1 files changed, 34 insertions, 24 deletions

diff --git a/kernel/lib/bitmap.c b/kernel/lib/bitmap.c
index 40162f87e..814814397 100644
--- a/kernel/lib/bitmap.c
+++ b/kernel/lib/bitmap.c
@@ -367,7 +367,8 @@ int __bitmap_parse(const char *buf, unsigned int buflen,
 
 	nchunks = nbits = totaldigits = c = 0;
 	do {
-		chunk = ndigits = 0;
+		chunk = 0;
+		ndigits = totaldigits;
 
 		/* Get the next chunk of the bitmap */
 		while (buflen) {
@@ -406,9 +407,9 @@ int __bitmap_parse(const char *buf, unsigned int buflen,
 				return -EOVERFLOW;
 
 			chunk = (chunk << 4) | hex_to_bin(c);
-			ndigits++; totaldigits++;
+			totaldigits++;
 		}
-		if (ndigits == 0)
+		if (ndigits == totaldigits)
 			return -EINVAL;
 		if (nchunks == 0 && chunk == 0)
 			continue;
@@ -462,19 +463,20 @@ EXPORT_SYMBOL(bitmap_parse_user);
  * Output format is a comma-separated list of decimal numbers and
  * ranges if list is specified or hex digits grouped into comma-separated
  * sets of 8 digits/set. Returns the number of characters written to buf.
+ *
+ * It is assumed that @buf is a pointer into a PAGE_SIZE area and that
+ * sufficient storage remains at @buf to accommodate the
+ * bitmap_print_to_pagebuf() output.
  */
 int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
 			    int nmaskbits)
 {
-	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2;
+	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
 	int n = 0;
 
-	if (len > 1) {
-		n = list ? scnprintf(buf, len, "%*pbl", nmaskbits, maskp) :
-			   scnprintf(buf, len, "%*pb", nmaskbits, maskp);
-		buf[n++] = '\n';
-		buf[n] = '\0';
-	}
+	if (len > 1)
+		n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
+			   scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
 	return n;
 }
 EXPORT_SYMBOL(bitmap_print_to_pagebuf);
@@ -504,7 +506,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
 		int nmaskbits)
 {
 	unsigned a, b;
-	int c, old_c, totaldigits;
+	int c, old_c, totaldigits, ndigits;
 	const char __user __force *ubuf = (const char __user __force *)buf;
 	int at_start, in_range;
 
@@ -514,6 +516,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
 		at_start = 1;
 		in_range = 0;
 		a = b = 0;
+		ndigits = totaldigits;
 
 		/* Get the next cpu# or a range of cpu#'s */
 		while (buflen) {
@@ -527,23 +530,27 @@ static int __bitmap_parselist(const char *buf, unsigned int 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;
+			/*
+			* 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 == '-') {
 				if (at_start || in_range)
 					return -EINVAL;
 				b = 0;
 				in_range = 1;
+				at_start = 1;
 				continue;
 			}
 
@@ -556,15 +563,18 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
 			at_start = 0;
 			totaldigits++;
 		}
+		if (ndigits == totaldigits)
+			continue;
+		/* if no digit is after '-', it's wrong*/
+		if (at_start && in_range)
+			return -EINVAL;
 		if (!(a <= b))
 			return -EINVAL;
 		if (b >= nmaskbits)
 			return -ERANGE;
-		if (!at_start) {
-			while (a <= b) {
-				set_bit(a, maskp);
-				a++;
-			}
+		while (a <= b) {
+			set_bit(a, maskp);
+			a++;
 		}
 	} while (buflen && c == ',');
 	return 0;