest_access_ops = { + .unmap = iommufd_test_access_unmap, +}; + +static const struct file_operations iommfd_test_staccess_fops = { + .release = iommufd_test_staccess_release, +}; + +static struct selftest_access *iommufd_test_alloc_access(void) +{ + struct selftest_access *staccess; + struct file *filep; + + staccess = kzalloc(sizeof(*staccess), GFP_KERNEL_ACCOUNT); + if (!staccess) + return ERR_PTR(-ENOMEM); + INIT_LIST_HEAD(&staccess->items); + mutex_init(&staccess->lock); + + filep = anon_inode_getfile("[iommufd_test_staccess]", + &iommfd_test_staccess_fops, staccess, + O_RDWR); + if (IS_ERR(filep)) { + kfree(staccess); + return ERR_CAST(filep); + } + staccess->file = filep; + return staccess; +} + +static int iommufd_test_create_access(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, unsigned int flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access *staccess; + struct iommufd_access *access; + u32 id; + int fdno; + int rc; + + if (flags & ~MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) + return -EOPNOTSUPP; + + staccess = iommufd_test_alloc_access(); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + fdno = get_unused_fd_flags(O_CLOEXEC); + if (fdno < 0) { + rc = -ENOMEM; + goto out_free_staccess; + } + + access = iommufd_access_create( + ucmd->ictx, + (flags & MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) ? + &selftest_access_ops_pin : + &selftest_access_ops, + staccess, &id); + if (IS_ERR(access)) { + rc = PTR_ERR(access); + goto out_put_fdno; + } + rc = iommufd_access_attach(access, ioas_id); + if (rc) + goto out_destroy; + cmd->create_access.out_access_fd = fdno; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_destroy; + + staccess->access = access; + fd_install(fdno, staccess->file); + return 0; + +out_destroy: + iommufd_access_destroy(access); +out_put_fdno: + put_unused_fd(fdno); +out_free_staccess: + fput(staccess->file); + return rc; +} + +static int iommufd_test_access_replace_ioas(struct iommufd_ucmd *ucmd, + unsigned int access_id, + unsigned int ioas_id) +{ + struct selftest_access *staccess; + int rc; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + rc = iommufd_access_replace(staccess->access, ioas_id); + fput(staccess->file); + return rc; +} + +/* Check that the pages in a page array match the pages in the user VA */ +static int iommufd_test_check_pages(void __user *uptr, struct page **pages, + size_t npages) +{ + for (; npages; npages--) { + struct page *tmp_pages[1]; + long rc; + + rc = get_user_pages_fast((uintptr_t)uptr, 1, 0, tmp_pages); + if (rc < 0) + return rc; + if (WARN_ON(rc != 1)) + return -EFAULT; + put_page(tmp_pages[0]); + if (tmp_pages[0] != *pages) + return -EBADE; + pages++; + uptr += PAGE_SIZE; + } + return 0; +} + +static int iommufd_test_access_pages(struct iommufd_ucmd *ucmd, + unsigned int access_id, unsigned long iova, + size_t length, void __user *uptr, + u32 flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access_item *item; + struct selftest_access *staccess; + struct page **pages; + size_t npages; + int rc; + + /* Prevent syzkaller from triggering a WARN_ON in kvzalloc() */ + if (length > 16*1024*1024) + return -ENOMEM; + + if (flags & ~(MOCK_FLAGS_ACCESS_WRITE | MOCK_FLAGS_ACCESS_SYZ)) + return -EOPNOTSUPP; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + if (staccess->access->ops != &selftest_access_ops_pin) { + rc = -EOPNOTSUPP; + goto out_put; + } + + if (flags & MOCK_FLAGS_ACCESS_SYZ) + iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, + &cmd->access_pages.iova); + + npages = (ALIGN(iova + length, PAGE_SIZE) - + ALIGN_DOWN(iova, PAGE_SIZE)) / + PAGE_SIZE; + pages = kvcalloc(npages, sizeof(*pages), GFP_KERNEL_ACCOUNT); + if (!pages) { + rc = -ENOMEM; + goto out_put; + } + + /* + * Drivers will need to think very carefully about this locking. The + * core code can do multiple unmaps instantaneously after + * iommufd_access_pin_pages() and *all* the unmaps must not return until + * the range is unpinned. This simple implementation puts a global lock + * around the pin, which may not suit drivers that want this to be a + * performance path. drivers that get this wrong will trigger WARN_ON + * races and cause EDEADLOCK failures to userspace. + */ + mutex_lock(&staccess->lock); + rc = iommufd_access_pin_pages(staccess->access, iova, length, pages, + flags & MOCK_FLAGS_ACCESS_WRITE); + if (rc) + goto out_unlock; + + /* For syzkaller allow uptr to be NULL to skip this check */ + if (uptr) { + rc = iommufd_test_check_pages( + uptr - (iova - ALIGN_DOWN(iova, PAGE_SIZE)), pages, + npages); + if (rc) + goto out_unaccess; + } + + item = kzalloc(sizeof(*item), GFP_KERNEL_ACCOUNT); + if (!item) { + rc = -ENOMEM; + goto out_unaccess; + } + + item->iova = iova; + item->length = length; + item->id = staccess->next_id++; + list_add_tail(&item->items_elm, &staccess->items); + + cmd->access_pages.out_access_pages_id = item->id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_free_item; + goto out_unlock; + +out_free_item: + list_del(&item->items_elm); + kfree(item); +out_unaccess: + iommufd_access_unpin_pages(staccess->access, iova, length); +out_unlock: + mutex_unlock(&staccess->lock); + kvfree(pages); +out_put: + fput(staccess->file); + return rc; +} + +static int iommufd_test_access_rw(struct iommufd_ucmd *ucmd, + unsigned int access_id, unsigned long iova, + size_t length, void __user *ubuf, + unsigned int flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access *staccess; + void *tmp; + int rc; + + /* Prevent syzkaller from triggering a WARN_ON in kvzalloc() */ + if (length > 16*1024*1024) + return -ENOMEM; + + if (flags & ~(MOCK_ACCESS_RW_WRITE | MOCK_ACCESS_RW_SLOW_PATH | + MOCK_FLAGS_ACCESS_SYZ)) + return -EOPNOTSUPP; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + tmp = kvzalloc(length, GFP_KERNEL_ACCOUNT); + if (!tmp) { + rc = -ENOMEM; + goto out_put; + } + + if (flags & MOCK_ACCESS_RW_WRITE) { + if (copy_from_user(tmp, ubuf, length)) { + rc = -EFAULT; + goto out_free; + } + } + + if (flags & MOCK_FLAGS_ACCESS_SYZ) + iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, + &cmd->access_rw.iova); + + rc = iommufd_access_rw(staccess->access, iova, tmp, length, flags); + if (rc) + goto out_free; + if (!(flags & MOCK_ACCESS_RW_WRITE)) { + if (copy_to_user(ubuf, tmp, length)) { + rc = -EFAULT; + goto out_free; + } + } + +out_free: + kvfree(tmp); +out_put: + fput(staccess->file); + return rc; +} +static_assert((unsigned int)MOCK_ACCESS_RW_WRITE == IOMMUFD_ACCESS_RW_WRITE); +static_assert((unsigned int)MOCK_ACCESS_RW_SLOW_PATH == + __IOMMUFD_ACCESS_RW_SLOW_PATH); + +void iommufd_selftest_destroy(struct iommufd_object *obj) +{ + struct selftest_obj *sobj = container_of(obj, struct selftest_obj, obj); + + switch (sobj->type) { + case TYPE_IDEV: + iommufd_device_detach(sobj->idev.idev); + iommufd_device_unbind(sobj->idev.idev); + mock_dev_destroy(sobj->idev.mock_dev); + break; + } +} + +int iommufd_test(struct iommufd_ucmd *ucmd) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + + switch (cmd->op) { + case IOMMU_TEST_OP_ADD_RESERVED: + return iommufd_test_add_reserved(ucmd, cmd->id, + cmd->add_reserved.start, + cmd->add_reserved.length); + case IOMMU_TEST_OP_MOCK_DOMAIN: + return iommufd_test_mock_domain(ucmd, cmd); + case IOMMU_TEST_OP_MOCK_DOMAIN_REPLACE: + return iommufd_test_mock_domain_replace( + ucmd, cmd->id, cmd->mock_domain_replace.pt_id, cmd); + case IOMMU_TEST_OP_MD_CHECK_MAP: + return iommufd_test_md_check_pa( + ucmd, cmd->id, cmd->check_map.iova, + cmd->check_map.length, + u64_to_user_ptr(cmd->check_map.uptr)); + case IOMMU_TEST_OP_MD_CHECK_REFS: + return iommufd_test_md_check_refs( + ucmd, u64_to_user_ptr(cmd->check_refs.uptr), + cmd->check_refs.length, cmd->check_refs.refs); + case IOMMU_TEST_OP_CREATE_ACCESS: + return iommufd_test_create_access(ucmd, cmd->id, + cmd->create_access.flags); + case IOMMU_TEST_OP_ACCESS_REPLACE_IOAS: + return iommufd_test_access_replace_ioas( + ucmd, cmd->id, cmd->access_replace_ioas.ioas_id); + case IOMMU_TEST_OP_ACCESS_PAGES: + return iommufd_test_access_pages( + ucmd, cmd->id, cmd->access_pages.iova, + cmd->access_pages.length, + u64_to_user_ptr(cmd->access_pages.uptr), + cmd->access_pages.flags); + case IOMMU_TEST_OP_ACCESS_RW: + return iommufd_test_access_rw( + ucmd, cmd->id, cmd->access_rw.iova, + cmd->access_rw.length, + u64_to_user_ptr(cmd->access_rw.uptr), + cmd->access_rw.flags); + case IOMMU_TEST_OP_DESTROY_ACCESS_PAGES: + return iommufd_test_access_item_destroy( + ucmd, cmd->id, cmd->destroy_access_pages.access_pages_id); + case IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT: + /* Protect _batch_init(), can not be less than elmsz */ + if (cmd->memory_limit.limit < + sizeof(unsigned long) + sizeof(u32)) + return -EINVAL; + iommufd_test_memory_limit = cmd->memory_limit.limit; + return 0; + default: + return -EOPNOTSUPP; + } +} + +bool iommufd_should_fail(void) +{ + return should_fail(&fail_iommufd, 1); +} + +int __init iommufd_test_init(void) +{ + struct platform_device_info pdevinfo = { + .name = "iommufd_selftest_iommu", + }; + int rc; + + dbgfs_root = + fault_create_debugfs_attr("fail_iommufd", NULL, &fail_iommufd); + + selftest_iommu_dev = platform_device_register_full(&pdevinfo); + if (IS_ERR(selftest_iommu_dev)) { + rc = PTR_ERR(selftest_iommu_dev); + goto err_dbgfs; + } + + rc = bus_register(&iommufd_mock_bus_type.bus); + if (rc) + goto err_platform; + + rc = iommu_device_sysfs_add(&mock_iommu_device, + &selftest_iommu_dev->dev, NULL, "%s", + dev_name(&selftest_iommu_dev->dev)); + if (rc) + goto err_bus; + + rc = iommu_device_register_bus(&mock_iommu_device, &mock_ops, + &iommufd_mock_bus_type.bus, + &iommufd_mock_bus_type.nb); + if (rc) + goto err_sysfs; + return 0; + +err_sysfs: + iommu_device_sysfs_remove(&mock_iommu_device); +err_bus: + bus_unregister(&iommufd_mock_bus_type.bus); +err_platform: + platform_device_unregister(selftest_iommu_dev); +err_dbgfs: + debugfs_remove_recursive(dbgfs_root); + return rc; +} + +void iommufd_test_exit(void) +{ + iommu_device_sysfs_remove(&mock_iommu_device); + iommu_device_unregister_bus(&mock_iommu_device, + &iommufd_mock_bus_type.bus, + &iommufd_mock_bus_type.nb); + bus_unregister(&iommufd_mock_bus_type.bus); + platform_device_unregister(selftest_iommu_dev); + debugfs_remove_recursive(dbgfs_root); +} |