diff options
| -rw-r--r-- | MAINTAINERS | 2 | ||||
| -rw-r--r-- | include/linux/bitmap-str.h | 16 | ||||
| -rw-r--r-- | include/linux/bitmap.h | 18 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/bitmap-str.c | 510 | ||||
| -rw-r--r-- | lib/bitmap.c | 512 |
6 files changed, 530 insertions, 530 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 6c4cce45a09d..561def8239f9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3506,12 +3506,14 @@ R: Andy Shevchenko <andriy.shevchenko@linux.intel.com> R: Rasmus Villemoes <linux@rasmusvillemoes.dk> S: Maintained F: include/linux/bitfield.h +F: include/linux/bitmap-str.h F: include/linux/bitmap.h F: include/linux/bits.h F: include/linux/cpumask.h F: include/linux/find.h F: include/linux/nodemask.h F: include/vdso/bits.h +F: lib/bitmap-str.c F: lib/bitmap.c F: lib/cpumask.c F: lib/cpumask_kunit.c diff --git a/include/linux/bitmap-str.h b/include/linux/bitmap-str.h new file mode 100644 index 000000000000..17caeca94cab --- /dev/null +++ b/include/linux/bitmap-str.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_BITMAP_STR_H +#define __LINUX_BITMAP_STR_H + +int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, unsigned long *dst, int nbits); +int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits); +extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); +extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); +int bitmap_parse(const char *buf, unsigned int buflen, unsigned long *dst, int nbits); +int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits); +int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, + unsigned long *dst, int nbits); + +#endif /* __LINUX_BITMAP_STR_H */ diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 1516ff979315..1cca950a54ae 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -10,6 +10,7 @@ #include <linux/limits.h> #include <linux/string.h> #include <linux/types.h> +#include <linux/bitmap-str.h> struct device; @@ -200,14 +201,6 @@ bitmap_find_next_zero_area(unsigned long *map, align_mask, 0); } -int bitmap_parse(const char *buf, unsigned int buflen, - unsigned long *dst, int nbits); -int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, - unsigned long *dst, int nbits); -int bitmap_parselist(const char *buf, unsigned long *maskp, - int nmaskbits); -int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, - unsigned long *dst, int nbits); void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, unsigned int nbits); int bitmap_bitremap(int oldbit, @@ -220,15 +213,6 @@ int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); -int bitmap_print_to_pagebuf(bool list, char *buf, - const unsigned long *maskp, int nmaskbits); - -extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count); - -extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count); - #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) diff --git a/lib/Makefile b/lib/Makefile index 740109b6e2c8..9e8f9f6dd3b2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -48,7 +48,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ percpu-refcount.o rhashtable.o base64.o \ once.o refcount.o rcuref.o usercopy.o errseq.o bucket_locks.o \ - generic-radix-tree.o + generic-radix-tree.o bitmap-str.o obj-$(CONFIG_STRING_SELFTEST) += test_string.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c new file mode 100644 index 000000000000..be745209507a --- /dev/null +++ b/lib/bitmap-str.c @@ -0,0 +1,510 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/bitmap.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/hex.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> + +#include "kstrtox.h" + +/** + * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + */ +int bitmap_parse_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int 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); + +/** + * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * @buf: page aligned buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * + * Output format is a comma-separated list of decimal numbers and + * ranges if list is specified or hex digits grouped into comma-separated + * sets of 8 digits/set. Returns the number of characters written to buf. + * + * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned + * area and that sufficient storage remains at @buf to accommodate the + * bitmap_print_to_pagebuf() output. Returns the number of characters + * actually printed to @buf, excluding terminating '\0'. + */ +int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits) +{ + ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); + + return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : + scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); +} +EXPORT_SYMBOL(bitmap_print_to_pagebuf); + +/** + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * true: print in decimal list format + * false: print in hexadecimal bitmask format + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + */ +static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + const char *fmt = list ? "%*pbl\n" : "%*pb\n"; + ssize_t size; + void *data; + + data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); + if (!data) + return -ENOMEM; + + size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); + kfree(data); + + return size; +} + +/** + * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + * + * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper + * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal + * bitmask and decimal list to userspace by sysfs ABI. + * Drivers might be using a normal attribute for this kind of ABIs. A + * normal attribute typically has show entry as below:: + * + * static ssize_t example_attribute_show(struct device *dev, + * struct device_attribute *attr, char *buf) + * { + * ... + * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); + * } + * + * show entry of attribute has no offset and count parameters and this + * means the file is limited to one page only. + * bitmap_print_to_pagebuf() API works terribly well for this kind of + * normal attribute with buf parameter and without offset, count:: + * + * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, + * int nmaskbits) + * { + * } + * + * The problem is once we have a large bitmap, we have a chance to get a + * bitmask or list more than one page. Especially for list, it could be + * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. + * It turns out bin_attribute is a way to break this limit. bin_attribute + * has show entry as below:: + * + * static ssize_t + * example_bin_attribute_show(struct file *filp, struct kobject *kobj, + * struct bin_attribute *attr, char *buf, + * loff_t offset, size_t count) + * { + * ... + * } + * + * With the new offset and count parameters, this makes sysfs ABI be able + * to support file size more than one page. For example, offset could be + * >= 4096. + * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their + * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() + * make those drivers be able to support large bitmask and list after they + * move to use bin_attribute. In result, we have to pass the corresponding + * parameters such as off, count from bin_attribute show entry to this API. + * + * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() + * is similar with cpumap_print_to_pagebuf(), the difference is that + * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption + * the destination buffer is exactly one page and won't be more than one page. + * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other + * hand, mainly serves bin_attribute which doesn't work with exact one page, + * and it can break the size limit of converted decimal list and hexadecimal + * bitmask. + * + * WARNING! + * + * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). + * It is intended to workaround sysfs limitations discussed above and should be + * used carefully in general case for the following reasons: + * + * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). + * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). + * - @off and @count are NOT offset and number of bits to print. + * - If printing part of bitmap as list, the resulting string is not a correct + * list representation of bitmap. Particularly, some bits within or out of + * related interval may be erroneously set or unset. The format of the string + * may be broken, so bitmap_parselist-like parser may fail parsing it. + * - If printing the whole bitmap as list by parts, user must ensure the order + * of calls of the function such that the offset is incremented linearly. + * - If printing the whole bitmap as list by parts, user must keep bitmap + * unchanged between the very first and very last call. Otherwise concatenated + * result may be incorrect, and format may be broken. + * + * Returns the number of characters actually printed to @buf + */ +int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); +} +EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); + +/** + * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + * + * Everything is same with the above bitmap_print_bitmask_to_buf() except + * the print format. + */ +int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); +} +EXPORT_SYMBOL(bitmap_print_list_to_buf); + +/* + * Region 9-38:4/10 describes the following bitmap structure: + * 0 9 12 18 38 N + * .........****......****......****.................. + * ^ ^ ^ ^ ^ + * start off group_len end nbits + */ +struct region { + unsigned int start; + unsigned int off; + unsigned int group_len; + unsigned int end; + unsigned int nbits; +}; + +static void bitmap_set_region(const struct region *r, unsigned long *bitmap) +{ + unsigned int start; + + for (start = r->start; start <= r->end; start += r->group_len) + bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); +} + +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; + + if (r->end >= r->nbits) + return -ERANGE; + + return 0; +} + +static const char *bitmap_getnum(const char *str, unsigned int *num, + unsigned int lastbit) +{ + unsigned long long n; + unsigned int len; + + if (str[0] == 'N') { + *num = lastbit; + return str + 1; + } + + 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) +{ + unsigned int lastbit = r->nbits - 1; + + if (!strncasecmp(str, "all", 3)) { + r->start = 0; + r->end = lastbit; + str += 3; + + goto check_pattern; + } + + str = bitmap_getnum(str, &r->start, lastbit); + 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, lastbit); + if (IS_ERR(str)) + return str; + +check_pattern: + if (end_of_region(*str)) + goto no_pattern; + + if (*str != ':') + return ERR_PTR(-EINVAL); + + str = bitmap_getnum(str + 1, &r->off, lastbit); + if (IS_ERR(str)) + return str; + + if (*str != '/') + return ERR_PTR(-EINVAL); + + return bitmap_getnum(str + 1, &r->group_len, lastbit); + +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 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 + * + * Input format is a comma-separated list of decimal numbers and + * ranges. Consecutively set bits are shown as two hyphen-separated + * decimal numbers, the smallest and largest bit numbers set in + * the range. + * Optionally each range can be postfixed to denote that only parts of it + * should be set. The range will divided to groups of specific size. + * From each group will be used only defined amount of bits. + * Syntax: range:used_size/group_size + * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 + * The value 'N' can be used as a dynamically substituted token for the + * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is + * dynamic, so if system changes cause the bitmap width to change, such + * as more cores in a CPU list, then any ranges using N will also change. + * + * Returns: 0 on success, -errno on invalid input strings. Error values: + * + * - ``-EINVAL``: wrong region format + * - ``-EINVAL``: invalid character in string + * - ``-ERANGE``: bit number specified too large for mask + * - ``-EOVERFLOW``: integer overflow in the input parameters + */ +int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) +{ + struct region r; + long ret; + + r.nbits = nmaskbits; + bitmap_zero(maskp, r.nbits); + + while (buf) { + buf = bitmap_find_region(buf); + if (buf == NULL) + return 0; + + buf = bitmap_parse_region(buf, &r); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_check_region(&r); + if (ret) + return ret; + + bitmap_set_region(&r, maskp); + } + + return 0; +} +EXPORT_SYMBOL(bitmap_parselist); + + +/** + * bitmap_parselist_user() - convert user buffer's list format ASCII + * string to bitmap + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * 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_parselist(), providing it with user buffer. + */ +int bitmap_parselist_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int 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); diff --git a/lib/bitmap.c b/lib/bitmap.c index 935e0f96e785..abc5579768e9 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -6,21 +6,11 @@ #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 @@ -440,508 +430,6 @@ again: } EXPORT_SYMBOL(bitmap_find_next_zero_area_off); -/* - * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, - * second version by Paul Jackson, third by Joe Korty. - */ - -/** - * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap - * - * @ubuf: pointer to user buffer containing string. - * @ulen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0. - * @maskp: pointer to bitmap array that will contain result. - * @nmaskbits: size of bitmap, in bits. - */ -int bitmap_parse_user(const char __user *ubuf, - unsigned int ulen, unsigned long *maskp, - int 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); - -/** - * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string - * @list: indicates whether the bitmap must be list - * @buf: page aligned buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * - * Output format is a comma-separated list of decimal numbers and - * ranges if list is specified or hex digits grouped into comma-separated - * sets of 8 digits/set. Returns the number of characters written to buf. - * - * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned - * area and that sufficient storage remains at @buf to accommodate the - * bitmap_print_to_pagebuf() output. Returns the number of characters - * actually printed to @buf, excluding terminating '\0'. - */ -int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, - int nmaskbits) -{ - ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); - - return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : - scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); -} -EXPORT_SYMBOL(bitmap_print_to_pagebuf); - -/** - * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string - * @list: indicates whether the bitmap must be list - * true: print in decimal list format - * false: print in hexadecimal bitmask format - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - */ -static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - const char *fmt = list ? "%*pbl\n" : "%*pb\n"; - ssize_t size; - void *data; - - data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); - if (!data) - return -ENOMEM; - - size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); - kfree(data); - - return size; -} - -/** - * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper - * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal - * bitmask and decimal list to userspace by sysfs ABI. - * Drivers might be using a normal attribute for this kind of ABIs. A - * normal attribute typically has show entry as below:: - * - * static ssize_t example_attribute_show(struct device *dev, - * struct device_attribute *attr, char *buf) - * { - * ... - * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); - * } - * - * show entry of attribute has no offset and count parameters and this - * means the file is limited to one page only. - * bitmap_print_to_pagebuf() API works terribly well for this kind of - * normal attribute with buf parameter and without offset, count:: - * - * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, - * int nmaskbits) - * { - * } - * - * The problem is once we have a large bitmap, we have a chance to get a - * bitmask or list more than one page. Especially for list, it could be - * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. - * It turns out bin_attribute is a way to break this limit. bin_attribute - * has show entry as below:: - * - * static ssize_t - * example_bin_attribute_show(struct file *filp, struct kobject *kobj, - * struct bin_attribute *attr, char *buf, - * loff_t offset, size_t count) - * { - * ... - * } - * - * With the new offset and count parameters, this makes sysfs ABI be able - * to support file size more than one page. For example, offset could be - * >= 4096. - * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their - * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() - * make those drivers be able to support large bitmask and list after they - * move to use bin_attribute. In result, we have to pass the corresponding - * parameters such as off, count from bin_attribute show entry to this API. - * - * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() - * is similar with cpumap_print_to_pagebuf(), the difference is that - * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption - * the destination buffer is exactly one page and won't be more than one page. - * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other - * hand, mainly serves bin_attribute which doesn't work with exact one page, - * and it can break the size limit of converted decimal list and hexadecimal - * bitmask. - * - * WARNING! - * - * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). - * It is intended to workaround sysfs limitations discussed above and should be - * used carefully in general case for the following reasons: - * - * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). - * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). - * - @off and @count are NOT offset and number of bits to print. - * - If printing part of bitmap as list, the resulting string is not a correct - * list representation of bitmap. Particularly, some bits within or out of - * related interval may be erroneously set or unset. The format of the string - * may be broken, so bitmap_parselist-like parser may fail parsing it. - * - If printing the whole bitmap as list by parts, user must ensure the order - * of calls of the function such that the offset is incremented linearly. - * - If printing the whole bitmap as list by parts, user must keep bitmap - * unchanged between the very first and very last call. Otherwise concatenated - * result may be incorrect, and format may be broken. - * - * Returns the number of characters actually printed to @buf - */ -int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); - -/** - * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * Everything is same with the above bitmap_print_bitmask_to_buf() except - * the print format. - */ -int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_list_to_buf); - -/* - * Region 9-38:4/10 describes the following bitmap structure: - * 0 9 12 18 38 N - * .........****......****......****.................. - * ^ ^ ^ ^ ^ - * start off group_len end nbits - */ -struct region { - unsigned int start; - unsigned int off; - unsigned int group_len; - unsigned int end; - unsigned int nbits; -}; - -static void bitmap_set_region(const struct region *r, unsigned long *bitmap) -{ - unsigned int start; - - for (start = r->start; start <= r->end; start += r->group_len) - bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); -} - -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; - - if (r->end >= r->nbits) - return -ERANGE; - - return 0; -} - -static const char *bitmap_getnum(const char *str, unsigned int *num, - unsigned int lastbit) -{ - unsigned long long n; - unsigned int len; - - if (str[0] == 'N') { - *num = lastbit; - return str + 1; - } - - 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) -{ - unsigned int lastbit = r->nbits - 1; - - if (!strncasecmp(str, "all", 3)) { - r->start = 0; - r->end = lastbit; - str += 3; - - goto check_pattern; - } - - str = bitmap_getnum(str, &r->start, lastbit); - 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, lastbit); - if (IS_ERR(str)) - return str; - -check_pattern: - if (end_of_region(*str)) - goto no_pattern; - - if (*str != ':') - return ERR_PTR(-EINVAL); - - str = bitmap_getnum(str + 1, &r->off, lastbit); - if (IS_ERR(str)) - return str; - - if (*str != '/') - return ERR_PTR(-EINVAL); - - return bitmap_getnum(str + 1, &r->group_len, lastbit); - -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 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 - * - * Input format is a comma-separated list of decimal numbers and - * ranges. Consecutively set bits are shown as two hyphen-separated - * decimal numbers, the smallest and largest bit numbers set in - * the range. - * Optionally each range can be postfixed to denote that only parts of it - * should be set. The range will divided to groups of specific size. - * From each group will be used only defined amount of bits. - * Syntax: range:used_size/group_size - * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 - * The value 'N' can be used as a dynamically substituted token for the - * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is - * dynamic, so if system changes cause the bitmap width to change, such - * as more cores in a CPU list, then any ranges using N will also change. - * - * Returns: 0 on success, -errno on invalid input strings. Error values: - * - * - ``-EINVAL``: wrong region format - * - ``-EINVAL``: invalid character in string - * - ``-ERANGE``: bit number specified too large for mask - * - ``-EOVERFLOW``: integer overflow in the input parameters - */ -int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) -{ - struct region r; - long ret; - - r.nbits = nmaskbits; - bitmap_zero(maskp, r.nbits); - - while (buf) { - buf = bitmap_find_region(buf); - if (buf == NULL) - return 0; - - buf = bitmap_parse_region(buf, &r); - if (IS_ERR(buf)) - return PTR_ERR(buf); - - ret = bitmap_check_region(&r); - if (ret) - return ret; - - bitmap_set_region(&r, maskp); - } - - return 0; -} -EXPORT_SYMBOL(bitmap_parselist); - - -/** - * bitmap_parselist_user() - convert user buffer's list format ASCII - * string to bitmap - * - * @ubuf: pointer to user buffer containing string. - * @ulen: buffer size in bytes. If string is smaller than this - * 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_parselist(), providing it with user buffer. - */ -int bitmap_parselist_user(const char __user *ubuf, - unsigned int ulen, unsigned long *maskp, - int 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); - /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap |