Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754012AbbGAKzf (ORCPT ); Wed, 1 Jul 2015 06:55:35 -0400 Received: from mga03.intel.com ([134.134.136.65]:51284 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753824AbbGAKzZ (ORCPT ); Wed, 1 Jul 2015 06:55:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,384,1432623600"; d="scan'208";a="517127396" Message-ID: <5593C686.8090907@intel.com> Date: Wed, 01 Jul 2015 18:52:54 +0800 From: Pan Xinhui User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" CC: Yury Norov , Andrew Morton , Rasmus Villemoes , tj@kernel.org, peterz@infradead.org, sudeep.holla@arm.com, mina86@mina86.com, "mnipxh@163.com" , Alexey Klimov , "yanmin_zhang@linux.intel.com" Subject: [PATCH 3/3, RESEND] lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or tail References: <5593C5F2.2090000@intel.com> <5593C63A.7000106@intel.com> In-Reply-To: <5593C63A.7000106@intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3008 Lines: 98 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 Cc: Yury Norov --- lib/bitmap.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index f549176..8148143 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -506,7 +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; @@ -516,6 +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) { @@ -529,17 +530,20 @@ 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) @@ -559,6 +563,8 @@ 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; @@ -566,11 +572,9 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen, 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; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/