xref: /linux/arch/s390/boot/string.c (revision 955abe0a1b41de5ba61fe4cd614ebc123084d499)
1 // SPDX-License-Identifier: GPL-2.0
2 #define IN_BOOT_STRING_C 1
3 #include <linux/ctype.h>
4 #include <linux/kernel.h>
5 #include <linux/errno.h>
6 #undef CONFIG_KASAN
7 #undef CONFIG_KASAN_GENERIC
8 #undef CONFIG_KMSAN
9 #include "../lib/string.c"
10 
11 /*
12  * Duplicate some functions from the common lib/string.c
13  * instead of fully including it.
14  */
15 
16 int strncmp(const char *cs, const char *ct, size_t count)
17 {
18 	unsigned char c1, c2;
19 
20 	while (count) {
21 		c1 = *cs++;
22 		c2 = *ct++;
23 		if (c1 != c2)
24 			return c1 < c2 ? -1 : 1;
25 		if (!c1)
26 			break;
27 		count--;
28 	}
29 	return 0;
30 }
31 
32 void *memset64(uint64_t *s, uint64_t v, size_t count)
33 {
34 	uint64_t *xs = s;
35 
36 	while (count--)
37 		*xs++ = v;
38 	return s;
39 }
40 
41 char *skip_spaces(const char *str)
42 {
43 	while (isspace(*str))
44 		++str;
45 	return (char *)str;
46 }
47 
48 char *strim(char *s)
49 {
50 	size_t size;
51 	char *end;
52 
53 	size = strlen(s);
54 	if (!size)
55 		return s;
56 
57 	end = s + size - 1;
58 	while (end >= s && isspace(*end))
59 		end--;
60 	*(end + 1) = '\0';
61 
62 	return skip_spaces(s);
63 }
64 
65 /* Works only for digits and letters, but small and fast */
66 #define TOLOWER(x) ((x) | 0x20)
67 
68 static unsigned int simple_guess_base(const char *cp)
69 {
70 	if (cp[0] == '0') {
71 		if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
72 			return 16;
73 		else
74 			return 8;
75 	} else {
76 		return 10;
77 	}
78 }
79 
80 /**
81  * simple_strtoull - convert a string to an unsigned long long
82  * @cp: The start of the string
83  * @endp: A pointer to the end of the parsed string will be placed here
84  * @base: The number base to use
85  */
86 
87 unsigned long long simple_strtoull(const char *cp, char **endp,
88 				   unsigned int base)
89 {
90 	unsigned long long result = 0;
91 
92 	if (!base)
93 		base = simple_guess_base(cp);
94 
95 	if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
96 		cp += 2;
97 
98 	while (isxdigit(*cp)) {
99 		unsigned int value;
100 
101 		value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
102 		if (value >= base)
103 			break;
104 		result = result * base + value;
105 		cp++;
106 	}
107 	if (endp)
108 		*endp = (char *)cp;
109 
110 	return result;
111 }
112 
113 long simple_strtol(const char *cp, char **endp, unsigned int base)
114 {
115 	if (*cp == '-')
116 		return -simple_strtoull(cp + 1, endp, base);
117 
118 	return simple_strtoull(cp, endp, base);
119 }
120 
121 int kstrtobool(const char *s, bool *res)
122 {
123 	if (!s)
124 		return -EINVAL;
125 
126 	switch (s[0]) {
127 	case 'y':
128 	case 'Y':
129 	case '1':
130 		*res = true;
131 		return 0;
132 	case 'n':
133 	case 'N':
134 	case '0':
135 		*res = false;
136 		return 0;
137 	case 'o':
138 	case 'O':
139 		switch (s[1]) {
140 		case 'n':
141 		case 'N':
142 			*res = true;
143 			return 0;
144 		case 'f':
145 		case 'F':
146 			*res = false;
147 			return 0;
148 		default:
149 			break;
150 		}
151 	default:
152 		break;
153 	}
154 
155 	return -EINVAL;
156 }
157