diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bitmap.c | 109 |
1 files changed, 97 insertions, 12 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index 91e0ccfdb424..41baf02924e6 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -571,8 +571,11 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnlistprintf); /** - * bitmap_parselist - convert list format ASCII string to bitmap + * __bitmap_parselist - convert list format ASCII string to bitmap * @bp: 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 * @@ -587,20 +590,63 @@ 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 *ubuf = 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; + + /* 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 = simple_strtoul(bp, (char **)&bp, BASEDEC); + + b = b * 10 + (c - '0'); + if (!in_range) + a = b; + exp_digit = 0; + totaldigits++; } if (!(a <= b)) return -EINVAL; @@ -610,13 +656,52 @@ 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_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 *)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 |
