From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Tue, 20 Feb 2024 01:20:52 +0000 Subject: [PATCH] add new system file --- kernel/lib/bitmap.c | 637 +++++++++++++++++++++++++++++++++++---------------------- 1 files changed, 393 insertions(+), 244 deletions(-) diff --git a/kernel/lib/bitmap.c b/kernel/lib/bitmap.c index c4ca9ce..27e08c0 100644 --- a/kernel/lib/bitmap.c +++ b/kernel/lib/bitmap.c @@ -1,29 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * lib/bitmap.c * Helper functions for bitmap.h. - * - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. */ -#include <linux/export.h> -#include <linux/thread_info.h> -#include <linux/ctype.h> -#include <linux/errno.h> + #include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/bug.h> +#include <linux/ctype.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/export.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/thread_info.h> #include <linux/uaccess.h> #include <asm/page.h> +#include "kstrtox.h" + /** * DOC: bitmap introduction * - * bitmaps provide an array of bits, implemented using an an + * bitmaps provide an array of bits, implemented using an * array of unsigned longs. The number of valid bits in a * given bitmap does _not_ need to be an exact multiple of * BITS_PER_LONG. @@ -36,11 +38,6 @@ * for example) or scalar (bitmap_weight, for example) results * carefully filter out these unused bits from impacting their * results. - * - * These operations actually hold to a slightly stronger rule: - * if you don't input any bitmaps to these ops that have some - * unused bits set, then they won't output any set unused bits - * in output bitmaps. * * The byte ordering of bitmaps is more natural on little * endian architectures. See the big-endian headers @@ -63,6 +60,26 @@ return 1; } EXPORT_SYMBOL(__bitmap_equal); + +bool __bitmap_or_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, + const unsigned long *bitmap3, + unsigned int bits) +{ + unsigned int k, lim = bits / BITS_PER_LONG; + unsigned long tmp; + + for (k = 0; k < lim; ++k) { + if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) + return false; + } + + if (!(bits % BITS_PER_LONG)) + return true; + + tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; + return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; +} void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) { @@ -153,6 +170,73 @@ } EXPORT_SYMBOL(__bitmap_shift_left); +/** + * bitmap_cut() - remove bit region from bitmap and right shift remaining bits + * @dst: destination bitmap, might overlap with src + * @src: source bitmap + * @first: start bit of region to be removed + * @cut: number of bits to remove + * @nbits: bitmap size, in bits + * + * Set the n-th bit of @dst iff the n-th bit of @src is set and + * n is less than @first, or the m-th bit of @src is set for any + * m such that @first <= n < nbits, and m = n + @cut. + * + * In pictures, example for a big-endian 32-bit architecture: + * + * The @src bitmap is:: + * + * 31 63 + * | | + * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 + * | | | | + * 16 14 0 32 + * + * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: + * + * 31 63 + * | | + * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 + * | | | + * 14 (bit 17 0 32 + * from @src) + * + * Note that @dst and @src might overlap partially or entirely. + * + * This is implemented in the obvious way, with a shift and carry + * step for each moved bit. Optimisation is left as an exercise + * for the compiler. + */ +void bitmap_cut(unsigned long *dst, const unsigned long *src, + unsigned int first, unsigned int cut, unsigned int nbits) +{ + unsigned int len = BITS_TO_LONGS(nbits); + unsigned long keep = 0, carry; + int i; + + if (first % BITS_PER_LONG) { + keep = src[first / BITS_PER_LONG] & + (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); + } + + memmove(dst, src, len * sizeof(*dst)); + + while (cut--) { + for (i = first / BITS_PER_LONG; i < len; i++) { + if (i < len - 1) + carry = dst[i + 1] & 1UL; + else + carry = 0; + + dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); + } + } + + dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); + dst[first / BITS_PER_LONG] |= keep; +} +EXPORT_SYMBOL(bitmap_cut); + int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { @@ -206,6 +290,18 @@ return result != 0; } EXPORT_SYMBOL(__bitmap_andnot); + +void __bitmap_replace(unsigned long *dst, + const unsigned long *old, const unsigned long *new, + const unsigned long *mask, unsigned int nbits) +{ + unsigned int k; + unsigned int nr = BITS_TO_LONGS(nbits); + + for (k = 0; k < nr; k++) + dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); +} +EXPORT_SYMBOL(__bitmap_replace); int __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) @@ -338,97 +434,6 @@ * second version by Paul Jackson, third by Joe Korty. */ -#define CHUNKSZ 32 -#define nbits_to_hold_value(val) fls(val) -#define BASEDEC 10 /* fancier cpuset lists input in decimal */ - -/** - * __bitmap_parse - convert an ASCII hex string into a bitmap. - * @buf: pointer to buffer containing string. - * @buflen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0. - * @is_user: location of buffer, 0 indicates kernel space - * @maskp: pointer to bitmap array that will contain result. - * @nmaskbits: size of bitmap, in bits. - * - * Commas group hex digits into chunks. Each chunk defines exactly 32 - * bits of the resultant bitmask. No chunk may specify a value larger - * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value - * then leading 0-bits are prepended. %-EINVAL is returned for illegal - * characters and for grouping errors such as "1,,5", ",44", "," and "". - * Leading and trailing whitespace accepted, but not embedded whitespace. - */ -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; - u32 chunk; - const char __user __force *ubuf = (const char __user __force *)buf; - - bitmap_zero(maskp, nmaskbits); - - nchunks = nbits = totaldigits = c = 0; - do { - chunk = 0; - ndigits = totaldigits; - - /* 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); - totaldigits++; - } - if (ndigits == totaldigits) - return -EINVAL; - if (nchunks == 0 && chunk == 0) - continue; - - __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); - *maskp |= chunk; - nchunks++; - nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; - if (nbits > nmaskbits) - return -EOVERFLOW; - } while (buflen && c == ','); - - return 0; -} -EXPORT_SYMBOL(__bitmap_parse); - /** * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap * @@ -437,22 +442,22 @@ * then it must be terminated with a \0. * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. - * - * Wrapper for __bitmap_parse(), providing it with user buffer. - * - * We cannot have this as an inline function in bitmap.h because it needs - * linux/uaccess.h to get the access_ok() declaration and this causes - * cyclic dependencies. */ int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, unsigned long *maskp, int nmaskbits) { - if (!access_ok(VERIFY_READ, ubuf, ulen)) - return -EFAULT; - return __bitmap_parse((const char __force *)ubuf, - ulen, 1, maskp, nmaskbits); + char *buf; + int ret; + buf = memdup_user_nul(ubuf, ulen); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); + + kfree(buf); + return ret; } EXPORT_SYMBOL(bitmap_parse_user); @@ -476,21 +481,142 @@ int nmaskbits) { ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); - int n = 0; - if (len > 1) - n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : - scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); - return n; + return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : + scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); } EXPORT_SYMBOL(bitmap_print_to_pagebuf); +/* + * Region 9-38:4/10 describes the following bitmap structure: + * 0 9 12 18 38 + * .........****......****......****...... + * ^ ^ ^ ^ + * start off group_len end + */ +struct region { + unsigned int start; + unsigned int off; + unsigned int group_len; + unsigned int end; +}; + +static int bitmap_set_region(const struct region *r, + unsigned long *bitmap, int nbits) +{ + unsigned int start; + + if (r->end >= nbits) + return -ERANGE; + + for (start = r->start; start <= r->end; start += r->group_len) + bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); + + return 0; +} + +static int bitmap_check_region(const struct region *r) +{ + if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) + return -EINVAL; + + return 0; +} + +static const char *bitmap_getnum(const char *str, unsigned int *num) +{ + unsigned long long n; + unsigned int len; + + len = _parse_integer(str, 10, &n); + if (!len) + return ERR_PTR(-EINVAL); + if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) + return ERR_PTR(-EOVERFLOW); + + *num = n; + return str + len; +} + +static inline bool end_of_str(char c) +{ + return c == '\0' || c == '\n'; +} + +static inline bool __end_of_region(char c) +{ + return isspace(c) || c == ','; +} + +static inline bool end_of_region(char c) +{ + return __end_of_region(c) || end_of_str(c); +} + +/* + * The format allows commas and whitespaces at the beginning + * of the region. + */ +static const char *bitmap_find_region(const char *str) +{ + while (__end_of_region(*str)) + str++; + + return end_of_str(*str) ? NULL : str; +} + +static const char *bitmap_find_region_reverse(const char *start, const char *end) +{ + while (start <= end && __end_of_region(*end)) + end--; + + return end; +} + +static const char *bitmap_parse_region(const char *str, struct region *r) +{ + str = bitmap_getnum(str, &r->start); + if (IS_ERR(str)) + return str; + + if (end_of_region(*str)) + goto no_end; + + if (*str != '-') + return ERR_PTR(-EINVAL); + + str = bitmap_getnum(str + 1, &r->end); + if (IS_ERR(str)) + return str; + + if (end_of_region(*str)) + goto no_pattern; + + if (*str != ':') + return ERR_PTR(-EINVAL); + + str = bitmap_getnum(str + 1, &r->off); + if (IS_ERR(str)) + return str; + + if (*str != '/') + return ERR_PTR(-EINVAL); + + return bitmap_getnum(str + 1, &r->group_len); + +no_end: + r->end = r->start; +no_pattern: + r->off = r->end + 1; + r->group_len = r->end + 1; + + return end_of_str(*str) ? NULL : str; +} + /** - * __bitmap_parselist - convert list format ASCII string to bitmap - * @buf: read nul-terminated user string from this buffer - * @buflen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0. - * @is_user: location of buffer, 0 indicates kernel space + * bitmap_parselist - convert list format ASCII string to bitmap + * @buf: read user string from this buffer; must be terminated + * with a \0 or \n. * @maskp: write resulting mask here * @nmaskbits: number of bits in mask to be written * @@ -506,126 +632,37 @@ * * Returns: 0 on success, -errno on invalid input strings. Error values: * - * - ``-EINVAL``: second number in range smaller than first + * - ``-EINVAL``: wrong region format * - ``-EINVAL``: invalid character in string * - ``-ERANGE``: bit number specified too large for mask + * - ``-EOVERFLOW``: integer overflow in the input parameters */ -static int __bitmap_parselist(const char *buf, unsigned int buflen, - int is_user, unsigned long *maskp, - int nmaskbits) +int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) { - unsigned int a, b, old_a, old_b; - unsigned int group_size, used_size, off; - int c, old_c, totaldigits, ndigits; - const char __user __force *ubuf = (const char __user __force *)buf; - int at_start, in_range, in_partial_range; + struct region r; + long ret; - totaldigits = c = 0; - old_a = old_b = 0; - group_size = used_size = 0; bitmap_zero(maskp, nmaskbits); - do { - at_start = 1; - in_range = 0; - in_partial_range = 0; - a = b = 0; - ndigits = totaldigits; - /* 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; + while (buf) { + buf = bitmap_find_region(buf); + if (buf == NULL) + return 0; - /* 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; + buf = bitmap_parse_region(buf, &r); + if (IS_ERR(buf)) + return PTR_ERR(buf); - if (c == '/') { - used_size = a; - at_start = 1; - in_range = 0; - a = b = 0; - continue; - } + ret = bitmap_check_region(&r); + if (ret) + return ret; - if (c == ':') { - old_a = a; - old_b = b; - at_start = 1; - in_range = 0; - in_partial_range = 1; - a = b = 0; - continue; - } + ret = bitmap_set_region(&r, maskp, nmaskbits); + if (ret) + return ret; + } - if (c == '-') { - if (at_start || in_range) - return -EINVAL; - b = 0; - in_range = 1; - at_start = 1; - continue; - } - - if (!isdigit(c)) - return -EINVAL; - - b = b * 10 + (c - '0'); - if (!in_range) - a = b; - at_start = 0; - totaldigits++; - } - if (ndigits == totaldigits) - continue; - if (in_partial_range) { - group_size = a; - a = old_a; - b = old_b; - old_a = old_b = 0; - } else { - used_size = group_size = b - a + 1; - } - /* if no digit is after '-', it's wrong*/ - if (at_start && in_range) - return -EINVAL; - if (!(a <= b) || group_size == 0 || !(used_size <= group_size)) - return -EINVAL; - if (b >= nmaskbits) - return -ERANGE; - while (a <= b) { - off = min(b - a + 1, used_size); - bitmap_set(maskp, a, off); - a += group_size; - } - } while (buflen && c == ','); return 0; -} - -int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) -{ - char *nl = strchrnul(bp, '\n'); - int len = nl - bp; - - return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); } EXPORT_SYMBOL(bitmap_parselist); @@ -640,23 +677,106 @@ * @nmaskbits: size of bitmap, in bits. * * Wrapper for bitmap_parselist(), providing it with user buffer. - * - * We cannot have this as an inline function in bitmap.h because it needs - * linux/uaccess.h to get the access_ok() declaration and this causes - * cyclic dependencies. */ int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, unsigned long *maskp, int nmaskbits) { - if (!access_ok(VERIFY_READ, ubuf, ulen)) - return -EFAULT; - return __bitmap_parselist((const char __force *)ubuf, - ulen, 1, maskp, nmaskbits); + char *buf; + int ret; + + buf = memdup_user_nul(ubuf, ulen); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_parselist(buf, maskp, nmaskbits); + + kfree(buf); + return ret; } EXPORT_SYMBOL(bitmap_parselist_user); +static const char *bitmap_get_x32_reverse(const char *start, + const char *end, u32 *num) +{ + u32 ret = 0; + int c, i; + for (i = 0; i < 32; i += 4) { + c = hex_to_bin(*end--); + if (c < 0) + return ERR_PTR(-EINVAL); + + ret |= c << i; + + if (start > end || __end_of_region(*end)) + goto out; + } + + if (hex_to_bin(*end--) >= 0) + return ERR_PTR(-EOVERFLOW); +out: + *num = ret; + return end; +} + +/** + * bitmap_parse - convert an ASCII hex string into a bitmap. + * @start: pointer to buffer containing string. + * @buflen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0 or \n. In that case, + * UINT_MAX may be provided instead of string length. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Commas group hex digits into chunks. Each chunk defines exactly 32 + * bits of the resultant bitmask. No chunk may specify a value larger + * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value + * then leading 0-bits are prepended. %-EINVAL is returned for illegal + * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. + * Leading, embedded and trailing whitespace accepted. + */ +int bitmap_parse(const char *start, unsigned int buflen, + unsigned long *maskp, int nmaskbits) +{ + const char *end = strnchrnul(start, buflen, '\n') - 1; + int chunks = BITS_TO_U32(nmaskbits); + u32 *bitmap = (u32 *)maskp; + int unset_bit; + int chunk; + + for (chunk = 0; ; chunk++) { + end = bitmap_find_region_reverse(start, end); + if (start > end) + break; + + if (!chunks--) + return -EOVERFLOW; + +#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); +#else + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); +#endif + if (IS_ERR(end)) + return PTR_ERR(end); + } + + unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; + if (unset_bit < nmaskbits) { + bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); + return 0; + } + + if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) + return -EOVERFLOW; + + return 0; +} +EXPORT_SYMBOL(bitmap_parse); + + +#ifdef CONFIG_NUMA /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap @@ -765,7 +885,6 @@ set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); } } -EXPORT_SYMBOL(bitmap_remap); /** * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit @@ -803,7 +922,6 @@ else return bitmap_ord_to_pos(new, n % w, bits); } -EXPORT_SYMBOL(bitmap_bitremap); /** * bitmap_onto - translate one bitmap relative to another @@ -938,7 +1056,6 @@ m++; } } -EXPORT_SYMBOL(bitmap_onto); /** * bitmap_fold - fold larger bitmap into smaller, modulo specified size @@ -963,7 +1080,7 @@ for_each_set_bit(oldbit, orig, nbits) set_bit(oldbit % sz, dst); } -EXPORT_SYMBOL(bitmap_fold); +#endif /* CONFIG_NUMA */ /* * Common code for bitmap_*_region() routines. @@ -1147,6 +1264,38 @@ } EXPORT_SYMBOL(bitmap_free); +static void devm_bitmap_free(void *data) +{ + unsigned long *bitmap = data; + + bitmap_free(bitmap); +} + +unsigned long *devm_bitmap_alloc(struct device *dev, + unsigned int nbits, gfp_t flags) +{ + unsigned long *bitmap; + int ret; + + bitmap = bitmap_alloc(nbits, flags); + if (!bitmap) + return NULL; + + ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap); + if (ret) + return NULL; + + return bitmap; +} +EXPORT_SYMBOL_GPL(devm_bitmap_alloc); + +unsigned long *devm_bitmap_zalloc(struct device *dev, + unsigned int nbits, gfp_t flags) +{ + return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO); +} +EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); + #if BITS_PER_LONG == 64 /** * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap -- Gitblit v1.6.2