From 8e78871bc1e5efec22c950d3fd24ddb63d4ff28a Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Fri, 17 Jan 2020 13:24:13 +0000 Subject: [PATCH] drm/i915/userptr: fix size calculation If we create a rather large userptr object(e.g 1ULL << 32) we might shift past the type-width of num_pages: (int)num_pages << PAGE_SHIFT, resulting in a totally bogus sg_table, which fortunately will eventually manifest as: gen8_ppgtt_insert_huge:463 GEM_BUG_ON(iter->sg->length < page_size) kernel BUG at drivers/gpu/drm/i915/gt/gen8_ppgtt.c:463! v2: more unsigned long prefer I915_GTT_PAGE_SIZE Fixes: 5cc9ed4b9a7a ("drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl") Signed-off-by: Matthew Auld Cc: Chris Wilson Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20200117132413.1170563-2-matthew.auld@intel.com --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 9 +++++---- drivers/gpu/drm/i915/gt/gen6_ppgtt.c | 1 + drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 1 + 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index b64b0f383a56..a74d4ac6a39f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -403,7 +403,7 @@ struct get_pages_work { static struct sg_table * __i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj, - struct page **pvec, int num_pages) + struct page **pvec, unsigned long num_pages) { unsigned int max_segment = i915_sg_segment_size(); struct sg_table *st; @@ -449,9 +449,10 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work) { struct get_pages_work *work = container_of(_work, typeof(*work), work); struct drm_i915_gem_object *obj = work->obj; - const int npages = obj->base.size >> PAGE_SHIFT; + const unsigned long npages = obj->base.size >> PAGE_SHIFT; + unsigned long pinned; struct page **pvec; - int pinned, ret; + int ret; ret = -ENOMEM; pinned = 0; @@ -559,7 +560,7 @@ __i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj) static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) { - const int num_pages = obj->base.size >> PAGE_SHIFT; + const unsigned long num_pages = obj->base.size >> PAGE_SHIFT; struct mm_struct *mm = obj->userptr.mm->mm; struct page **pvec; struct sg_table *pages; diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c index f10b2c41571c..f4fec7eb4064 100644 --- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c @@ -131,6 +131,7 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm, vaddr = kmap_atomic_px(i915_pt_entry(pd, act_pt)); do { + GEM_BUG_ON(iter.sg->length < I915_GTT_PAGE_SIZE); vaddr[act_pte] = pte_encode | GEN6_PTE_ADDR_ENCODE(iter.dma); iter.dma += I915_GTT_PAGE_SIZE; diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c index 077b8f7cf6cb..4d1de2d97d5c 100644 --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c @@ -379,6 +379,7 @@ gen8_ppgtt_insert_pte(struct i915_ppgtt *ppgtt, pd = i915_pd_entry(pdp, gen8_pd_index(idx, 2)); vaddr = kmap_atomic_px(i915_pt_entry(pd, gen8_pd_index(idx, 1))); do { + GEM_BUG_ON(iter->sg->length < I915_GTT_PAGE_SIZE); vaddr[gen8_pd_index(idx, 0)] = pte_encode | iter->dma; iter->dma += I915_GTT_PAGE_SIZE; -- 2.30.2