tools include: Adopt linux/bits.h

So that we reduce the difference of tools/include/linux/bitops.h to the
original kernel file, include/linux/bitops.h, trying to remove the need
to define BITS_PER_LONG, to avoid clashes with asm/bitsperlong.h.

And the things removed from tools/include/linux/bitops.h are really in
linux/bits.h, so that we can have a copy and then
tools/perf/check_headers.sh will tell us when new stuff gets added to
linux/bits.h so that we can check if it is useful and if any adjustment
needs to be done to the tools/{include,arch}/ copies.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-y1sqyydvfzo0bjjoj4zsl562@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

CVE-2018-12126
CVE-2018-12127
CVE-2018-12130

(backported from commit ba4aa02b)
[juergh:
 - Adjusted context.
 - Dropped modification of perf/check-headers.sh (doesn't exist in
   Xenial).]
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

tools/include/linux/bitops.h

@@ -3,17 +3,15 @@
 
 #include <asm/types.h>
 #include <linux/kernel.h>
-#include <linux/compiler.h>
 
 #ifndef __WORDSIZE
 #define __WORDSIZE (__SIZEOF_LONG__ * 8)
 #endif
 
 #define BITS_PER_LONG __WORDSIZE
+#include <linux/bits.h>
+#include <linux/compiler.h>
 
-#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
-#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
-#define BITS_PER_BYTE		8
 #define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
 #define BITS_TO_U64(nr)		DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
 #define BITS_TO_U32(nr)		DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))

tools/include/linux/bits.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_BITS_H
+#define __LINUX_BITS_H
+#include <asm/bitsperlong.h>
+
+#define BIT(nr)			(1UL << (nr))
+#define BIT_ULL(nr)		(1ULL << (nr))
+#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
+#define BIT_ULL_MASK(nr)	(1ULL << ((nr) % BITS_PER_LONG_LONG))
+#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)
+#define BITS_PER_BYTE		8
+
+/*
+ * Create a contiguous bitmask starting at bit position @l and ending at
+ * position @h. For example
+ * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
+ */
+#define GENMASK(h, l) \
+	(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
+
+#define GENMASK_ULL(h, l) \
+	(((~0ULL) - (1ULL << (l)) + 1) & \
+	 (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
+
+#endif	/* __LINUX_BITS_H */