drm/i915: use check_add_overflow() and drop local variants

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@chromium.org>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240405202625.2525671-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Jani Nikula 2024-04-05 23:26:25 +03:00
parent 860cefce5e
commit fdac5a10b4
2 changed files with 3 additions and 17 deletions

View File

@ -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],

View File

@ -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); \