Rev 2996 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
2995 | svoboda | 1 | /* |
2 | * Copyright (c) 2008 Jiri Svoboda |
||
3 | * All rights reserved. |
||
4 | * |
||
5 | * Redistribution and use in source and binary forms, with or without |
||
6 | * modification, are permitted provided that the following conditions |
||
7 | * are met: |
||
8 | * |
||
9 | * - Redistributions of source code must retain the above copyright |
||
10 | * notice, this list of conditions and the following disclaimer. |
||
11 | * - Redistributions in binary form must reproduce the above copyright |
||
12 | * notice, this list of conditions and the following disclaimer in the |
||
13 | * documentation and/or other materials provided with the distribution. |
||
14 | * - The name of the author may not be used to endorse or promote products |
||
15 | * derived from this software without specific prior written permission. |
||
16 | * |
||
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
||
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
||
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
||
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
||
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
||
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
||
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
||
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
||
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
||
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
27 | */ |
||
28 | |||
29 | /** @addtogroup rtld rtld |
||
30 | * @brief |
||
31 | * @{ |
||
32 | */ |
||
33 | /** |
||
34 | * @file |
||
35 | */ |
||
36 | |||
37 | #include <elf_dyn.h> |
||
38 | #include <rtld.h> |
||
39 | #include <pcb.h> |
||
40 | |||
41 | // for testing printf |
||
42 | #include <stdio.h> |
||
43 | |||
44 | void __main(void); |
||
45 | void __io_init(void); |
||
46 | void __exit(void); |
||
47 | |||
48 | static void kputint(unsigned i) |
||
49 | { |
||
50 | asm volatile ( |
||
51 | "mr %%r3, %0\n" |
||
52 | "li %%r9, 30\n" |
||
53 | "sc\n" |
||
54 | : |
||
55 | : "r" (i) |
||
56 | : "%r3","%r9" |
||
57 | ) ; |
||
58 | } |
||
59 | |||
60 | #define __L(ptr) ((uint32_t)(ptr) & 0x0000ffff) |
||
61 | #define __HA(ptr) ((uint32_t)(ptr) >> 16) |
||
62 | |||
63 | // ldis r11, .PLTtable@ha |
||
64 | static inline uint32_t _ldis(unsigned rD, uint16_t imm16) |
||
65 | { |
||
66 | /* Special case of addis: ldis rD,SIMM == addis rD,0,SIMM */ |
||
67 | return 0x3C000000 | (rD << 21) | imm16; |
||
68 | } |
||
69 | |||
70 | static inline uint32_t _lwz(unsigned rD, uint16_t disp16, unsigned rA) |
||
71 | { |
||
72 | return 0x80000000 | (rD << 21) | (rA << 16) | disp16; |
||
73 | } |
||
74 | |||
75 | static inline uint32_t _mtctr(unsigned rS) |
||
76 | { |
||
77 | /* mtctr rD == mtspr 9, rD */ |
||
78 | return 0x7c0003a6 | (rS << 21) | (9/*CTR*/ << 16); |
||
79 | } |
||
80 | |||
81 | static inline uint32_t _bctr() |
||
82 | { |
||
83 | /* bcctr 0x1f, 0 */ |
||
84 | return 0x4c000420 | (0x1f/*always*/ << 21); |
||
85 | } |
||
86 | |||
87 | /* branch */ |
||
88 | static inline uint32_t _b(uint32_t *addr, uint32_t *location) |
||
89 | { |
||
90 | uint32_t raddr = ((uint32_t)addr - (uint32_t)location) & 0x03fffffc; |
||
91 | return 0x48000000 | raddr; |
||
92 | } |
||
93 | |||
94 | void test_func(void) |
||
95 | { |
||
96 | kputint(-1); |
||
97 | kputint(42); |
||
98 | kputint(-1); |
||
99 | } |
||
100 | |||
2997 | svoboda | 101 | int test_var = 0x818283; |
102 | |||
2995 | svoboda | 103 | void __bootstrap(void); |
104 | |||
105 | void __bootstrap(void) |
||
106 | { |
||
107 | unsigned bias; |
||
108 | uint32_t *plt; |
||
109 | elf_dyn_t *dynamic; |
||
110 | void *dptr; |
||
111 | unsigned dval; |
||
112 | int i; |
||
113 | |||
114 | size_t rel_entries; |
||
115 | size_t r_offset; |
||
116 | elf_word r_info; |
||
117 | unsigned rel_type; |
||
118 | elf_word sym_idx; |
||
119 | uintptr_t sym_addr; |
||
120 | |||
121 | elf_symbol_t *sym_table; |
||
122 | elf_rela_t *rel_table; |
||
123 | elf_rela_t *jmp_rel_table; |
||
124 | size_t jmp_rel_entries; |
||
125 | pcb_t *pcb; |
||
126 | uint32_t a, res; |
||
127 | uint32_t *r_ptr; |
||
128 | uint32_t *_plt_ent; |
||
129 | |||
130 | kputint(42); |
||
131 | pcb = __pcb_get(); |
||
132 | |||
133 | /* The program loader (iloader) kindly provided us with these */ |
||
134 | dynamic = pcb->rtld_dynamic; |
||
135 | bias = pcb->rtld_bias; |
||
136 | |||
137 | kputint(bias); |
||
138 | kputint((unsigned)dynamic); |
||
139 | |||
140 | /* parse DYNAMIC */ |
||
141 | plt = 0; |
||
142 | sym_table = 0; |
||
143 | rel_table = 0; |
||
144 | rel_entries = 0; |
||
145 | jmp_rel_table = 0; |
||
146 | jmp_rel_entries = 0; |
||
147 | |||
148 | i = 0; |
||
149 | while (dynamic[i].d_tag != 0) { |
||
150 | // kputint((uintptr_t)&dynamic[i]); |
||
151 | // kputint((uintptr_t)&(dynamic[i].d_tag)); |
||
152 | // kputint(dynamic[i].d_tag); |
||
153 | |||
154 | dptr = (void *)(dynamic[i].d_un.d_val + bias); |
||
155 | dval = dynamic[i].d_un.d_val; |
||
156 | |||
157 | // kputint(0x10); |
||
158 | register unsigned tag = dynamic[i].d_tag; |
||
159 | |||
160 | /* |
||
161 | * Note that switches only work because we are using |
||
162 | * -fno-jump-tables. |
||
163 | */ |
||
164 | switch (tag) { |
||
2996 | svoboda | 165 | case DT_PLTRELSZ: jmp_rel_entries = dval/sizeof(elf_rela_t); break; |
2995 | svoboda | 166 | case DT_JMPREL: jmp_rel_table = dptr; break; |
167 | case DT_PLTGOT: |
||
168 | /* PLT address */ |
||
169 | plt = dptr; break; |
||
170 | case DT_SYMTAB: sym_table = dptr; break; |
||
171 | case DT_RELA: rel_table = dptr; break; |
||
2996 | svoboda | 172 | case DT_RELASZ: rel_entries = dval / sizeof(elf_rela_t); break; |
2995 | svoboda | 173 | default: break; |
174 | } |
||
175 | |||
176 | // kputint(0x20); |
||
177 | |||
178 | ++i; |
||
179 | } |
||
180 | |||
181 | kputint(1); |
||
182 | kputint((unsigned)sym_table); |
||
183 | kputint((unsigned)rel_table); |
||
184 | kputint((unsigned)rel_entries); |
||
185 | |||
186 | /* Now relocate all our dynsyms */ |
||
187 | kputint(-1); |
||
188 | |||
189 | // PLT entries start here. However, each occupies 2 words |
||
190 | _plt_ent = plt + 18; |
||
191 | |||
192 | // By definition of the ppc ABI, there's 1:1 correspondence |
||
193 | // between JMPREL entries and PLT entries |
||
194 | unsigned plt_n = jmp_rel_entries; |
||
195 | |||
196 | uint32_t *_plt_table; |
||
197 | uint32_t *_plt_call; |
||
198 | uint32_t *_plt_resolve; |
||
199 | |||
200 | _plt_resolve = plt; |
||
201 | _plt_call = plt + 6; |
||
202 | _plt_table = plt + 18 + plt_n; |
||
203 | |||
204 | for (i=0; i<rel_entries; i++) { |
||
205 | // kputint(i); |
||
206 | r_offset = rel_table[i].r_offset; |
||
207 | r_info = rel_table[i].r_info; |
||
208 | r_ptr = (uint32_t *)(r_offset + bias); |
||
209 | a = rel_table[i].r_addend; |
||
210 | // kputint(-2); |
||
211 | // kputint(a); |
||
212 | // kputint(ELF32_R_TYPE(r_info)); |
||
213 | // kputint(ELF32_R_SYM(r_info)); |
||
214 | |||
215 | rel_type = ELF32_R_TYPE(r_info); |
||
216 | |||
217 | // kputint(rel_type); |
||
218 | // kputint(r_offset); |
||
219 | |||
220 | switch (rel_type) { |
||
221 | case R_PPC_JMP_SLOT: |
||
2997 | svoboda | 222 | // kputint(0xa); |
2995 | svoboda | 223 | sym_idx = ELF32_R_SYM(r_info); |
224 | |||
225 | sym_addr = sym_table[sym_idx].st_value + bias; |
||
2997 | svoboda | 226 | // kputint(sym_idx); |
227 | // kputint(sym_addr); |
||
2995 | svoboda | 228 | |
229 | // r_ptr should point to a plt entry... |
||
230 | uint32_t pidx = (r_ptr - _plt_ent) / 2; |
||
231 | if (pidx >= plt_n) { |
||
232 | kputint(0xee00ee0ee00); |
||
2997 | svoboda | 233 | while(1); |
2995 | svoboda | 234 | } |
2997 | svoboda | 235 | // _plt_table[pidx] = sym_addr; |
2995 | svoboda | 236 | // kputint(pidx); |
2997 | svoboda | 237 | plt[18+2*pidx] = _b(sym_addr, &plt[18+2*pidx]); |
2995 | svoboda | 238 | // kputint(&plt[18]); |
239 | // kputint(plt[18]); |
||
240 | // while(1); |
||
241 | // while(1); |
||
242 | //*r_ptr = sym_addr; |
||
2997 | svoboda | 243 | |
2995 | svoboda | 244 | break; |
245 | |||
246 | case R_PPC_ADDR32: |
||
247 | kputint(0xb); |
||
248 | sym_idx = ELF32_R_SYM(r_info); |
||
249 | |||
250 | sym_addr = sym_table[sym_idx].st_value + bias; |
||
251 | kputint(sym_idx); |
||
252 | kputint(sym_addr); |
||
253 | |||
254 | *r_ptr = a + sym_addr; |
||
255 | break; |
||
256 | |||
257 | case R_PPC_RELATIVE: |
||
2997 | svoboda | 258 | kputint(0xc); |
2995 | svoboda | 259 | *r_ptr = a + bias; |
260 | break; |
||
261 | |||
262 | case R_PPC_REL24: |
||
263 | kputint(0xd); |
||
264 | sym_idx = ELF32_R_SYM(r_info); |
||
265 | sym_addr = sym_table[sym_idx].st_value + bias; |
||
266 | kputint(sym_addr); |
||
267 | res = (sym_addr - (uint32_t)r_ptr + a) >> 2; |
||
268 | kputint(res); |
||
269 | if (res & 0xff000000) { |
||
270 | /* out of range?? */ |
||
271 | kputint(0xeeeeeeee); |
||
272 | //while(1); |
||
273 | } |
||
274 | *r_ptr = (*r_ptr & ~0x00ffffff) | (res & 0x00ffffff); |
||
275 | kputint(0x1d); |
||
276 | break; |
||
277 | } |
||
278 | } |
||
279 | |||
280 | kputint(-3); |
||
281 | if (plt != 0) { |
||
282 | |||
283 | /* .PLTcall: */ |
||
284 | plt[6] = _ldis(11, __HA(_plt_table)); // ldis r11, .PLTtable@ha |
||
285 | plt[7] = _lwz(11, __L(_plt_table), 11); // lwz r11, .PLTtable@l(r11) |
||
286 | plt[8] = _mtctr(11); // mtctr r11 |
||
287 | plt[9] = _bctr(); |
||
288 | |||
289 | /* .PLTi, i = 0..N-1 */ |
||
2997 | svoboda | 290 | /* kputint(-4); |
2995 | svoboda | 291 | for (i = 0; i < plt_n; ++i) { |
292 | //_plt_table[i] == function address; |
||
293 | plt[18+i] = _b(_plt_call, &plt[18+i]); // b .PLTcall |
||
294 | } |
||
2997 | svoboda | 295 | */ |
2995 | svoboda | 296 | kputint(-5); |
2996 | svoboda | 297 | kputint(_plt_table[0]); |
298 | } |
||
2995 | svoboda | 299 | |
2997 | svoboda | 300 | kputint(-6); |
2995 | svoboda | 301 | /* This will come in handy */ |
2996 | svoboda | 302 | runtime_env.rtld_dynamic = dynamic; |
303 | runtime_env.rtld.bias = bias; |
||
2995 | svoboda | 304 | |
305 | // volatile int ff=1; |
||
306 | // while(ff); |
||
2997 | svoboda | 307 | kputint(-7); |
2995 | svoboda | 308 | test_func(); |
309 | kputint(0x42); |
||
2997 | svoboda | 310 | kputint(test_var); |
2995 | svoboda | 311 | // while(1); |
2997 | svoboda | 312 | // while(1); |
2995 | svoboda | 313 | /* Init libc and run rtld main */ |
314 | kputint(0x22); |
||
315 | __main(); |
||
316 | |||
317 | kputint(33); |
||
318 | __io_init(); |
||
319 | kputint(-1); |
||
320 | kputint(0x52); |
||
2996 | svoboda | 321 | // printf("Hello, world! (from ppc rtld)\n"); |
2995 | svoboda | 322 | kputint(0x62); |
2996 | svoboda | 323 | // while(1); |
324 | kputint(34); |
||
325 | _rtld_main(); |
||
326 | kputint(35); |
||
327 | __exit(); |
||
2995 | svoboda | 328 | |
2996 | svoboda | 329 | kputint(36); |
2995 | svoboda | 330 | } |
331 | |||
332 | /** @} |
||
333 | */ |