| 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 | #include <unistd.h> |
| 9 | #include <sys/ioctl.h> |
| 10 | |
| 11 | #include "header.h" |
| 12 | #include "sys_cacheflush.h" |
| 13 | |
| 14 | #if 0 |
| 15 | #define strace printf |
| 16 | #else |
| 17 | #define strace(...) |
| 18 | #endif |
| 19 | |
| 20 | // note: first mask must be always full for search algo |
| 21 | static const unsigned int sig_mask_all[] = { |
| 22 | 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, |
| 23 | 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff |
| 24 | }; |
| 25 | |
| 26 | static const unsigned int sig_open[] = { |
| 27 | 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900005 |
| 28 | }; |
| 29 | #define sig_mask_open sig_mask_all |
| 30 | |
| 31 | static const unsigned int sig_mmap[] = { |
| 32 | 0xe92d000f, 0xe1a0000d, 0xef90005a, 0xe28dd010 |
| 33 | }; |
| 34 | #define sig_mask_mmap sig_mask_all |
| 35 | |
| 36 | static const unsigned int sig_mmap_[] = { |
| 37 | 0xe52d5004, 0xe59d5008, 0xe52d4004, 0xe59d4008, |
| 38 | 0xe1b0ca05, 0x1a000006, 0xe1a05625, 0xef9000c0 |
| 39 | }; |
| 40 | #define sig_mask_mmap_ sig_mask_all |
| 41 | |
| 42 | static const unsigned int sig_read[] = { |
| 43 | 0xe59fc080, 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900003 |
| 44 | }; |
| 45 | #define sig_mask_read sig_mask_all |
| 46 | |
| 47 | static const unsigned int sig_ioctl[] = { |
| 48 | 0xef900036, 0xe3700a01, 0x312fff1e |
| 49 | }; |
| 50 | #define sig_mask_ioctl sig_mask_all |
| 51 | |
| 52 | static const unsigned int sig_sigaction[] = { |
| 53 | 0xe59f300c, 0xe3530000, 0x0a000000, 0xea000000, 0xea000000 |
| 54 | }; |
| 55 | static const unsigned int sig_mask_sigaction[] = { |
| 56 | 0xffffffff, 0xffffffff, 0xffffffff, 0xff000000, 0xff000000 |
| 57 | }; |
| 58 | |
| 59 | static const struct dev_fd_t takeover_devs[] = { |
| 60 | { "/dev/mem", FAKEDEV_MEM }, |
| 61 | { "/dev/GPIO", FAKEDEV_GPIO }, |
| 62 | { "/dev/fb0", FAKEDEV_FB0 }, |
| 63 | { "/dev/fb/0", FAKEDEV_FB0 }, |
| 64 | { "/dev/fb1", FAKEDEV_FB1 }, |
| 65 | { "/dev/fb/1", FAKEDEV_FB1 }, |
| 66 | { "/dev/mmuhack", FAKEDEV_MMUHACK }, |
| 67 | }; |
| 68 | |
| 69 | static int w_open(const char *pathname, int flags, mode_t mode) |
| 70 | { |
| 71 | int i, ret; |
| 72 | |
| 73 | for (i = 0; i < ARRAY_SIZE(takeover_devs); i++) { |
| 74 | if (strcmp(pathname, takeover_devs[i].name) == 0) { |
| 75 | ret = takeover_devs[i].fd; |
| 76 | break; |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | if (i == ARRAY_SIZE(takeover_devs)) |
| 81 | ret = open(pathname, flags, mode); |
| 82 | |
| 83 | if (ret >= 0) { |
| 84 | for (i = 0; emu_interesting_fds[i].name != NULL; i++) { |
| 85 | if (strcmp(pathname, emu_interesting_fds[i].name) == 0) { |
| 86 | emu_interesting_fds[i].fd = ret; |
| 87 | break; |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | strace("open(%s) = %d\n", pathname, ret); |
| 93 | return ret; |
| 94 | } |
| 95 | |
| 96 | static void *w_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) |
| 97 | { |
| 98 | void *ret; |
| 99 | if (FAKEDEV_MEM <= fd && fd < FAKEDEV_FD_BOUNDARY) |
| 100 | ret = emu_do_mmap(length, prot, flags, fd, offset); |
| 101 | else |
| 102 | ret = mmap(addr, length, prot, flags, fd, offset); |
| 103 | |
| 104 | // threads are using heap before they mmap their stack |
| 105 | // printf needs valid stack for pthtead/errno |
| 106 | if (((long)&ret & 0xf0000000) == 0xb0000000) |
| 107 | strace("mmap(%p, %x, %x, %x, %d, %lx) = %p\n", addr, length, prot, flags, fd, (long)offset, ret); |
| 108 | return ret; |
| 109 | } |
| 110 | #define w_mmap_ w_mmap |
| 111 | |
| 112 | static ssize_t w_read(int fd, void *buf, size_t count) |
| 113 | { |
| 114 | ssize_t ret; |
| 115 | if (fd != FAKEDEV_GPIO) |
| 116 | return read(fd, buf, count); |
| 117 | |
| 118 | ret = emu_read_gpiodev(buf, count); |
| 119 | //strace("read(%d, %p, %d) = %d\n", fd, buf, count, ret); |
| 120 | return ret; |
| 121 | } |
| 122 | |
| 123 | static int w_ioctl(int fd, int request, void *argp) |
| 124 | { |
| 125 | int ret; |
| 126 | |
| 127 | if ((FAKEDEV_MEM <= fd && fd < FAKEDEV_FD_BOUNDARY) || |
| 128 | fd == emu_interesting_fds[IFD_SOUND].fd) |
| 129 | ret = emu_do_ioctl(fd, request, argp); |
| 130 | else |
| 131 | ret = ioctl(fd, request, argp); |
| 132 | |
| 133 | strace("ioctl(%d, %08x, %p) = %d\n", fd, request, argp, ret); |
| 134 | return ret; |
| 135 | } |
| 136 | |
| 137 | static int w_sigaction(int signum, const void *act, void *oldact) |
| 138 | { |
| 139 | strace("sigaction(%d, %p, %p) = %d\n", signum, act, oldact, 0); |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | #define PATCH(f) { sig_##f, sig_mask_##f, ARRAY_SIZE(sig_##f), w_##f } |
| 144 | |
| 145 | static const struct { |
| 146 | const unsigned int *sig; |
| 147 | const unsigned int *sig_mask; |
| 148 | size_t sig_cnt; |
| 149 | void *func; |
| 150 | } patches[] = { |
| 151 | PATCH(open), |
| 152 | PATCH(mmap), |
| 153 | PATCH(mmap_), // mmap using mmap2 syscall |
| 154 | PATCH(read), |
| 155 | PATCH(ioctl), |
| 156 | PATCH(sigaction), |
| 157 | }; |
| 158 | |
| 159 | void do_patches(void *ptr, unsigned int size) |
| 160 | { |
| 161 | int i, s; |
| 162 | |
| 163 | for (i = 0; i < ARRAY_SIZE(patches); i++) { |
| 164 | const unsigned int *sig = patches[i].sig; |
| 165 | const unsigned int *sig_mask = patches[i].sig_mask; |
| 166 | unsigned int *seg = (void *)(((long)ptr + 3) & ~3); |
| 167 | unsigned int *seg_end = seg + size / 4; |
| 168 | unsigned int sig0 = sig[0]; |
| 169 | |
| 170 | for (; seg < seg_end; seg++) { |
| 171 | if (*seg != sig0) |
| 172 | continue; |
| 173 | |
| 174 | for (s = 1; s < patches[i].sig_cnt; s++) |
| 175 | if ((seg[s] ^ sig[s]) & sig_mask[s]) |
| 176 | break; |
| 177 | |
| 178 | if (s == patches[i].sig_cnt) |
| 179 | goto found; |
| 180 | } |
| 181 | continue; |
| 182 | |
| 183 | found: |
| 184 | dbg(" patch #%i @ %08x\n", i, (int)seg); |
| 185 | seg[0] = 0xe59ff000; // ldr pc, [pc] |
| 186 | seg[1] = 0; |
| 187 | seg[2] = (unsigned int)patches[i].func; |
| 188 | } |
| 189 | |
| 190 | sys_cacheflush(ptr, (char *)ptr + size); |
| 191 | } |
| 192 | |