11913091 |
1 | // vim:shiftwidth=2:expandtab |
2 | #include <stdio.h> |
3 | #include <string.h> |
4 | #include <sys/types.h> |
5 | #include <sys/stat.h> |
6 | #include <fcntl.h> |
7 | #include <sys/mman.h> |
8 | |
9 | #include "header.h" |
10 | #include "sys_cacheflush.h" |
11 | |
12 | static const unsigned int sig_open[] = { |
13 | 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900005 |
14 | }; |
15 | |
16 | static const unsigned int sig_mmap[] = { |
17 | 0xe92d000f, 0xe1a0000d, 0xef90005a, 0xe28dd010 |
18 | }; |
19 | |
20 | static const unsigned int sig_mmap_[] = { |
21 | 0xe52d5004, 0xe59d5008, 0xe52d4004, 0xe59d4008, |
22 | 0xe1b0ca05, 0x1a000006, 0xe1a05625, 0xef9000c0 |
23 | }; |
24 | |
25 | #define FAKE_DEVMEM_DEVICE 10001 |
26 | |
27 | static int w_open(const char *pathname, int flags, mode_t mode) |
28 | { |
29 | int ret; |
30 | if (strcmp(pathname, "/dev/mem") != 0) |
31 | ret = open(pathname, flags, mode); |
32 | else |
33 | ret = FAKE_DEVMEM_DEVICE; |
34 | |
35 | printf("open(%s) = %d\n", pathname, ret); |
36 | return ret; |
37 | } |
38 | |
39 | static void *w_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) |
40 | { |
41 | void *ret; |
42 | if (fd != FAKE_DEVMEM_DEVICE) |
43 | ret = mmap(addr, length, prot, flags, fd, offset); |
44 | else |
45 | ret = emu_mmap_dev(length, prot, flags, offset); |
46 | |
47 | printf("mmap(%p, %x, %x, %x, %d, %lx) = %p\n", addr, length, prot, flags, fd, (long)offset, ret); |
48 | return ret; |
49 | } |
50 | #define w_mmap_ w_mmap |
51 | |
52 | #define PATCH(f) { sig_##f, ARRAY_SIZE(sig_##f), w_##f } |
53 | |
54 | static const struct { |
55 | const unsigned int *sig; |
56 | size_t sig_cnt; |
57 | void *func; |
58 | } patches[] = { |
59 | PATCH(open), |
60 | PATCH(mmap), |
61 | PATCH(mmap_), // mmap using mmap2 syscall |
62 | }; |
63 | |
64 | void do_patches(void *ptr, unsigned int size) |
65 | { |
66 | int i, s; |
67 | |
68 | for (i = 0; i < ARRAY_SIZE(patches); i++) { |
69 | const unsigned int *sig = patches[i].sig; |
70 | unsigned int *seg = (void *)(((long)ptr + 3) & ~3); |
71 | unsigned int *seg_end = seg + size / 4; |
72 | unsigned int sig0 = sig[0]; |
73 | |
74 | for (; seg < seg_end; seg++) { |
75 | if (*seg != sig0) |
76 | continue; |
77 | |
78 | for (s = 1; s < patches[i].sig_cnt; s++) |
79 | if (seg[s] != sig[s]) |
80 | break; |
81 | |
82 | if (s == patches[i].sig_cnt) |
83 | goto found; |
84 | } |
85 | continue; |
86 | |
87 | found: |
88 | printf(" patch #%i @ %08x\n", i, (int)seg); |
89 | seg[0] = 0xe59ff000; // ldr pc, [pc] |
90 | seg[1] = 0; |
91 | seg[2] = (unsigned int)patches[i].func; |
92 | } |
93 | |
94 | sys_cacheflush(ptr, (char *)ptr + size); |
95 | } |
96 | |