[PATCH 3/3] overflow: add range_overflows() and range_end_overflows()

[Jani Nikula <jani.nikula@intel.com>]

Move the range_overflows() and range_end_overflows() along with the _t
variants over from drm/i915 and drm/buddy to overflow.h.

Cc: Kees Cook <kees@kernel.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/i915_utils.h | 70 -------------------------------
 include/drm/drm_buddy.h           |  9 ----
 include/linux/overflow.h          | 70 +++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 79 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index 968dae941532..eb4d43c40009 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -67,76 +67,6 @@ bool i915_error_injected(void);
 		drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
 })
 
-/**
- * range_overflows() - Check if a range is out of bounds
- * @start: Start of the range.
- * @size:  Size of the range.
- * @max:   Exclusive upper boundary.
- *
- * A strict check to determine if the range [@start, @start + @size) is
- * invalid with respect to the allowable range [0, @max). Any range
- * starting at or beyond @max is considered an overflow, even if @size is 0.
- *
- * Returns: true if the range is out of bounds.
- */
-#define range_overflows(start, size, max) ({ \
-	typeof(start) start__ = (start); \
-	typeof(size) size__ = (size); \
-	typeof(max) max__ = (max); \
-	(void)(&start__ == &size__); \
-	(void)(&start__ == &max__); \
-	start__ >= max__ || size__ > max__ - start__; \
-})
-
-/**
- * range_overflows_t() - Check if a range is out of bounds
- * @type:  Data type to use.
- * @start: Start of the range.
- * @size:  Size of the range.
- * @max:   Exclusive upper boundary.
- *
- * Same as range_overflows() but forcing the parameters to @type.
- *
- * Returns: true if the range is out of bounds.
- */
-#define range_overflows_t(type, start, size, max) \
-	range_overflows((type)(start), (type)(size), (type)(max))
-
-/**
- * range_end_overflows() - Check if a range's endpoint is out of bounds
- * @start: Start of the range.
- * @size:  Size of the range.
- * @max:   Exclusive upper boundary.
- *
- * Checks only if the endpoint of a range (@start + @size) exceeds @max.
- * Unlike range_overflows(), a zero-sized range at the boundary (@start == @max)
- * is not considered an overflow. Useful for iterator-style checks.
- *
- * Returns: true if the endpoint exceeds the boundary.
- */
-#define range_end_overflows(start, size, max) ({ \
-	typeof(start) start__ = (start); \
-	typeof(size) size__ = (size); \
-	typeof(max) max__ = (max); \
-	(void)(&start__ == &size__); \
-	(void)(&start__ == &max__); \
-	start__ > max__ || size__ > max__ - start__; \
-})
-
-/**
- * range_end_overflows_t() - Check if a range's endpoint is out of bounds
- * @type:  Data type to use.
- * @start: Start of the range.
- * @size:  Size of the range.
- * @max:   Exclusive upper boundary.
- *
- * Same as range_end_overflows() but forcing the parameters to @type.
- *
- * Returns: true if the endpoint exceeds the boundary.
- */
-#define range_end_overflows_t(type, start, size, max) \
-	range_end_overflows((type)(start), (type)(size), (type)(max))
-
 #define ptr_mask_bits(ptr, n) ({					\
 	unsigned long __v = (unsigned long)(ptr);			\
 	(typeof(ptr))(__v & -BIT(n));					\
diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
index 513837632b7d..04afd7c21a82 100644
--- a/include/drm/drm_buddy.h
+++ b/include/drm/drm_buddy.h
@@ -13,15 +13,6 @@
 
 #include <drm/drm_print.h>
 
-#define range_overflows(start, size, max) ({ \
-	typeof(start) start__ = (start); \
-	typeof(size) size__ = (size); \
-	typeof(max) max__ = (max); \
-	(void)(&start__ == &size__); \
-	(void)(&start__ == &max__); \
-	start__ >= max__ || size__ > max__ - start__; \
-})
-
 #define DRM_BUDDY_RANGE_ALLOCATION		BIT(0)
 #define DRM_BUDDY_TOPDOWN_ALLOCATION		BIT(1)
 #define DRM_BUDDY_CONTIGUOUS_ALLOCATION		BIT(2)
diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 154ed0dbb43f..725f95f7e416 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -238,6 +238,76 @@ static inline bool __must_check __must_check_overflow(bool overflow)
 			      __overflows_type_constexpr(n, T),	\
 			      __overflows_type(n, T))
 
+/**
+ * range_overflows() - Check if a range is out of bounds
+ * @start: Start of the range.
+ * @size:  Size of the range.
+ * @max:   Exclusive upper boundary.
+ *
+ * A strict check to determine if the range [@start, @start + @size) is
+ * invalid with respect to the allowable range [0, @max). Any range
+ * starting at or beyond @max is considered an overflow, even if @size is 0.
+ *
+ * Returns: true if the range is out of bounds.
+ */
+#define range_overflows(start, size, max) ({ \
+	typeof(start) start__ = (start); \
+	typeof(size) size__ = (size); \
+	typeof(max) max__ = (max); \
+	(void)(&start__ == &size__); \
+	(void)(&start__ == &max__); \
+	start__ >= max__ || size__ > max__ - start__; \
+})
+
+/**
+ * range_overflows_t() - Check if a range is out of bounds
+ * @type:  Data type to use.
+ * @start: Start of the range.
+ * @size:  Size of the range.
+ * @max:   Exclusive upper boundary.
+ *
+ * Same as range_overflows() but forcing the parameters to @type.
+ *
+ * Returns: true if the range is out of bounds.
+ */
+#define range_overflows_t(type, start, size, max) \
+	range_overflows((type)(start), (type)(size), (type)(max))
+
+/**
+ * range_end_overflows() - Check if a range's endpoint is out of bounds
+ * @start: Start of the range.
+ * @size:  Size of the range.
+ * @max:   Exclusive upper boundary.
+ *
+ * Checks only if the endpoint of a range (@start + @size) exceeds @max.
+ * Unlike range_overflows(), a zero-sized range at the boundary (@start == @max)
+ * is not considered an overflow. Useful for iterator-style checks.
+ *
+ * Returns: true if the endpoint exceeds the boundary.
+ */
+#define range_end_overflows(start, size, max) ({ \
+	typeof(start) start__ = (start); \
+	typeof(size) size__ = (size); \
+	typeof(max) max__ = (max); \
+	(void)(&start__ == &size__); \
+	(void)(&start__ == &max__); \
+	start__ > max__ || size__ > max__ - start__; \
+})
+
+/**
+ * range_end_overflows_t() - Check if a range's endpoint is out of bounds
+ * @type:  Data type to use.
+ * @start: Start of the range.
+ * @size:  Size of the range.
+ * @max:   Exclusive upper boundary.
+ *
+ * Same as range_end_overflows() but forcing the parameters to @type.
+ *
+ * Returns: true if the endpoint exceeds the boundary.
+ */
+#define range_end_overflows_t(type, start, size, max) \
+	range_end_overflows((type)(start), (type)(size), (type)(max))
+
 /**
  * castable_to_type - like __same_type(), but also allows for casted literals
  *
-- 
2.47.2