1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/efi.h>
4 #include <asm/efi.h>
5 #include <asm/string.h>
6
7 #include "efistub.h"
8
9 #ifdef CONFIG_KASAN
10 #undef memcpy
11 #undef memmove
12 #undef memset
13 void *__memcpy(void *__dest, const void *__src, size_t __n) __alias(memcpy);
14 void *__memmove(void *__dest, const void *__src, size_t count) __alias(memmove);
15 void *__memset(void *s, int c, size_t count) __alias(memset);
16 #endif
17
efistub_memmove(u8 * dst,const u8 * src,size_t len)18 static void *efistub_memmove(u8 *dst, const u8 *src, size_t len)
19 {
20 if (src > dst || dst >= (src + len))
21 for (size_t i = 0; i < len; i++)
22 dst[i] = src[i];
23 else
24 for (ssize_t i = len - 1; i >= 0; i--)
25 dst[i] = src[i];
26
27 return dst;
28 }
29
efistub_memset(void * dst,int c,size_t len)30 static void *efistub_memset(void *dst, int c, size_t len)
31 {
32 for (u8 *d = dst; len--; d++)
33 *d = c;
34
35 return dst;
36 }
37
memcpy(void * dst,const void * src,size_t len)38 void *memcpy(void *dst, const void *src, size_t len)
39 {
40 if (efi_table_attr(efi_system_table, boottime) == NULL)
41 return efistub_memmove(dst, src, len);
42
43 efi_bs_call(copy_mem, dst, src, len);
44 return dst;
45 }
46
47 extern void *memmove(void *dst, const void *src, size_t len) __alias(memcpy);
48
memset(void * dst,int c,size_t len)49 void *memset(void *dst, int c, size_t len)
50 {
51 if (efi_table_attr(efi_system_table, boottime) == NULL)
52 return efistub_memset(dst, c, len);
53
54 efi_bs_call(set_mem, dst, len, c & U8_MAX);
55 return dst;
56 }
57
58 /**
59 * memcmp - Compare two areas of memory
60 * @cs: One area of memory
61 * @ct: Another area of memory
62 * @count: The size of the area.
63 */
64 #undef memcmp
memcmp(const void * cs,const void * ct,size_t count)65 int memcmp(const void *cs, const void *ct, size_t count)
66 {
67 const unsigned char *su1, *su2;
68 int res = 0;
69
70 for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
71 if ((res = *su1 - *su2) != 0)
72 break;
73 return res;
74 }
75