1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2019, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <compiler.h>
8 #include <confine_array_index.h>
9 #include <elf32.h>
10 #include <elf64.h>
11 #include <elf_common.h>
12 #include <string.h>
13 #include <tee_api_types.h>
14 #include <util.h>
15 
16 #include "sys.h"
17 #include "ta_elf.h"
18 
elf_hash(const char * name)19 static uint32_t elf_hash(const char *name)
20 {
21 	const unsigned char *p = (const unsigned char *)name;
22 	uint32_t h = 0;
23 	uint32_t g = 0;
24 
25 	while (*p) {
26 		h = (h << 4) + *p++;
27 		g = h & 0xf0000000;
28 		if (g)
29 			h ^= g >> 24;
30 		h &= ~g;
31 	}
32 	return h;
33 }
34 
gnu_hash(const char * name)35 static uint32_t gnu_hash(const char *name)
36 {
37 	const unsigned char *p = (const unsigned char *)name;
38 	uint32_t h = 5381;
39 
40 	while (*p)
41 		h = (h << 5) + h + *p++;
42 
43 	return h;
44 }
45 
sym_compare(struct ta_elf * elf,unsigned int st_bind,unsigned int st_type,size_t st_shndx,size_t st_name,size_t st_value,const char * name,vaddr_t * val,bool weak_ok)46 static bool sym_compare(struct ta_elf *elf, unsigned int st_bind,
47 			unsigned int st_type, size_t st_shndx,
48 			size_t st_name, size_t st_value, const char *name,
49 			vaddr_t *val, bool weak_ok)
50 {
51 	bool bind_ok = false;
52 
53 	if (!st_name)
54 		return false;
55 	if (st_name > elf->dynstr_size)
56 		err(TEE_ERROR_BAD_FORMAT, "Symbol name out of range");
57 	if (strcmp(name, elf->dynstr + st_name))
58 		return false;
59 	if (st_bind == STB_GLOBAL || (weak_ok && st_bind == STB_WEAK))
60 		bind_ok = true;
61 	if (!bind_ok)
62 		return false;
63 	if (st_bind == STB_WEAK && st_shndx == SHN_UNDEF) {
64 		if (val)
65 			*val = 0;
66 		return true;
67 	}
68 	if (st_shndx == SHN_UNDEF || st_shndx == SHN_XINDEX)
69 		return false;
70 
71 	switch (st_type) {
72 	case STT_NOTYPE:
73 	case STT_OBJECT:
74 	case STT_FUNC:
75 		if (st_value > (elf->max_addr - elf->load_addr))
76 			err(TEE_ERROR_BAD_FORMAT,
77 			    "Symbol location out of range");
78 		if (val)
79 			*val = st_value + elf->load_addr;
80 		break;
81 	case STT_TLS:
82 		if (val)
83 			*val = st_value;
84 		break;
85 	default:
86 		err(TEE_ERROR_NOT_SUPPORTED, "Symbol type not supported");
87 	}
88 
89 	return true;
90 }
91 
check_found_sym(struct ta_elf * elf,const char * name,vaddr_t * val,bool weak_ok,size_t n)92 static bool check_found_sym(struct ta_elf *elf, const char *name, vaddr_t *val,
93 			    bool weak_ok, size_t n)
94 {
95 	Elf32_Sym *sym32 = NULL;
96 	Elf64_Sym *sym64 = NULL;
97 	unsigned int st_bind = 0;
98 	unsigned int st_type = 0;
99 	size_t st_shndx = 0;
100 	size_t st_name = 0;
101 	size_t st_value = 0;
102 
103 	if (n >= elf->num_dynsyms)
104 		err(TEE_ERROR_BAD_FORMAT, "Index out of range");
105 
106 	/*
107 	 * We're loading values from sym[] which later
108 	 * will be used to load something.
109 	 * => Spectre V1 pattern, need to cap the index
110 	 * against speculation.
111 	 */
112 	n = confine_array_index(n, elf->num_dynsyms);
113 
114 	if (elf->is_32bit) {
115 		sym32 = elf->dynsymtab;
116 		st_bind = ELF32_ST_BIND(sym32[n].st_info);
117 		st_type = ELF32_ST_TYPE(sym32[n].st_info);
118 		st_shndx = sym32[n].st_shndx;
119 		st_name = sym32[n].st_name;
120 		st_value = sym32[n].st_value;
121 	} else {
122 		sym64 = elf->dynsymtab;
123 		st_bind = ELF64_ST_BIND(sym64[n].st_info);
124 		st_type = ELF64_ST_TYPE(sym64[n].st_info);
125 		st_shndx = sym64[n].st_shndx;
126 		st_name = sym64[n].st_name;
127 		st_value = sym64[n].st_value;
128 	}
129 
130 	return sym_compare(elf, st_bind, st_type, st_shndx, st_name, st_value,
131 			   name, val, weak_ok);
132 }
133 
resolve_sym_helper(const char * name,vaddr_t * val,struct ta_elf * elf,bool weak_ok)134 static TEE_Result resolve_sym_helper(const char *name, vaddr_t *val,
135 				     struct ta_elf *elf, bool weak_ok)
136 {
137 	uint32_t n = 0;
138 	uint32_t hash = 0;
139 
140 	if (elf->gnu_hashtab) {
141 		struct gnu_hashtab *h = elf->gnu_hashtab;
142 		uint32_t *end = (void *)((uint8_t *)elf->gnu_hashtab +
143 					 elf->gnu_hashtab_size);
144 		uint32_t *bucket = NULL;
145 		uint32_t *chain = NULL;
146 		uint32_t hashval = 0;
147 
148 		hash = gnu_hash(name);
149 
150 		if (elf->is_32bit) {
151 			uint32_t *bloom = (void *)(h + 1);
152 			uint32_t word = bloom[(hash / 32) % h->bloom_size];
153 			uint32_t mask = BIT32(hash % 32) |
154 					BIT32((hash >> h->bloom_shift) % 32);
155 
156 			if ((word & mask) != mask)
157 				return TEE_ERROR_ITEM_NOT_FOUND;
158 			bucket = bloom + h->bloom_size;
159 		} else {
160 			uint64_t *bloom = (void *)(h + 1);
161 			uint64_t word = bloom[(hash / 64) % h->bloom_size];
162 			uint64_t mask = BIT64(hash % 64) |
163 					BIT64((hash >> h->bloom_shift) % 64);
164 
165 			if ((word & mask) != mask)
166 				return TEE_ERROR_ITEM_NOT_FOUND;
167 			bucket = (uint32_t *)(bloom + h->bloom_size);
168 		}
169 		chain = bucket + h->nbuckets;
170 
171 		n = bucket[hash % h->nbuckets];
172 		if (n < h->symoffset)
173 			return TEE_ERROR_ITEM_NOT_FOUND;
174 
175 		hash |= 1;
176 		do {
177 			size_t idx = n - h->symoffset;
178 
179 			if (chain + idx > end)
180 				return TEE_ERROR_ITEM_NOT_FOUND;
181 
182 			hashval = chain[idx];
183 
184 			if ((hashval | 1) == hash &&
185 			    check_found_sym(elf, name, val, weak_ok, n))
186 				return TEE_SUCCESS;
187 
188 			n++;
189 		} while (!(hashval & 1));
190 	} else if (elf->hashtab) {
191 		/*
192 		 * Using uint32_t here for convenience because both Elf64_Word
193 		 * and Elf32_Word are 32-bit types
194 		 */
195 		uint32_t *hashtab = elf->hashtab;
196 		uint32_t nbuckets = hashtab[0];
197 		uint32_t nchains = hashtab[1];
198 		uint32_t *bucket = &hashtab[2];
199 		uint32_t *chain = &bucket[nbuckets];
200 
201 		hash = elf_hash(name);
202 
203 		for (n = bucket[hash % nbuckets]; n; n = chain[n]) {
204 			if (n >= nchains)
205 				err(TEE_ERROR_BAD_FORMAT, "Index out of range");
206 			if (check_found_sym(elf, name, val, weak_ok, n))
207 				return TEE_SUCCESS;
208 		}
209 	}
210 
211 	return TEE_ERROR_ITEM_NOT_FOUND;
212 }
213 
214 /*
215  * Look for named symbol in @elf, or all modules if @elf == NULL. Global symbols
216  * are searched first, then weak ones. Last option, when at least one weak but
217  * undefined symbol exists, resolve to zero. Otherwise return
218  * TEE_ERROR_ITEM_NOT_FOUND.
219  * @val (if != 0) receives the symbol value
220  * @found_elf (if != 0) receives the module where the symbol is found
221  */
ta_elf_resolve_sym(const char * name,vaddr_t * val,struct ta_elf ** found_elf,struct ta_elf * elf)222 TEE_Result ta_elf_resolve_sym(const char *name, vaddr_t *val,
223 			      struct ta_elf **found_elf,
224 			      struct ta_elf *elf)
225 {
226 	if (elf) {
227 		/* Search global symbols */
228 		if (!resolve_sym_helper(name, val, elf, false /* !weak_ok */))
229 			goto success;
230 		/* Search weak symbols */
231 		if (!resolve_sym_helper(name, val, elf, true /* weak_ok */))
232 			goto success;
233 	}
234 
235 	TAILQ_FOREACH(elf, &main_elf_queue, link) {
236 		if (!resolve_sym_helper(name, val, elf, false /* !weak_ok */))
237 			goto success;
238 		if (!resolve_sym_helper(name, val, elf, true /* weak_ok */))
239 			goto success;
240 	}
241 
242 	return TEE_ERROR_ITEM_NOT_FOUND;
243 
244 success:
245 	if (found_elf)
246 		*found_elf = elf;
247 	return TEE_SUCCESS;
248 }
249 
e32_get_sym_name(const Elf32_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf32_Rel * rel,const char ** name,bool * weak_undef)250 static void e32_get_sym_name(const Elf32_Sym *sym_tab, size_t num_syms,
251 			     const char *str_tab, size_t str_tab_size,
252 			     Elf32_Rel *rel, const char **name,
253 			     bool *weak_undef)
254 {
255 	size_t sym_idx = 0;
256 	size_t name_idx = 0;
257 
258 	sym_idx = ELF32_R_SYM(rel->r_info);
259 	if (sym_idx >= num_syms)
260 		err(TEE_ERROR_BAD_FORMAT, "Symbol index out of range");
261 	sym_idx = confine_array_index(sym_idx, num_syms);
262 
263 	name_idx = sym_tab[sym_idx].st_name;
264 	if (name_idx >= str_tab_size)
265 		err(TEE_ERROR_BAD_FORMAT, "Name index out of range");
266 	*name = str_tab + name_idx;
267 
268 	if (!weak_undef)
269 		return;
270 	if (sym_tab[sym_idx].st_shndx == SHN_UNDEF &&
271 	    ELF32_ST_BIND(sym_tab[sym_idx].st_info) == STB_WEAK)
272 		*weak_undef = true;
273 	else
274 		*weak_undef = false;
275 }
276 
resolve_sym(const char * name,vaddr_t * val,struct ta_elf ** mod,bool err_if_not_found)277 static void resolve_sym(const char *name, vaddr_t *val, struct ta_elf **mod,
278 			bool err_if_not_found)
279 {
280 	TEE_Result res = ta_elf_resolve_sym(name, val, mod, NULL);
281 
282 	if (res) {
283 		if (err_if_not_found)
284 			err(res, "Symbol %s not found", name);
285 		else
286 			*val = 0;
287 	}
288 }
289 
e32_process_dyn_rel(const Elf32_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf32_Rel * rel,Elf32_Addr * where)290 static void e32_process_dyn_rel(const Elf32_Sym *sym_tab, size_t num_syms,
291 				const char *str_tab, size_t str_tab_size,
292 				Elf32_Rel *rel, Elf32_Addr *where)
293 {
294 	const char *name = NULL;
295 	vaddr_t val = 0;
296 	bool weak_undef = false;
297 
298 	e32_get_sym_name(sym_tab, num_syms, str_tab, str_tab_size, rel, &name,
299 			 &weak_undef);
300 	resolve_sym(name, &val, NULL, !weak_undef);
301 	*where = val;
302 }
303 
e32_tls_get_module(const Elf32_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf32_Rel * rel,struct ta_elf ** mod)304 static void e32_tls_get_module(const Elf32_Sym *sym_tab, size_t num_syms,
305 			       const char *str_tab, size_t str_tab_size,
306 			       Elf32_Rel *rel, struct ta_elf **mod)
307 {
308 	const char *name = NULL;
309 	size_t sym_idx = 0;
310 
311 	sym_idx = ELF32_R_SYM(rel->r_info);
312 	if (sym_idx >= num_syms)
313 		err(TEE_ERROR_BAD_FORMAT, "Symbol index out of range");
314 	sym_idx = confine_array_index(sym_idx, num_syms);
315 	if (!sym_idx || sym_tab[sym_idx].st_shndx != SHN_UNDEF) {
316 		/* No symbol, or symbol is defined in current module */
317 		return;
318 	}
319 
320 	e32_get_sym_name(sym_tab, num_syms, str_tab, str_tab_size, rel, &name,
321 			 NULL);
322 	resolve_sym(name, NULL, mod, false);
323 }
324 
e32_tls_resolve(const Elf32_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf32_Rel * rel,vaddr_t * val)325 static void e32_tls_resolve(const Elf32_Sym *sym_tab, size_t num_syms,
326 			    const char *str_tab, size_t str_tab_size,
327 			    Elf32_Rel *rel, vaddr_t *val)
328 {
329 	const char *name = NULL;
330 
331 	e32_get_sym_name(sym_tab, num_syms, str_tab, str_tab_size, rel, &name,
332 			 NULL);
333 	resolve_sym(name, val, NULL, false);
334 }
335 
e32_relocate(struct ta_elf * elf,unsigned int rel_sidx)336 static void e32_relocate(struct ta_elf *elf, unsigned int rel_sidx)
337 {
338 	Elf32_Shdr *shdr = elf->shdr;
339 	Elf32_Rel *rel = NULL;
340 	Elf32_Rel *rel_end = NULL;
341 	size_t sym_tab_idx = 0;
342 	Elf32_Sym *sym_tab = NULL;
343 	size_t num_syms = 0;
344 	size_t sh_end = 0;
345 	const char *str_tab = NULL;
346 	size_t str_tab_size = 0;
347 
348 	assert(shdr[rel_sidx].sh_type == SHT_REL);
349 
350 	assert(shdr[rel_sidx].sh_entsize == sizeof(Elf32_Rel));
351 
352 	sym_tab_idx = shdr[rel_sidx].sh_link;
353 	if (sym_tab_idx) {
354 		size_t str_tab_idx = 0;
355 
356 		if (sym_tab_idx >= elf->e_shnum)
357 			err(TEE_ERROR_BAD_FORMAT, "SYMTAB index out of range");
358 		sym_tab_idx = confine_array_index(sym_tab_idx, elf->e_shnum);
359 
360 		assert(shdr[sym_tab_idx].sh_entsize == sizeof(Elf32_Sym));
361 
362 		/* Check the address is inside ELF memory */
363 		if (ADD_OVERFLOW(shdr[sym_tab_idx].sh_addr,
364 				 shdr[sym_tab_idx].sh_size, &sh_end))
365 			err(TEE_ERROR_BAD_FORMAT, "Overflow");
366 		if (sh_end >= (elf->max_addr - elf->load_addr))
367 			err(TEE_ERROR_BAD_FORMAT, "SYMTAB out of range");
368 
369 		sym_tab = (Elf32_Sym *)(elf->load_addr +
370 					shdr[sym_tab_idx].sh_addr);
371 
372 		num_syms = shdr[sym_tab_idx].sh_size / sizeof(Elf32_Sym);
373 
374 		str_tab_idx = shdr[sym_tab_idx].sh_link;
375 		if (str_tab_idx) {
376 			if (str_tab_idx >= elf->e_shnum)
377 				err(TEE_ERROR_BAD_FORMAT,
378 				    "STRTAB index out of range");
379 			str_tab_idx = confine_array_index(str_tab_idx,
380 							  elf->e_shnum);
381 
382 			/* Check the address is inside ELF memory */
383 			if (ADD_OVERFLOW(shdr[str_tab_idx].sh_addr,
384 					 shdr[str_tab_idx].sh_size, &sh_end))
385 				err(TEE_ERROR_BAD_FORMAT, "Overflow");
386 			if (sh_end >= (elf->max_addr - elf->load_addr))
387 				err(TEE_ERROR_BAD_FORMAT,
388 				    "STRTAB out of range");
389 
390 			str_tab = (const char *)(elf->load_addr +
391 						 shdr[str_tab_idx].sh_addr);
392 			str_tab_size = shdr[str_tab_idx].sh_size;
393 		}
394 	}
395 
396 	/* Check the address is inside TA memory */
397 	if (ADD_OVERFLOW(shdr[rel_sidx].sh_addr,
398 			 shdr[rel_sidx].sh_size, &sh_end))
399 		err(TEE_ERROR_BAD_FORMAT, "Overflow");
400 	if (sh_end >= (elf->max_addr - elf->load_addr))
401 		err(TEE_ERROR_BAD_FORMAT, ".rel.*/REL out of range");
402 	rel = (Elf32_Rel *)(elf->load_addr + shdr[rel_sidx].sh_addr);
403 
404 	rel_end = rel + shdr[rel_sidx].sh_size / sizeof(Elf32_Rel);
405 	for (; rel < rel_end; rel++) {
406 		struct ta_elf *mod = NULL;
407 		Elf32_Addr *where = NULL;
408 		size_t sym_idx = 0;
409 		vaddr_t val = 0;
410 
411 		/* Check the address is inside TA memory */
412 		if (rel->r_offset >= (elf->max_addr - elf->load_addr))
413 			err(TEE_ERROR_BAD_FORMAT,
414 			    "Relocation offset out of range");
415 		where = (Elf32_Addr *)(elf->load_addr + rel->r_offset);
416 
417 		switch (ELF32_R_TYPE(rel->r_info)) {
418 		case R_ARM_NONE:
419 			/*
420 			 * One would expect linker prevents such useless entry
421 			 * in the relocation table. We still handle this type
422 			 * here in case such entries exist.
423 			 */
424 			break;
425 		case R_ARM_ABS32:
426 			sym_idx = ELF32_R_SYM(rel->r_info);
427 			if (sym_idx >= num_syms)
428 				err(TEE_ERROR_BAD_FORMAT,
429 				    "Symbol index out of range");
430 			if (sym_tab[sym_idx].st_shndx == SHN_UNDEF) {
431 				/* Symbol is external */
432 				e32_process_dyn_rel(sym_tab, num_syms, str_tab,
433 						    str_tab_size, rel, where);
434 			} else {
435 				*where += elf->load_addr +
436 					  sym_tab[sym_idx].st_value;
437 			}
438 			break;
439 		case R_ARM_REL32:
440 			sym_idx = ELF32_R_SYM(rel->r_info);
441 			if (sym_idx >= num_syms)
442 				err(TEE_ERROR_BAD_FORMAT,
443 				    "Symbol index out of range");
444 			*where += sym_tab[sym_idx].st_value - rel->r_offset;
445 			break;
446 		case R_ARM_RELATIVE:
447 			*where += elf->load_addr;
448 			break;
449 		case R_ARM_GLOB_DAT:
450 		case R_ARM_JUMP_SLOT:
451 			if (!sym_tab)
452 				err(TEE_ERROR_BAD_FORMAT,
453 				    "Missing symbol table");
454 			e32_process_dyn_rel(sym_tab, num_syms, str_tab,
455 					    str_tab_size, rel, where);
456 			break;
457 		case R_ARM_TLS_DTPMOD32:
458 			if (!sym_tab)
459 				err(TEE_ERROR_BAD_FORMAT,
460 				    "Missing symbol table");
461 			mod = elf;
462 			e32_tls_get_module(sym_tab, num_syms, str_tab,
463 					   str_tab_size, rel, &mod);
464 			*where = mod->tls_mod_id;
465 			break;
466 		case R_ARM_TLS_DTPOFF32:
467 			if (!sym_tab)
468 				err(TEE_ERROR_BAD_FORMAT,
469 				    "Missing symbol table");
470 			e32_tls_resolve(sym_tab, num_syms, str_tab,
471 					str_tab_size, rel, &val);
472 			*where = val;
473 			break;
474 		default:
475 			err(TEE_ERROR_BAD_FORMAT, "Unknown relocation type %d",
476 			     ELF32_R_TYPE(rel->r_info));
477 		}
478 	}
479 }
480 
481 #if defined(ARM64) || defined(RV64)
e64_get_sym_name(const Elf64_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf64_Rela * rela,const char ** name,bool * weak_undef)482 static void e64_get_sym_name(const Elf64_Sym *sym_tab, size_t num_syms,
483 			     const char *str_tab, size_t str_tab_size,
484 			     Elf64_Rela *rela, const char **name,
485 			     bool *weak_undef)
486 {
487 	size_t sym_idx = 0;
488 	size_t name_idx = 0;
489 
490 	sym_idx = ELF64_R_SYM(rela->r_info);
491 	if (sym_idx >= num_syms)
492 		err(TEE_ERROR_BAD_FORMAT, "Symbol index out of range");
493 	sym_idx = confine_array_index(sym_idx, num_syms);
494 
495 	name_idx = sym_tab[sym_idx].st_name;
496 	if (name_idx >= str_tab_size)
497 		err(TEE_ERROR_BAD_FORMAT, "Name index out of range");
498 	*name = str_tab + name_idx;
499 
500 	if (sym_tab[sym_idx].st_shndx == SHN_UNDEF &&
501 	    ELF64_ST_BIND(sym_tab[sym_idx].st_info) == STB_WEAK)
502 		*weak_undef = true;
503 	else
504 		*weak_undef = false;
505 }
506 
e64_process_dyn_rela(const Elf64_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf64_Rela * rela,Elf64_Addr * where)507 static void e64_process_dyn_rela(const Elf64_Sym *sym_tab, size_t num_syms,
508 				 const char *str_tab, size_t str_tab_size,
509 				 Elf64_Rela *rela, Elf64_Addr *where)
510 {
511 	const char *name = NULL;
512 	uintptr_t val = 0;
513 	bool weak_undef = false;
514 
515 	e64_get_sym_name(sym_tab, num_syms, str_tab, str_tab_size, rela, &name,
516 			 &weak_undef);
517 	resolve_sym(name, &val, NULL, !weak_undef);
518 	*where = val;
519 }
520 
521 #ifdef ARM64
e64_process_tls_tprel_rela(const Elf64_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf64_Rela * rela,Elf64_Addr * where,struct ta_elf * elf)522 static void e64_process_tls_tprel_rela(const Elf64_Sym *sym_tab,
523 				       size_t num_syms, const char *str_tab,
524 				       size_t str_tab_size, Elf64_Rela *rela,
525 				       Elf64_Addr *where, struct ta_elf *elf)
526 {
527 	struct ta_elf *mod = NULL;
528 	bool weak_undef = false;
529 	const char *name = NULL;
530 	size_t sym_idx = 0;
531 	vaddr_t symval = 0;
532 
533 	sym_idx = ELF64_R_SYM(rela->r_info);
534 	if (sym_idx) {
535 		e64_get_sym_name(sym_tab, num_syms, str_tab, str_tab_size, rela,
536 				 &name, &weak_undef);
537 		resolve_sym(name, &symval, &mod, !weak_undef);
538 	} else {
539 		mod = elf;
540 	}
541 	*where = symval + mod->tls_tcb_offs + rela->r_addend;
542 }
543 
544 struct tlsdesc {
545 	long (*resolver)(struct tlsdesc *td);
546 	long value;
547 };
548 
549 /* Helper function written in assembly due to the calling convention */
550 long tlsdesc_resolve(struct tlsdesc *td);
551 
e64_process_tlsdesc_rela(const Elf64_Sym * sym_tab,size_t num_syms,const char * str_tab,size_t str_tab_size,Elf64_Rela * rela,Elf64_Addr * where,struct ta_elf * elf)552 static void e64_process_tlsdesc_rela(const Elf64_Sym *sym_tab, size_t num_syms,
553 				     const char *str_tab, size_t str_tab_size,
554 				     Elf64_Rela *rela, Elf64_Addr *where,
555 				     struct ta_elf *elf)
556 {
557 	/*
558 	 * @where points to a pair of 64-bit words in the GOT or PLT which is
559 	 * mapped to a struct tlsdesc:
560 	 *
561 	 * - resolver() must return the offset of the thread-local variable
562 	 *   relative to TPIDR_EL0.
563 	 * - value is implementation-dependent. The TLS_TPREL handling code is
564 	 *   re-used to get the desired offset so that tlsdesc_resolve() just
565 	 *   needs to return this value.
566 	 *
567 	 * Both the TA and ldelf are AArch64 so it is OK to point to a function
568 	 * in ldelf.
569 	 */
570 	*where = (Elf64_Addr)tlsdesc_resolve;
571 	e64_process_tls_tprel_rela(sym_tab, num_syms, str_tab, str_tab_size,
572 				   rela, where + 1, elf);
573 }
574 #endif /*ARM64*/
575 
e64_relocate(struct ta_elf * elf,unsigned int rel_sidx)576 static void e64_relocate(struct ta_elf *elf, unsigned int rel_sidx)
577 {
578 	Elf64_Shdr *shdr = elf->shdr;
579 	Elf64_Rela *rela = NULL;
580 	Elf64_Rela *rela_end = NULL;
581 	size_t sym_tab_idx = 0;
582 	Elf64_Sym *sym_tab = NULL;
583 	size_t num_syms = 0;
584 	size_t sh_end = 0;
585 	const char *str_tab = NULL;
586 	size_t str_tab_size = 0;
587 
588 	assert(shdr[rel_sidx].sh_type == SHT_RELA);
589 
590 	assert(shdr[rel_sidx].sh_entsize == sizeof(Elf64_Rela));
591 
592 	sym_tab_idx = shdr[rel_sidx].sh_link;
593 	if (sym_tab_idx) {
594 		size_t str_tab_idx = 0;
595 
596 		if (sym_tab_idx >= elf->e_shnum)
597 			err(TEE_ERROR_BAD_FORMAT, "SYMTAB index out of range");
598 		sym_tab_idx = confine_array_index(sym_tab_idx, elf->e_shnum);
599 
600 		assert(shdr[sym_tab_idx].sh_entsize == sizeof(Elf64_Sym));
601 
602 		/* Check the address is inside TA memory */
603 		if (ADD_OVERFLOW(shdr[sym_tab_idx].sh_addr,
604 				 shdr[sym_tab_idx].sh_size, &sh_end))
605 			err(TEE_ERROR_BAD_FORMAT, "Overflow");
606 		if (sh_end >= (elf->max_addr - elf->load_addr))
607 			err(TEE_ERROR_BAD_FORMAT, "SYMTAB out of range");
608 
609 		sym_tab = (Elf64_Sym *)(elf->load_addr +
610 					shdr[sym_tab_idx].sh_addr);
611 
612 		num_syms = shdr[sym_tab_idx].sh_size / sizeof(Elf64_Sym);
613 
614 		str_tab_idx = shdr[sym_tab_idx].sh_link;
615 		if (str_tab_idx) {
616 			if (str_tab_idx >= elf->e_shnum)
617 				err(TEE_ERROR_BAD_FORMAT,
618 				    "STRTAB index out of range");
619 			str_tab_idx = confine_array_index(str_tab_idx,
620 							  elf->e_shnum);
621 
622 			/* Check the address is inside ELF memory */
623 			if (ADD_OVERFLOW(shdr[str_tab_idx].sh_addr,
624 					 shdr[str_tab_idx].sh_size, &sh_end))
625 				err(TEE_ERROR_BAD_FORMAT, "Overflow");
626 			if (sh_end >= (elf->max_addr - elf->load_addr))
627 				err(TEE_ERROR_BAD_FORMAT,
628 				    "STRTAB out of range");
629 
630 			str_tab = (const char *)(elf->load_addr +
631 						 shdr[str_tab_idx].sh_addr);
632 			str_tab_size = shdr[str_tab_idx].sh_size;
633 		}
634 	}
635 
636 	/* Check the address is inside TA memory */
637 	if (ADD_OVERFLOW(shdr[rel_sidx].sh_addr,
638 			 shdr[rel_sidx].sh_size, &sh_end))
639 		err(TEE_ERROR_BAD_FORMAT, "Overflow");
640 	if (sh_end >= (elf->max_addr - elf->load_addr))
641 		err(TEE_ERROR_BAD_FORMAT, ".rel.*/REL out of range");
642 	rela = (Elf64_Rela *)(elf->load_addr + shdr[rel_sidx].sh_addr);
643 
644 	rela_end = rela + shdr[rel_sidx].sh_size / sizeof(Elf64_Rela);
645 	for (; rela < rela_end; rela++) {
646 		Elf64_Addr *where = NULL;
647 		size_t sym_idx = 0;
648 
649 		/* Check the address is inside TA memory */
650 		if (rela->r_offset >= (elf->max_addr - elf->load_addr))
651 			err(TEE_ERROR_BAD_FORMAT,
652 			    "Relocation offset out of range");
653 
654 		where = (Elf64_Addr *)(elf->load_addr + rela->r_offset);
655 
656 		switch (ELF64_R_TYPE(rela->r_info)) {
657 #ifdef ARM64
658 		case R_AARCH64_NONE:
659 			/*
660 			 * One would expect linker prevents such useless entry
661 			 * in the relocation table. We still handle this type
662 			 * here in case such entries exist.
663 			 */
664 			break;
665 		case R_AARCH64_ABS64:
666 			sym_idx = ELF64_R_SYM(rela->r_info);
667 			if (sym_idx >= num_syms)
668 				err(TEE_ERROR_BAD_FORMAT,
669 				    "Symbol index out of range");
670 			sym_idx = confine_array_index(sym_idx, num_syms);
671 			if (sym_tab[sym_idx].st_shndx == SHN_UNDEF) {
672 				/* Symbol is external */
673 				e64_process_dyn_rela(sym_tab, num_syms, str_tab,
674 						     str_tab_size, rela, where);
675 			} else {
676 				*where = rela->r_addend + elf->load_addr +
677 					 sym_tab[sym_idx].st_value;
678 			}
679 			break;
680 		case R_AARCH64_RELATIVE:
681 			*where = rela->r_addend + elf->load_addr;
682 			break;
683 		case R_AARCH64_GLOB_DAT:
684 		case R_AARCH64_JUMP_SLOT:
685 			e64_process_dyn_rela(sym_tab, num_syms, str_tab,
686 					     str_tab_size, rela, where);
687 			break;
688 		case R_AARCH64_TLS_TPREL:
689 			e64_process_tls_tprel_rela(sym_tab, num_syms, str_tab,
690 						   str_tab_size, rela, where,
691 						   elf);
692 			break;
693 		case R_AARCH64_TLSDESC:
694 			e64_process_tlsdesc_rela(sym_tab, num_syms, str_tab,
695 						 str_tab_size, rela, where,
696 						 elf);
697 			break;
698 #endif /*ARM64*/
699 #ifdef RV64
700 		case R_RISCV_NONE:
701 			/*
702 			 * One would expect linker prevents such useless entry
703 			 * in the relocation table. We still handle this type
704 			 * here in case such entries exist.
705 			 */
706 			break;
707 		case R_RISCV_RELATIVE:
708 			*where = rela->r_addend + elf->load_addr;
709 			break;
710 		case R_RISCV_64:
711 			e64_process_dyn_rela(sym_tab, num_syms, str_tab,
712 					     str_tab_size, rela, where);
713 			*where += rela->r_addend;
714 			break;
715 		case R_RISCV_JUMP_SLOT:
716 			e64_process_dyn_rela(sym_tab, num_syms, str_tab,
717 					     str_tab_size, rela, where);
718 			break;
719 #endif /*RV64*/
720 		default:
721 			err(TEE_ERROR_BAD_FORMAT, "Unknown relocation type %zd",
722 			     ELF64_R_TYPE(rela->r_info));
723 		}
724 	}
725 }
726 #else /*ARM64 || RV64*/
e64_relocate(struct ta_elf * elf __unused,unsigned int rel_sidx __unused)727 static void __noreturn e64_relocate(struct ta_elf *elf __unused,
728 				    unsigned int rel_sidx __unused)
729 {
730 	err(TEE_ERROR_NOT_SUPPORTED, "arm64 not supported");
731 }
732 #endif /*ARM64 || RV64*/
733 
ta_elf_relocate(struct ta_elf * elf)734 void ta_elf_relocate(struct ta_elf *elf)
735 {
736 	size_t n = 0;
737 
738 	if (elf->is_32bit) {
739 		Elf32_Shdr *shdr = elf->shdr;
740 
741 		for (n = 0; n < elf->e_shnum; n++)
742 			if (shdr[n].sh_type == SHT_REL)
743 				e32_relocate(elf, n);
744 	} else {
745 		Elf64_Shdr *shdr = elf->shdr;
746 
747 		for (n = 0; n < elf->e_shnum; n++)
748 			if (shdr[n].sh_type == SHT_RELA)
749 				e64_relocate(elf, n);
750 
751 	}
752 }
753