+static inline uint32_t *create_bits(pixman_format_code_t format,
+ int width,
+ int height,
+ int *rowstride_bytes)
+{
+ int stride = 0;
+ size_t buf_size = 0;
+ int bpp = PIXMAN_FORMAT_BPP(format);
+
+ /*
+ * Calculate the following while checking for overflow truncation:
+ * stride = ((width * bpp + 0x1f) >> 5) * sizeof(uint32_t);
+ */
+
+ if (unlikely(__builtin_mul_overflow(width, bpp, &stride))) {
+ return NULL;
+ }
+
+ if (unlikely(__builtin_add_overflow(stride, 0x1f, &stride))) {
+ return NULL;
+ }
+
+ stride >>= 5;
+
+ stride *= sizeof(uint32_t);
+
+ if (unlikely(__builtin_mul_overflow((size_t) height,
+ (size_t) stride,
+ &buf_size))) {
+ return NULL;
+ }
+
+ if (rowstride_bytes) {
+ *rowstride_bytes = stride;
+ }
+
+ return g_malloc0(buf_size);
+}
+