From e26eed4f623da70913b535631a29764d108efe98 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:40 -0400 Subject: iommufd: Add some fault injection points This increases the coverage the fail_nth test gets, as well as via syzkaller. Link: https://lore.kernel.org/r/17-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Matthew Rosato # s390 Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/main.c | 3 +++ drivers/iommu/iommufd/pages.c | 26 ++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 7c8f40bc8d98..bcb463e58100 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -102,6 +102,9 @@ struct iommufd_object *iommufd_get_object(struct iommufd_ctx *ictx, u32 id, { struct iommufd_object *obj; + if (iommufd_should_fail()) + return ERR_PTR(-ENOENT); + xa_lock(&ictx->objects); obj = xa_load(&ictx->objects, id); if (!obj || (type != IOMMUFD_OBJ_ANY && obj->type != type) || diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 640331b8a079..c5d2d9a8c562 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -80,6 +80,10 @@ static void *temp_kmalloc(size_t *size, void *backup, size_t backup_len) if (*size < backup_len) return backup; + + if (!backup && iommufd_should_fail()) + return NULL; + *size = min_t(size_t, *size, TEMP_MEMORY_LIMIT); res = kmalloc(*size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); if (res) @@ -544,6 +548,7 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, unsigned long last_index, struct page **pages) { struct page **end_pages = pages + (last_index - start_index) + 1; + struct page **half_pages = pages + (end_pages - pages) / 2; XA_STATE(xas, xa, start_index); do { @@ -551,6 +556,15 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, xas_lock(&xas); while (pages != end_pages) { + /* xarray does not participate in fault injection */ + if (pages == half_pages && iommufd_should_fail()) { + xas_set_err(&xas, -EINVAL); + xas_unlock(&xas); + /* aka xas_destroy() */ + xas_nomem(&xas, GFP_KERNEL); + goto err_clear; + } + old = xas_store(&xas, xa_mk_value(page_to_pfn(*pages))); if (xas_error(&xas)) break; @@ -561,6 +575,7 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, xas_unlock(&xas); } while (xas_nomem(&xas, GFP_KERNEL)); +err_clear: if (xas_error(&xas)) { if (xas.xa_index != start_index) clear_xarray(xa, start_index, xas.xa_index - 1); @@ -728,6 +743,10 @@ static int pfn_reader_user_pin(struct pfn_reader_user *user, npages = min_t(unsigned long, last_index - start_index + 1, user->upages_len / sizeof(*user->upages)); + + if (iommufd_should_fail()) + return -EFAULT; + uptr = (uintptr_t)(pages->uptr + start_index * PAGE_SIZE); if (!remote_mm) rc = pin_user_pages_fast(uptr, npages, user->gup_flags, @@ -872,6 +891,8 @@ static int pfn_reader_user_update_pinned(struct pfn_reader_user *user, npages = pages->last_npinned - pages->npinned; inc = false; } else { + if (iommufd_should_fail()) + return -ENOMEM; npages = pages->npinned - pages->last_npinned; inc = true; } @@ -1721,6 +1742,11 @@ static int iopt_pages_rw_page(struct iopt_pages *pages, unsigned long index, return iopt_pages_rw_slow(pages, index, index, offset, data, length, flags); + if (iommufd_should_fail()) { + rc = -EINVAL; + goto out_mmput; + } + mmap_read_lock(pages->source_mm); rc = pin_user_pages_remote( pages->source_mm, (uintptr_t)(pages->uptr + index * PAGE_SIZE), -- cgit v1.2.3