lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or tail
In __bitmap_parselist we can accept whitespaces on head or tail during
every parsing procedure. If input has valid ranges, there is no reason to
reject the user.
For example, bitmap_parselist(" 1-3, 5, ", &mask, nmaskbits). After
separating the string, we get " 1-3", " 5", and " ". It's possible and
reasonable to accept such string as long as the parsing result is correct.
Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/bitmap.c b/lib/bitmap.c
index f549176..81481439 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -506,7 +506,7 @@
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;
@@ -516,6 +516,7 @@
at_start = 1;
in_range = 0;
a = b = 0;
+ ndigits = totaldigits;
/* Get the next cpu# or a range of cpu#'s */
while (buflen) {
@@ -529,17 +530,20 @@
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)
@@ -559,6 +563,8 @@
at_start = 0;
totaldigits++;
}
+ if (ndigits == totaldigits)
+ continue;
/* if no digit is after '-', it's wrong*/
if (at_start && in_range)
return -EINVAL;
@@ -566,11 +572,9 @@
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;