| 1 | // vim:shiftwidth=2:expandtab |
| 2 | #include <stdio.h> |
| 3 | |
| 4 | #include "header.h" |
| 5 | #include "sys_cacheflush.h" |
| 6 | |
| 7 | #include "override.c" |
| 8 | |
| 9 | // note: first mask must be always full for search algo |
| 10 | static const unsigned int sig_mask_all[] = { |
| 11 | 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, |
| 12 | 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff |
| 13 | }; |
| 14 | |
| 15 | static const unsigned int sig_open[] = { |
| 16 | 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900005 |
| 17 | }; |
| 18 | #define sig_mask_open sig_mask_all |
| 19 | |
| 20 | static const unsigned int sig_mmap[] = { |
| 21 | 0xe92d000f, 0xe1a0000d, 0xef90005a, 0xe28dd010 |
| 22 | }; |
| 23 | #define sig_mask_mmap sig_mask_all |
| 24 | |
| 25 | static const unsigned int sig_mmap2[] = { |
| 26 | 0xe52d5004, 0xe59d5008, 0xe52d4004, 0xe59d4008, |
| 27 | 0xe1b0ca05, 0x1a000006, 0xe1a05625, 0xef9000c0 |
| 28 | }; |
| 29 | #define sig_mask_mmap2 sig_mask_all |
| 30 | |
| 31 | static const unsigned int sig_read[] = { |
| 32 | 0xe59fc080, 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900003 |
| 33 | }; |
| 34 | #define sig_mask_read sig_mask_all |
| 35 | |
| 36 | static const unsigned int sig_ioctl[] = { |
| 37 | 0xef900036, 0xe3700a01, 0x312fff1e |
| 38 | }; |
| 39 | #define sig_mask_ioctl sig_mask_all |
| 40 | |
| 41 | static const unsigned int sig_sigaction[] = { |
| 42 | 0xe59f300c, 0xe3530000, 0x0a000000, 0xea000000, 0xea000000 |
| 43 | }; |
| 44 | static const unsigned int sig_mask_sigaction[] = { |
| 45 | 0xffffffff, 0xffffffff, 0xffffffff, 0xff000000, 0xff000000 |
| 46 | }; |
| 47 | |
| 48 | static const unsigned int sig_execve[] = { |
| 49 | 0xef90000b, 0xe1a04000, 0xe3700a01 |
| 50 | }; |
| 51 | #define sig_mask_execve sig_mask_all |
| 52 | |
| 53 | static const unsigned int sig_execve2[] = { |
| 54 | 0xef90000b, 0xe3700a01, 0xe1a04000 |
| 55 | }; |
| 56 | #define sig_mask_execve2 sig_mask_all |
| 57 | |
| 58 | static const unsigned int sig_chdir[] = { |
| 59 | 0xef90000c, 0xe3700a01, 0x312fff1e, 0xea0004bb |
| 60 | }; |
| 61 | static const unsigned int sig_mask_chdir[] = { |
| 62 | 0xffffffff, 0xffffffff, 0xffffffff, 0xff000000 |
| 63 | }; |
| 64 | |
| 65 | #define PATCH_(f,p) { sig_##p, sig_mask_##p, ARRAY_SIZE(sig_##p), w_##f } |
| 66 | #define PATCH(f) PATCH_(f,f) |
| 67 | |
| 68 | static const struct { |
| 69 | const unsigned int *sig; |
| 70 | const unsigned int *sig_mask; |
| 71 | size_t sig_cnt; |
| 72 | void *func; |
| 73 | } patches[] = { |
| 74 | PATCH(open), |
| 75 | PATCH(mmap), |
| 76 | PATCH(mmap2), // mmap2 syscall |
| 77 | PATCH(read), |
| 78 | PATCH(ioctl), |
| 79 | PATCH(sigaction), |
| 80 | // PATCH_(execve, execve2), // hangs |
| 81 | PATCH(chdir), |
| 82 | }; |
| 83 | |
| 84 | void do_patches(void *ptr, unsigned int size) |
| 85 | { |
| 86 | int i, s; |
| 87 | |
| 88 | for (i = 0; i < ARRAY_SIZE(patches); i++) { |
| 89 | const unsigned int *sig = patches[i].sig; |
| 90 | const unsigned int *sig_mask = patches[i].sig_mask; |
| 91 | unsigned int *seg = (void *)(((long)ptr + 3) & ~3); |
| 92 | unsigned int *seg_end = seg + size / 4; |
| 93 | unsigned int sig0 = sig[0]; |
| 94 | |
| 95 | for (; seg < seg_end; seg++) { |
| 96 | if (*seg != sig0) |
| 97 | continue; |
| 98 | |
| 99 | for (s = 1; s < patches[i].sig_cnt; s++) |
| 100 | if ((seg[s] ^ sig[s]) & sig_mask[s]) |
| 101 | break; |
| 102 | |
| 103 | if (s == patches[i].sig_cnt) |
| 104 | goto found; |
| 105 | } |
| 106 | continue; |
| 107 | |
| 108 | found: |
| 109 | dbg(" patch #%i @ %08x\n", i, (int)seg); |
| 110 | seg[0] = 0xe59ff000; // ldr pc, [pc] |
| 111 | seg[1] = 0; |
| 112 | seg[2] = (unsigned int)patches[i].func; |
| 113 | } |
| 114 | |
| 115 | sys_cacheflush(ptr, (char *)ptr + size); |
| 116 | } |
| 117 | |