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lib: rework bitmap_parselist
Remove __bitmap_parselist helper and split the function to logical parts. [ynorov@marvell.com: v5] Link: http://lkml.kernel.org/r/20190416063801.20134-3-ynorov@marvell.com Link: http://lkml.kernel.org/r/20190405173211.11373-3-ynorov@marvell.com Signed-off-by: Yury Norov <ynorov@marvell.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Travis <travis@sgi.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yury Norov
Linus Torvalds
parent
281327c99b
commit
e371c481d8
255
lib/bitmap.c
255
lib/bitmap.c
@ -20,6 +20,8 @@
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#include <asm/page.h>
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#include "kstrtox.h"
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/**
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* DOC: bitmap introduction
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*
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@ -477,12 +479,128 @@ int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
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}
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EXPORT_SYMBOL(bitmap_print_to_pagebuf);
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/*
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* Region 9-38:4/10 describes the following bitmap structure:
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* 0 9 12 18 38
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* .........****......****......****......
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* ^ ^ ^ ^
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* start off group_len end
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*/
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struct region {
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unsigned int start;
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unsigned int off;
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unsigned int group_len;
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unsigned int end;
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};
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static int bitmap_set_region(const struct region *r,
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unsigned long *bitmap, int nbits)
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{
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unsigned int start;
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if (r->end >= nbits)
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return -ERANGE;
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for (start = r->start; start <= r->end; start += r->group_len)
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bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
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return 0;
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}
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static int bitmap_check_region(const struct region *r)
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{
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if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
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return -EINVAL;
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return 0;
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}
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static const char *bitmap_getnum(const char *str, unsigned int *num)
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{
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unsigned long long n;
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unsigned int len;
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len = _parse_integer(str, 10, &n);
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if (!len)
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return ERR_PTR(-EINVAL);
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if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
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return ERR_PTR(-EOVERFLOW);
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*num = n;
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return str + len;
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}
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static inline bool end_of_str(char c)
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{
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return c == '\0' || c == '\n';
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}
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static inline bool __end_of_region(char c)
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{
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return isspace(c) || c == ',';
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}
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static inline bool end_of_region(char c)
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{
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return __end_of_region(c) || end_of_str(c);
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}
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/*
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* The format allows commas and whitespases at the beginning
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* of the region.
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*/
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static const char *bitmap_find_region(const char *str)
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{
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while (__end_of_region(*str))
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str++;
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return end_of_str(*str) ? NULL : str;
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}
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static const char *bitmap_parse_region(const char *str, struct region *r)
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{
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str = bitmap_getnum(str, &r->start);
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if (IS_ERR(str))
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return str;
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if (end_of_region(*str))
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goto no_end;
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if (*str != '-')
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return ERR_PTR(-EINVAL);
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str = bitmap_getnum(str + 1, &r->end);
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if (IS_ERR(str))
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return str;
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if (end_of_region(*str))
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goto no_pattern;
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if (*str != ':')
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return ERR_PTR(-EINVAL);
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str = bitmap_getnum(str + 1, &r->off);
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if (IS_ERR(str))
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return str;
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if (*str != '/')
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return ERR_PTR(-EINVAL);
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return bitmap_getnum(str + 1, &r->group_len);
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no_end:
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r->end = r->start;
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no_pattern:
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r->off = r->end + 1;
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r->group_len = r->end + 1;
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return end_of_str(*str) ? NULL : str;
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}
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/**
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* __bitmap_parselist - convert list format ASCII string to bitmap
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* @buf: read nul-terminated user string from this buffer
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* @buflen: buffer size in bytes. If string is smaller than this
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* then it must be terminated with a \0.
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* @is_user: location of buffer, 0 indicates kernel space
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* bitmap_parselist - convert list format ASCII string to bitmap
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* @buf: read user string from this buffer; must be terminated
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* with a \0 or \n.
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* @maskp: write resulting mask here
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* @nmaskbits: number of bits in mask to be written
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*
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@ -498,127 +616,38 @@ EXPORT_SYMBOL(bitmap_print_to_pagebuf);
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*
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* Returns: 0 on success, -errno on invalid input strings. Error values:
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*
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* - ``-EINVAL``: second number in range smaller than first
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* - ``-EINVAL``: wrong region format
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* - ``-EINVAL``: invalid character in string
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* - ``-ERANGE``: bit number specified too large for mask
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* - ``-EOVERFLOW``: integer overflow in the input parameters
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*/
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static int __bitmap_parselist(const char *buf, unsigned int buflen,
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int is_user, unsigned long *maskp,
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int nmaskbits)
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int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
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{
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unsigned int a, b, old_a, old_b;
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unsigned int group_size, used_size, off;
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int c, old_c, totaldigits, ndigits;
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const char __user __force *ubuf = (const char __user __force *)buf;
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int at_start, in_range, in_partial_range;
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struct region r;
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long ret;
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totaldigits = c = 0;
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old_a = old_b = 0;
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group_size = used_size = 0;
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bitmap_zero(maskp, nmaskbits);
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do {
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at_start = 1;
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in_range = 0;
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in_partial_range = 0;
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a = b = 0;
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ndigits = totaldigits;
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/* Get the next cpu# or a range of cpu#'s */
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while (buflen) {
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old_c = c;
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if (is_user) {
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if (__get_user(c, ubuf++))
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return -EFAULT;
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} else
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c = *buf++;
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buflen--;
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if (isspace(c))
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continue;
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while (buf) {
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buf = bitmap_find_region(buf);
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if (buf == NULL)
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return 0;
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/* A '\0' or a ',' signal the end of a cpu# or range */
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if (c == '\0' || c == ',')
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break;
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/*
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* whitespaces between digits are not allowed,
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* but it's ok if whitespaces are on head or tail.
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* when old_c is whilespace,
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* if totaldigits == ndigits, whitespace is on head.
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* if whitespace is on tail, it should not run here.
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* as c was ',' or '\0',
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* the last code line has broken the current loop.
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*/
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if ((totaldigits != ndigits) && isspace(old_c))
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return -EINVAL;
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buf = bitmap_parse_region(buf, &r);
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if (IS_ERR(buf))
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return PTR_ERR(buf);
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if (c == '/') {
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used_size = a;
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at_start = 1;
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in_range = 0;
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a = b = 0;
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continue;
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}
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ret = bitmap_check_region(&r);
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if (ret)
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return ret;
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if (c == ':') {
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old_a = a;
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old_b = b;
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at_start = 1;
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in_range = 0;
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in_partial_range = 1;
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a = b = 0;
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continue;
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}
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ret = bitmap_set_region(&r, maskp, nmaskbits);
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if (ret)
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return ret;
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}
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if (c == '-') {
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if (at_start || in_range)
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return -EINVAL;
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b = 0;
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in_range = 1;
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at_start = 1;
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continue;
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}
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if (!isdigit(c))
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return -EINVAL;
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b = b * 10 + (c - '0');
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if (!in_range)
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a = b;
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at_start = 0;
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totaldigits++;
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}
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if (ndigits == totaldigits)
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continue;
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if (in_partial_range) {
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group_size = a;
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a = old_a;
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b = old_b;
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old_a = old_b = 0;
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} else {
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used_size = group_size = b - a + 1;
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}
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/* if no digit is after '-', it's wrong*/
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if (at_start && in_range)
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return -EINVAL;
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if (!(a <= b) || group_size == 0 || !(used_size <= group_size))
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return -EINVAL;
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if (b >= nmaskbits)
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return -ERANGE;
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while (a <= b) {
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off = min(b - a + 1, used_size);
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bitmap_set(maskp, a, off);
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a += group_size;
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}
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} while (buflen && c == ',');
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return 0;
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}
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int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
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{
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char *nl = strchrnul(bp, '\n');
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int len = nl - bp;
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return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
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}
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EXPORT_SYMBOL(bitmap_parselist);
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