xref: /optee_os/core/kernel/ldelf_loader.c (revision 04e46975d8f02e25209af552aaea4acb4d70c7f9)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2014, STMicroelectronics International N.V.
4  * Copyright (c) 2015-2020, 2022 Linaro Limited
5  * Copyright (c) 2020-2023, Arm Limited
6  */
7 
8 #include <assert.h>
9 #include <kernel/ldelf_loader.h>
10 #include <kernel/ldelf_syscalls.h>
11 #include <kernel/scall.h>
12 #include <kernel/user_access.h>
13 #include <ldelf.h>
14 #include <mm/mobj.h>
15 #include <mm/vm.h>
16 
17 #define BOUNCE_BUFFER_SIZE	4096
18 
19 extern uint8_t ldelf_data[];
20 extern const unsigned int ldelf_code_size;
21 extern const unsigned int ldelf_data_size;
22 extern const unsigned int ldelf_entry;
23 
24 /* ldelf has the same architecture/register width as the kernel */
25 #if defined(ARM32) || defined(RV32)
26 static const bool is_32bit = true;
27 #else
28 static const bool is_32bit;
29 #endif
30 
alloc_and_map_fobj(struct user_mode_ctx * uctx,size_t sz,uint32_t prot,uint32_t flags,vaddr_t * va)31 static TEE_Result alloc_and_map_fobj(struct user_mode_ctx *uctx, size_t sz,
32 				     uint32_t prot, uint32_t flags, vaddr_t *va)
33 {
34 	size_t num_pgs = ROUNDUP_DIV(sz, SMALL_PAGE_SIZE);
35 	struct fobj *fobj = fobj_ta_mem_alloc(num_pgs);
36 	struct mobj *mobj = mobj_with_fobj_alloc(fobj, NULL,
37 						 TEE_MATTR_MEM_TYPE_TAGGED);
38 	TEE_Result res = TEE_SUCCESS;
39 
40 	fobj_put(fobj);
41 	if (!mobj)
42 		return TEE_ERROR_OUT_OF_MEMORY;
43 	res = vm_map(uctx, va, num_pgs * SMALL_PAGE_SIZE, prot, flags, mobj, 0);
44 	mobj_put(mobj);
45 
46 	return res;
47 }
48 
49 /*
50  * This function may leave a few mappings behind on error, but that's taken
51  * care of by tee_ta_init_user_ta_session() since the entire context is
52  * removed then.
53  */
ldelf_load_ldelf(struct user_mode_ctx * uctx)54 TEE_Result ldelf_load_ldelf(struct user_mode_ctx *uctx)
55 {
56 	TEE_Result res = TEE_SUCCESS;
57 	vaddr_t stack_addr = 0;
58 	vaddr_t code_addr = 0;
59 	vaddr_t rw_addr = 0;
60 	vaddr_t bb_addr = 0;
61 	uint32_t prot = 0;
62 
63 	uctx->is_32bit = is_32bit;
64 
65 	res = alloc_and_map_fobj(uctx, BOUNCE_BUFFER_SIZE, TEE_MATTR_PRW, 0,
66 				 &bb_addr);
67 	if (res)
68 		return res;
69 	uctx->bbuf = (void *)bb_addr;
70 	uctx->bbuf_size = BOUNCE_BUFFER_SIZE;
71 
72 	res = alloc_and_map_fobj(uctx, LDELF_STACK_SIZE,
73 				 TEE_MATTR_URW | TEE_MATTR_PRW, VM_FLAG_LDELF,
74 				 &stack_addr);
75 	if (res)
76 		return res;
77 	uctx->ldelf_stack_ptr = stack_addr + LDELF_STACK_SIZE;
78 
79 	res = alloc_and_map_fobj(uctx, ldelf_code_size, TEE_MATTR_PRW,
80 				 VM_FLAG_LDELF, &code_addr);
81 	if (res)
82 		return res;
83 	uctx->entry_func = code_addr + ldelf_entry;
84 
85 	rw_addr = ROUNDUP(code_addr + ldelf_code_size, SMALL_PAGE_SIZE);
86 	res = alloc_and_map_fobj(uctx, ldelf_data_size,
87 				 TEE_MATTR_URW | TEE_MATTR_PRW, VM_FLAG_LDELF,
88 				 &rw_addr);
89 	if (res)
90 		return res;
91 
92 	vm_set_ctx(uctx->ts_ctx);
93 
94 	memcpy((void *)code_addr, ldelf_data, ldelf_code_size);
95 
96 	res = copy_to_user((void *)rw_addr, ldelf_data + ldelf_code_size,
97 			   ldelf_data_size);
98 	if (res)
99 		return res;
100 
101 	prot = TEE_MATTR_URX;
102 	if (IS_ENABLED(CFG_CORE_BTI))
103 		prot |= TEE_MATTR_GUARDED;
104 
105 	res = vm_set_prot(uctx, code_addr,
106 			  ROUNDUP(ldelf_code_size, SMALL_PAGE_SIZE), prot);
107 	if (res)
108 		return res;
109 
110 	DMSG("ldelf load address %#"PRIxVA, code_addr);
111 
112 	return TEE_SUCCESS;
113 }
114 
ldelf_init_with_ldelf(struct ts_session * sess,struct user_mode_ctx * uctx)115 TEE_Result ldelf_init_with_ldelf(struct ts_session *sess,
116 				 struct user_mode_ctx *uctx)
117 {
118 	TEE_Result res = TEE_SUCCESS;
119 	struct ldelf_arg *arg = NULL;
120 	uint32_t panic_code = 0;
121 	uint32_t panicked = 0;
122 	uaddr_t usr_stack = 0;
123 	struct ldelf_arg *arg_bbuf = NULL;
124 
125 	usr_stack = uctx->ldelf_stack_ptr;
126 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
127 	arg = (struct ldelf_arg *)usr_stack;
128 	sess->handle_scall = scall_handle_ldelf;
129 
130 	res = clear_user(arg, sizeof(*arg));
131 	if (res)
132 		return res;
133 
134 	res = PUT_USER_SCALAR(uctx->ts_ctx->uuid, &arg->uuid);
135 	if (res)
136 		return res;
137 
138 	res = thread_enter_user_mode((vaddr_t)arg, 0, 0, 0,
139 				     usr_stack, uctx->entry_func,
140 				     is_32bit, &panicked, &panic_code);
141 
142 	sess->handle_scall = sess->ctx->ops->handle_scall;
143 	thread_user_clear_vfp(uctx);
144 	ldelf_sess_cleanup(sess);
145 
146 	if (panicked) {
147 		abort_print_current_ts();
148 		EMSG("ldelf panicked");
149 		return TEE_ERROR_GENERIC;
150 	}
151 	if (res) {
152 		EMSG("ldelf failed with res: %#"PRIx32, res);
153 		return res;
154 	}
155 
156 	res = BB_MEMDUP_USER(arg, sizeof(*arg), &arg_bbuf);
157 	if (res)
158 		return res;
159 
160 	if (is_user_ta_ctx(uctx->ts_ctx)) {
161 		/*
162 		 * This is already checked by the elf loader, but since it runs
163 		 * in user mode we're not trusting it entirely.
164 		 */
165 		if (arg_bbuf->flags & ~TA_FLAGS_MASK)
166 			return TEE_ERROR_BAD_FORMAT;
167 
168 		to_user_ta_ctx(uctx->ts_ctx)->ta_ctx.flags = arg_bbuf->flags;
169 	}
170 
171 	uctx->is_32bit = arg_bbuf->is_32bit;
172 	uctx->entry_func = arg_bbuf->entry_func;
173 	uctx->load_addr = arg_bbuf->load_addr;
174 	uctx->stack_ptr = arg_bbuf->stack_ptr;
175 	uctx->dump_entry_func = arg_bbuf->dump_entry;
176 #ifdef CFG_FTRACE_SUPPORT
177 	uctx->ftrace_entry_func = arg_bbuf->ftrace_entry;
178 	sess->fbuf = arg_bbuf->fbuf;
179 #endif
180 	uctx->dl_entry_func = arg_bbuf->dl_entry;
181 
182 	bb_free(arg_bbuf, sizeof(*arg));
183 
184 	return TEE_SUCCESS;
185 }
186 
ldelf_dump_state(struct user_mode_ctx * uctx)187 TEE_Result ldelf_dump_state(struct user_mode_ctx *uctx)
188 {
189 	TEE_Result res = TEE_SUCCESS;
190 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
191 	struct dump_entry_arg *arg = NULL;
192 	uint32_t panic_code = 0;
193 	uint32_t panicked = 0;
194 	struct thread_specific_data *tsd = thread_get_tsd();
195 	struct ts_session *sess = NULL;
196 	struct vm_region *r = NULL;
197 	size_t arg_size = 0;
198 	size_t n = 0;
199 
200 	TAILQ_FOREACH(r, &uctx->vm_info.regions, link)
201 		if (r->attr & TEE_MATTR_URWX)
202 			n++;
203 
204 	arg_size = ROUNDUP(sizeof(*arg) + n * sizeof(struct dump_map),
205 			   STACK_ALIGNMENT);
206 
207 	usr_stack = uctx->ldelf_stack_ptr;
208 	usr_stack -= arg_size;
209 
210 	arg = bb_alloc(arg_size);
211 	if (!arg)
212 		return TEE_ERROR_OUT_OF_MEMORY;
213 	memset(arg, 0, arg_size);
214 
215 	arg->num_maps = n;
216 	n = 0;
217 	TAILQ_FOREACH(r, &uctx->vm_info.regions, link) {
218 		if (r->attr & TEE_MATTR_URWX) {
219 			if (r->mobj)
220 				mobj_get_pa(r->mobj, r->offset, 0,
221 					    &arg->maps[n].pa);
222 			arg->maps[n].va = r->va;
223 			arg->maps[n].sz = r->size;
224 			if (r->attr & TEE_MATTR_UR)
225 				arg->maps[n].flags |= DUMP_MAP_READ;
226 			if (r->attr & TEE_MATTR_UW)
227 				arg->maps[n].flags |= DUMP_MAP_WRITE;
228 			if (r->attr & TEE_MATTR_UX)
229 				arg->maps[n].flags |= DUMP_MAP_EXEC;
230 			if (r->attr & TEE_MATTR_SECURE)
231 				arg->maps[n].flags |= DUMP_MAP_SECURE;
232 			if (r->flags & VM_FLAG_EPHEMERAL)
233 				arg->maps[n].flags |= DUMP_MAP_EPHEM;
234 			if (r->flags & VM_FLAG_LDELF)
235 				arg->maps[n].flags |= DUMP_MAP_LDELF;
236 			n++;
237 		}
238 	}
239 
240 	arg->is_32bit = uctx->is_32bit;
241 #ifdef ARM32
242 	arg->arm32.regs[0] = tsd->abort_regs.r0;
243 	arg->arm32.regs[1] = tsd->abort_regs.r1;
244 	arg->arm32.regs[2] = tsd->abort_regs.r2;
245 	arg->arm32.regs[3] = tsd->abort_regs.r3;
246 	arg->arm32.regs[4] = tsd->abort_regs.r4;
247 	arg->arm32.regs[5] = tsd->abort_regs.r5;
248 	arg->arm32.regs[6] = tsd->abort_regs.r6;
249 	arg->arm32.regs[7] = tsd->abort_regs.r7;
250 	arg->arm32.regs[8] = tsd->abort_regs.r8;
251 	arg->arm32.regs[9] = tsd->abort_regs.r9;
252 	arg->arm32.regs[10] = tsd->abort_regs.r10;
253 	arg->arm32.regs[11] = tsd->abort_regs.r11;
254 	arg->arm32.regs[12] = tsd->abort_regs.ip;
255 	arg->arm32.regs[13] = tsd->abort_regs.usr_sp; /*SP*/
256 	arg->arm32.regs[14] = tsd->abort_regs.usr_lr; /*LR*/
257 	arg->arm32.regs[15] = tsd->abort_regs.elr; /*PC*/
258 #endif /*ARM32*/
259 #ifdef ARM64
260 	if (uctx->is_32bit) {
261 		arg->arm32.regs[0] = tsd->abort_regs.x0;
262 		arg->arm32.regs[1] = tsd->abort_regs.x1;
263 		arg->arm32.regs[2] = tsd->abort_regs.x2;
264 		arg->arm32.regs[3] = tsd->abort_regs.x3;
265 		arg->arm32.regs[4] = tsd->abort_regs.x4;
266 		arg->arm32.regs[5] = tsd->abort_regs.x5;
267 		arg->arm32.regs[6] = tsd->abort_regs.x6;
268 		arg->arm32.regs[7] = tsd->abort_regs.x7;
269 		arg->arm32.regs[8] = tsd->abort_regs.x8;
270 		arg->arm32.regs[9] = tsd->abort_regs.x9;
271 		arg->arm32.regs[10] = tsd->abort_regs.x10;
272 		arg->arm32.regs[11] = tsd->abort_regs.x11;
273 		arg->arm32.regs[12] = tsd->abort_regs.x12;
274 		arg->arm32.regs[13] = tsd->abort_regs.x13; /*SP*/
275 		arg->arm32.regs[14] = tsd->abort_regs.x14; /*LR*/
276 		arg->arm32.regs[15] = tsd->abort_regs.elr; /*PC*/
277 	} else {
278 		arg->arm64.fp = tsd->abort_regs.x29;
279 		arg->arm64.pc = tsd->abort_regs.elr;
280 		arg->arm64.sp = tsd->abort_regs.sp_el0;
281 	}
282 #endif /*ARM64*/
283 #if defined(RV64) || defined(RV32)
284 	arg->rv.fp = tsd->abort_regs.s0;
285 	arg->rv.pc = tsd->abort_regs.epc;
286 	arg->rv.sp = tsd->abort_regs.sp;
287 #endif /*RV64||RV32*/
288 
289 	res = copy_to_user((void *)usr_stack, arg, arg_size);
290 	if (res)
291 		return res;
292 
293 	sess = ts_get_current_session();
294 	sess->handle_scall = scall_handle_ldelf;
295 
296 	res = thread_enter_user_mode(usr_stack, 0, 0, 0,
297 				     usr_stack, uctx->dump_entry_func,
298 				     is_32bit, &panicked, &panic_code);
299 
300 	sess->handle_scall = sess->ctx->ops->handle_scall;
301 	thread_user_clear_vfp(uctx);
302 	ldelf_sess_cleanup(sess);
303 
304 	if (panicked) {
305 		uctx->dump_entry_func = 0;
306 		EMSG("ldelf dump function panicked");
307 		abort_print_current_ts();
308 		res = TEE_ERROR_TARGET_DEAD;
309 	}
310 
311 	return res;
312 }
313 
314 #ifdef CFG_FTRACE_SUPPORT
ldelf_dump_ftrace(struct user_mode_ctx * uctx,void * buf,size_t * blen)315 TEE_Result ldelf_dump_ftrace(struct user_mode_ctx *uctx,
316 			     void *buf, size_t *blen)
317 {
318 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
319 	TEE_Result res = TEE_SUCCESS;
320 	uint32_t panic_code = 0;
321 	uint32_t panicked = 0;
322 	size_t *arg = NULL;
323 	struct ts_session *sess = NULL;
324 
325 	if (!uctx->ftrace_entry_func)
326 		return TEE_ERROR_NOT_SUPPORTED;
327 
328 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
329 	arg = (size_t *)usr_stack;
330 
331 	res = vm_check_access_rights(uctx,
332 				     TEE_MEMORY_ACCESS_READ |
333 				     TEE_MEMORY_ACCESS_ANY_OWNER,
334 				     (uaddr_t)arg, sizeof(*arg));
335 	if (res) {
336 		EMSG("ldelf stack is inaccessible!");
337 		return res;
338 	}
339 
340 	*arg = *blen;
341 
342 	sess = ts_get_current_session();
343 	sess->handle_scall = scall_handle_ldelf;
344 
345 	res = thread_enter_user_mode((vaddr_t)buf, (vaddr_t)arg, 0, 0,
346 				     usr_stack, uctx->ftrace_entry_func,
347 				     is_32bit, &panicked, &panic_code);
348 
349 	sess->handle_scall = sess->ctx->ops->handle_scall;
350 	thread_user_clear_vfp(uctx);
351 	ldelf_sess_cleanup(sess);
352 
353 	if (panicked) {
354 		uctx->ftrace_entry_func = 0;
355 		EMSG("ldelf ftrace function panicked");
356 		abort_print_current_ts();
357 		res = TEE_ERROR_TARGET_DEAD;
358 	}
359 
360 	if (!res) {
361 		if (*arg > *blen)
362 			res = TEE_ERROR_SHORT_BUFFER;
363 		*blen = *arg;
364 	}
365 
366 	return res;
367 }
368 #endif /*CFG_FTRACE_SUPPORT*/
369 
ldelf_dlopen(struct user_mode_ctx * uctx,TEE_UUID * uuid,uint32_t flags)370 TEE_Result ldelf_dlopen(struct user_mode_ctx *uctx, TEE_UUID *uuid,
371 			uint32_t flags)
372 {
373 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
374 	TEE_Result res = TEE_ERROR_GENERIC;
375 	struct dl_entry_arg *usr_arg = NULL;
376 	struct dl_entry_arg *arg = NULL;
377 	uint32_t panic_code = 0;
378 	uint32_t panicked = 0;
379 	struct ts_session *sess = NULL;
380 
381 	assert(uuid);
382 
383 	arg = bb_alloc(sizeof(*arg));
384 	if (!arg)
385 		return TEE_ERROR_OUT_OF_MEMORY;
386 
387 	memset(arg, 0, sizeof(*arg));
388 	arg->cmd = LDELF_DL_ENTRY_DLOPEN;
389 	arg->dlopen.uuid = *uuid;
390 	arg->dlopen.flags = flags;
391 
392 	usr_stack -= ROUNDUP(sizeof(*arg), STACK_ALIGNMENT);
393 	usr_arg = (void *)usr_stack;
394 
395 	res = copy_to_user(usr_arg, arg, sizeof(*arg));
396 	if (res)
397 		return res;
398 
399 	sess = ts_get_current_session();
400 	sess->handle_scall = scall_handle_ldelf;
401 
402 	res = thread_enter_user_mode(usr_stack, 0, 0, 0,
403 				     usr_stack, uctx->dl_entry_func,
404 				     is_32bit, &panicked, &panic_code);
405 
406 	sess->handle_scall = sess->ctx->ops->handle_scall;
407 	ldelf_sess_cleanup(sess);
408 
409 	if (panicked) {
410 		EMSG("ldelf dl_entry function panicked");
411 		abort_print_current_ts();
412 		res = TEE_ERROR_TARGET_DEAD;
413 	}
414 	if (!res) {
415 		TEE_Result res2 = TEE_SUCCESS;
416 
417 		res2 = GET_USER_SCALAR(res, &usr_arg->ret);
418 		if (res2)
419 			res = res2;
420 	}
421 
422 	return res;
423 }
424 
ldelf_dlsym(struct user_mode_ctx * uctx,TEE_UUID * uuid,const char * sym,size_t symlen,vaddr_t * val)425 TEE_Result ldelf_dlsym(struct user_mode_ctx *uctx, TEE_UUID *uuid,
426 		       const char *sym, size_t symlen, vaddr_t *val)
427 {
428 	uaddr_t usr_stack = uctx->ldelf_stack_ptr;
429 	TEE_Result res = TEE_ERROR_GENERIC;
430 	struct dl_entry_arg *usr_arg = NULL;
431 	struct dl_entry_arg *arg = NULL;
432 	uint32_t panic_code = 0;
433 	uint32_t panicked = 0;
434 	struct ts_session *sess = NULL;
435 
436 	usr_stack -= ROUNDUP(sizeof(*arg) + symlen + 1, STACK_ALIGNMENT);
437 	usr_arg = (void *)usr_stack;
438 	arg = bb_alloc(sizeof(*arg));
439 	if (!arg)
440 		return TEE_ERROR_OUT_OF_MEMORY;
441 	memset(arg, 0, sizeof(*arg));
442 	arg->cmd = LDELF_DL_ENTRY_DLSYM;
443 	arg->dlsym.uuid = *uuid;
444 	res = copy_to_user(usr_arg, arg, sizeof(*arg));
445 	if (res)
446 		return res;
447 	res = copy_to_user(usr_arg->dlsym.symbol, sym, symlen + 1);
448 	if (res)
449 		return res;
450 
451 	sess = ts_get_current_session();
452 	sess->handle_scall = scall_handle_ldelf;
453 
454 	res = thread_enter_user_mode((vaddr_t)usr_arg, 0, 0, 0,
455 				     usr_stack, uctx->dl_entry_func,
456 				     is_32bit, &panicked, &panic_code);
457 
458 	sess->handle_scall = sess->ctx->ops->handle_scall;
459 	ldelf_sess_cleanup(sess);
460 
461 	if (panicked) {
462 		EMSG("ldelf dl_entry function panicked");
463 		abort_print_current_ts();
464 		res = TEE_ERROR_TARGET_DEAD;
465 	}
466 	if (!res) {
467 		TEE_Result res2 = TEE_SUCCESS;
468 
469 		res2 = GET_USER_SCALAR(res, &usr_arg->ret);
470 		if (res2)
471 			res = res2;
472 		if (!res)
473 			res = GET_USER_SCALAR(*val, &usr_arg->dlsym.val);
474 	}
475 
476 	return res;
477 }
478