Linux Audio

Check our new training course

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
/* powerpc shared library loader suppport
 *
 * Copyright (C) 2001-2002 David A. Schleef
 * Copyright (C) 2003-2004 Erik Andersen
 * Copyright (C) 2004 Joakim Tjernlund
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. The name of the above contributors may not be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "ldso.h"
#define TLS_DTV_OFFSET 0x8000
#define TLS_TP_OFFSET 0x7000

extern int _dl_linux_resolve(void);

void _dl_init_got(unsigned long *plt,struct elf_resolve *tpnt)
{
	Elf32_Word *tramp;
	Elf32_Word num_plt_entries;
	Elf32_Word data_words;
	Elf32_Word rel_offset_words;
	Elf32_Word dlrr = (Elf32_Word) _dl_linux_resolve;

	if (tpnt->dynamic_info[DT_JMPREL] == 0)
		return;
	if (tpnt->dynamic_info[DT_PPC_GOT_IDX] != 0) {
		tpnt->dynamic_info[DT_PPC_GOT_IDX] += tpnt->loadaddr;
		return;
	}
	num_plt_entries = tpnt->dynamic_info[DT_PLTRELSZ] / sizeof(ELF_RELOC);
	rel_offset_words = PLT_DATA_START_WORDS(num_plt_entries);
	data_words = (Elf32_Word) (plt + rel_offset_words);
	tpnt->data_words = data_words;

	plt[PLT_LONGBRANCH_ENTRY_WORDS] = OPCODE_ADDIS_HI(11, 11, data_words);
	plt[PLT_LONGBRANCH_ENTRY_WORDS+1] = OPCODE_LWZ(11,data_words,11);

	plt[PLT_LONGBRANCH_ENTRY_WORDS+2] = OPCODE_MTCTR(11);
	plt[PLT_LONGBRANCH_ENTRY_WORDS+3] = OPCODE_BCTR();

	/* [4] */
	/* [5] */
	tramp = (Elf32_Word *) (plt + PLT_TRAMPOLINE_ENTRY_WORDS);

	/* For the long entries, subtract off data_words.  */
	tramp[0] = OPCODE_ADDIS_HI(11,11,-data_words);
	tramp[1] = OPCODE_ADDI(11,11,-data_words);

	/* Multiply index of entry by 3 (in r11).  */
	tramp[2] = OPCODE_SLWI(12,11,1);
	tramp[3] = OPCODE_ADD(11,12,11);
	if (dlrr <= 0x01fffffc || dlrr >= 0xfe000000) {
		/* Load address of link map in r12.  */
		tramp[4] = OPCODE_LI (12, (Elf32_Word) tpnt);
		tramp[5] = OPCODE_ADDIS_HI (12, 12, (Elf32_Word) tpnt);

		/* Call _dl_linux_resolve .  */
		tramp[6] = OPCODE_BA (dlrr);
	} else {
		/* Get address of _dl_linux_resolve in CTR.  */
		tramp[4] = OPCODE_LI(12,dlrr);
		tramp[5] = OPCODE_ADDIS_HI(12,12,dlrr);
		tramp[6] = OPCODE_MTCTR(12);

		/* Load address of link map in r12.  */
		tramp[7] = OPCODE_LI(12,(Elf32_Word) tpnt);
		tramp[8] = OPCODE_ADDIS_HI(12,12,(Elf32_Word) tpnt);

		/* Call _dl_linux_resolve.  */
		tramp[9] = OPCODE_BCTR();
	}
	/* [16] unused */
	/* [17] unused */

	PPC_DCBST(plt);
	PPC_DCBST(plt+4);
	PPC_DCBST(plt+8);
	PPC_DCBST(plt+12);
	PPC_DCBST(plt+16-1);
	PPC_SYNC;
	PPC_ICBI(plt);
	PPC_ICBI(plt+16-1);
	PPC_ISYNC;
}

unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
{
	ELF_RELOC *this_reloc;
	char *strtab;
	ElfW(Sym) *symtab;
	ELF_RELOC *rel_addr;
	int symtab_index;
	char *symname;
	ElfW(Addr) *reloc_addr;
	ElfW(Addr)  finaladdr;
	Elf32_Sword delta;

	rel_addr = (ELF_RELOC *)tpnt->dynamic_info[DT_JMPREL];

	this_reloc = (void *)rel_addr + reloc_entry;
	symtab_index = ELF_R_SYM(this_reloc->r_info);

	symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
	strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
	symname = strtab + symtab[symtab_index].st_name;

	debug_sym(symtab,strtab,symtab_index);
	debug_reloc(symtab,strtab,this_reloc);

	/* Address of dump instruction to fix up */
	reloc_addr = (ElfW(Addr) *) (tpnt->loadaddr + this_reloc->r_offset);

#if defined (__SUPPORT_LD_DEBUG__)
	if (_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "\n\tResolving symbol %s %x --> ", symname, (ElfW(Addr))reloc_addr);
#endif

	/* Get the address of the GOT entry */
	finaladdr = (ElfW(Addr)) _dl_find_hash(symname,
			&_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
	if (unlikely(!finaladdr)) {
		_dl_dprintf(2, "%s: can't resolve symbol '%s' in lib '%s'.\n", _dl_progname, symname, tpnt->libname);
		_dl_exit(1);
	}
	finaladdr += this_reloc->r_addend;
#if defined (__SUPPORT_LD_DEBUG__)
	if (_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "%x\n", finaladdr);
#endif
	if (tpnt->dynamic_info[DT_PPC_GOT_IDX] != 0) {
		*reloc_addr = finaladdr;
	} else {
		delta = finaladdr - (Elf32_Word)reloc_addr;
		if (delta<<6>>6 == delta) {
			*reloc_addr = OPCODE_B(delta);
		} else if (finaladdr <= 0x01fffffc) {
			*reloc_addr = OPCODE_BA (finaladdr);
		} else {
			/* Warning: we don't handle double-sized PLT entries */
			Elf32_Word *plt, *data_words, idx, offset;

			plt = (Elf32_Word *)tpnt->dynamic_info[DT_PLTGOT];
			offset = reloc_addr - plt;
			idx = (offset - PLT_INITIAL_ENTRY_WORDS)/2;
			data_words = (Elf32_Word *)tpnt->data_words;
			reloc_addr += 1;

			data_words[idx] = finaladdr;
			PPC_SYNC;
			*reloc_addr =  OPCODE_B ((PLT_LONGBRANCH_ENTRY_WORDS - (offset+1)) * 4);
		}

		/* instructions were modified */
		PPC_DCBST(reloc_addr);
		PPC_SYNC;
		PPC_ICBI(reloc_addr);
		PPC_ISYNC;
	}
	return finaladdr;
}

static __inline__ int
_dl_do_reloc (struct elf_resolve *tpnt,struct r_scope_elem *scope,
	      ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
{
	int reloc_type;
	int symtab_index;
	struct symbol_ref sym_ref;
	ElfW(Addr) *reloc_addr;
	ElfW(Addr) finaladdr;
	struct elf_resolve *tls_tpnt = NULL;
	unsigned long symbol_addr;
	char *symname;
#if defined (__SUPPORT_LD_DEBUG__)
	unsigned long old_val;
#endif

	symbol_addr  = tpnt->loadaddr; /* For R_PPC_RELATIVE */
	reloc_addr   = (ElfW(Addr) *)(intptr_t) (symbol_addr + (unsigned long) rpnt->r_offset);
	reloc_type   = ELF_R_TYPE(rpnt->r_info);
	symtab_index = ELF_R_SYM(rpnt->r_info);
	sym_ref.sym  = &symtab[symtab_index];
	sym_ref.tpnt = NULL;
	symname      = strtab + sym_ref.sym->st_name;
	if (symtab_index) {
		symbol_addr = (unsigned long) _dl_find_hash(symname, scope, tpnt,
							    elf_machine_type_class(reloc_type),  &sym_ref);
		/* We want to allow undefined references to weak symbols - this might
		 * have been intentional.  We should not be linking local symbols
		 * here, so all bases should be covered.
		 */
		if (unlikely(!symbol_addr
			&& (ELF_ST_TYPE(sym_ref.sym->st_info) != STT_TLS
				&& ELF_ST_BIND(sym_ref.sym->st_info) != STB_WEAK)))
			return 1;
		if (_dl_trace_prelink) {
			_dl_debug_lookup (symname, tpnt, &symtab[symtab_index],
						&sym_ref, elf_machine_type_class(reloc_type));
		}
		tls_tpnt = sym_ref.tpnt;
	} else {
		symbol_addr = sym_ref.sym->st_value;
		tls_tpnt = tpnt;
	}
#if defined (__SUPPORT_LD_DEBUG__)
	old_val = *reloc_addr;
#endif
	finaladdr = (ElfW(Addr)) (symbol_addr + rpnt->r_addend);

	switch (reloc_type) {
	case R_PPC_RELATIVE:
	case R_PPC_ADDR32:
	case R_PPC_GLOB_DAT:
		*reloc_addr = finaladdr;
		goto out_nocode; /* No code modified */
	case R_PPC_JMP_SLOT:
	{
		if (tpnt->dynamic_info[DT_PPC_GOT_IDX] != 0) {
			*reloc_addr = finaladdr;
			goto out_nocode; /* No code modified */
		} else {
			Elf32_Sword delta = finaladdr - (Elf32_Word)reloc_addr;
			if (delta<<6>>6 == delta) {
				*reloc_addr = OPCODE_B(delta);
			} else if (finaladdr <= 0x01fffffc) {
				*reloc_addr = OPCODE_BA (finaladdr);
			} else {
				/* Warning: we don't handle double-sized PLT entries */
				Elf32_Word *plt, *data_words, idx, offset;

				plt = (Elf32_Word *)tpnt->dynamic_info[DT_PLTGOT];
				offset = reloc_addr - plt;
				idx = (offset - PLT_INITIAL_ENTRY_WORDS)/2;
				data_words = (Elf32_Word *)tpnt->data_words;

				data_words[idx] = finaladdr;
				reloc_addr[0] = OPCODE_LI(11,idx*4);
				reloc_addr[1] = OPCODE_B((PLT_LONGBRANCH_ENTRY_WORDS - (offset+1)) * 4);

				/* instructions were modified */
				PPC_DCBST(reloc_addr+1);
				PPC_SYNC;
				PPC_ICBI(reloc_addr+1);
			}
		}
		break;
	}
	case R_PPC_COPY:
#if defined (__SUPPORT_LD_DEBUG__)
		if (_dl_debug_move)
			_dl_dprintf(_dl_debug_file,"\n%s move %x bytes from %x to %x",
				    symname, sym_ref.sym->st_size,
				    symbol_addr, reloc_addr);
#endif
		_dl_memcpy((char *) reloc_addr, (char *) finaladdr, sym_ref.sym->st_size);
		goto out_nocode; /* No code modified */
	case R_PPC_ADDR16_HA:
		finaladdr += 0x8000; /* fall through. */
	case R_PPC_ADDR16_HI:
		finaladdr >>= 16; /* fall through. */
	case R_PPC_ADDR16_LO:
		*(short *)reloc_addr = finaladdr;
		break;
#if USE_TLS
	case R_PPC_DTPMOD32:
		*reloc_addr = tls_tpnt->l_tls_modid;
		break;
	case R_PPC_DTPREL32:
		/* During relocation all TLS symbols are defined and used.
		   Therefore the offset is already correct.  */
		*reloc_addr = finaladdr - TLS_DTV_OFFSET;
		break;
	case R_PPC_TPREL32:
		*reloc_addr = tls_tpnt->l_tls_offset + finaladdr - TLS_TP_OFFSET;
		break;
#endif
	case R_PPC_REL24:
#if 0
		{
			Elf32_Sword delta = finaladdr - (Elf32_Word)reloc_addr;
			if (unlikely(delta<<6>>6 != delta)) {
				_dl_dprintf(2, "%s: symbol '%s' R_PPC_REL24 is out of range.\n\t"
						"Compile shared libraries with -fPIC!\n",
						_dl_progname, symname);
				_dl_exit(1);
			}
			*reloc_addr = (*reloc_addr & 0xfc000003) | (delta & 0x3fffffc);
			break;
		}
#else
		_dl_dprintf(2,"R_PPC_REL24: Compile shared libraries with -fPIC!\n");
		return -1;
#endif
	case R_PPC_NONE:
		goto out_nocode; /* No code modified */
	default:
		_dl_dprintf(2, "%s: can't handle reloc type ", _dl_progname);
		if (symtab_index)
			_dl_dprintf(2, "'%s'\n", symname);
		return -1;
	}

	/* instructions were modified */
	PPC_DCBST(reloc_addr);
	PPC_SYNC;
	PPC_ICBI(reloc_addr);
	PPC_ISYNC;
 out_nocode:
#if defined (__SUPPORT_LD_DEBUG__)
	if (_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", old_val, *reloc_addr, reloc_addr);
#endif
	return 0;
}

void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
	unsigned long rel_addr, unsigned long rel_size)
{
	struct elf_resolve *tpnt = rpnt->dyn;
	Elf32_Word *plt, offset, i,  num_plt_entries, rel_offset_words;

	num_plt_entries = rel_size / sizeof(ELF_RELOC);
	plt = (Elf32_Word *)tpnt->dynamic_info[DT_PLTGOT];
	if (tpnt->dynamic_info[DT_PPC_GOT_IDX] != 0) {
		/* Secure PLT */
		ElfW(Addr) *got = (ElfW(Addr) *)tpnt->dynamic_info[DT_PPC_GOT_IDX];
		Elf32_Word dlrr = (Elf32_Word) _dl_linux_resolve;

		got[1] = (ElfW(Addr)) dlrr;
		got[2] = (ElfW(Addr)) tpnt;

		/* Relocate everything in .plt by the load address offset.  */
		while (num_plt_entries-- != 0)
			*plt++ += tpnt->loadaddr;
		return;
	}

	rel_offset_words = PLT_DATA_START_WORDS(num_plt_entries);

	/* Set up the lazy PLT entries.  */
	offset = PLT_INITIAL_ENTRY_WORDS;
	i = 0;
	/* Warning: we don't handle double-sized PLT entries */
	while (i < num_plt_entries) {
		plt[offset  ] = OPCODE_LI(11, i * 4);
		plt[offset+1] = OPCODE_B((PLT_TRAMPOLINE_ENTRY_WORDS + 2 - (offset+1)) * 4);
		i++;
		offset += 2;
	}
	/* Now, we've modified code.  We need to write the changes from
	   the data cache to a second-level unified cache, then make
	   sure that stale data in the instruction cache is removed.
	   (In a multiprocessor system, the effect is more complex.)
	   Most of the PLT shouldn't be in the instruction cache, but
	   there may be a little overlap at the start and the end.

	   Assumes that dcbst and icbi apply to lines of 16 bytes or
	   more.  Current known line sizes are 16, 32, and 128 bytes.  */
	for (i = 0; i < rel_offset_words; i += 4)
		PPC_DCBST (plt + i);
	PPC_DCBST (plt + rel_offset_words - 1);
	PPC_SYNC;
	PPC_ICBI (plt);
	PPC_ICBI (plt + rel_offset_words - 1);
	PPC_ISYNC;
}

static __inline__ int
_dl_parse(struct elf_resolve *tpnt, struct r_scope_elem *scope,
	  unsigned long rel_addr, unsigned long rel_size,
	  int (*reloc_fnc) (struct elf_resolve *tpnt, struct r_scope_elem *scope,
			    ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab))
{
	unsigned int i;
	char *strtab;
	ElfW(Sym) *symtab;
	ELF_RELOC *rpnt;
	int symtab_index;

	/* Now parse the relocation information */
	rpnt = (ELF_RELOC *)(intptr_t)rel_addr;
	rel_size = rel_size / sizeof(ELF_RELOC);

	symtab = (ElfW(Sym) *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
	strtab = (char *)tpnt->dynamic_info[DT_STRTAB];

	  for (i = 0; i < rel_size; i++, rpnt++) {
	        int res;

		symtab_index = ELF_R_SYM(rpnt->r_info);

		debug_sym(symtab,strtab,symtab_index);
		debug_reloc(symtab,strtab,rpnt);

		res = reloc_fnc (tpnt, scope, rpnt, symtab, strtab);

		if (res==0) continue;

		_dl_dprintf(2, "\n%s: ",_dl_progname);

		if (symtab_index)
		  _dl_dprintf(2, "symbol '%s': ", strtab + symtab[symtab_index].st_name);

		if (unlikely(res <0))
		{
		        int reloc_type = ELF_R_TYPE(rpnt->r_info);
			_dl_dprintf(2, "can't handle reloc type %x in lib '%s'\n", reloc_type, tpnt->libname);
			return res;
		}
		if (unlikely(res >0))
		{
			_dl_dprintf(2, "can't resolve symbol in lib '%s'.\n", tpnt->libname);
			return res;
		}
	  }
	  return 0;
}

int _dl_parse_relocation_information(struct dyn_elf *rpnt,
	struct r_scope_elem *scope, unsigned long rel_addr, unsigned long rel_size)
{
	return _dl_parse(rpnt->dyn, scope, rel_addr, rel_size, _dl_do_reloc);
}