Prefer common check_add_overflow() from overflow.h over the locally
rolled versions of it. While check_add_overflow() does require a
variable to assign to, unlike add_overflows_t(), it's still better than
having multiple versions around.
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_fb.c | 6 +++---
drivers/gpu/drm/i915/i915_utils.h | 14 --------------
2 files changed, 3 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
index 3ea6470d6d92..86b443433e8b 100644
--- a/drivers/gpu/drm/i915/display/intel_fb.c
+++ b/drivers/gpu/drm/i915/display/intel_fb.c
@@ -1106,7 +1106,7 @@ static int intel_fb_offset_to_xy(int *x, int *y,
{
struct drm_i915_private *i915 = to_i915(fb->dev);
unsigned int height;
- u32 alignment;
+ u32 alignment, unused;
if (DISPLAY_VER(i915) >= 12 &&
!intel_fb_needs_pot_stride_remap(to_intel_framebuffer(fb)) &&
@@ -1128,8 +1128,8 @@ static int intel_fb_offset_to_xy(int *x, int *y,
height = ALIGN(height, intel_tile_height(fb, color_plane));
/* Catch potential overflows early */
- if (add_overflows_t(u32, mul_u32_u32(height, fb->pitches[color_plane]),
- fb->offsets[color_plane])) {
+ if (check_add_overflow(mul_u32_u32(height, fb->pitches[color_plane]),
+ fb->offsets[color_plane], &unused)) {
drm_dbg_kms(&i915->drm,
"Bad offset 0x%08x or pitch %d for color plane %d\n",
fb->offsets[color_plane], fb->pitches[color_plane],
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index b45ef0560611..06ec6ceb61d5 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -73,20 +73,6 @@ bool i915_error_injected(void);
__i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
fmt, ##__VA_ARGS__)
-#if defined(GCC_VERSION) && GCC_VERSION >= 70000
-#define add_overflows_t(T, A, B) \
- __builtin_add_overflow_p((A), (B), (T)0)
-#else
-#define add_overflows_t(T, A, B) ({ \
- typeof(A) a = (A); \
- typeof(B) b = (B); \
- (T)(a + b) < a; \
-})
-#endif
-
-#define add_overflows(A, B) \
- add_overflows_t(typeof((A) + (B)), (A), (B))
-
#define range_overflows(start, size, max) ({ \
typeof(start) start__ = (start); \
typeof(size) size__ = (size); \
--
2.39.2
