From 73635c7e096eb36b52c1e874f9b76856c6a41228 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Mon, 17 Jun 2019 16:37:29 -0400

Subject: [PATCH 36/63] util.h: implement add()/mul()/sub() for more integer

 types.

This adds the following:

uint_add()

uint_mul()

uint_sub()

long_sub()

ulong_sub()

Additionally it renames ulong_mult() to ulong_mul() and long_mult() to

long_mul().

As before, all of these are available without caring about the types,

as if declared:

bool add(TYPE addend, TYPE addend, TYPE *sum);

bool mul(TYPE factor, TYPE factor, TYPE *product);

bool sub(TYPE minuend, TYPE subtractahend, TYPE *difference);

If overflow would occur, the pointer target for the result is not

changed and the function returns true, otherwise it returns false.

Signed-off-by: Peter Jones <pjones@redhat.com>

---

 src/efivar.h   |   1 +

 src/safemath.h | 208 +++++++++++++++++++++++++++++++++++++++++++++++++

 src/util.h     |  96 -----------------------

 3 files changed, 209 insertions(+), 96 deletions(-)

 create mode 100644 src/safemath.h

diff --git a/src/efivar.h b/src/efivar.h

index 3d4b429631e..646863d14c5 100644

--- a/src/efivar.h

+++ b/src/efivar.h

@@ -23,6 +23,7 @@

 #include <efivar/efivar.h>

 #include "util.h"

+#include "safemath.h"

 #include "efivar_endian.h"

 #include "lib.h"

 #include "guid.h"

diff --git a/src/safemath.h b/src/safemath.h

new file mode 100644

index 00000000000..08dfef7ec0b

--- /dev/null

+++ b/src/safemath.h

@@ -0,0 +1,208 @@

+/*

+ * safemath.h

+ * Copyright 2016-2019 Peter Jones <pjones@redhat.com>

+ *

+ * This library is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public License as

+ * published by the Free Software Foundation; either version 2.1 of the

+ * License, or (at your option) any later version.

+ *

+ * This library is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with this library; if not, see

+ * <http://www.gnu.org/licenses/>.

+ *

+ */

+

+#ifndef SAFEMATH_H_

+#define SAFEMATH_H_

+

+/*

+ * I'm not actually sure when these appear, but they're present in the

+ * version in front of me.

+ */

+#if defined(__GNUC__) && defined(__GNUC_MINOR__)

+#if __GNUC__ >= 5 && __GNUC_MINOR__ >= 1

+#define int_add(a, b, c) __builtin_add_overflow(a, b, c)

+#define uint_add(a, b, c) __builtin_add_overflow(a, b, c)

+#define long_add(a, b, c) __builtin_add_overflow(a, b, c)

+#define ulong_add(a, b, c) __builtin_add_overflow(a, b, c)

+

+#define int_mul(a, b, c) __builtin_mul_overflow(a, b, c)

+#define uint_mul(a, b, c) __builtin_mul_overflow(a, b, c)

+#define long_mul(a, b, c) __builtin_mul_overflow(a, b, c)

+#define ulong_mul(a, b, c) __builtin_mul_overflow(a, b, c)

+

+#define int_sub(a, b, c) __builtin_sub_overflow(a, b, c)

+#define uint_sub(a, b, c) __builtin_sub_overflow(a, b, c)

+#define long_sub(a, b, c) __builtin_sub_overflow(a, b, c)

+#define ulong_sub(a, b, c) __builtin_sub_overflow(a, b, c)

+#endif

+#endif

+

+#ifndef int_add

+#define int_add(a, b, c) ({					\

+		const int _limit = INT_MAX;			\

+		long int _ret = _limit - (a);			\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) + (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef uint_add

+#define uint_add(a, b, c) ({					\

+		const unsigned int _limit = UINT_MAX;		\

+		unsigned int _ret = _limit - (a);		\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) + (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef long_add

+#define long_add(a, b, c) ({					\

+		const long _limit = LONG_MAX;			\

+		long _ret = _limit - (a);			\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) + (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef ulong_add

+#define ulong_add(a, b, c) ({					\

+		const unsigned long _limit = ULONG_MAX;		\

+		unsigned long _ret = _limit - (a);		\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) + (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef int_mul

+#define int_mul(a, b, c) ({						\

+		int _ret;						\

+		_ret = __builtin_popcount(a) + __builtin_popcount(b);	\

+		_ret = _ret < ((sizeof(a) + sizeof(b)) << 4);		\

+		if (!_ret)						\

+			*(c) = ((a) * (b));				\

+		(bool)_ret;						\

+	})

+#endif

+

+#ifndef uint_mul

+#define uint_mul(a, b, c) int_mul(a, b, c)

+#endif

+

+#ifndef long_mul

+#define long_mul(a, b, c) int_mul(a, b, c)

+#endif

+

+#ifndef ulong_mul

+#define ulong_mul(a, b, c) int_mul(a, b, c)

+#endif

+

+#ifndef int_sub

+#define int_sub(a, b, c) ({					\

+		const long _min_limit = INT_MIN;		\

+		const long _max_limit = INT_MAX;		\

+		int _ret;					\

+		_ret = _min_limit + (b);			\

+		_ret = !(_ret < (a));				\

+		if (!_ret) {					\

+			_ret = _max_limit - (a);		\

+			_ret = _ret > (b);			\

+		}						\

+		if (!_ret)					\

+			*(c) = ((a) - (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef uint_sub

+#define uint_sub(a, b, c) ({					\

+		const unsigned int _limit = UINT_MAX;		\

+		unsigned int _ret = _limit - (a);		\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) - (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef long_sub

+#define long_sub(a, b, c) ({					\

+		const long _min_limit = LONG_MIN;		\

+		const long _max_limit = LONG_MAX;		\

+		int _ret;					\

+		_ret = _min_limit + (b);			\

+		_ret = !(_ret < (a));				\

+		if (!_ret) {					\

+			_ret = _max_limit - (a);		\

+			_ret = _ret > (b);			\

+		}						\

+		if (!_ret)					\

+			*(c) = ((a) - (b));			\

+		(bool)_ret;					\

+	})

+#endif

+

+#ifndef ulong_sub

+#define ulong_sub(a, b, c) ({					\

+		const unsigned long _limit = ULONG_MAX;		\

+		unsigned long _ret = _limit - (a);		\

+		_ret = _ret > (b);				\

+		if (!_ret)					\

+			*(c) = ((a) - (b));			\

+		_ret;						\

+	})

+#endif

+

+#if defined(__GNUC__) && defined(__GNUC_MINOR__)

+#if __GNUC__ >= 5 && __GNUC_MINOR__ >= 1

+#define add(a, b, c) _Generic((c),					\

+			      int *: int_add(a, b, c),			\

+			      unsigned int *: uint_add(a, b, c),	\

+			      long *: long_add(a, b, c),		\

+			      unsigned long *: ulong_add(a, b, c))

+#define sub(a, b, c) _Generic((c),					\

+			      int *: int_sub(a, b, c),			\

+			      unsigned int *: uint_sub(a, b, c),	\

+			      long *: long_sub(a, b, c),		\

+			      unsigned long *: ulong_sub(a, b, c))

+#define mul(a, b, c) _Generic((c),					\

+			      int *: int_sub(a, b, c),			\

+			      unsigned int *: uint_mul(a, b, c),	\

+			      long *: long_mul(a, b, c),		\

+			      unsigned long *: ulong_mul(a, b, c))

+#endif

+#endif

+

+#ifndef add

+#define add(a, b, c) ({						\

+		(*(c)) = ((a) + (b));				\

+		})

+#endif

+#ifndef mul

+#define mul(a, b, c) ({						\

+		(*(c)) = ((a) * (b));				\

+		})

+#endif

+#ifndef sub

+#define sub(a, b, c) ({						\

+		(*(c)) = ((a) - (b));				\

+		})

+#endif

+

+

+#endif /* !SAFEMATH_H_ */

+// vim:fenc=utf-8:tw=75:noet

diff --git a/src/util.h b/src/util.h

index 712abea2d42..3f68d812700 100644

--- a/src/util.h

+++ b/src/util.h

@@ -61,102 +61,6 @@

 #define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))

 #endif

-/*

- * I'm not actually sure when these appear, but they're present in the

- * version in front of me.

- */

-#if defined(__GNUC__) && defined(__GNUC_MINOR__)

-#if __GNUC__ >= 5 && __GNUC_MINOR__ >= 1

-#define int_add(a, b, c) __builtin_add_overflow(a, b, c)

-#define long_add(a, b, c) __builtin_add_overflow(a, b, c)

-#define long_mult(a, b, c) __builtin_mul_overflow(a, b, c)

-#define ulong_add(a, b, c) __builtin_add_overflow(a, b, c)

-#define ulong_mult(a, b, c) __builtin_mul_overflow(a, b, c)

-#endif

-#endif

-#ifndef int_add

-#define int_add(a, b, c) ({					\

-		const int _limit = INT_MAX;			\

-		int _ret;					\

-		_ret = _limit - ((unsigned long long)a) >	\

-			  ((unsigned long long)b);		\

-		if (!_ret)					\

-			*(c) = ((a) + (b));			\

-		_ret;						\

-	})

-#endif

-#ifndef long_add

-#define long_add(a, b, c) ({					\

-		const long _limit = LONG_MAX;			\

-		int _ret;					\

-		_ret = _limit - ((unsigned long long)a) >	\

-			   ((unsigned long long)b);		\

-		if (!_ret)					\

-			*(c) = ((a) + (b));			\

-		_ret;						\

-	})

-#endif

-#ifndef long_mult

-#define long_mult(a, b, c) ({					\

-		const long _limit = LONG_MAX;			\

-		int _ret = 1;					\

-		if ((a) == 0 || (b) == 0)			\

-			_ret = 0;				\

-		else						\

-			_ret = _limit / (a) < (b);		\

-		if (!_ret)					\

-			*(c) = ((a) * (b));			\

-		_ret;						\

-	})

-#endif

-#ifndef ulong_add

-#define ulong_add(a, b, c) ({					\

-		const unsigned long _limit = ULONG_MAX;		\

-		int _ret;					\

-		_ret = _limit - ((unsigned long long)a) >	\

-			    ((unsigned long long)b);		\

-		if (!_ret)					\

-			*(c) = ((a) + (b));			\

-		_ret;						\

-	})

-#endif

-#ifndef ulong_mult

-#define ulong_mult(a, b, c) ({					\

-		const unsigned long _limit = ULONG_MAX;		\

-		int _ret = 1;					\

-		if ((a) == 0 || (b) == 0)			\

-			_ret = 0;				\

-		else						\

-			_ret = _limit / (a) < (b);		\

-		if (!_ret)					\

-			*(c) = ((a) * (b));			\

-		_ret;						\

-	})

-#endif

-

-#if defined(__GNUC__) && defined(__GNUC_MINOR__)

-#if __GNUC__ >= 5 && __GNUC_MINOR__ >= 1

-#define add(a, b, c) _Generic((c),				\

-			      int *: int_add(a,b,c),		\

-			      long *: long_add(a,b,c),		\

-			      unsigned long *: ulong_add(a,b,c))

-#define mult(a, b, c) _Generic((c),				\

-			      long *: long_mult(a,b,c),		\

-			      unsigned long *: ulong_mult(a,b,c))

-#endif

-#endif

-

-#ifndef add

-#define add(a, b, c) ({						\

-		(*(c)) = ((a) + (b));				\

-		})

-#endif

-#ifndef mult

-#define mult(a, b, c) ({					\

-		(*(c)) = ((a) * (b));				\

-		})

-#endif

-

 static inline int UNUSED

 read_file(int fd, uint8_t **result, size_t *bufsize)

 {

-- 

2.26.2