linux-stable/tools/include/linux/bitmap.h
Kees Cook 005f17007f bitmap: Fix return values to be unsigned
Both nodemask and bitmap routines had mixed return values that provided
potentially signed return values that could never happen. This was
leading to the compiler getting confusing about the range of possible
return values (it was thinking things could be negative where they could
not be). In preparation for fixing nodemask, fix all the bitmap routines
that should be returning unsigned (or bool) values.

Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Christophe de Dinechin <dinechin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
2022-06-03 06:52:58 -07:00

186 lines
5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TOOLS_LINUX_BITMAP_H
#define _TOOLS_LINUX_BITMAP_H
#include <string.h>
#include <linux/bitops.h>
#include <linux/find.h>
#include <stdlib.h>
#include <linux/kernel.h>
#define DECLARE_BITMAP(name,bits) \
unsigned long name[BITS_TO_LONGS(bits)]
int __bitmap_weight(const unsigned long *bitmap, int bits);
void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits);
bool __bitmap_equal(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits);
void bitmap_clear(unsigned long *map, unsigned int start, int len);
bool __bitmap_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits);
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
if (small_const_nbits(nbits))
*dst = 0UL;
else {
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
memset(dst, 0, len);
}
}
static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
{
unsigned int nlongs = BITS_TO_LONGS(nbits);
if (!small_const_nbits(nbits)) {
unsigned int len = (nlongs - 1) * sizeof(unsigned long);
memset(dst, 0xff, len);
}
dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
}
static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
{
if (small_const_nbits(nbits))
return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
return find_first_bit(src, nbits) == nbits;
}
static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
return find_first_zero_bit(src, nbits) == nbits;
}
static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
return __bitmap_weight(src, nbits);
}
static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
*dst = *src1 | *src2;
else
__bitmap_or(dst, src1, src2, nbits);
}
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*/
static inline int test_and_set_bit(int nr, unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
unsigned long old;
old = *p;
*p = old | mask;
return (old & mask) != 0;
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*/
static inline int test_and_clear_bit(int nr, unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
unsigned long old;
old = *p;
*p = old & ~mask;
return (old & mask) != 0;
}
/**
* bitmap_zalloc - Allocate bitmap
* @nbits: Number of bits
*/
static inline unsigned long *bitmap_zalloc(int nbits)
{
return calloc(1, BITS_TO_LONGS(nbits) * sizeof(unsigned long));
}
/*
* bitmap_free - Free bitmap
* @bitmap: pointer to bitmap
*/
static inline void bitmap_free(unsigned long *bitmap)
{
free(bitmap);
}
/*
* bitmap_scnprintf - print bitmap list into buffer
* @bitmap: bitmap
* @nbits: size of bitmap
* @buf: buffer to store output
* @size: size of @buf
*/
size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
char *buf, size_t size);
/**
* bitmap_and - Do logical and on bitmaps
* @dst: resulting bitmap
* @src1: operand 1
* @src2: operand 2
* @nbits: size of bitmap
*/
static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
return __bitmap_and(dst, src1, src2, nbits);
}
#ifdef __LITTLE_ENDIAN
#define BITMAP_MEM_ALIGNMENT 8
#else
#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
#endif
#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
static inline bool bitmap_equal(const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
return !memcmp(src1, src2, nbits / 8);
return __bitmap_equal(src1, src2, nbits);
}
static inline bool bitmap_intersects(const unsigned long *src1,
const unsigned long *src2,
unsigned int nbits)
{
if (small_const_nbits(nbits))
return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
else
return __bitmap_intersects(src1, src2, nbits);
}
#endif /* _TOOLS_LINUX_BITMAP_H */