55fe8e70 |
1 | // vim:shiftwidth=2:expandtab |
2 | #include <stdio.h> |
3 | #include <stdlib.h> |
4 | #include <string.h> |
5 | #include <elf.h> |
6 | #include <sys/mman.h> |
7 | |
11913091 |
8 | #include "header.h" |
7fd42181 |
9 | #include "realfuncs.h" |
11913091 |
10 | |
55fe8e70 |
11 | #define CHECK_(val, fail_operator, expect, err_msg) \ |
12 | if (val fail_operator expect) { \ |
13 | fprintf(stderr, err_msg ", exiting (%d)\n", (int)(long)val); \ |
14 | return 1; \ |
15 | } |
16 | |
17 | #define CHECK_EQ(val, expect, err_msg) \ |
18 | CHECK_(val, !=, expect, err_msg) |
19 | |
20 | #define CHECK_NE(val, expect, err_msg) \ |
21 | CHECK_(val, ==, expect, err_msg) |
22 | |
23 | #define HDR_CHECK_EQ(field, expect, err_msg) \ |
24 | CHECK_(hdr.field, !=, expect, err_msg) |
25 | |
26 | #define HDR_CHECK_NE(field, expect, err_msg) \ |
27 | CHECK_(hdr.field, ==, expect, err_msg) |
28 | |
29 | #define FAIL_PERROR(msg) { \ |
30 | perror(msg); \ |
31 | return 1; \ |
32 | } |
33 | |
55fe8e70 |
34 | typedef struct { |
35 | unsigned long start; |
36 | unsigned long end; |
37 | } maps_range; |
38 | |
39 | static int is_range_used(maps_range *maps, int map_cnt, unsigned long start, unsigned long end) |
40 | { |
41 | int i; |
42 | for (i = 0; i < map_cnt; i++) { |
43 | if (maps[i].end <= start) |
44 | continue; |
45 | if (end <= maps[i].start) |
46 | continue; |
47 | |
48 | return i + 1; |
49 | } |
50 | |
51 | return 0; |
52 | } |
53 | |
54 | extern char **environ; |
55fe8e70 |
55 | |
56 | int main(int argc, char *argv[]) |
57 | { |
11913091 |
58 | void *lowest_segment = (void *)-1; |
55fe8e70 |
59 | Elf32_Ehdr hdr; |
60 | Elf32_Phdr *phdr; |
61 | FILE *fi; |
62 | maps_range maps[16]; |
63 | int map_cnt; |
306e06f7 |
64 | int i, ret, envc, sfp; |
65 | long *stack_frame; |
55fe8e70 |
66 | |
306e06f7 |
67 | if (argc < 2) { |
68 | fprintf(stderr, "usage: %s <program> [args]\n", argv[0]); |
55fe8e70 |
69 | return 1; |
70 | } |
71 | |
72 | fi = fopen("/proc/self/maps", "r"); |
73 | CHECK_NE(fi, NULL, "fopen maps"); |
74 | |
75 | for (i = 0; i < ARRAY_SIZE(maps); i++) { |
76 | ret = fscanf(fi, "%lx-%lx %*s %*s %*s %*s %*s\n", &maps[i].start, &maps[i].end); |
7fd42181 |
77 | if (ret <= 0) |
55fe8e70 |
78 | break; |
79 | CHECK_EQ(ret, 2, "maps parse error"); |
80 | } |
81 | fclose(fi); |
82 | map_cnt = i; |
83 | CHECK_NE(map_cnt, 0, "no maps"); |
84 | CHECK_NE(map_cnt, ARRAY_SIZE(maps), "too many maps"); |
85 | |
86 | fi = fopen(argv[1], "rb"); |
87 | if (fi == NULL) |
88 | FAIL_PERROR("fopen"); |
89 | |
90 | if (fread(&hdr, 1, sizeof(hdr), fi) != sizeof(hdr)) |
91 | FAIL_PERROR("too small or"); |
92 | |
93 | if (memcmp(hdr.e_ident, ELFMAG "\x01\x01", SELFMAG + 2) != 0) { |
94 | fprintf(stderr, "not 32bit LE ELF?\n"); |
95 | return 1; |
96 | } |
97 | |
98 | HDR_CHECK_EQ(e_type, ET_EXEC, "not executable"); |
306e06f7 |
99 | HDR_CHECK_EQ(e_machine, EM_ARM, "not ARM"); |
55fe8e70 |
100 | HDR_CHECK_EQ(e_phentsize, sizeof(Elf32_Phdr), "bad PH entry size"); |
101 | HDR_CHECK_NE(e_phnum, 0, "no PH entries"); |
102 | |
103 | phdr = malloc(hdr.e_phnum * hdr.e_phentsize); |
104 | CHECK_NE(phdr, NULL, "OOM"); |
105 | |
106 | if (fread(phdr, hdr.e_phentsize, hdr.e_phnum, fi) != hdr.e_phnum) |
107 | FAIL_PERROR("too small or"); |
108 | |
109 | for (i = 0; i < hdr.e_phnum; i++) { |
110 | Elf32_Addr end_addr = phdr[i].p_vaddr + phdr[i].p_memsz; |
111 | Elf32_Addr align; |
112 | void *ptr, *map_ptr; |
113 | |
114 | if (phdr[i].p_type == PT_NOTE) |
115 | continue; |
116 | if (phdr[i].p_type != PT_LOAD) { |
117 | fprintf(stderr, "skipping section %d\n", phdr[i].p_type); |
118 | continue; |
119 | } |
120 | |
121 | ret = is_range_used(maps, map_cnt, phdr[i].p_vaddr, end_addr); |
122 | if (ret) { |
123 | fprintf(stderr, "segment %d (%08x-%08x) hits %08lx-%08lx in maps\n", |
124 | i, phdr[i].p_vaddr, end_addr, maps[ret - 1].start, maps[ret - 1].end); |
125 | return 1; |
126 | } |
127 | |
4d045184 |
128 | log("load %d %08x-%08x from %08x\n", phdr[i].p_type, |
55fe8e70 |
129 | phdr[i].p_vaddr, end_addr, phdr[i].p_offset); |
130 | |
131 | align = phdr[i].p_vaddr & 0xfff; |
132 | map_ptr = (void *)(phdr[i].p_vaddr - align); |
133 | ptr = mmap(map_ptr, phdr[i].p_memsz + align, PROT_READ|PROT_WRITE|PROT_EXEC, |
134 | MAP_FIXED|MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
135 | if (ptr == MAP_FAILED || ptr != map_ptr) |
136 | FAIL_PERROR("mmap"); |
137 | |
138 | if (phdr[i].p_filesz > 0) { |
139 | if (fseek(fi, phdr[i].p_offset, SEEK_SET) != 0) |
140 | FAIL_PERROR("fseek"); |
141 | if (fread((char *)ptr + align, 1, phdr[i].p_filesz, fi) != phdr[i].p_filesz) |
142 | FAIL_PERROR("too small or"); |
11913091 |
143 | |
144 | if (phdr[i].p_flags & PF_X) |
145 | do_patches((char *)ptr + align, phdr[i].p_filesz); |
55fe8e70 |
146 | } |
11913091 |
147 | |
148 | if (map_ptr < lowest_segment) |
149 | lowest_segment = map_ptr; |
55fe8e70 |
150 | } |
151 | |
11913091 |
152 | emu_init(lowest_segment); |
153 | |
306e06f7 |
154 | // generate stack frame: argc, argv[], NULL, env[], NULL |
155 | for (envc = 0; environ[envc] != NULL; envc++) |
156 | ; |
55fe8e70 |
157 | |
306e06f7 |
158 | stack_frame = calloc(argc + envc + 3, sizeof(stack_frame[0])); |
159 | if (stack_frame == NULL) { |
160 | fprintf(stderr, "stack_frame OOM\n"); |
161 | return 1; |
162 | } |
55fe8e70 |
163 | |
306e06f7 |
164 | sfp = 0; |
165 | stack_frame[sfp++] = argc - 1; |
166 | for (i = 1; i < argc; i++) |
167 | stack_frame[sfp++] = (long)argv[i]; |
168 | stack_frame[sfp++] = 0; |
169 | for (i = 0; i < envc; i++) |
170 | stack_frame[sfp++] = (long)environ[i]; |
171 | stack_frame[sfp++] = 0; |
172 | |
4d045184 |
173 | log("entering %08x, %d stack entries\n", hdr.e_entry, sfp); |
306e06f7 |
174 | do_entry(hdr.e_entry, stack_frame, sfp, NULL); |
175 | |
176 | fprintf(stderr, "do_entry failed!\n"); |
177 | return 1; |
55fe8e70 |
178 | } |
179 | |