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lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or tail

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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>
This commit is contained in:
Pan Xinhui 2015-09-09 15:37:08 -07:00 committed by Linus Torvalds
parent d9282cb663
commit 9bf98f168b
1 changed files with 18 additions and 14 deletions
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32
lib/bitmap.c
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@ -506,7 +506,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
int nmaskbits) int nmaskbits)
{ {
unsigned a, b; unsigned a, b;
int c, old_c, totaldigits; int c, old_c, totaldigits, ndigits;
const char __user __force *ubuf = (const char __user __force *)buf; const char __user __force *ubuf = (const char __user __force *)buf;
int at_start, in_range; int at_start, in_range;
@ -516,6 +516,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
at_start = 1; at_start = 1;
in_range = 0; in_range = 0;
a = b = 0; a = b = 0;
ndigits = totaldigits;
/* Get the next cpu# or a range of cpu#'s */ /* Get the next cpu# or a range of cpu#'s */
while (buflen) { while (buflen) {
@ -529,17 +530,20 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
if (isspace(c)) if (isspace(c))
continue; 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 */ /* A '\0' or a ',' signal the end of a cpu# or range */
if (c == '\0' || c == ',') if (c == '\0' || c == ',')
break; 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 (c == '-') {
if (at_start || in_range) if (at_start || in_range)
@ -559,6 +563,8 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
at_start = 0; at_start = 0;
totaldigits++; totaldigits++;
} }
if (ndigits == totaldigits)
continue;
/* if no digit is after '-', it's wrong*/ /* if no digit is after '-', it's wrong*/
if (at_start && in_range) if (at_start && in_range)
return -EINVAL; return -EINVAL;
@ -566,11 +572,9 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
return -EINVAL; return -EINVAL;
if (b >= nmaskbits) if (b >= nmaskbits)
return -ERANGE; return -ERANGE;
if (!at_start) { while (a <= b) {
while (a <= b) { set_bit(a, maskp);
set_bit(a, maskp); a++;
a++;
}
} }
} while (buflen && c == ','); } while (buflen && c == ',');
return 0; return 0;