1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * This provides an optimized implementation o !! 3 * arch/mips/boot/compressed/string.c
4 * implementation of memset and memmove. These !! 4 *
5 * standard kernel runtime versions are not ye !! 5 * Very small subset of simple string routines
6 * trust the gcc built-in implementations as t <<
7 * (e.g. FPU ops) in the minimal decompression <<
8 */ 6 */
9 #include "error.h" <<
10 7
11 #include "../string.c" !! 8 #include <linux/compiler_attributes.h>
>> 9 #include <linux/types.h>
>> 10 #include <asm/string.h>
12 11
13 #ifdef CONFIG_X86_32 !! 12 void *memcpy(void *dest, const void *src, size_t n)
14 static void *____memcpy(void *dest, const void <<
15 { <<
16 int d0, d1, d2; <<
17 asm volatile( <<
18 "rep ; movsl\n\t" <<
19 "movl %4,%%ecx\n\t" <<
20 "rep ; movsb\n\t" <<
21 : "=&c" (d0), "=&D" (d1), "=&S <<
22 : "" (n >> 2), "g" (n & 3), "1 <<
23 : "memory"); <<
24 <<
25 return dest; <<
26 } <<
27 #else <<
28 static void *____memcpy(void *dest, const void <<
29 { 13 {
30 long d0, d1, d2; !! 14 int i;
31 asm volatile( !! 15 const char *s = src;
32 "rep ; movsq\n\t" !! 16 char *d = dest;
33 "movq %4,%%rcx\n\t" <<
34 "rep ; movsb\n\t" <<
35 : "=&c" (d0), "=&D" (d1), "=&S <<
36 : "" (n >> 3), "g" (n & 7), "1 <<
37 : "memory"); <<
38 17
>> 18 for (i = 0; i < n; i++)
>> 19 d[i] = s[i];
39 return dest; 20 return dest;
40 } 21 }
41 #endif <<
42 22
43 void *memset(void *s, int c, size_t n) 23 void *memset(void *s, int c, size_t n)
44 { 24 {
45 int i; 25 int i;
46 char *ss = s; 26 char *ss = s;
47 27
48 for (i = 0; i < n; i++) 28 for (i = 0; i < n; i++)
49 ss[i] = c; 29 ss[i] = c;
50 return s; 30 return s;
51 } 31 }
52 32
53 void *memmove(void *dest, const void *src, siz !! 33 void * __weak memmove(void *dest, const void *src, size_t n)
54 { 34 {
55 unsigned char *d = dest; !! 35 unsigned int i;
56 const unsigned char *s = src; !! 36 const char *s = src;
57 !! 37 char *d = dest;
58 if (d <= s || d - s >= n) !! 38
59 return ____memcpy(dest, src, n !! 39 if ((uintptr_t)dest < (uintptr_t)src) {
60 !! 40 for (i = 0; i < n; i++)
61 while (n-- > 0) !! 41 d[i] = s[i];
62 d[n] = s[n]; !! 42 } else {
63 !! 43 for (i = n; i > 0; i--)
64 return dest; !! 44 d[i - 1] = s[i - 1];
65 } <<
66 <<
67 /* Detect and warn about potential overlaps, b <<
68 void *memcpy(void *dest, const void *src, size <<
69 { <<
70 if (dest > src && dest - src < n) { <<
71 warn("Avoiding potentially uns <<
72 return memmove(dest, src, n); <<
73 } 45 }
74 return ____memcpy(dest, src, n); !! 46 return dest;
75 } 47 }
76 <<
77 #ifdef CONFIG_KASAN <<
78 extern void *__memset(void *s, int c, size_t n <<
79 extern void *__memmove(void *dest, const void <<
80 extern void *__memcpy(void *dest, const void * <<
81 #endif <<
82 48
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