svn commit: r363791 - stable/11/sys/compat/linuxkpi/common/include/linux

[Hans Petter Selasky]

Author: hselasky
Date: Mon Aug  3 09:14:16 2020
New Revision: 363791
URL: https://svnweb.freebsd.org/changeset/base/363791

Log:
  MFC r361549:
  Add overflow.h to the LinuxKPI.
  
  Only add check_add_overflow and check_mul_overflow as those are the only
  two needed function by DRM v5.3.
  Both gcc and clang have builtin to do this check so use them directly
  but throw an error if the compiler/code checker doesn't support this builtin.
  
  Sponsored-by: The FreeBSD Foundation
  Reviewed by:	hselsasky
  Differential Revision:	https://reviews.freebsd.org/D25015

Added:
  stable/11/sys/compat/linuxkpi/common/include/linux/overflow.h
     - copied unchanged from r361549, head/sys/compat/linuxkpi/common/include/linux/overflow.h
Modified:
Directory Properties:
  stable/11/   (props changed)

Copied: stable/11/sys/compat/linuxkpi/common/include/linux/overflow.h (from r361549, head/sys/compat/linuxkpi/common/include/linux/overflow.h)
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ stable/11/sys/compat/linuxkpi/common/include/linux/overflow.h	Mon Aug  3 09:14:16 2020	(r363791, copy of r361549, head/sys/compat/linuxkpi/common/include/linux/overflow.h)
@@ -0,0 +1,52 @@
+/*-
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Emmanuel Vadot under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef __LINUX_OVERFLOW_H__
+#define	__LINUX_OVERFLOW_H__
+
+#ifndef	__has_builtin
+#define	__has_builtin(x)	0
+#endif
+
+#if __has_builtin(__builtin_add_overflow)
+#define check_add_overflow(a, b, c)		\
+	__builtin_add_overflow(a, b, c)
+#else
+#error "Compiler does not support __builtin_add_overflow"
+#endif
+
+#if __has_builtin(__builtin_mul_overflow)
+#define check_mul_overflow(a, b, c)	\
+	__builtin_mul_overflow(a, b, c)
+#else
+#error "Compiler does not support __builtin_mul_overflow"
+#endif
+
+#endif	/* __LINUX_OVERFLOW_H__ */