1 files changed, 142 insertions, 113 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index c63ddd06a5da..f235434df87b 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -20,6 +20,8 @@
 
 #include <asm/page.h>
 
+#include "kstrtox.h"
+
 /**
  * DOC: bitmap introduction
  *
@@ -477,12 +479,128 @@ int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
 }
 EXPORT_SYMBOL(bitmap_print_to_pagebuf);
 
+/*
+ * Region 9-38:4/10 describes the following bitmap structure:
+ * 0       9  12    18                  38
+ * .........****......****......****......
+ *          ^  ^     ^                   ^
+ *      start  off   group_len         end
+ */
+struct region {
+        unsigned int start;
+        unsigned int off;
+        unsigned int group_len;
+        unsigned int end;
+};
+
+static int bitmap_set_region(const struct region *r,
+                                unsigned long *bitmap, int nbits)
+{
+        unsigned int start;
+
+        if (r->end >= nbits)
+                return -ERANGE;
+
+        for (start = r->start; start <= r->end; start += r->group_len)
+                bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
+
+        return 0;
+}
+
+static int bitmap_check_region(const struct region *r)
+{
+        if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
+                return -EINVAL;
+
+        return 0;
+}
+
+static const char *bitmap_getnum(const char *str, unsigned int *num)
+{
+        unsigned long long n;
+        unsigned int len;
+
+        len = _parse_integer(str, 10, &n);
+        if (!len)
+                return ERR_PTR(-EINVAL);
+        if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
+                return ERR_PTR(-EOVERFLOW);
+
+        *num = n;
+        return str + len;
+}
+
+static inline bool end_of_str(char c)
+{
+        return c == '\0' || c == '\n';
+}
+
+static inline bool __end_of_region(char c)
+{
+        return isspace(c) || c == ',';
+}
+
+static inline bool end_of_region(char c)
+{
+        return __end_of_region(c) || end_of_str(c);
+}
+
+/*
+ * The format allows commas and whitespases at the beginning
+ * of the region.
+ */
+static const char *bitmap_find_region(const char *str)
+{
+        while (__end_of_region(*str))
+                str++;
+
+        return end_of_str(*str) ? NULL : str;
+}
+
+static const char *bitmap_parse_region(const char *str, struct region *r)
+{
+        str = bitmap_getnum(str, &r->start);
+        if (IS_ERR(str))
+                return str;
+
+        if (end_of_region(*str))
+                goto no_end;
+
+        if (*str != '-')
+                return ERR_PTR(-EINVAL);
+
+        str = bitmap_getnum(str + 1, &r->end);
+        if (IS_ERR(str))
+                return str;
+
+        if (end_of_region(*str))
+                goto no_pattern;
+
+        if (*str != ':')
+                return ERR_PTR(-EINVAL);
+
+        str = bitmap_getnum(str + 1, &r->off);
+        if (IS_ERR(str))
+                return str;
+
+        if (*str != '/')
+                return ERR_PTR(-EINVAL);
+
+        return bitmap_getnum(str + 1, &r->group_len);
+
+no_end:
+        r->end = r->start;
+no_pattern:
+        r->off = r->end + 1;
+        r->group_len = r->end + 1;
+
+        return end_of_str(*str) ? NULL : str;
+}
+
 /**
- * __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
+ * bitmap_parselist - convert list format ASCII string to bitmap
+ * @buf: read user string from this buffer; must be terminated
+ *    with a \0 or \n.
  * @maskp: write resulting mask here
  * @nmaskbits: number of bits in mask to be written
  *
@@ -498,127 +616,38 @@ EXPORT_SYMBOL(bitmap_print_to_pagebuf);
  *
  * Returns: 0 on success, -errno on invalid input strings. Error values:
  *
- *   - ``-EINVAL``: second number in range smaller than first
+ *   - ``-EINVAL``: wrong region format
  *   - ``-EINVAL``: invalid character in string
  *   - ``-ERANGE``: bit number specified too large for mask
+ *   - ``-EOVERFLOW``: integer overflow in the input parameters
  */
-static int __bitmap_parselist(const char *buf, unsigned int buflen,
-                int is_user, unsigned long *maskp,
-                int nmaskbits)
+int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
 {
-        unsigned int a, b, old_a, old_b;
-        unsigned int group_size, used_size, off;
-        int c, old_c, totaldigits, ndigits;
-        const char __user __force *ubuf = (const char __user __force *)buf;
-        int at_start, in_range, in_partial_range;
+        struct region r;
+        long ret;
 
-        totaldigits = c = 0;
-        old_a = old_b = 0;
-        group_size = used_size = 0;
         bitmap_zero(maskp, nmaskbits);
-        do {
-                at_start = 1;
-                in_range = 0;
-                in_partial_range = 0;
-                a = b = 0;
-                ndigits = totaldigits;
-
-                /* 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;
 
-                        /* A '\0' or a ',' signal the end of a cpu# or range */
-                        if (c == '\0' || c == ',')
-                                break;
-                        /*
-                        * whitespaces between digits are not allowed,
-                        * but it's ok if whitespaces are on head or tail.
-                        * when old_c is whilespace,
-                        * if totaldigits == ndigits, whitespace is on head.
-                        * if whitespace is on tail, it should not run here.
-                        * as c was ',' or '\0',
-                        * the last code line has broken the current loop.
-                        */
-                        if ((totaldigits != ndigits) && isspace(old_c))
-                                return -EINVAL;
-
-                        if (c == '/') {
-                                used_size = a;
-                                at_start = 1;
-                                in_range = 0;
-                                a = b = 0;
-                                continue;
-                        }
+        while (buf) {
+                buf = bitmap_find_region(buf);
+                if (buf == NULL)
+                        return 0;
 
-                        if (c == ':') {
-                                old_a = a;
-                                old_b = b;
-                                at_start = 1;
-                                in_range = 0;
-                                in_partial_range = 1;
-                                a = b = 0;
-                                continue;
-                        }
+                buf = bitmap_parse_region(buf, &r);
+                if (IS_ERR(buf))
+                        return PTR_ERR(buf);
 
-                        if (c == '-') {
-                                if (at_start || in_range)
-                                        return -EINVAL;
-                                b = 0;
-                                in_range = 1;
-                                at_start = 1;
-                                continue;
-                        }
+                ret = bitmap_check_region(&r);
+                if (ret)
+                        return ret;
 
-                        if (!isdigit(c))
-                                return -EINVAL;
+                ret = bitmap_set_region(&r, maskp, nmaskbits);
+                if (ret)
+                        return ret;
+        }
 
-                        b = b * 10 + (c - '0');
-                        if (!in_range)
-                                a = b;
-                        at_start = 0;
-                        totaldigits++;
-                }
-                if (ndigits == totaldigits)
-                        continue;
-                if (in_partial_range) {
-                        group_size = a;
-                        a = old_a;
-                        b = old_b;
-                        old_a = old_b = 0;
-                } else {
-                        used_size = group_size = b - a + 1;
-                }
-                /* if no digit is after '-', it's wrong*/
-                if (at_start && in_range)
-                        return -EINVAL;
-                if (!(a <= b) || group_size == 0 || !(used_size <= group_size))
-                        return -EINVAL;
-                if (b >= nmaskbits)
-                        return -ERANGE;
-                while (a <= b) {
-                        off = min(b - a + 1, used_size);
-                        bitmap_set(maskp, a, off);
-                        a += group_size;
-                }
-        } while (buflen && c == ',');
         return 0;
 }
-
-int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
-{
-        char *nl  = strchrnul(bp, '\n');
-        int len = nl - bp;
-
-        return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
-}
 EXPORT_SYMBOL(bitmap_parselist);