| 1 | |
| 2 | * linux/lib/cmdline.c
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| 3 | * Helper functions generally used for parsing kernel command line
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| 4 | * and module options.
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| 5 | *
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| 6 | * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
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| 7 | *
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| 8 | * This source code is licensed under the GNU General Public License,
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| 9 | * Version 2. See the file COPYING for more details.
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| 10 | *
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| 11 | * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
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| 12 | *
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| 13 |
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| 14 |
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| 15 | #include <linux/export.h>
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| 16 | #include <linux/kernel.h>
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| 17 | #include <linux/string.h>
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| 18 |
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| 19 | |
| 20 | * If a hyphen was found in get_option, this will handle the
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| 21 | * range of numbers, M-N. This will expand the range and insert
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| 22 | * the values[M, M+1, ..., N] into the ints array in get_options.
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| 23 |
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| 24 |
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| 25 | static int get_range(char **str, int *pint)
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| 26 | {
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| 27 | int x, inc_counter, upper_range;
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| 28 |
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| 29 | (*str)++;
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| 30 | upper_range = simple_strtol((*str), NULL, 0);
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| 31 | inc_counter = upper_range - *pint;
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| 32 | for (x = *pint; x < upper_range; x++)
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| 33 | *pint++ = x;
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| 34 | return inc_counter;
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| 35 | }
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| 36 |
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| 37 | |
| 38 | * get_option - Parse integer from an option string
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| 39 | * @str: option string
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| 40 | * @pint: (output) integer value parsed from @str
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| 41 | *
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| 42 | * Read an int from an option string; if available accept a subsequent
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| 43 | * comma as well.
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| 44 | *
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| 45 | * Return values:
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| 46 | * 0 - no int in string
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| 47 | * 1 - int found, no subsequent comma
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| 48 | * 2 - int found including a subsequent comma
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| 49 | * 3 - hyphen found to denote a range
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| 50 |
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| 51 |
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| 52 | int get_option(char **str, int *pint)
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| 53 | {
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| 54 | char *cur = *str;
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| 55 |
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| 56 | if (!cur || !(*cur))
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| 57 | return 0;
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| 58 | *pint = simple_strtol(cur, str, 0);
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| 59 | if (cur == *str)
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| 60 | return 0;
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| 61 | if (**str == ',') {
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| 62 | (*str)++;
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| 63 | return 2;
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| 64 | }
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| 65 | if (**str == '-')
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| 66 | return 3;
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| 67 |
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| 68 | return 1;
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| 69 | }
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| 70 | EXPORT_SYMBOL(get_option);
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| 71 |
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| 72 | |
| 73 | * get_options - Parse a string into a list of integers
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| 74 | * @str: String to be parsed
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| 75 | * @nints: size of integer array
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| 76 | * @ints: integer array
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| 77 | *
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| 78 | * This function parses a string containing a comma-separated
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| 79 | * list of integers, a hyphen-separated range of _positive_ integers,
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| 80 | * or a combination of both. The parse halts when the array is
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| 81 | * full, or when no more numbers can be retrieved from the
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| 82 | * string.
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| 83 | *
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| 84 | * Return value is the character in the string which caused
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| 85 | * the parse to end (typically a null terminator, if @str is
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| 86 | * completely parseable).
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| 87 |
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| 88 |
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| 89 | char *get_options(const char *str, int nints, int *ints)
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| 90 | {
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| 91 | int res, i = 1;
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| 92 |
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| 93 | while (i < nints) {
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| 94 | res = get_option((char **)&str, ints + i);
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| 95 | if (res == 0)
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| 96 | break;
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| 97 | if (res == 3) {
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| 98 | int range_nums;
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| 99 | range_nums = get_range((char **)&str, ints + i);
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| 100 | if (range_nums < 0)
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| 101 | break;
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| 102 | |
| 103 | * Decrement the result by one to leave out the
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| 104 | * last number in the range. The next iteration
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| 105 | * will handle the upper number in the range
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| 106 |
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| 107 | i += (range_nums - 1);
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| 108 | }
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| 109 | i++;
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| 110 | if (res == 1)
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| 111 | break;
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| 112 | }
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| 113 | ints[0] = i - 1;
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| 114 | return (char *)str;
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| 115 | }
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| 116 | EXPORT_SYMBOL(get_options);
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| 117 |
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| 118 | |
| 119 | * memparse - parse a string with mem suffixes into a number
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| 120 | * @ptr: Where parse begins
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| 121 | * @retptr: (output) Optional pointer to next char after parse completes
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| 122 | *
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| 123 | * Parses a string into a number. The number stored at @ptr is
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| 124 | * potentially suffixed with K, M, G, T, P, E.
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| 125 |
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| 126 |
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| 127 | unsigned long long memparse(const char *ptr, char **retptr)
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| 128 | {
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| 129 | char *endptr;
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| 130 |
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| 131 | unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
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| 132 |
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| 133 | switch (*endptr) {
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| 134 | case 'E':
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| 135 | case 'e':
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| 136 | ret <<= 10;
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| 137 | case 'P':
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| 138 | case 'p':
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| 139 | ret <<= 10;
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| 140 | case 'T':
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| 141 | case 't':
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| 142 | ret <<= 10;
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| 143 | case 'G':
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| 144 | case 'g':
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| 145 | ret <<= 10;
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| 146 | case 'M':
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| 147 | case 'm':
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| 148 | ret <<= 10;
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| 149 | case 'K':
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| 150 | case 'k':
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| 151 | ret <<= 10;
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| 152 | endptr++;
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| 153 | default:
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| 154 | break;
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| 155 | }
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| 156 |
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| 157 | if (retptr)
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| 158 | *retptr = endptr;
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| 159 |
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| 160 | return ret;
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| 161 | }
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| 162 | EXPORT_SYMBOL(memparse);
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| 163 |
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| 164 | |
| 165 | * parse_option_str - Parse a string and check an option is set or not
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| 166 | * @str: String to be parsed
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| 167 | * @option: option name
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| 168 | *
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| 169 | * This function parses a string containing a comma-separated list of
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| 170 | * strings like a=b,c.
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| 171 | *
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| 172 | * Return true if there's such option in the string, or return false.
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| 173 |
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| 174 | bool parse_option_str(const char *str, const char *option)
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| 175 | {
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| 176 | while (*str) {
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| 177 | if (!strncmp(str, option, strlen(option))) {
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| 178 | str += strlen(option);
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| 179 | if (!*str || *str == ',')
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| 180 | return true;
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| 181 | }
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| 182 |
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| 183 | while (*str && *str != ',')
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| 184 | str++;
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| 185 |
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| 186 | if (*str == ',')
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| 187 | str++;
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| 188 | }
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| 189 |
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| 190 | return false;
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| 191 | }
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