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1 | // vim:shiftwidth=2:expandtab |
2 | #define _GNU_SOURCE |
3 | #include <stdio.h> |
4 | #include <stdlib.h> |
5 | #include <sys/mman.h> |
6 | #include <dlfcn.h> |
7 | #include "header.h" |
8 | |
9 | #define DL |
10 | #include "override.c" |
11 | |
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12 | static void next_line(FILE *f) |
13 | { |
14 | int c; |
15 | do { |
16 | c = fgetc(f); |
17 | } while (c != EOF && c != '\n'); |
18 | } |
19 | |
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20 | __attribute__((constructor)) |
21 | static void ginge_init(void) |
22 | { |
23 | unsigned int lowest_segment = (unsigned int)-1; |
24 | unsigned int start, end; |
25 | int i, ret; |
26 | FILE *f; |
27 | |
28 | for (i = 0; i < ARRAY_SIZE(real_funcs_np); i++) { |
29 | *real_funcs_np[i].func_ptr = dlsym(RTLD_NEXT, real_funcs_np[i].name); |
30 | if (*real_funcs_np[i].func_ptr == NULL) { |
31 | fprintf(stderr, "dlsym %s: %s\n", real_funcs_np[i].name, dlerror()); |
32 | exit(1); |
33 | } |
34 | // dbg("%p %s\n", *real_funcs_np[i].func_ptr, real_funcs_np[i].name); |
35 | } |
36 | |
37 | f = fopen("/proc/self/maps", "r"); |
38 | if (f == NULL) { |
39 | perror("open /proc/self/maps"); |
40 | exit(1); |
41 | } |
42 | |
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43 | ret = fscanf(f, "%x-%x ", &start, &end); |
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44 | if (ret != 2) { |
45 | perror("parse maps"); |
46 | exit(1); |
47 | } |
48 | lowest_segment = start; |
49 | |
50 | // assume first entry lists program's text section. |
51 | // unprotect it in case we need some patching. |
52 | ret = mprotect((void *)start, end - start, PROT_READ|PROT_WRITE|PROT_EXEC); |
53 | if (ret != 0) |
54 | perror("warning: mprotect"); |
55 | |
56 | while (1) { |
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57 | next_line(f); |
58 | |
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59 | ret = fscanf(f, "%x-%*s %*s %*s %*s %*s %*s\n", &start); |
60 | if (ret <= 0) |
61 | break; |
62 | |
63 | if (start < lowest_segment) |
64 | lowest_segment = start; |
65 | } |
66 | |
67 | #if 0 |
68 | rewind(f); |
69 | char buff[256]; |
70 | while (fgets(buff, sizeof(buff), f)) |
71 | fputs(buff, stdout); |
72 | #endif |
73 | fclose(f); |
74 | |
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75 | // remove self from preload, further commands (from system() and such) |
76 | // will be handled by ginge_prep. |
77 | unsetenv("LD_PRELOAD"); |
78 | |
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79 | emu_init((void *)lowest_segment); |
80 | } |
81 | |