Throw it into a simple helper, and throw a warning if we encounter an
object which has been initialised with an object size that exceeds our
limit of INT_MAX pages.
Suggested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 9 +------
drivers/gpu/drm/i915/gem/i915_gem_object.h | 26 +++++++++++++++++++++
drivers/gpu/drm/i915/gem/i915_gem_region.c | 12 +---------
drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 16 +------------
4 files changed, 29 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index dc11497f830b..5cc8a0b2387f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -244,14 +244,7 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
}
}
- /*
- * XXX: There is a prevalence of the assumption that we fit the
- * object's page count inside a 32bit _signed_ variable. Let's document
- * this and catch if we ever need to fix it. In the meantime, if you do
- * spot such a local variable, please consider fixing!
- */
-
- if (dma_buf->size >> PAGE_SHIFT > INT_MAX)
+ if (i915_gem_object_size_2big(dma_buf->size))
return ERR_PTR(-E2BIG);
/* need to attach */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index d0ae834d787a..3411ad197fa6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -16,6 +16,32 @@
#include "i915_gem_gtt.h"
#include "i915_vma_types.h"
+/*
+ * XXX: There is a prevalence of the assumption that we fit the
+ * object's page count inside a 32bit _signed_ variable. Let's document
+ * this and catch if we ever need to fix it. In the meantime, if you do
+ * spot such a local variable, please consider fixing!
+ *
+ * Aside from our own locals (for which we have no excuse!):
+ * - sg_table embeds unsigned int for num_pages
+ * - get_user_pages*() mixed ints with longs
+ */
+#define GEM_CHECK_SIZE_OVERFLOW(sz) \
+ GEM_WARN_ON((sz) >> PAGE_SHIFT > INT_MAX)
+
+static inline bool i915_gem_object_size_2big(u64 size)
+{
+ struct drm_i915_gem_object *obj;
+
+ if (GEM_CHECK_SIZE_OVERFLOW(size))
+ return true;
+
+ if (overflows_type(size, obj->base.size))
+ return true;
+
+ return false;
+}
+
void i915_gem_init__objects(struct drm_i915_private *i915);
struct drm_i915_gem_object *i915_gem_object_alloc(void);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index 3e3dad22a683..77dfa908f156 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -161,17 +161,7 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
GEM_BUG_ON(!size);
GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_MIN_ALIGNMENT));
- /*
- * XXX: There is a prevalence of the assumption that we fit the
- * object's page count inside a 32bit _signed_ variable. Let's document
- * this and catch if we ever need to fix it. In the meantime, if you do
- * spot such a local variable, please consider fixing!
- */
-
- if (size >> PAGE_SHIFT > INT_MAX)
- return ERR_PTR(-E2BIG);
-
- if (overflows_type(size, obj->base.size))
+ if (i915_gem_object_size_2big(size))
return ERR_PTR(-E2BIG);
obj = i915_gem_object_alloc();
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index f2eaed6aca3d..3e4785c2dfa2 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -770,21 +770,7 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
I915_USERPTR_UNSYNCHRONIZED))
return -EINVAL;
- /*
- * XXX: There is a prevalence of the assumption that we fit the
- * object's page count inside a 32bit _signed_ variable. Let's document
- * this and catch if we ever need to fix it. In the meantime, if you do
- * spot such a local variable, please consider fixing!
- *
- * Aside from our own locals (for which we have no excuse!):
- * - sg_table embeds unsigned int for num_pages
- * - get_user_pages*() mixed ints with longs
- */
-
- if (args->user_size >> PAGE_SHIFT > INT_MAX)
- return -E2BIG;
-
- if (overflows_type(args->user_size, obj->base.size))
+ if (i915_gem_object_size_2big(args->user_size))
return -E2BIG;
if (!args->user_size)
--
2.26.2
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