Commit ecc4d2a5 authored by Matthew Auld's avatar Matthew Auld Committed by Joonas Lahtinen
Browse files

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: 5cc9ed4b

 ("drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl")
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200117132413.1170563-2-matthew.auld@intel.com


(cherry picked from commit 8e78871bc1e5efec22c950d3fd24ddb63d4ff28a)
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
parent def9d278
......@@ -402,7 +402,7 @@ 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;
......@@ -448,9 +448,10 @@ __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;
......@@ -553,7 +554,7 @@ __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;
......
......@@ -1177,6 +1177,7 @@ 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;
......@@ -1660,6 +1661,7 @@ 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;
......
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