diff options
Diffstat (limited to 'lib/bitmap.c')
| -rw-r--r-- | lib/bitmap.c | 240 |
1 files changed, 201 insertions, 39 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index 702565821c99..06f7e4fe8d2d 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -5,11 +5,13 @@ * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ -#include <linux/module.h> +#include <linux/export.h> +#include <linux/thread_info.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/bitmap.h> #include <linux/bitops.h> +#include <linux/bug.h> #include <asm/uaccess.h> /* @@ -271,14 +273,92 @@ int __bitmap_weight(const unsigned long *bitmap, int bits) } EXPORT_SYMBOL(__bitmap_weight); +void bitmap_set(unsigned long *map, int start, int nr) +{ + unsigned long *p = map + BIT_WORD(start); + const int size = start + nr; + int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + + while (nr - bits_to_set >= 0) { + *p |= mask_to_set; + nr -= bits_to_set; + bits_to_set = BITS_PER_LONG; + mask_to_set = ~0UL; + p++; + } + if (nr) { + mask_to_set &= BITMAP_LAST_WORD_MASK(size); + *p |= mask_to_set; + } +} +EXPORT_SYMBOL(bitmap_set); + +void bitmap_clear(unsigned long *map, int start, int nr) +{ + unsigned long *p = map + BIT_WORD(start); + const int size = start + nr; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (nr - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + nr -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (nr) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; + } +} +EXPORT_SYMBOL(bitmap_clear); + /* - * Bitmap printing & parsing functions: first version by Bill Irwin, + * bitmap_find_next_zero_area - find a contiguous aligned zero area + * @map: The address to base the search on + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at + * @nr: The number of zeroed bits we're looking for + * @align_mask: Alignment mask for zero area + * + * The @align_mask should be one less than a power of 2; the effect is that + * the bit offset of all zero areas this function finds is multiples of that + * power of 2. A @align_mask of 0 means no alignment is required. + */ +unsigned long bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask) +{ + unsigned long index, end, i; +again: + index = find_next_zero_bit(map, size, start); + + /* Align allocation */ + index = __ALIGN_MASK(index, align_mask); + + end = index + nr; + if (end > size) + return end; + i = find_next_bit(map, end, index); + if (i < end) { + start = i + 1; + goto again; + } + return index; +} +EXPORT_SYMBOL(bitmap_find_next_zero_area); + +/* + * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, * second version by Paul Jackson, third by Joe Korty. */ #define CHUNKSZ 32 #define nbits_to_hold_value(val) fls(val) -#define unhex(c) (isdigit(c) ? (c - '0') : (toupper(c) - 'A' + 10)) #define BASEDEC 10 /* fancier cpuset lists input in decimal */ /** @@ -289,7 +369,8 @@ EXPORT_SYMBOL(__bitmap_weight); * @nmaskbits: size of bitmap, in bits * * Exactly @nmaskbits bits are displayed. Hex digits are grouped into - * comma-separated sets of eight digits per set. + * comma-separated sets of eight digits per set. Returns the number of + * characters which were written to *buf, excluding the trailing \0. */ int bitmap_scnprintf(char *buf, unsigned int buflen, const unsigned long *maskp, int nmaskbits) @@ -341,7 +422,7 @@ int __bitmap_parse(const char *buf, unsigned int buflen, { int c, old_c, totaldigits, ndigits, nchunks, nbits; u32 chunk; - const char __user *ubuf = buf; + const char __user __force *ubuf = (const char __user __force *)buf; bitmap_zero(maskp, nmaskbits); @@ -385,7 +466,7 @@ int __bitmap_parse(const char *buf, unsigned int buflen, if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) return -EOVERFLOW; - chunk = (chunk << 4) | unhex(c); + chunk = (chunk << 4) | hex_to_bin(c); ndigits++; totaldigits++; } if (ndigits == 0) @@ -406,7 +487,7 @@ int __bitmap_parse(const char *buf, unsigned int buflen, EXPORT_SYMBOL(__bitmap_parse); /** - * bitmap_parse_user() + * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap * * @ubuf: pointer to user buffer containing string. * @ulen: buffer size in bytes. If string is smaller than this @@ -426,7 +507,9 @@ int bitmap_parse_user(const char __user *ubuf, { if (!access_ok(VERIFY_READ, ubuf, ulen)) return -EFAULT; - return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits); + return __bitmap_parse((const char __force *)ubuf, + ulen, 1, maskp, nmaskbits); + } EXPORT_SYMBOL(bitmap_parse_user); @@ -435,8 +518,8 @@ EXPORT_SYMBOL(bitmap_parse_user); * * Helper routine for bitmap_scnlistprintf(). Write decimal number * or range to buf, suppressing output past buf+buflen, with optional - * comma-prefix. Return len of what would be written to buf, if it - * all fit. + * comma-prefix. Return len of what was written to *buf, excluding the + * trailing \0. */ static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) { @@ -462,9 +545,8 @@ static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) * the range. Output format is compatible with the format * accepted as input by bitmap_parselist(). * - * The return value is the number of characters which would be - * generated for the given input, excluding the trailing '\0', as - * per ISO C99. + * The return value is the number of characters which were written to *buf + * excluding the trailing '\0', as per ISO C99's scnprintf. */ int bitmap_scnlistprintf(char *buf, unsigned int buflen, const unsigned long *maskp, int nmaskbits) @@ -491,8 +573,11 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnlistprintf); /** - * bitmap_parselist - convert list format ASCII string to bitmap - * @bp: read nul-terminated user string from this buffer + * __bitmap_parselist - convert list format ASCII string to bitmap + * @buf: read nul-terminated user string from this buffer + * @buflen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @is_user: location of buffer, 0 indicates kernel space * @maskp: write resulting mask here * @nmaskbits: number of bits in mask to be written * @@ -507,20 +592,63 @@ EXPORT_SYMBOL(bitmap_scnlistprintf); * %-EINVAL: invalid character in string * %-ERANGE: bit number specified too large for mask */ -int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) +static int __bitmap_parselist(const char *buf, unsigned int buflen, + int is_user, unsigned long *maskp, + int nmaskbits) { unsigned a, b; + int c, old_c, totaldigits; + const char __user __force *ubuf = (const char __user __force *)buf; + int exp_digit, in_range; + totaldigits = c = 0; bitmap_zero(maskp, nmaskbits); do { - if (!isdigit(*bp)) - return -EINVAL; - b = a = simple_strtoul(bp, (char **)&bp, BASEDEC); - if (*bp == '-') { - bp++; - if (!isdigit(*bp)) + exp_digit = 1; + in_range = 0; + a = b = 0; + + /* Get the next cpu# or a range of cpu#'s */ + while (buflen) { + old_c = c; + if (is_user) { + if (__get_user(c, ubuf++)) + return -EFAULT; + } else + c = *buf++; + buflen--; + if (isspace(c)) + continue; + + /* + * If the last character was a space and the current + * character isn't '\0', we've got embedded whitespace. + * This is a no-no, so throw an error. + */ + if (totaldigits && c && isspace(old_c)) return -EINVAL; - b = simple_strtoul(bp, (char **)&bp, BASEDEC); + + /* A '\0' or a ',' signal the end of a cpu# or range */ + if (c == '\0' || c == ',') + break; + + if (c == '-') { + if (exp_digit || in_range) + return -EINVAL; + b = 0; + in_range = 1; + exp_digit = 1; + continue; + } + + if (!isdigit(c)) + return -EINVAL; + + b = b * 10 + (c - '0'); + if (!in_range) + a = b; + exp_digit = 0; + totaldigits++; } if (!(a <= b)) return -EINVAL; @@ -530,15 +658,54 @@ int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) set_bit(a, maskp); a++; } - if (*bp == ',') - bp++; - } while (*bp != '\0' && *bp != '\n'); + } while (buflen && c == ','); return 0; } + +int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) +{ + char *nl = strchr(bp, '\n'); + int len; + + if (nl) + len = nl - bp; + else + len = strlen(bp); + + return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); +} EXPORT_SYMBOL(bitmap_parselist); + /** - * bitmap_pos_to_ord(buf, pos, bits) + * bitmap_parselist_user() + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Wrapper for bitmap_parselist(), providing it with user buffer. + * + * We cannot have this as an inline function in bitmap.h because it needs + * linux/uaccess.h to get the access_ok() declaration and this causes + * cyclic dependencies. + */ +int bitmap_parselist_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int nmaskbits) +{ + if (!access_ok(VERIFY_READ, ubuf, ulen)) + return -EFAULT; + return __bitmap_parselist((const char __force *)ubuf, + ulen, 1, maskp, nmaskbits); +} +EXPORT_SYMBOL(bitmap_parselist_user); + + +/** + * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap * @pos: a bit position in @buf (0 <= @pos < @bits) * @bits: number of valid bit positions in @buf @@ -574,7 +741,7 @@ static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) } /** - * bitmap_ord_to_pos(buf, ord, bits) + * bitmap_ord_to_pos - find position of n-th set bit in bitmap * @buf: pointer to bitmap * @ord: ordinal bit position (n-th set bit, n >= 0) * @bits: number of valid bit positions in @buf @@ -591,7 +758,7 @@ static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) * * The bit positions 0 through @bits are valid positions in @buf. */ -static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) +int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) { int pos = 0; @@ -652,10 +819,9 @@ void bitmap_remap(unsigned long *dst, const unsigned long *src, bitmap_zero(dst, bits); w = bitmap_weight(new, bits); - for (oldbit = find_first_bit(src, bits); - oldbit < bits; - oldbit = find_next_bit(src, bits, oldbit + 1)) { + for_each_set_bit(oldbit, src, bits) { int n = bitmap_pos_to_ord(old, oldbit, bits); + if (n < 0 || w == 0) set_bit(oldbit, dst); /* identity map */ else @@ -751,7 +917,7 @@ EXPORT_SYMBOL(bitmap_bitremap); * @orig (i.e. bits 3, 5, 7 and 9) were also set. * * When bit 11 is set in @orig, it means turn on the bit in - * @dst corresponding to whatever is the twelth bit that is + * @dst corresponding to whatever is the twelfth bit that is * turned on in @relmap. In the above example, there were * only ten bits turned on in @relmap (30..39), so that bit * 11 was set in @orig had no affect on @dst. @@ -822,9 +988,7 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig, */ m = 0; - for (n = find_first_bit(relmap, bits); - n < bits; - n = find_next_bit(relmap, bits, n + 1)) { + for_each_set_bit(n, relmap, bits) { /* m == bitmap_pos_to_ord(relmap, n, bits) */ if (test_bit(m, orig)) set_bit(n, dst); @@ -853,9 +1017,7 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, return; bitmap_zero(dst, bits); - for (oldbit = find_first_bit(orig, bits); - oldbit < bits; - oldbit = find_next_bit(orig, bits, oldbit + 1)) + for_each_set_bit(oldbit, orig, bits) set_bit(oldbit % sz, dst); } EXPORT_SYMBOL(bitmap_fold); |