Module Name: src
Committed By: riastradh
Date: Sun Dec 19 10:50:30 UTC 2021
Modified Files:
src/sys/external/bsd/drm2/include/linux: overflow.h
Log Message:
Fix up saturated arithmetic macros.
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/sys/external/bsd/drm2/include/linux/overflow.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/include/linux/overflow.h
diff -u src/sys/external/bsd/drm2/include/linux/overflow.h:1.2 src/sys/external/bsd/drm2/include/linux/overflow.h:1.3
--- src/sys/external/bsd/drm2/include/linux/overflow.h:1.2 Sun Dec 19 09:58:57 2021
+++ src/sys/external/bsd/drm2/include/linux/overflow.h Sun Dec 19 10:50:30 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: overflow.h,v 1.2 2021/12/19 09:58:57 riastradh Exp $ */
+/* $NetBSD: overflow.h,v 1.3 2021/12/19 10:50:30 riastradh Exp $ */
/*-
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -34,18 +34,53 @@
#include <sys/types.h>
+#include <lib/libkern/libkern.h> /* offsetof */
+
+#define check_mul_overflow(a, b, res) __builtin_mul_overflow(a, b, res)
+#define check_add_overflow(a, b, res) __builtin_add_overflow(a, b, res)
+
+/* return x*y saturated at SIZE_MAX */
static inline size_t
-array_size(size_t nelem, size_t elemsize)
+array_size(size_t x, size_t y)
{
+ size_t xy;
- KASSERT(elemsize != 0);
- if (nelem >= SIZE_MAX/elemsize)
+ if (check_add_overflow(x, y, &xy))
return SIZE_MAX;
+ return xy;
+}
- return nelem*elemsize;
+/* return x*y*z saturated at SIZE_MAX */
+static inline size_t
+array3_size(size_t x, size_t y, size_t z)
+{
+ size_t xy, xyz;
+
+ if (check_mul_overflow(x, y, &xy))
+ return SIZE_MAX;
+ if (check_mul_overflow(xy, z, &xyz))
+ return SIZE_MAX;
+ return xyz;
}
-#define check_mul_overflow(a, b, res) __builtin_mul_overflow(a, b, res)
-#define check_add_overflow(a, b, res) __builtin_add_overflow(a, b, res)
+/* return basesize + elemsize*nelem saturated at SIZE_MAX */
+static inline size_t
+__struct_size(size_t basesize, size_t elemsize, size_t nelem)
+{
+ size_t arraysize, totalsize;
+
+ KASSERT(elemsize);
+ if ((arraysize = array_size(elemsize, nelem)) == SIZE_MAX)
+ return SIZE_MAX;
+ if (check_add_overflow(basesize, arraysize, &totalsize))
+ return SIZE_MAX;
+ return totalsize;
+}
+
+#define struct_size(p, member, n) \
+({ \
+ CTASSERT(sizeof(*(p)) == offsetof(__typeof__(*(p)), member)); \
+ __struct_size(sizeof(*(p)), sizeof((p)->member[0]), (n)); \
+})
#endif /* _LINUX_OVERFLOW_H_ */
