[1/7] drm/i915: Do not define vma on stack

Commit Message

John Harrison Sept. 1, 2021, 2:20 a.m. UTC

From: Venkata Sandeep Dhanalakota <[e-mail]>

Defining vma on stack can cause stack overflow, if
vma gets populated with new fields.

Cc: Daniele Ceraolo Spurio <[e-mail]>
Cc: Tvrtko Ursulin <[e-mail]>
Signed-off-by: Venkata Sandeep Dhanalakota <[e-mail]>
Signed-off-by: Matthew Brost <[e-mail]>
---
 drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 18 +++++++++---------
 drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h |  2 ++
 2 files changed, 11 insertions(+), 9 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
index 3a16d08608a5..f632dbd32b42 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
@@ -413,20 +413,20 @@  static void uc_fw_bind_ggtt(struct intel_uc_fw *uc_fw)
 {
 	struct drm_i915_gem_object *obj = uc_fw->obj;
 	struct i915_ggtt *ggtt = __uc_fw_to_gt(uc_fw)->ggtt;
-	struct i915_vma dummy = {
-		.node.start = uc_fw_ggtt_offset(uc_fw),
-		.node.size = obj->base.size,
-		.pages = obj->mm.pages,
-		.vm = &ggtt->vm,
-	};
+	struct i915_vma *dummy = &uc_fw->dummy;
+
+	dummy->node.start = uc_fw_ggtt_offset(uc_fw);
+	dummy->node.size = obj->base.size;
+	dummy->pages = obj->mm.pages;
+	dummy->vm = &ggtt->vm;
 
 	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
-	GEM_BUG_ON(dummy.node.size > ggtt->uc_fw.size);
+	GEM_BUG_ON(dummy->node.size > ggtt->uc_fw.size);
 
 	/* uc_fw->obj cache domains were not controlled across suspend */
-	drm_clflush_sg(dummy.pages);
+	drm_clflush_sg(dummy->pages);
 
-	ggtt->vm.insert_entries(&ggtt->vm, &dummy, I915_CACHE_NONE, 0);
+	ggtt->vm.insert_entries(&ggtt->vm, dummy, I915_CACHE_NONE, 0);
 }
 
 static void uc_fw_unbind_ggtt(struct intel_uc_fw *uc_fw)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
index 99bb1fe1af66..693cc0ebcd63 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
@@ -10,6 +10,7 @@ 
 #include "intel_uc_fw_abi.h"
 #include "intel_device_info.h"
 #include "i915_gem.h"
+#include "i915_vma.h"
 
 struct drm_printer;
 struct drm_i915_private;
@@ -75,6 +76,7 @@  struct intel_uc_fw {
 	bool user_overridden;
 	size_t size;
 	struct drm_i915_gem_object *obj;
+	struct i915_vma dummy;
 
 	/*
 	 * The firmware build process will generate a version header file with major and