Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752837AbbF3IeJ (ORCPT ); Tue, 30 Jun 2015 04:34:09 -0400 Received: from mga03.intel.com ([134.134.136.65]:24699 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338AbbF3IeD (ORCPT ); Tue, 30 Jun 2015 04:34:03 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,376,1432623600"; d="scan'208";a="737522865" Message-ID: <559253E0.2020602@intel.com> Date: Tue, 30 Jun 2015 16:31:28 +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 Subject: [PATCH V2] lib/bitmap.c: rewrite __bitmap_parse && __bitmap_parselist References: <5592487D.7080006@intel.com> <55934441.9010304@intel.com> <55924CD9.9020001@intel.com> In-Reply-To: <55924CD9.9020001@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7293 Lines: 316 add __bitmap_parse_common to match any contents and return expected reslut. as __bitmap_parse_common need NULL-terminated string, we alloc a new buf. this patch also fix some parse issues in __bitmap_parselist. now it can handle grouping errors with input like " ", ",", etc. Signed-off-by: Pan Xinhui --- lib/bitmap.c | 234 +++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 130 insertions(+), 104 deletions(-) --- change log V2: __bitmap_parse_common need *base* to parse correct result V1: add __bitmap_parse_common and rewrite __bitmap_parse && __bitmap_parselist --- diff --git a/lib/bitmap.c b/lib/bitmap.c index 64c0926..dde19bf 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -16,6 +16,8 @@ #include #include +#include +#include /* * bitmaps provide an array of bits, implemented using an an * array of unsigned longs. The number of valid bits in a @@ -331,6 +333,58 @@ again: EXPORT_SYMBOL(bitmap_find_next_zero_area_off); /* + * __bitmap_parse_common - parse expected number from buf + * Return 0 on success. + * there two patterns. + * if buf's contents did not match any of them, reutrn equivalent error. + * Notice buf's contents may be changed. + */ +static int __bitmap_parse_common(char *buf, unsigned int buflen, + unsigned long *a, unsigned long *b, int base) +{ + int ret; + int token; + const match_table_t table = { + { + .token = 1, + .pattern = "%x", + }, + { + .token = 2, + .pattern = "%x-%x", + }, + { + .token = 0, + .pattern = NULL, + } + }; + substring_t substr[MAX_OPT_ARGS]; + + if (!buflen || !a) + return -EINVAL; + + token = match_token((char *)buf, table, substr); + switch (token) { + case 1: + *substr[0].to = '\0'; + ret = kstrtoul(substr[0].from, base, a); + if (b) + *b = *a; + break; + case 2: + *substr[0].to = '\0'; + *substr[1].to = '\0'; + ret = kstrtoul(substr[0].from, base, a); + ret |= b ? kstrtoul(substr[1].from, base, b) : -EINVAL; + break; + default: + ret = -EINVAL; + break; + } + return ret; +} + +/* * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, * second version by Paul Jackson, third by Joe Korty. */ @@ -359,57 +413,45 @@ int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, unsigned long *maskp, int nmaskbits) { - int c, old_c, totaldigits, ndigits, nchunks, nbits; + int nchunks, nbits, ret; + unsigned long a; u32 chunk; const char __user __force *ubuf = (const char __user __force *)buf; + char *kbuf, *endp; + + if (!buflen) + return -EINVAL; + kbuf = kmalloc(buflen + 1, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + if (is_user) { + if (copy_from_user(kbuf, ubuf, buflen) != 0) { + kfree(kbuf); + return -EFAULT; + } + } else + memcpy(kbuf, buf, buflen); + kbuf[buflen] = '\0'; + buf = strim(kbuf); bitmap_zero(maskp, nmaskbits); - nchunks = nbits = totaldigits = c = 0; + nchunks = nbits = 0; do { - chunk = ndigits = 0; - - /* Get the next chunk of the bitmap */ - while (buflen) { - old_c = c; - if (is_user) { - if (__get_user(c, ubuf++)) - return -EFAULT; - } - else - c = *buf++; - 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 the chunk */ - if (c == '\0' || c == ',') - break; - - if (!isxdigit(c)) - return -EINVAL; - - /* - * Make sure there are at least 4 free bits in 'chunk'. - * If not, this hexdigit will overflow 'chunk', so - * throw an error. - */ - if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) - return -EOVERFLOW; - - chunk = (chunk << 4) | hex_to_bin(c); - ndigits++; totaldigits++; + endp = strchr(buf, ','); + if (endp) + *endp = '\0'; + ret = __bitmap_parse_common((char *)buf, strlen(buf), + &a, NULL, 16); + if (ret) + break; + buf = endp + 1; + + if (unlikely(a > U32_MAX)) { + ret = -ERANGE; + break; } - if (ndigits == 0) - return -EINVAL; + chunk = (u32)a; if (nchunks == 0 && chunk == 0) continue; @@ -417,11 +459,13 @@ int __bitmap_parse(const char *buf, unsigned int buflen, *maskp |= chunk; nchunks++; nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; - if (nbits > nmaskbits) - return -EOVERFLOW; - } while (buflen && c == ','); - - return 0; + if (nbits > nmaskbits) { + ret = -EOVERFLOW; + break; + } + } while (endp); + kfree(kbuf); + return ret; } EXPORT_SYMBOL(__bitmap_parse); @@ -503,70 +547,52 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen, int is_user, unsigned long *maskp, int nmaskbits) { - unsigned a, b; - int c, old_c, totaldigits; + unsigned long a, b; + int ret = 0; const char __user __force *ubuf = (const char __user __force *)buf; - int exp_digit, in_range; + char *kbuf, *endp; + + if (!buflen) + return -EINVAL; + kbuf = kmalloc(buflen + 1, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + if (is_user) { + if (copy_from_user(kbuf, ubuf, buflen) != 0) { + kfree(kbuf); + return -EFAULT; + } + } else + memcpy(kbuf, buf, buflen); + kbuf[buflen] = '\0'; + buf = strim(kbuf); - totaldigits = c = 0; bitmap_zero(maskp, nmaskbits); do { - exp_digit = 1; - in_range = 0; - a = b = 0; - - /* 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; - - /* - * 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; - - if (c == '-') { - if (exp_digit || in_range) - return -EINVAL; - b = 0; - in_range = 1; - exp_digit = 1; - continue; - } - - if (!isdigit(c)) - return -EINVAL; - - b = b * 10 + (c - '0'); - if (!in_range) - a = b; - exp_digit = 0; - totaldigits++; + endp = strchr(buf, ','); + if (endp) + *endp = '\0'; + ret = __bitmap_parse_common((char *)buf, strlen(buf), + &a, &b, 0); + if (ret) + break; + buf = endp + 1; + + if (!(a <= b)) { + ret = -EINVAL; + break; + } + if (b >= nmaskbits) { + ret = -ERANGE; + break; } - if (!(a <= b)) - return -EINVAL; - if (b >= nmaskbits) - return -ERANGE; while (a <= b) { set_bit(a, maskp); a++; } - } while (buflen && c == ','); - return 0; + } while (endp); + kfree(kbuf); + return ret; } int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) -- 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/