This increases the coverage the fail_nth test gets, as well as via syzkaller.
Signed-off-by: Jason Gunthorpe jgg@nvidia.com --- drivers/iommu/iommufd/main.c | 3 +++ drivers/iommu/iommufd/pages.c | 26 ++++++++++++++++++++++++++ 2 files changed, 29 insertions(+)
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 7de0f95f2ee68a..ab3fa05f38505d 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 c3783ea01d7996..2ddcb0d4f71e04 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) @@ -482,6 +486,7 @@ 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 { @@ -489,6 +494,15 @@ 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; @@ -499,6 +513,7 @@ 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); @@ -662,6 +677,10 @@ 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, @@ -806,6 +825,8 @@ 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; } @@ -1636,6 +1657,11 @@ 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),