From 2db0fce27c5bbd8383485abdac53636be7b6bb83 Mon Sep 17 00:00:00 2001
From: Jon Bloomfield <jon.bloomfield@intel.com>
Date: Thu, 12 Jul 2018 19:53:10 +0100
Subject: [PATCH 01/23] drm/i915/gtt: Add read only pages to gen8_pte_encode
References: CVE-2019-0154,bsc#1135966,CVE-2019-0155,bsc#1135967
Git-commit: 25dda4dabeeb12af5209b0183c788ef2a88dabbe
Patch-mainline: v4.19-rc1
We can set a bit inside the ppGTT PTE to indicate a page is read-only;
writes from the GPU will be discarded. We can use this to protect pages
and in particular support read-only userptr mappings (necessary for
importing PROT_READ vma).
Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180712185315.3288-1-chris@chris-wilson.co.uk
(backported from commit 25dda4dabeeb12af5209b0183c788ef2a88dabbe)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -221,10 +221,13 @@ static void ppgtt_unbind_vma(struct i915
}
static gen8_pte_t gen8_pte_encode(dma_addr_t addr,
- enum i915_cache_level level)
+ enum i915_cache_level level,
+ u32 flags)
{
- gen8_pte_t pte = _PAGE_PRESENT | _PAGE_RW;
- pte |= addr;
+ gen8_pte_t pte = addr | _PAGE_PRESENT | _PAGE_RW;
+
+ if (unlikely(flags & PTE_READ_ONLY))
+ pte &= ~_PAGE_RW;
switch (level) {
case I915_CACHE_NONE:
@@ -577,7 +580,7 @@ static void gen8_initialize_pt(struct i9
struct i915_page_table *pt)
{
fill_px(vm, pt,
- gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC));
+ gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC, 0));
}
static void gen6_initialize_pt(struct i915_address_space *vm,
@@ -781,7 +784,7 @@ static bool gen8_ppgtt_clear_pt(struct i
unsigned int pte = gen8_pte_index(start);
unsigned int pte_end = pte + num_entries;
const gen8_pte_t scratch_pte =
- gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC);
+ gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC, 0);
gen8_pte_t *vaddr;
GEM_BUG_ON(num_entries > pt->used_ptes);
@@ -956,7 +959,7 @@ gen8_ppgtt_insert_pte_entries(struct i91
enum i915_cache_level cache_level)
{
struct i915_page_directory *pd;
- const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level);
+ const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, 0);
gen8_pte_t *vaddr;
bool ret;
@@ -1363,7 +1366,7 @@ static void gen8_dump_ppgtt(struct i915_
{
struct i915_address_space *vm = &ppgtt->base;
const gen8_pte_t scratch_pte =
- gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC);
+ gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC, 0);
u64 start = 0, length = ppgtt->base.total;
if (use_4lvl(vm)) {
@@ -2215,7 +2218,7 @@ static void gen8_ggtt_insert_page(struct
gen8_pte_t __iomem *pte =
(gen8_pte_t __iomem *)ggtt->gsm + (offset >> PAGE_SHIFT);
- gen8_set_pte(pte, gen8_pte_encode(addr, level));
+ gen8_set_pte(pte, gen8_pte_encode(addr, level, 0));
ggtt->invalidate(vm->i915);
}
@@ -2228,7 +2231,7 @@ static void gen8_ggtt_insert_entries(str
struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
struct sgt_iter sgt_iter;
gen8_pte_t __iomem *gtt_entries;
- const gen8_pte_t pte_encode = gen8_pte_encode(0, level);
+ const gen8_pte_t pte_encode = gen8_pte_encode(0, level, 0);
dma_addr_t addr;
gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm;
@@ -2299,7 +2302,7 @@ static void gen8_ggtt_clear_range(struct
unsigned first_entry = start >> PAGE_SHIFT;
unsigned num_entries = length >> PAGE_SHIFT;
const gen8_pte_t scratch_pte =
- gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC);
+ gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC, 0);
gen8_pte_t __iomem *gtt_base =
(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
const int max_entries = ggtt_total_entries(ggtt) - first_entry;