drm/i915: Assert we do not overflow 4lvl page directories

Before looking up the page directory entry, check we are still within
bounds.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170225181122.4788-2-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2017-02-25 18:11:20 +00:00
parent b3bb82885f
commit 357480ce2f

View File

@ -830,6 +830,7 @@ gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt,
gen8_pte_t *vaddr;
bool ret;
GEM_BUG_ON(pdpe >= I915_PDPES_PER_PDP(vm));
pd = pdp->page_directory[pdpe];
vaddr = kmap_atomic_px(pd->page_table[pde]);
do {
@ -854,8 +855,7 @@ gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt,
break;
}
GEM_BUG_ON(!i915_vm_is_48bit(&ppgtt->base) &&
pdpe >= GEN8_LEGACY_PDPES);
GEM_BUG_ON(pdpe >= I915_PDPES_PER_PDP(vm));
pd = pdp->page_directory[pdpe];
pde = 0;
}
@ -904,7 +904,7 @@ static void gen8_ppgtt_insert_4lvl(struct i915_address_space *vm,
while (gen8_ppgtt_insert_pte_entries(ppgtt, pdps[pml4e++], &iter,
start, cache_level))
;
GEM_BUG_ON(pml4e >= GEN8_PML4ES_PER_PML4);
}
static void gen8_free_page_tables(struct i915_address_space *vm,